1
|
Alfa R, Considine T, Virani S, Pfeiffer M, Donato A, Dickerson D, Shuster D, Ellis J, Rushton K, Wei H, Gibson C. Clinical pharmacology and tolerability of REC-994, a redox-cycling nitroxide compound, in randomized phase 1 dose-finding studies. Pharmacol Res Perspect 2024; 12:e1200. [PMID: 38655895 PMCID: PMC11040693 DOI: 10.1002/prp2.1200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 03/28/2024] [Accepted: 04/05/2024] [Indexed: 04/26/2024] Open
Abstract
Cerebral cavernous malformation (CCM) has variable clinical symptoms, including potentially fatal hemorrhagic stroke. Treatment options are very limited, presenting a large unmet need. REC-994 (also known as tempol), identified as a potential treatment through an unbiased drug discovery platform, is hypothesized to treat CCMs through a reduction in superoxide, a reactive oxygen species. We investigated the safety, tolerability, and pharmacokinetic profile of REC-994 in healthy volunteers. Single- and multiple-ascending dose (SAD and MAD, respectively) studies were conducted in adult volunteers (ages 18-55). SAD study participants received an oral dose of REC-994 or placebo. MAD study participants were randomized 3:1 to oral doses of REC-994 or matching placebo, once daily for 10 days. Thirty-two healthy volunteers participated in the SAD study and 52 in the MAD study. Systemic exposure increased in proportion to REC-994 dose after single doses of 50-800 mg and after 10 days of dosing over the 16-fold dose range of 50-800 mg. Median Tmax and mean t1/2 were independent of dose in both studies, and the solution formulation was more rapidly absorbed. REC-994 was well tolerated. Treatment-emergent adverse effects across both studies were mild and transient and resolved by the end of the study. REC-994 has a favorable safety profile and was well tolerated in single and multiple doses up to 800 mg with no dose-limiting adverse effects identified. Data support conducting a phase 2 clinical trial in patients with symptomatic CCM.
Collapse
Affiliation(s)
- Ron Alfa
- Recursion Pharmaceuticals, Inc.Salt Lake CityUtahUSA
- Present address:
NoetikSan FranciscoCaliforniaUSA
| | - Timothy Considine
- Recursion Pharmaceuticals, Inc.Salt Lake CityUtahUSA
- Present address:
Considine Comprehensive ConsultingSan DiegoCaliforniaUSA
| | | | - Matt Pfeiffer
- Recursion Pharmaceuticals, Inc.Salt Lake CityUtahUSA
| | - Anthony Donato
- Department of Internal MedicineUniversity of UtahSalt Lake CityUtahUSA
| | | | - Diana Shuster
- Recursion Pharmaceuticals, Inc.Salt Lake CityUtahUSA
- Present address:
CenExelSalt Lake CityUtahUSA
| | - Joel Ellis
- Recursion Pharmaceuticals, Inc.Salt Lake CityUtahUSA
- Present address:
Mariner BioPharmaSan JoseCaliforniaUSA
| | | | - Helen Wei
- Recursion Pharmaceuticals, Inc.Salt Lake CityUtahUSA
| | | |
Collapse
|
2
|
Saito K, Sail D, Yamamoto K, Matsumoto S, Blackman B, Kishimoto S, Brender JR, Swenson RE, Mitchell JB, Krishna MC. Synthesis and evaluation of 13C-labeled 5-5-dimethyl-1-pyrroline-N-oxide aimed at in vivo detection of reactive oxygen species using hyperpolarized 13C-MRI. Free Radic Biol Med 2019; 131:18-26. [PMID: 30471347 PMCID: PMC6983923 DOI: 10.1016/j.freeradbiomed.2018.11.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/30/2018] [Accepted: 11/13/2018] [Indexed: 02/08/2023]
Abstract
Effective means to identify the role of reactive oxygen species (ROS) mediating several diseases including cancer, ischemic heart disease, stroke, Alzheimer's and other inflammatory conditions in in vivo models would be useful. The cyclic nitrone 5,5-Dimethyl-1-pyrroline-N-oxide (DMPO) is a spin trap frequently used to detect free radicals in vitro using Electron Paramagnetic Resonance (EPR) spectroscopy. In this study, we synthesized 13C-labeled DMPO for hyperpolarization by dynamic nuclear polarization, in which 13C NMR signal increases more than 10,000-fold. This allows in vivo 13C MRI to investigate the feasibility of in vivo ROS detection by the 13C-MRI. DMPO was 13C-labeled at C5 position, and deuterated to prolong the T1 relaxation time. The overall yield achieved for 5-13C-DMPO-d9 was 15%. Hyperpolarized 5-13C-DMPO-d9 provided a single peak at 76 ppm in the 13C-spectrum, and the T1 was 60 s in phosphate buffer making it optimal for in vivo 13C MRI. The buffered solution of hyperpolarized 5-13C-DMPO-d9 was injected into a mouse placed in a 3 T scanner, and 13C-spectra were acquired every 1 s. In vivo studies showed the signal of 5-13C-DMPO-d9 was detected in the mouse, and the T1 decay of 13C signal of hyperpolarized 5-13C-DMPO-d9 was 29 s. 13C-chemical shift imaging revealed that 5-13C-DMPO-d9 was distributed throughout the body in a minute after the intravenous injection. A strong signal of 5-13C-DMPO-d9 was detected in heart/lung and kidney, whereas the signal in liver was small compared to other organs. The results indicate hyperpolarized 5-13C-DMPO-d9 provided sufficient 13C signal to be detected in the mouse in several organs, and can be used to detect ROS in vivo.
Collapse
Affiliation(s)
- Keita Saito
- Radiation Biology Branch, National Cancer Institute, Bethesda, MD, USA
| | - Deepak Sail
- Imaging Probe Development Center, National Heart, Lung, and Blood Institute, Rockville, MD, USA
| | | | - Shingo Matsumoto
- Graduate School of Information Science and Technology, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Burchelle Blackman
- Imaging Probe Development Center, National Heart, Lung, and Blood Institute, Rockville, MD, USA
| | - Shun Kishimoto
- Radiation Biology Branch, National Cancer Institute, Bethesda, MD, USA
| | - Jeffrey R Brender
- Radiation Biology Branch, National Cancer Institute, Bethesda, MD, USA
| | - Rolf E Swenson
- Imaging Probe Development Center, National Heart, Lung, and Blood Institute, Rockville, MD, USA
| | - James B Mitchell
- Radiation Biology Branch, National Cancer Institute, Bethesda, MD, USA
| | - Murali C Krishna
- Radiation Biology Branch, National Cancer Institute, Bethesda, MD, USA.
| |
Collapse
|
3
|
Paccaly A, Ozoux ML, Chu V, Simcox K, Marks V, Freyburger G, Sibille M, Shukla U. Pharmacodynamic markers in the early clinical assessment of otamixaban, a direct factor Xa inhibitor. Thromb Haemost 2017; 94:1156-63. [PMID: 16411387 DOI: 10.1160/th05-05-0347] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
SummaryThis manuscript reports the assessment of pharmacodynamic (PD) markers of anti-coagulation in the first-in-man study with the novel direct Factor Xa (FXa) inhibitor, otamixaban, with a brief description of safety and pharmacokinetic (PK) findings. The study comprised ten consecutive parallel groups of healthy male subjects (6 active, 2 placebo per group). Eight groups received escalating intravenous doses of otamixaban as 6-hour infusions (1.7 to 183 μg/kg/h) and two groups received a bolus dose (30 or 120 μg/kg) with a 6-hour infusion (60 or 140 μg/ kg/h, respectively). PD markers included anti-FXa activity and clotting time measurements, i.e. activated Thromboplastin Time (aPTT), ProthrombinTime (PT), Heptest® ClottingTime (HCT), and Russell’s Viper Venom-induced clotting Time (RVVT). In addition, Endogenous Thrombin Potential (ETP) was assessed in the bolus-plus-infusion dose groups. Otamixaban was well tolerated. Otamixaban plasma concentrations increased with escalating dose, were maximal at the end-of-infusion (Ceoi), and decreased rapidly as the infusion was stopped. Anti-FXa activity coincided with otamixaban plasma concentrations and clotting time measurements followed the same pattern. Maximal changes from baseline at Ceoi were 1.9 ± 0.2 for aPTT, 2.0 ± 0.2 for PT, 5.1 ± 0.6 for HCT, and 4.5 ± 1.2 for RVVT. Otamixaban inhibited thrombin generation (24% decrease in ETP) and a delay in thrombin generation was noticed in vitro at high concentrations.
Collapse
Affiliation(s)
- Anne Paccaly
- Sanofi-aventis, Science and Medical Affairs, Bridgewater, New Jersey 08807-0800, USA.
| | | | | | | | | | | | | | | |
Collapse
|
4
|
Hinder M, Frick A, Rosenburg R, Hesse G, Ozoux ML, Laux V, Scholtz H, Gebauer A, Paccaly A. Anticoagulant and anti-platelet effects are maintained following coadministration of otamixaban, a direct factor Xa inhibitor, and acetylsalicylic acid. Thromb Haemost 2017; 95:224-8. [PMID: 16493482 DOI: 10.1160/th05-08-0592] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
SummaryThe pharmacokinetics, pharmacodynamics and safety of the direct factor Xa inhibitor, otamixaban, with and without concomitant acetylsalicylic acid (ASA) were investigated in healthy volunteers. The study was a double-blind, placebo-controlled 3-way crossover study. Sixty-eight male volunteers in total were randomised to otamixaban, ASA, or otamixaban with ASA. ASA (300 mg once a day) was started2 days before and continued on the day of the otamixaban 6-hour IV infusion (0.3 and 0.5 mg/kg). Pharmacokinetic and pharmacodynamic parameters (coagulation markers, platelet function tests and skin bleeding time) were determined. Drug interaction was assessed by the ratios of geometric means and 90 confidence intervals (90% CI)of the parameter estimates.Pharmacokinetic parameters of otamixaban remain ed unchanged with ASA. Ratios of geometric means (90% CI) were for Ceoi 96.54 (91.21–102.19) and 95. 04 (90. 10–100. 24) and for AUC 98. 0 (93. 92–102. 25) and 95. 90 (92. 61–99. 31), for 0. 3 and 0. 5 mg/kg, respectively. No drug interaction was observed between otamixaban andASA on the coagulation and platelet function parameters. Neither otamixaban nor ASA had an effect on skin bleeding time; their co-administration led toa slight prolongation of skin bleeding time above the normal range without any clinically relevant bleeding. This study demonstrated that the desired effects of otamixaban and ASA, namely anticoagulation and platelet inhibition, respectively, are maintained during co-administration of both drugs.
Collapse
Affiliation(s)
- Markus Hinder
- Science and Medical Affairs, Sanofi-Aventis, Frankfurt, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Stamenković S, Pavićević A, Mojović M, Popović-Bijelić A, Selaković V, Andjus P, Bačić G. In vivo EPR pharmacokinetic evaluation of the redox status and the blood brain barrier permeability in the SOD1 G93A ALS rat model. Free Radic Biol Med 2017; 108:258-269. [PMID: 28366802 DOI: 10.1016/j.freeradbiomed.2017.03.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 03/25/2017] [Accepted: 03/27/2017] [Indexed: 12/14/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder affecting the motor pathways of the central nervous system. Although a number of pathophysiological mechanisms have been described in the disease, post mortem and animal model studies indicate blood-brain barrier (BBB) disruption and elevated production of reactive oxygen species as major contributors to disease pathology. In this study, the BBB permeability and the brain tissue redox status of the SOD1G93A ALS rat model in the presymptomatic (preALS) and symptomatic (ALS) stages of the disease were investigated by in vivo EPR spectroscopy using three aminoxyl radicals with different cell membrane and BBB permeabilities, Tempol, 3-carbamoyl proxyl (3CP), and 3-carboxy proxyl (3CxP). Additionally, the redox status of the two brain regions previously implicated in disease pathology, brainstem and hippocampus, was investigated by spectrophotometric biochemical assays. The EPR results indicated that among the three spin probes, 3CP is the most suitable for reporting the intracellular redox status changes, as Tempol was reduced in vivo within minutes (t1/2 =2.0±0.5min), thus preventing reliable kinetic modeling, whereas 3CxP reduction kinetics gave divergent conclusions, most probably due to its membrane impermeability. It was observed that the reduction kinetics of 3CP in vivo, in the head of preALS and ALS SOD1G93A rats was altered compared to the controls. Pharmacokinetic modeling of 3CP reduction in vivo, revealed elevated tissue distribution and tissue reduction rate constants indicating an altered brain tissue redox status, and possibly BBB disruption in these animals. The preALS and ALS brain tissue homogenates also showed increased nitrilation, superoxide production, lipid peroxidation and manganese superoxide dismutase activity, and a decreased copper-zinc superoxide dismutase activity. The present study highlights in vivo EPR spectroscopy as a reliable tool for the investigation of changes in BBB permeability and for the unprecedented in vivo monitoring of the brain tissue redox status, as early markers of ALS.
Collapse
Affiliation(s)
- Stefan Stamenković
- University of Belgrade - Faculty of Biology, Center for Laser Microscopy, Studentski trg 3, 11158 Belgrade, Serbia
| | - Aleksandra Pavićević
- University of Belgrade - Faculty of Physical Chemistry, EPR Laboratory, Studentski trg 12-16, 11158 Belgrade, Serbia
| | - Miloš Mojović
- University of Belgrade - Faculty of Physical Chemistry, EPR Laboratory, Studentski trg 12-16, 11158 Belgrade, Serbia
| | - Ana Popović-Bijelić
- University of Belgrade - Faculty of Physical Chemistry, EPR Laboratory, Studentski trg 12-16, 11158 Belgrade, Serbia
| | - Vesna Selaković
- Institute for Medical Research, Military Medical Academy, Crnotravska 17, 11000 Belgrade, Serbia
| | - Pavle Andjus
- University of Belgrade - Faculty of Biology, Center for Laser Microscopy, Studentski trg 3, 11158 Belgrade, Serbia.
| | - Goran Bačić
- University of Belgrade - Faculty of Physical Chemistry, EPR Laboratory, Studentski trg 12-16, 11158 Belgrade, Serbia
| |
Collapse
|
6
|
Gonzalez-Paredes FJ, Hernández Mesa G, Morales Arraez D, Marcelino Reyes R, Abrante B, Diaz-Flores F, Salido E, Quintero E, Hernández-Guerra M. Contribution of Cyclooxygenase End Products and Oxidative Stress to Intrahepatic Endothelial Dysfunction in Early Non-Alcoholic Fatty Liver Disease. PLoS One 2016; 11:e0156650. [PMID: 27227672 PMCID: PMC4882009 DOI: 10.1371/journal.pone.0156650] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 05/17/2016] [Indexed: 01/02/2023] Open
Abstract
Introduction Metabolic syndrome induces endothelial dysfunction, a surrogate marker of cardiovascular disease. In parallel, metabolic syndrome is frequently associated with non-alcoholic fatty liver disease (NAFLD), which may progress to cirrhosis. The aim of the present study was to evaluate intrahepatic endothelial dysfunction related to cyclooxygenase end products and oxidative stress as possible mechanisms involved in the pathophysiology of NAFLD. Materials and Methods Sprague-Dawley rats were fed standard diet (control-diet, CD) or high-fat-diet (HFD) for 6 weeks. Metabolic syndrome was assessed by recording arterial pressure, lipids, glycemia and rat body weight. Splanchnic hemodynamics were measured, and endothelial dysfunction was evaluated using concentration-effect curves to acetylcholine. Response was assessed with either vehicle, L-NG-Nitroarginine (L-NNA), indomethacin, tempol, or a thromboxane receptor antagonist, SQ 29548. We quantified inflammation, fibrosis, oxidative stress, nitric oxide (NO) bioavailability and thromboxane B2 levels. Results HFD rats exhibited metabolic syndrome together with the presence of NAFLD. Compared to control-diet livers, HFD livers showed increased hepatic vascular resistance unrelated to inflammation or fibrosis, but with decreased NO activity and increased oxidative stress. Endothelial dysfunction was observed in HFD livers compared with CD rats and improved after cyclooxygenase inhibition or tempol pre-incubation. However, pre-incubation with SQ 29548 did not modify acetylcholine response. Conclusions Our study provides evidence that endothelial dysfunction at an early stage of NAFLD is associated with reduced NO bioavailability together with increased cyclooxygenase end products and oxidative stress, which suggests that both pathways are involved in the pathophysiology and may be worth exploring as therapeutic targets to prevent progression of the disease.
Collapse
Affiliation(s)
- Francisco Javier Gonzalez-Paredes
- Institute of Biomedical Technologies and Center of Biomedical Research of the Canary Islands (CIBICAN), University of La Laguna, La Laguna, Tenerife, Spain
| | - Goretti Hernández Mesa
- Gastroenterology Department, University Hospital of the Canary Islands, La Laguna, Tenerife, Spain
| | - Dalia Morales Arraez
- Gastroenterology Department, University Hospital of the Canary Islands, La Laguna, Tenerife, Spain
| | - Raquel Marcelino Reyes
- Gastroenterology Department, University Hospital of the Canary Islands, La Laguna, Tenerife, Spain
| | - Beatriz Abrante
- Institute of Biomedical Technologies and Center of Biomedical Research of the Canary Islands (CIBICAN), University of La Laguna, La Laguna, Tenerife, Spain
| | - Felicitas Diaz-Flores
- Central Laboratory, University Hospital of the Canary Islands, La Laguna, Tenerife, Spain
| | - Eduardo Salido
- Institute of Biomedical Technologies and Center of Biomedical Research of the Canary Islands (CIBICAN), University of La Laguna, La Laguna, Tenerife, Spain
| | - Enrique Quintero
- Institute of Biomedical Technologies and Center of Biomedical Research of the Canary Islands (CIBICAN), University of La Laguna, La Laguna, Tenerife, Spain
- Gastroenterology Department, University Hospital of the Canary Islands, La Laguna, Tenerife, Spain
- Department of Medicine and Psychiatry, University of La Laguna, La Laguna, Tenerife, Spain
| | - Manuel Hernández-Guerra
- Institute of Biomedical Technologies and Center of Biomedical Research of the Canary Islands (CIBICAN), University of La Laguna, La Laguna, Tenerife, Spain
- Gastroenterology Department, University Hospital of the Canary Islands, La Laguna, Tenerife, Spain
- Department of Medicine and Psychiatry, University of La Laguna, La Laguna, Tenerife, Spain
- * E-mail:
| |
Collapse
|
7
|
Hunter FW, Young RJ, Shalev Z, Vellanki RN, Wang J, Gu Y, Joshi N, Sreebhavan S, Weinreb I, Goldstein DP, Moffat J, Ketela T, Brown KR, Koritzinsky M, Solomon B, Rischin D, Wilson WR, Wouters BG. Identification of P450 Oxidoreductase as a Major Determinant of Sensitivity to Hypoxia-Activated Prodrugs. Cancer Res 2015; 75:4211-23. [PMID: 26297733 DOI: 10.1158/0008-5472.can-15-1107] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 07/15/2015] [Indexed: 11/16/2022]
Affiliation(s)
- Francis W Hunter
- Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Richard J Young
- Research Division, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia. Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria, Australia
| | - Zvi Shalev
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Ravi N Vellanki
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Jingli Wang
- Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Yongchuan Gu
- Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand. AnQual Laboratories, School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Naveen Joshi
- Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Sreevalsan Sreebhavan
- Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Ilan Weinreb
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - David P Goldstein
- Department of Otolaryngology-Head and Neck Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Jason Moffat
- Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Troy Ketela
- Donnelly Centre and Banting and Best Department of Medical Research, University of Toronto, Toronto, Ontario, Canada
| | - Kevin R Brown
- Donnelly Centre and Banting and Best Department of Medical Research, University of Toronto, Toronto, Ontario, Canada
| | - Marianne Koritzinsky
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada. Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada. Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Benjamin Solomon
- Research Division, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia. Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria, Australia. Department of Medical Oncology, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Danny Rischin
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria, Australia. Department of Medical Oncology, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - William R Wilson
- Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Bradly G Wouters
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada. Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada. Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada. Ontario Institute for Cancer Research, Toronto, Ontario, Canada.
| |
Collapse
|
8
|
Turjeman K, Bavli Y, Kizelsztein P, Schilt Y, Allon N, Katzir TB, Sasson E, Raviv U, Ovadia H, Barenholz Y. Nano-Drugs Based on Nano Sterically Stabilized Liposomes for the Treatment of Inflammatory Neurodegenerative Diseases. PLoS One 2015; 10:e0130442. [PMID: 26147975 PMCID: PMC4492950 DOI: 10.1371/journal.pone.0130442] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 05/20/2015] [Indexed: 12/28/2022] Open
Abstract
The present study shows the advantages of liposome-based nano-drugs as a novel strategy of delivering active pharmaceutical ingredients for treatment of neurodegenerative diseases that involve neuroinflammation. We used the most common animal model for multiple sclerosis (MS), mice experimental autoimmune encephalomyelitis (EAE). The main challenges to overcome are the drugs’ unfavorable pharmacokinetics and biodistribution, which result in inadequate therapeutic efficacy and in drug toxicity (due to high and repeated dosage). We designed two different liposomal nano-drugs, i.e., nano sterically stabilized liposomes (NSSL), remote loaded with: (a) a “water-soluble” amphipathic weak acid glucocorticosteroid prodrug, methylprednisolone hemisuccinate (MPS) or (b) the amphipathic weak base nitroxide, Tempamine (TMN). For the NSSL-MPS we also compared the effect of passive targeting alone and of active targeting based on short peptide fragments of ApoE or of β-amyloid. Our results clearly show that for NSSL-MPS, active targeting is not superior to passive targeting. For the NSSL-MPS and the NSSL-TMN it was demonstrated that these nano-drugs ameliorate the clinical signs and the pathology of EAE. We have further investigated the MPS nano-drug’s therapeutic efficacy and its mechanism of action in both the acute and the adoptive transfer EAE models, as well as optimizing the perfomance of the TMN nano-drug. The highly efficacious anti-inflammatory therapeutic feature of these two nano-drugs meets the criteria of disease-modifying drugs and supports further development and evaluation of these nano-drugs as potential therapeutic agents for diseases with an inflammatory component.
Collapse
Affiliation(s)
- Keren Turjeman
- Laboratory of Membrane and Liposome Research, Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, Jerusalem, Israel
- * E-mail:
| | - Yaelle Bavli
- Laboratory of Membrane and Liposome Research, Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Pablo Kizelsztein
- Laboratory of Membrane and Liposome Research, Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Yaelle Schilt
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, Israel
| | - Nahum Allon
- Laboratory of Membrane and Liposome Research, Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | | | - Efrat Sasson
- BioImage MRI Research & Consulting, Tel Aviv, Israel
| | - Uri Raviv
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, Israel
| | - Haim Ovadia
- Department of Neurology, Agnes Ginges Center for Human Neurogenetics, Hadassah University Hospital, Jerusalem, Israel
| | - Yechezkel Barenholz
- Laboratory of Membrane and Liposome Research, Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| |
Collapse
|
9
|
Emoto MC, Sato-Akaba H, Hirata H, Fujii HG. Dynamic changes in the distribution and time course of blood-brain barrier-permeative nitroxides in the mouse head with EPR imaging: visualization of blood flow in a mouse model of ischemia. Free Radic Biol Med 2014; 74:222-8. [PMID: 25014567 DOI: 10.1016/j.freeradbiomed.2014.06.026] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 05/20/2014] [Accepted: 06/30/2014] [Indexed: 12/13/2022]
Abstract
Electron paramagnetic resonance (EPR) imaging using nitroxides as redox-sensitive probes is a powerful, noninvasive method that can be used under various physiological conditions to visualize changes in redox status that result from oxidative damage. Two blood-brain barrier-permeative nitroxides, 3-hydroxymethyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (HMP) and 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-yloxy (MCP), have been widely used as redox-sensitive probes in the brains of small animals, but their in vivo distribution and properties have not yet been analyzed in detail. In this study, a custom-made continuous-wave three-dimensional (3D) EPR imager was used to obtain 3D EPR images of mouse heads using MCP or HMP. This EPR imager made it possible to take 3D EPR images reconstructed from data from 181 projections acquired every 60s. Using this improved EPR imager and magnetic resonance imaging, the distribution and reduction time courses of HMP and MCP were examined in mouse heads. EPR images of living mice revealed that HMP and MCP have different distributions and different time courses for entering the brain. Based on the pharmacokinetics of the reduction reactions of HMP and MCP in the mouse head, the half-lives of HMP and MCP were clearly and accurately mapped pixel by pixel. An ischemic mouse model was prepared, and the half-life of MCP was mapped in the mouse head. Compared to the half-life in control mice, the half-life of MCP in the ischemic model mouse brain was significantly increased, suggesting a shift in the redox balance. This in vivo EPR imaging method using BBB-permeative MCP is a useful noninvasive method for assessing changes in the redox status in mouse brains under oxidative stress.
Collapse
Affiliation(s)
- Miho C Emoto
- Center for Medical Education, Sapporo Medical University, Sapporo, Hokkaido 060-8556, Japan
| | - Hideo Sato-Akaba
- Department of Systems Innovation, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Hiroshi Hirata
- Division of Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University, Sapporo, Hokkaido 060-0814, Japan
| | - Hirotada G Fujii
- Center for Medical Education, Sapporo Medical University, Sapporo, Hokkaido 060-8556, Japan.
| |
Collapse
|
10
|
Paccaly A, Frick A, Rohatagi S, Liu J, Shukla U, Rosenburg R, Hinder M, Jensen BK. Pharmacokinetics of Otamixaban, a Direct Factor Xa Inhibitor, in Healthy Male Subjects: Pharmacokinetic Model Development for Phase 2/3 Simulation of Exposure. J Clin Pharmacol 2013; 46:37-44. [PMID: 16397282 DOI: 10.1177/0091270005281817] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The pharmacokinetics of otamixaban was investigated in healthy male subjects over a wide range of intravenous doses, with duration of administration varying between 1-minute infusions (bolus dose) and 24-hour infusions, using noncompartmental and multicompartmental methods. A global compartmental analysis (2 and 3 compartments) generated a single set of pharmacokinetic parameters, regardless of infusion rate and duration, and took into account the 30% decrease in clearance and volume of distribution observed over the dose range. The 2-compartment model was retained to predict bolus plus 3-hour-infusion doses of otamixaban for future phase (2/3) studies. Otamixaban exhibited in healthy subjects several interesting pharmacokinetic features in view of its potential therapeutic use in coronary thrombosis: a rapid plasma distribution and elimination, a well-described dose-exposure relationship, a low intersubject variability in plasma exposure, and a mixed renal and biliary excretion with constant renal clearance.
Collapse
Affiliation(s)
- Anne Paccaly
- Sanofi Aventis, 1041 Route 202-206, PO Box 6800, Mail Stop M303A, Bridgewater, NJ 08807-0800, USA
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Dogan S, Ozlem Elpek G, Kirimlioglu Konuk E, Demir N, Aslan M. Measurement of intracellular biomolecular oxidation in liver ischemia-reperfusion injury via immuno-spin trapping. Free Radic Biol Med 2012; 53:406-14. [PMID: 22634144 DOI: 10.1016/j.freeradbiomed.2012.05.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 05/08/2012] [Accepted: 05/15/2012] [Indexed: 12/29/2022]
Abstract
Hepatic ischemia-reperfusion (I/R) can lead to liver failure in association with remote organ damage, both of which have significant rates of morbidity and mortality. In this study, novel spin trapping and histopathological techniques have been used to investigate in vivo free radical formation in a rat model of warm liver I/R injury. 5,5-Dimethyl-1-pyrroline N-oxide (DMPO) was administered to rats via intraperitoneal injection at a single dose of 1.5g of pure DMPO/kg body wt 2h before the initiation of liver ischemia. Blood vessels supplying the median and left lateral hepatic lobes were occluded with an arterial clamp for 60min, followed by 60min reperfusion. The effects of DMPO on I/R injury were evaluated by assessing the hepatic ultrastructure via transmission electron microscopy and by histopathological scoring. Immunoelectron microscopy was performed to determine the cellular localization of DMPO nitrone adducts. Levels of nitrone adducts were also measured to determine in situ scavenging of protein and DNA radicals. Total histopathological scoring of cellular damage was significantly decreased in hepatic I/R injury after DMPO treatment. DMPO treatment significantly decreased the hepatic conversion of xanthine oxidase and 4-hydroxynonenal formation in I/R injury compared to the untreated I/R group. The distribution of gold-nanoparticle-labeled DMPO nitrone adducts was observed in mitochondria, cytoplasm, and nucleus of hepatocytes. The formation of protein- and DNA-nitrone adducts was increased in DMPO-treated I/R livers compared to DMPO controls, indicating increased in situ protein and DNA radical formation and scavenging by DMPO. These results suggest that DMPO reduces I/R damage via protection against oxidative injury.
Collapse
Affiliation(s)
- Serdar Dogan
- Department of Medical Biochemistry, Akdeniz University Medical School, Antalya, Turkey
| | | | | | | | | |
Collapse
|
12
|
Kosem N, Naganuma T, Ichikawa K, Phumala Morales N, Yasukawa K, Hyodo F, Yamada KI, Utsumi H. Whole-body kinetic image of a redox probe in mice using Overhauser-enhanced MRI. Free Radic Biol Med 2012; 53:328-36. [PMID: 22579576 DOI: 10.1016/j.freeradbiomed.2012.04.026] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 04/23/2012] [Accepted: 04/24/2012] [Indexed: 02/03/2023]
Abstract
Overhauser-enhanced MRI (OMRI) enables visualization of free radicals in animals based on dynamic nuclear polarization. Real-time data of tissue redox status gathered from kinetic images of redox-sensitive nitroxyl radical probes using OMRI provided both anatomic and physiological information. Phantom experiments demonstrated the linear correlation between the enhancement factor and the concentration of a membrane-impermeable probe, carboxy-PROXYL (3-carboxy-2,2,5,5-tetramethyl- pyrrolidine-1-oxyl). Whole-body OMRI images illustrated the in vivo kinetics of carboxy-PROXYL for 25 min. Initial distribution was observed in lung, heart, liver, and kidney, but not brain, corresponding to its minimal lipophilicity. Based on these images (pixel size, 1.33 × 1.33 mm; slice thickness, 50mm), a time-concentration curve with low coefficient of variance (<0.21) was created to assess pharmacokinetic behaviors. A biexponential curve showed a distribution phase from 1 to 10 min and an elimination phase from 15 to 25 min. The α rate constant was greater than the β rate constant in ROIs, confirming that its pharmacokinetics obeyed a two-compartment model. As a noninvasive technique, combining OMRI imaging with redox probes to monitor tissue redox status may be useful in acquiring valuable information regarding organ function for preclinical and clinical studies of oxidative diseases.
Collapse
Affiliation(s)
- Nuttavut Kosem
- Innovation Center for Medical Redox Navigation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Mukhopadhyay P, Horváth B, Zsengellér Z, Zielonka J, Tanchian G, Holovac E, Kechrid M, Patel V, Stillman IE, Parikh SM, Joseph J, Kalyanaraman B, Pacher P. Mitochondrial-targeted antioxidants represent a promising approach for prevention of cisplatin-induced nephropathy. Free Radic Biol Med 2012; 52:497-506. [PMID: 22120494 PMCID: PMC3253235 DOI: 10.1016/j.freeradbiomed.2011.11.001] [Citation(s) in RCA: 158] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 10/23/2011] [Accepted: 11/03/2011] [Indexed: 02/04/2023]
Abstract
Cisplatin is a widely used antineoplastic agent; however, its major limitation is the development of dose-dependent nephrotoxicity whose precise mechanisms are poorly understood. Here we show not only that mitochondrial dysfunction is a feature of cisplatin nephrotoxicity, but also that targeted delivery of superoxide dismutase mimetics to mitochondria largely prevents the renal effects of cisplatin. Cisplatin induced renal oxidative stress, deterioration of mitochondrial structure and function, an intense inflammatory response, histopathological injury, and renal dysfunction. A single systemic dose of mitochondrially targeted antioxidants, MitoQ or Mito-CP, dose-dependently prevented cisplatin-induced renal dysfunction. Mito-CP also prevented mitochondrial injury and dysfunction, renal inflammation, and tubular injury and apoptosis. Despite being broadly renoprotective against cisplatin, Mito-CP did not diminish cisplatin's antineoplastic effect in a human bladder cancer cell line. Our results highlight the central role of mitochondrially generated oxidants in the pathogenesis of cisplatin nephrotoxicity. Because similar compounds seem to be safe in humans, mitochondrially targeted antioxidants may represent a novel therapeutic approach against cisplatin nephrotoxicity.
Collapse
Affiliation(s)
- Partha Mukhopadhyay
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| | - Béla Horváth
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| | - Zsuzsanna Zsengellér
- Department of Pathology, Beth Israel Deaconess Medical Center, and Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Jacek Zielonka
- Free Radical Research Center, Biophysics Department, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Galin Tanchian
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| | - Eileen Holovac
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| | - Malek Kechrid
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| | - Vivek Patel
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| | - Isaac E. Stillman
- Department of Pathology, Beth Israel Deaconess Medical Center, and Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Samir M. Parikh
- Division of Nephrology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215 USA
| | - Joy Joseph
- Free Radical Research Center, Biophysics Department, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Balaraman Kalyanaraman
- Free Radical Research Center, Biophysics Department, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Pál Pacher
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| |
Collapse
|
14
|
Wu K, Zheng Y, Cong J, Zhang Q, Wang C, Xian H, Sun C. [Application of ESR imaging technique in studying of skin-penetration properties of nitroxide free radical]. Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 2008; 25:925-929. [PMID: 18788310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A set of L-band electron spin resonance imaging (ESRI) equipment suitable for biological species was developed and an ESRI experiment model for viable skin samples was established. The mechanic process of nitroxide free radical TEMPO (2,2, 6, 6-tetramethyl-1-piperidinyloxy) penetrating through skin sample and the spin density distribution of TEMPO after it interacted with skin sample were detected by the developed ESRI method. Skin samples were extracted from mice back. The experimental samples were prepared by cutting the skin pieces into square shape of 2 x 2 cm2 and then the samples were divided into three groups by treating them with three different methods: Method A, simple treatment by simply cutting the hair; method B, 8% Na2S depilation treatment for 10 min; method C, 8% Na2S depilation and then 5% pancreatic digestion treatment for 2 hours. The liposoluble solvent DMSO (dimethyl sulfoxide) and distilled water were used as two kinds of solvent for the TEMPO liquor. The results indicated that the skin-penetration properties of TEMPO were significantly different among samples treated with different methods and the surface cornifin of skin offered remarkable resistance to TEMPO. The TEMPO liquor of water could hardly penetrate through skins, whereas about 20%-30% of the original TEMPO compounds that solved in liposoluble solvent DMSO could penetrate through the skin sample treated with method C after 16 hours of interaction. Furthermore, the penetration rate of TEMPO through the skin tissue was a strong time dependent process. The preliminary application results suggested that ESRI technique could provide an effective and applicable method for dynamically researching skin-penetration properties of some special kinds of materials such as paramagnetic compounds.
Collapse
Affiliation(s)
- Ke Wu
- Beijing Institute of Radiation Medicine, Beijing 100850, China
| | | | | | | | | | | | | |
Collapse
|
15
|
Meineke I, Steinmetz H, Kirchheiner J, Brockmöller J. Therapeutic drug monitoring of mirtazapine, desmethylmirtazapine, 8-hydroxymirtazapine, and mirtazapine-N-oxide by enantioselective HPLC with fluorescence detection. Ther Drug Monit 2007; 28:760-5. [PMID: 17164691 DOI: 10.1097/ftd.0b013e31802c0264] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The tetracyclic antidepressant mirtazapine has been in clinical use for several years as a racemic drug. Because of a relatively narrow therapeutic index, therapeutic drug monitoring may be helpful to individually optimize therapy with mirtazapine. An enantioselective high-performance liquid chromatography (HPLC) method with fluorescence detection has been developed for the quantification of mirtazapine, desmethyl mirtazapine, 8-hydroxy mirtazapine, and mirtazapine N-oxide. The method is suitable for the analysis of plasma and urine samples in the range from 1 to 100 ng/mL with precision (coefficient of variation, or CV) between 12% and 19%. The sample preparation step comprises a liquid-solid extraction procedure with good recoveries, between 85% and 99%. Patient samples for therapeutic drug monitoring as well as concentration-time series were assayed and the resulting enantiomer ratios analyzed. Typical trough levels were between 1 and 100 ng/mL, with enantiomer ratios of approximately 0.42 (S/R). In concentration-time series, enantiomer ratios distinctively greater than 1 were observed at early time points. Because the enantiomers of mirtazapine and desmethyl mirtazapine have different pharmacological properties, the method is believed to be helpful in understanding the concentration-effect relationships in the former.
Collapse
Affiliation(s)
- Ingolf Meineke
- Department of Clinical Pharmacology University of Goettingen, Goettingen, Germany.
| | | | | | | |
Collapse
|
16
|
Nutescu EA, Pater K. Drug evaluation: the directly activated Factor Xa inhibitor otamixaban. IDrugs 2006; 9:854-65. [PMID: 17139573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Otamixaban, under development by sanofi-aventis, is a directly activated Factor X (FXa) inhibitor that is currently in phase IIb clinical trials for acute coronary syndrome and myocardial infarction. Preclinical studies with otamixaban demonstrated high selectivity of the compound for FXa. Otamixaban effectively inhibited thrombin generation without interfering with existing thrombin activity. Intravenously administered otamixaban was well tolerated in both male and female patients, independent of age. Otamixaban exhibited a well-described dose-exposure relationship, a low inter-patient variability in plasma exposure, and was both rapidly distributed in the plasma and quickly eliminated. The rapid decrease in otamixaban plasma concentrations following the termination of an infusion is an advantage over other FXa inhibitors that have longer half-lives. Otamixaban exhibited an improved pharmacodynamic profile over conventional anticoagulant therapies such as heparin. During clinical trials with otamixaban, no major drug interactions were observed with agents that were likely to be used in combination therapy. Otamixaban is a promising agent that merits further consideration for clinical trials in patients with coronary thrombosis.
Collapse
Affiliation(s)
- Edith A Nutescu
- Antithrombosis Center, Department of Pharmacy Practice, College of Pharmacy, The University of Illinois at Chicago, Chicago, IL 60612-7230, USA.
| | | |
Collapse
|
17
|
Hinder M, Frick A, Jordaan P, Hesse G, Gebauer A, Maas J, Paccaly A. Direct and rapid inhibition of factor Xa by otamixaban: A pharmacokinetic and pharmacodynamic investigation in patients with coronary artery disease. Clin Pharmacol Ther 2006; 80:691-702. [PMID: 17178269 DOI: 10.1016/j.clpt.2006.09.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2006] [Accepted: 09/01/2006] [Indexed: 11/16/2022]
Abstract
BACKGROUND New anticoagulants that combine effective anticoagulation with low bleeding rates are still sought after. We investigated the safety, pharmacokinetics, and pharmacodynamics of otamixaban, a direct factor Xa inhibitor, in patients with stable coronary artery disease. METHODS This was a randomized, placebo-controlled, double-blind, multicenter study in 119 patients with stable coronary artery disease taking maintenance doses of their comedication. Of these patients, 50% had mild renal impairment (creatinine clearance >45 mL/min but <80 mL/min). Patients were randomized in a 4:1 ratio to receive either otamixaban or placebo as a 1-minute bolus followed by a 24-hour continuous infusion. Anti-factor Xa activity, clotting times (activated partial thromboplastin time, dilute prothrombin time, Russell's viper venom test), and international normalized ratio were measured. RESULTS All patients completed the study according to the protocol. No major or minor bleeding occurred according to Thrombosis in Myocardial Infarction criteria. Anti-factor Xa activity and anticoagulant effect were measurable early after the start of the infusion and remained during the infusion. Upon cessation, these effects declined rapidly and returned to baseline within 6 hours after the end of infusion. Anti-factor Xa activity coincided with the otamixaban plasma concentrations. The fold changes from baseline at the end of infusion with regard to the clotting times ranged from 1.7 to 4.4 (1.15 for placebo), 1.29 to 3.15 (0.98 for placebo), and 1.19 to 2.11 (0.94 for placebo) for Russell's viper venom test, dilute prothrombin time, and activated partial thromboplastin time, respectively, and ranged from 0.94 to 1.70 (0.94 for placebo) for the international normalized ratio. CONCLUSION In patients with stable coronary artery disease taking maintenance doses of their usual concomitant medication, otamixaban exerts a rapid onset of anticoagulation and anti-factor Xa activity. Our data provide evidence that further studies are warranted to investigate the safety and efficacy of otamixaban in the target population.
Collapse
Affiliation(s)
- Markus Hinder
- Science & Medical Affairs, Sanofi-Aventis, Frankfurt am Main, Germany.
| | | | | | | | | | | | | |
Collapse
|
18
|
Hyodo F, Matsumoto KI, Matsumoto A, Mitchell JB, Krishna MC. Probing the Intracellular Redox Status of Tumors with Magnetic Resonance Imaging and Redox-Sensitive Contrast Agents. Cancer Res 2006; 66:9921-8. [PMID: 17047054 DOI: 10.1158/0008-5472.can-06-0879] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Nitroxide radicals are paramagnetic contrast agents, used in magnetic resonance imaging (MRI), that also exert antioxidant effects. Participating in cellular redox reactions, they lose their ability to provide contrast as a function of time after administration. In this study, the rate of contrast loss was correlated to the reducing power of the tissue or the "redox status." The preferential reduction of nitroxides in tumors compared with normal tissue was observed by MRI. The influence of the structure of the nitroxide on the reduction rate was investigated by MRI using two cell-permeable nitroxides, 4-hydroxy-2,2,6,6,-tetramethyl-1-piperidynyloxyl (Tempol) and 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (3CP), and one cell-impermeable nitroxide, 3-carboxy-2,2,5,5,5-tetramethylpyrrolidine-1-oxyl (3CxP). Pharmacokinetic images of these nitroxides in normal tissue, tumor, kidney, and artery regions in mice were simultaneously obtained using MRI. The decay of Tempol and 3CP in tumor tissue was significantly faster than in normal tissue. No significant change in the total nitroxide (oxidized + reduced forms) was noted from tissue extracts, suggesting that the loss in contrast as a function of time is a result of intracellular bioreduction. However, in the case of 3CxP (membrane impermeable), there was no difference in the reduction rates between normal and tumor tissue. The time course of T(1) enhancement by 3CxP and the total amount of 3CxP (oxidized + reduced) in the femoral region showed similar pharmacokinetics. These results show that the differential bioreduction of cell-permeable nitroxides in tumor and normal tissue is supported by intracellular processes and the reduction rates are a means by which the intracellular redox status can be assessed noninvasively.
Collapse
Affiliation(s)
- Fuminori Hyodo
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892, USA
| | | | | | | | | |
Collapse
|
19
|
Garland LL, Taylor C, Pilkington DL, Cohen JL, Von Hoff DD. A phase I pharmacokinetic study of HMN-214, a novel oral stilbene derivative with polo-like kinase-1-interacting properties, in patients with advanced solid tumors. Clin Cancer Res 2006; 12:5182-9. [PMID: 16951237 DOI: 10.1158/1078-0432.ccr-06-0214] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
PURPOSE HMN-214 is an oral prodrug of HMN-176, a stilbene derivative that interferes with the subcellular spatial location of polo-like kinase-1, a serine/threonine kinase that regulates critical mitotic events. We conducted a dose escalation study of HMN-214 in patients with advanced cancer to assess the safety profile and pharmacokinetics of HMN-214 and to establish the maximum tolerated dose. EXPERIMENTAL DESIGN Thirty-three patients were enrolled onto four dosing cohorts of HMN-214 from 3 to 9.9 mg/m2/d using a continuous 21-day dosing schedule every 28 days, with pharmacokinetic sampling during cycle 1. RESULTS A severe myalgia/bone pain syndrome and hyperglycemia were dose-limiting toxicities at 9.9 mg/m2/d. A dose reduction and separate enrollment by pretreatment status (lightly versus heavily pretreated) was undertaken, with one dose-limiting toxicity (grade 3 bone pain) at 8 mg/m2/d. The maximum tolerated dose was defined as 8 mg/m2/d for both treatment cohorts. Dose-proportional increases were observed in AUC but not Cmax. There was no accumulation of HMN-176, the metabolite of HMN-214, with repeated dosing. Seven of 29 patients had stable disease as best tumor response, including 6-month stable disease in a heavily pretreated breast cancer patient. A transient decline in carcinoembryonic antigen in a patient with colorectal cancer was noted. CONCLUSIONS The maximum tolerated dose and recommended phase II dose of HMN-214 when administered on this schedule was 8 mg/m2/d regardless of pretreatment status. Further development of HMN-214 will focus on patient populations for which high expression of polo-like kinase-1 is seen (i.e., prostate and pancreatic cancer patients).
Collapse
Affiliation(s)
- Linda L Garland
- Arizona Cancer Center, University of Arizona, Tucson, Arizona 85724, USA.
| | | | | | | | | |
Collapse
|
20
|
Paccaly A, Frick A, Ozoux ML, Chu V, Rosenburg R, Hinder M, Shukla U, Jensen BK. Pharmacokinetic/pharmacodynamic relationships for otamixaban, a direct factor Xa inhibitor, in healthy subjects. J Clin Pharmacol 2006; 46:45-51. [PMID: 16397283 DOI: 10.1177/0091270005281818] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Direct pharmacokinetic/pharmacodynamic relationships for otamixaban were investigated after rising doses in healthy subjects using mixed-effect modeling. Activated partial thromboplastin time, prothrombin time, dilute prothrombin time, and Russell's viper venom-induced clotting time (RVVT) related linearly, whereas Heptest clotting time (HCT) followed a sigmoidal E(max) model. The pharmacokinetic/pharmacodynamic response (slope) and their corresponding interindividual variability (seconds per ng/mL, [% coefficient of variation]) were 0.263 (29%) for Russell's viper venom-induced clotting time, 0.117 (10%) for dilute prothrombin time, 0.058 (19%) for activated partial thromboplastin time, and 0.021 (11%) for prothrombin time. For Heptest clotting time, the parameter estimates with their corresponding interindividual variability (% coefficient of variation) were 71 ng/mL (30%) for EC(50), 186 seconds (64%) for E(max), and 17 seconds (16%) for E(0). The model predicted otamixaban plasma concentrations to double the clotting times that were close to those observed. These pharmacokinetic/pharmacodynamic relationships, together with the predictable pharmacokinetics, allowed the anticoagulant effect at given doses of otamixaban to be foreseen in healthy subjects.
Collapse
Affiliation(s)
- Anne Paccaly
- Sanofi Aventis, 1041 Route 202-206, Mail Stop M303A, Bridgewater, NJ 08807-0800, USA.
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Yokoyama H, Morinobu S, Ueda Y. EPRI to estimate the in vivo intracerebral reducing ability in adolescent rats subjected to neonatal isolation. J Magn Reson Imaging 2006; 23:637-40. [PMID: 16568429 DOI: 10.1002/jmri.20560] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To estimate the in vivo intracerebral reducing ability after acute stress in adolescent rats subjected to early neonatal isolation (NI), by performing temporal electron paramagnetic resonance imaging (EPRI) of the brain. MATERIALS AND METHODS An EPRI system operating at an EPR frequency of 700 MHz was used. The intracerebral reducing ability was estimated based on the halflife of the EPR signal of the blood-brain barrier (BBB)-permeable nitroxide radical. The NI treatment was performed for a period of one hour per day over postnatal days 2-9. Six-week-old rats were exposed to acute stress (immobilization for 90 minutes) prior to the EPRI study. RESULTS Depletion of the intracerebral reducing ability caused by the acute stress was observed; however, this depletion phenomenon did not occur in animals that were not subjected to NI. CONCLUSION The results obtained in this study prove that NI induces cerebral vulnerability to acute stress in adolescence.
Collapse
MESH Headings
- Analysis of Variance
- Animals
- Animals, Newborn/metabolism
- Blood-Brain Barrier/metabolism
- Brain/metabolism
- Brain/physiopathology
- Brain Diseases, Metabolic/etiology
- Brain Diseases, Metabolic/metabolism
- Brain Diseases, Metabolic/psychology
- Cyclic N-Oxides/metabolism
- Cyclic N-Oxides/pharmacokinetics
- Disease Models, Animal
- Electron Spin Resonance Spectroscopy/methods
- Imaging, Three-Dimensional/methods
- Oxidation-Reduction
- Pyrrolidines
- Rats
- Rats, Sprague-Dawley
- Restraint, Physical
- Social Isolation
- Stress, Psychological/complications
- Stress, Psychological/metabolism
- Time Factors
Collapse
Affiliation(s)
- Hidekatsu Yokoyama
- National Institute of Advanced Industrial Science and Technology, Nagoya, Japan.
| | | | | |
Collapse
|
22
|
Anzai K, Ueno M, Yoshida A, Furuse M, Aung W, Nakanishi I, Moritake T, Takeshita K, Ikota N. Comparison of stable nitroxide, 3-substituted 2,2,5,5-tetramethylpyrrolidine-N-oxyls, with respect to protection from radiation, prevention of DNA damage, and distribution in mice. Free Radic Biol Med 2006; 40:1170-8. [PMID: 16545684 DOI: 10.1016/j.freeradbiomed.2005.11.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2005] [Revised: 10/17/2005] [Accepted: 11/07/2005] [Indexed: 11/26/2022]
Abstract
We compared three 3-substituted 2,2,5,5-tetramethylpyrrolidine-N-oxyls (PROXYLs): carbamoyl-, methoxycarbonyl-, and hydroxymethyl-PROXYL (CM-, MC-, and HM-PROXYL, respectively) with respect to radioprotection, prevention of DNA damage, and in vivo distribution in mice. The PROXYLs provided protection to C3H mice against lethal X-irradiation (8 Gy) with the following order of magnitude, HM- > CM- approximately MC-PROXYL. In contrast, radioprotection at the cellular level assessed by the colony formation of leukemia cell line L5178Y showed no difference among them. The degree of protection from X ray-induced oxidation of DNA bases measured by the formation of 8-hydroxydeoxyguanosine in salmon DNA and the cleavage of DNA measured by electrophoresis of plasmid pBR322 DNA did not differ among the PROXYLs. Redox potentials were also similar for each. However, the blood concentration of the PROXYLs injected ip into the mice showed different maximum concentrations (HM- > CM- approximately MC-PROXYL), although all reached a maximum at around 5-10 min and gradually decreased thereafter. Their concentration in bone marrow showed a similar pattern, suggesting that the difference in in vivo radioprotection among the three PROXYLs is due to the difference in their distribution to bone marrow. In general, the radioprotection provided by stable nitroxides is affected not only by redox potential and reactivity in vitro but also by pharmacokinetics.
Collapse
Affiliation(s)
- Kazunori Anzai
- Redox Regulation Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Chiba 263-8555, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Takeshita K, Chi C, Hirata H, Ono M, Ozawa T. In vivo generation of free radicals in the skin of live mice under ultraviolet light, measured by L-band EPR spectroscopy. Free Radic Biol Med 2006; 40:876-85. [PMID: 16520239 DOI: 10.1016/j.freeradbiomed.2005.10.049] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Revised: 09/27/2005] [Accepted: 10/16/2005] [Indexed: 11/18/2022]
Abstract
Although free radicals may be involved in various types of UV-induced injuries, only a few in vivo studies of the generation of free radicals, including oxygen radicals, during exposure to ultraviolet light (UV) have been reported. In this study, the nitroxyl probe 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-N-oxyl was intravenously injected into hairless mice, and its decay was monitored in the skin with an in vivo EPR spectrometer equipped with a surface-coil-type resonator. The rate of decay of the EPR signal increased during UV (UVA+B) irradiation. This increase in signal decay was suppressed by preadministration of a spin trap, N-tert-butyl-alpha-phenylnitrone (PBN). PBN did not change the rate of signal decay in nonirradiated mice. The correlation between signal decay rate and physiological parameters such as blood velocity, blood mass, or skin temperature was low. The decay rate responded rapidly and reversibly to starting and stopping the UV illumination. Hydroxyl and peroxyl radicals caused reduction of the probe signal in vitro, and PBN inhibited only the peroxyl radical-induced signal reduction. These observations suggest that peroxyl radicals are generated in the skin of live mice during UVA+B irradiation.
Collapse
Affiliation(s)
- Keizo Takeshita
- Faculty of Pharmaceutical Sciences, Sojo University, Ikeda, Kumamoto, Japan.
| | | | | | | | | |
Collapse
|
24
|
Anderson RF, Shinde SS, Hay MP, Denny WA. Potentiation of the cytotoxicity of the anticancer agent tirapazamine by benzotriazine N-oxides: the role of redox equilibria. J Am Chem Soc 2006; 128:245-9. [PMID: 16390153 DOI: 10.1021/ja0559101] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Tirapazamine (3-amino-1,2,4-benzotriazine 1,4-dioxide), the lead bioreductive drug with selective toxicity for hypoxic cells in tumors, is thought to act by forming an active oxidizing radical of high one-electron reduction potential, E(1), when reduced by reductases. It has a dual mechanism of action, both generating DNA radicals, following its one-electron reduction and subsequently oxidizing these DNA radicals to form labile cations or hydrolyzable lactones through transferring an O atom, resulting in DNA strand breaks. These parallel secondary reactions have been proposed to be also initiated by its two-electron reduced metabolite, the 1-oxide. We have used pulse radiolysis to show that the benzotriazinyl radical of a highly soluble analogue of tirapazamine, the 3-(N,N-dimethyl-1,2-ethanediamine) analogue, is able to oxidize tirapazamine itself. We have found that both tirapazamine and the 1-oxides are in equilibrium with their respective benzotriazinyl radicals, with high concentrations of the more soluble 1-oxide maintaining a high concentration of the more reactive oxidizing radical of tirapazamine. The one-electron reduction potentials, E(1), of the 1-oxides and related compounds have been measured and, together with the E(1) values of tirapazamine and the 2-nitroimidazole radiosensitizer, misonidazole, are shown to predict the published percentages of electron transfer. This radical chemistry study gives an insight into the mechanisms of the potentiation of radical damage, reported for DNA, that underlies the hypoxic cytotoxicity of electron affinic compounds. The E(1) values of the benzotriazinyl radicals of the benzotriazine compounds govern the position of the redox equilibria, which determine the amount of initial radical damage. The E(1) values of the 1,4-dioxides and 1-oxide compounds govern the degree of potentiation of the initial radical damage once formed.
Collapse
Affiliation(s)
- Robert F Anderson
- Department of Chemistry and Auckland Cancer Society Research Centre, The University of Auckland, Private Bag 92019, Auckland 1, New Zealand.
| | | | | | | |
Collapse
|
25
|
Cotrim AP, Sowers AL, Lodde BM, Vitolo JM, Kingman A, Russo A, Mitchell JB, Baum BJ. Kinetics of tempol for prevention of xerostomia following head and neck irradiation in a mouse model. Clin Cancer Res 2006; 11:7564-8. [PMID: 16243832 DOI: 10.1158/1078-0432.ccr-05-0958] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Radiotherapy is commonly used to treat the majority of patients with head and neck cancers. Salivary glands in the radiation field are dramatically affected by this procedure. The purpose of this study was to examine pharmacokinetic characteristics of the stable nitroxide 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (tempol) with respect to radioprotection of the salivary glands. EXPERIMENTAL DESIGN To evaluate the effect of different doses and times of administration, the heads of C3H mice were exposed to a single irradiation dose of 15 Gy, with i.p. tempol injection. To analyze other routes of administration, we injected 275 mg/kg tempol by an i.m., i.v., or s.c. route, 10 minutes before irradiation. We also tested whether oral administration of tempol in a topical form (either in a mouthwash or gel) provided any salivary gland protection. RESULTS Tempol treatment (137.5 or 275 mg/kg, i.p., 10 minutes before irradiation) significantly reduced irradiation-induced salivary hypofunction (approximately 50-60%). I.v. or s.c. administration of tempol also showed significant radioprotection, whereas i.m. administration proved to be ineffective. Topical use of tempol, either as a mouthwash or gel, also was radioprotective. CONCLUSIONS Our results strongly suggest that tempol is a promising candidate for clinical application to protect salivary glands in patients undergoing radiotherapy for head and neck cancers.
Collapse
Affiliation(s)
- Ana P Cotrim
- Gene Therapy and Therapeutics Branch and Biostatistics Core, Division of Clinical Research and Health Promotion, National Institute of Dental and Craniofacial Research, NIH, Bethesda, Maryland 20892, USA.
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Uwayama J, Hirayama A, Yanagawa T, Warabi E, Sugimoto R, Itoh K, Yamamoto M, Yoshida H, Koyama A, Ishii T. Tissue Prx I in the protection against Fe-NTA and the reduction of nitroxyl radicals. Biochem Biophys Res Commun 2005; 339:226-31. [PMID: 16297875 DOI: 10.1016/j.bbrc.2005.10.192] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Accepted: 10/28/2005] [Indexed: 11/25/2022]
Abstract
Peroxiredoxin I (Prx I) is a key cytoplasmic peroxidase that reduces intracellular hydroperoxides in concert with thioredoxin. To study the role of tissue Prx I in protection from oxidative stress, we generated Prx I-/- mice by gene trapping. We then evaluated the acute-phase tissue damage caused by ferric-nitrilotriacetate (Fe-NTA). Increases in serum aspartate aminotransferase and alanine aminotransferase levels were significantly greater in Prx I-/- than wild-type mice, 4 and 12 h after the injection of Fe-NTA. Using real-time EPR imaging, we examined the reduction of the stable paramagnetic nitroxyl radical 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl in vivo, and found that the half-life of this spin probe in the liver and kidney was significantly prolonged in the Prx I-/- mice. These results demonstrate that Prx I-/- mice have less reducing activity and are more susceptible to the damage mediated by reactive oxygen species in vivo than wild-type mice.
Collapse
Affiliation(s)
- Junya Uwayama
- Biomolecular and Integrated Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Hinder M, Paccaly A, Frick A, Shukla U, Simcox K, Miller B, Gebauer A. Anticoagulant and anti-platelet effects are maintained following coadministration of otamixaban, a direct factor Xa inhibitor, with tirofiban in healthy volunteers. Thromb Haemost 2005; 93:794-5. [PMID: 15841331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
|
28
|
Metz JM, Smith D, Mick R, Lustig R, Mitchell J, Cherakuri M, Glatstein E, Hahn SM. A phase I study of topical Tempol for the prevention of alopecia induced by whole brain radiotherapy. Clin Cancer Res 2005; 10:6411-7. [PMID: 15475427 DOI: 10.1158/1078-0432.ccr-04-0658] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Complete alopecia is a universal complication of whole brain radiation therapy which contributes to patient anxiety over treatment. Tempol, a nitroxide radioprotector, has been shown to protect against radiation-induced alopecia in an animal model. This phase Ib study was designed to evaluate the safety and side effect profile of topical Tempol in patients with brain metastases being treated with whole brain radiotherapy. EXPERIMENTAL DESIGN Twelve patients with metastatic cancer to the brain were enrolled in the study between October 2000 and February 2003. Tempol (70 mg/ml concentration solution) was applied topically to the scalp 15 minutes before and washed off immediately after the completion of each of 10 fractions of whole brain radiation. Pharmacokinetic studies to evaluate the systemic absorption of Tempol were performed. Patients were assessed for toxicity before, during, and after Tempol administration. A secondary end point of the study, hair retention, was also scored. RESULTS Eleven patients were treated with topical Tempol. Adverse events that were considered possibly, probably, or definitely related to Tempol, included asymptomatic grade 2 (two patients) and grade 1 (one patient) hypoglycemia, grade 1 forehead skin redness (one patient), grade 1 dry scalp (one patient), and grade 1 tingling sensation on the scalp (one patient). Tempol was not detected in blood samples from more than 50% of the patients. Mean maximum Tempol levels for individual patients at any time point varied from 0.4 to 3.1 micromol/L. Hair retention was localized to the base of the scalp where the Tempol solution pooled after application in the first four patients on the study. Subsequently, full scalp hair retention was seen in three of final five evaluable patients after gauze had been wrapped around the head to hold the solution against the scalp. CONCLUSIONS This study demonstrates that topical application of Tempol to the scalp before whole brain radiation is safe and well tolerated. Evidence of protection against radiation-induced alopecia was observed. A phase II study that uses a gel formulation to increase the exposure of scalp to Tempol has been initiated.
Collapse
Affiliation(s)
- James M Metz
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia 19104-4283, USA.
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Abstract
Ageing is associated with structural and functional alterations of the vasculature. The nature of age-related vascular disorders is not completely understood. Oxidative stress is hypothesized to play a crucial role in the pathophysiology of vascular complications. We investigated the effects of chronic treatment with the superoxide dismutase mimetic tempol (4-hydroxy-2,2,6,6-tetramethyl piperidinoxyl) on vascular function in the mesenteric vasculature of aged rats. Young (3 weeks) and old (40 weeks) Sprague-Dawley rats were treated with tempol (1 mM in drinking water) or vehicle for 3 weeks. Arterial blood pressure was slightly, but significantly, higher in old than in young rats. Tempol had no effect on arterial blood pressure. The vasoconstrictor responses to norepinephrine (NE) and serotonin (5-HT) were exaggerated in the mesenteric vascular bed (MVB) removed from old rats. Vasodilator responses to acetylcholine (ACh), papaverine (PPV), and isoprenaline (ISO) were reduced in the MVB of old rats in comparison with young rats. Chronic treatment of old rats with tempol normalized their responses to NE and 5-HT. The dilator responses to ACh, PPV, and ISO were similar between old rats receiving tempol and young rats. The present findings suggest that oxidative stress contributes to vascular dysfunction in the mesentery of old rats. The vasculoprotective effects of tempol remain to be elucidated.
Collapse
Affiliation(s)
- R Tatchum-Talom
- Division of Basic Biomedical Sciences, University of South Dakota School of Medicine, Vermillion 57069, USA
| | | |
Collapse
|
30
|
Mikuni T, He G, Petryakov S, Fallouh MM, Deng Y, Ishihara R, Kuppusamy P, Tatsuta M, Zweier JL. In vivo detection of gastric cancer in rats by electron paramagnetic resonance imaging. Cancer Res 2004; 64:6495-502. [PMID: 15374960 DOI: 10.1158/0008-5472.can-04-0319] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Electron paramagnetic resonance imaging (EPRI) enables noninvasive spatial mapping of free radical metabolism and has recently been shown to provide in vivo physiologic information regarding alterations in the redox state of tumors and neoplastic tissues. With the use of nitroxide spin probes, it has been shown that certain tumors possess a highly reduced state. To determine whether EPRI can be used for early detection and visualization of gastric carcinoma based on its altered redox metabolism, studies were performed in a rat gastric cancer model induced by 1-methyl-3-nitro-1-nitrosoguanidine. Using a specialized 750 MHz resonator and EPRI instrument, a technique was developed for imaging nitroxide radicals in the whole stomach. In vivo three-dimensional EPRI of the stomach of rats with continuous intravenous administration of nitroxide 3-carboxamido-2,2,5,5-tetramethylpyrrolidine-N-oxyl (3-carbamoyl-proxyl) [3-CP] was performed. Whereas electron paramagnetic resonance images from untreated controls provide a uniform visualization of the stomach mucosa and wall, in the treated rats with gastric cancer, holes were present in the image at the locations of tumors. With localized spectroscopy, it was confirmed that the tumor regions were devoid of signal, and this was largely due to the presence of a more reduced state with rapid reduction of nitroxide. Pharmacokinetic studies indicated that 3-CP in tumors was rapidly reduced to an undetectable level, whereas the 3-CP levels in normal stomach tissue persisted. Near-infrared reflectance measurements of indocyanine green dye uptake indicated that there were no significant differences in tumor versus normal mucosal perfusion. From these results, we concluded that gastric cancer tumors could be distinguished from normal tissue based primarily on the marked difference in their rate of radical metabolism. Because alterations in cellular redox state and radical metabolism are of critical importance in tumor biology and treatment, this methodology should provide an important new tool for the study and visualization of gastric carcinoma and may also be of use in other cancer models.
Collapse
Affiliation(s)
- Tomiko Mikuni
- Center for Biomedical Electron Paramagnetic Resonance Spectroscopy and Imaging, Davis Heart and Lung Research Institute, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Yokoyama H, Ueda Y, Itoh O, Ikeda T, Noor JI, Ikenoue T. EPR imaging to estimate the in vivo intracerebral reducing ability of mature rats after neonatal hypoxic–ischemic brain injury. Magn Reson Imaging 2004; 22:1305-9. [PMID: 15607103 DOI: 10.1016/j.mri.2004.09.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2004] [Accepted: 09/22/2004] [Indexed: 11/16/2022]
Abstract
A rat model of neonatal hypoxic-ischemic encephalopathy (Rice's model) was obtained by unilateral ligation of the common carotid artery of 7-day-old rats with hypoxia (exposure to 8% oxygen). To estimate the in vivo intracerebral reducing ability of the mature rats (8 weeks old) of Rice's model, temporal electron paramagnetic resonance (EPR) imaging of the brain of a rat receiving a blood-brain barrier-permeable nitroxide radical, 3-hydroxymethyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl, was performed. In this imaging technique, the decay rate of the EPR signal intensity in a selected region of the brain is indicative of region-specific reducing ability. The effect of neonatal treatment of an antioxidant agent, 3-methyl-1-phenyl-2-pyrazolin-5-one (MCI-186), after a hypoxic-ischemic insult was also tested. It was found that the reducing ability had been depleted in the contralateral hemisphere of Rice's model rats; this depletion was suppressed by administering MCI-186.
Collapse
Affiliation(s)
- Hidekatsu Yokoyama
- Institute for Life Support Technology, Yamagata Promotional Organization for Industrial Technology, Yamagata 990-2473, Japan.
| | | | | | | | | | | |
Collapse
|
32
|
Tada M, Yokoyama H, Ito O, Ohya H, Ogata T. Evaluation of the hepatic reduction of a nitroxide radical in rats receiving ascorbic acid, glutathione or ascorbic acid oxidase by in vivo electron spin resonance study. J Gastroenterol Hepatol 2004; 19:99-105. [PMID: 14675250 DOI: 10.1111/j.1440-1746.2004.03201.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
BACKGROUND A nitroxide radical, 4-hydroxyl-2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPOL), is directly reduced to hydroxylamine by ascorbic acid (AsA). Ascorbic acid is oxidized to dehydroascorbic acid (DHA) by ascorbic acid oxidase (AAOx), and DHA is reduced to AsA by glutathione (GSH). In the present study, in vivo and ex vivo reduction of TEMPOL in the rat liver under various conditions of AsA supply was investigated using an electron spin resonance (ESR) spectrometer equipped with a surface coil-type resonator. METHODS To investigate in vivo hepatic reduction of TEMPOL, an ESR study of the liver of living rats which orally received AsA or intravenously received GSH or AAOx was made. To investigate direct interactions between TEMPOL and GSH or AAOx, an in vitro ESR study was conducted. To investigate TEMPOL reduction in the hepatic homogenate, an ex vivo ESR study was performed. RESULTS Ascorbic acid and GSH administration increased the in vivo hepatic reducing ability of TEMPOL. In contrast, AAOx administration decreased the reducing ability. In vitro TEMPOL was not reduced by GSH and hydroxylamine was not oxidized by AAOx. Reducing ability in the hepatic homogenate of AAOx-treated rats decreased, but that for GSH-treated rats was unchanged. CONCLUSION Ascorbic acid administration directly increases hepatic reducing ability. Ascorbic acid, which increased in the plasma due to GSH administration, entered the liver and enhanced the hepatic reducing ability. Administration of AAOx impaired the hepatic reducing ability by oxidizing AsA in the plasma and/or the liver.
Collapse
Affiliation(s)
- Mika Tada
- Regional Joint Research Project of Yamagata Prefecture, Japan Science and Technology Corporation, Yamagata, Japan
| | | | | | | | | |
Collapse
|
33
|
Elmedal B, de Dam MY, Mulvany MJ, Simonsen U. The superoxide dismutase mimetic, tempol, blunts right ventricular hypertrophy in chronic hypoxic rats. Br J Pharmacol 2003; 141:105-13. [PMID: 14656807 PMCID: PMC1574166 DOI: 10.1038/sj.bjp.0705580] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1. The purpose of this study was to investigate whether a membrane-permeable superoxide dismutase mimetic, tempol, added either alone or in combination with the nitric oxide (NO) donor molsidomine, prevents the development of pulmonary hypertension (PH) in chronic hypoxic rats. 2. Chronic hypobaric hypoxia (10% oxygen) for 2 weeks increased the right ventricular systolic pressure (RVSP), right ventricle and lung wet weight. Relaxations evoked by acetylcholine (ACh) and the molsidomine metabolite SIN-1 were impaired in isolated proximal, but not distal pulmonary arteries, from chronic hypoxic rats. 3. Treatment with tempol (86 mg x kg(-1) day(-1) in drinking water) normalized RVSP and reduced right ventricular hypertrophy, while systemic blood pressure, lung and liver weights, and blunted ACh relaxation of pulmonary arteries were unchanged. 4. Treatment with molsidomine (15 mg x kg(-1) day(-1) in drinking water) had the same effects as tempol, except that liver weight was reduced, and potassium and U46619-evoked vasoconstrictions in pulmonary arteries were increased. Combining tempol and molsidomine did not have additional effects compared to tempol alone. ACh relaxation in pulmonary arteries was not normalized by these treatments. 5. The media to lumen diameter ratio of the pulmonary arteries was greater for the hypoxic rats compared to the normoxic rats, and was not reversed by treatment with tempol, molsidomine, or the combination of tempol and molsidomine. 6. We conclude that tempol, like molsidomine, is able to correct RVSP and reduce right ventricular weight in the rat hypoxic model. Functional and structural properties of pulmonary small arteries were little affected. The results support the possibility that superoxide dismutase mimetics may be a useful means for the treatment of PH.
Collapse
MESH Headings
- 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid/administration & dosage
- Acetylcholine/pharmacology
- Administration, Oral
- Animals
- Body Weight/drug effects
- Body Weight/physiology
- Chronic Disease
- Cyclic N-Oxides/administration & dosage
- Cyclic N-Oxides/pharmacokinetics
- Cyclic N-Oxides/therapeutic use
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Drug Synergism
- Drug Therapy, Combination
- Endothelin-1/pharmacology
- Free Radical Scavengers/administration & dosage
- Free Radical Scavengers/pharmacokinetics
- Free Radical Scavengers/therapeutic use
- Heart Rate/drug effects
- Hypertrophy, Right Ventricular/complications
- Hypertrophy, Right Ventricular/physiopathology
- Hypertrophy, Right Ventricular/prevention & control
- Hypoxia/complications
- Hypoxia/drug therapy
- Hypoxia/physiopathology
- Male
- Molsidomine/analogs & derivatives
- Molsidomine/metabolism
- Molsidomine/pharmacology
- Molsidomine/therapeutic use
- Muscle, Smooth, Vascular
- Organ Size/drug effects
- Pulmonary Artery/anatomy & histology
- Pulmonary Artery/drug effects
- Rats
- Rats, Wistar
- Spin Labels
- Superoxide Dismutase/administration & dosage
- Superoxide Dismutase/therapeutic use
- Vasoconstriction/drug effects
- Vasodilation/drug effects
- Ventricular Pressure/drug effects
Collapse
Affiliation(s)
- Britt Elmedal
- Department of Pharmacology, University of Aarhus, 8000 Aarhus C, Denmark
| | - Mette Y de Dam
- Department of Pharmacology, University of Aarhus, 8000 Aarhus C, Denmark
| | | | - Ulf Simonsen
- Department of Pharmacology, University of Aarhus, 8000 Aarhus C, Denmark
- Author for correspondence:
| |
Collapse
|
34
|
Abstract
We present a method for measuring the transmembrane pH difference (deltapH=pHin-pHout) in chloroplasts with a spin label TEMPAMINE (4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl) accumulating inside the thylakoids in response to generation of deltapH. Experiments with chloroplasts suspended in the media of different osmolarity demonstrated that most of TEMPAMINE (TA) molecules taken up by chloroplasts were localized in the bulk of the thylakoid lumen. The DeltapH value was determined from the relationship deltapH=lg([H+]in/[H+]out) approximately equal to lg(Cin/Cout), where Cin and Cout are the concentrations of TA inside and outside the thylakoids, respectively. To quantify the internal concentration Cin, we used the threshold nature of the concentration-dependent broadening of the EPR signal from TA. It was demonstrated that spin-exchange interactions between TA molecules caused an observable broadening of the signal only when the concentration of TA exceeded the threshold level, [TA]theta approximately 2.0-2.2mM. The concentration dependencies of the signal parameters (the peak-to-peak amplitude, App, and the linewidth, deltaHpp) were described within a model of the non-homogeneous broadening of an unresolved hyperfine multiplet from the protons of TA molecule. If the concentration of TA inside the thylakoids went beyond the threshold level, the spin-exchange broadening of the EPR signal was accompanied by a reversible decrease in the signal height (parameter deltaA). By measuring the signal behavior at different levels of microwave power, we were able to discriminate between the line broadening effects caused by concentrating TA molecules inside the thylakoids or the light-induced changes in the concentration of oxygen. We developed a general algorithm for determination of the deltapH value and the internal volume of thylakoids, Vin, from the non-linear dependence of parameter deltaA on the concentration C0 of TA in a chloroplast suspension. Advantages of this method are: (i) it avoids the use of a broadening agent; (ii) it allows the internal volume of thylakoids to be evaluated; and (iii) the concentrations of TA used to measure the deltapH are below the range of concentrations that could cause the uncoupling electron transport to ATP synthesis in chloroplasts. Results of our measurements are consistent with the literature data on deltapH determinations by other methods.
Collapse
Affiliation(s)
- Boris V Trubitsin
- Department of Biophysics, Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow 119992, Russia
| | | |
Collapse
|
35
|
Friesen RW, Ducharme Y, Ball RG, Blouin M, Boulet L, Côté B, Frenette R, Girard M, Guay D, Huang Z, Jones TR, Laliberté F, Lynch JJ, Mancini J, Martins E, Masson P, Muise E, Pon DJ, Siegl PKS, Styhler A, Tsou NN, Turner MJ, Young RN, Girard Y. Optimization of a tertiary alcohol series of phosphodiesterase-4 (PDE4) inhibitors: structure-activity relationship related to PDE4 inhibition and human ether-a-go-go related gene potassium channel binding affinity. J Med Chem 2003; 46:2413-26. [PMID: 12773045 DOI: 10.1021/jm0204542] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A SAR study on the tertiary alcohol series of phosphodiesterase-4 (PDE4) inhibitors related to 1 is described. In addition to inhibitory potency against PDE4 and the lipopolysaccharide-induced production of TNFalpha in human whole blood, the binding affinity of these compounds for the human ether-a-go-go related gene (hERG) potassium channel (an in vitro measure for the potential to cause QTc prolongation) was assessed. Four key structural moieties in the molecule were studied, and the impact of the resulting modifications in modulating these activities was evaluated. From these studies, (+)-3d (L-869,298) was identified as an optimized structure with respect to PDE4 inhibitory potency, lack of binding affinity to the hERG potassium channel, and pharmacokinetic behavior. (+)-3d exhibited good in vivo efficacy in several models of pulmonary function with a wide therapeutic index with respect to emesis and prolongation of the QTc interval.
Collapse
Affiliation(s)
- Richard W Friesen
- Department of Biology and Medicinal Chemistry, Merck Frosst Centre for Therapeutic Research, P.O. Box 1005, Pointe Claire-Dorval, Quebec, H9R 4P8, Canada.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Xu XY, Cai BC, Pan Y, Wang TS. [Pharmacokinetics of the alkaloids from the processed seeds of Strychnos nux-vomica in rats]. Yao Xue Xue Bao 2003; 38:458-61. [PMID: 14513809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
AIM To study the pharmacokinetic process about the concentration in rat plasma of the alkaloids from processed seeds of Strychnos nux-vomica with RP-HPLC method. METHODS Hypersil BDS C18 column was used and the mobile phase consisted of acetonitrile-water at the flow rate of 0.8 mL.min-1. The UV detection wave length was 254 nm. RESULTS The concentration-time data of strychnine, brucine, strychnine N-oxide and brucine N-oxide were all in accordance with an open two-compartment model after i.v. alkaloids. Their parameters were as follows: T1/2 alpha were (8 +/- 5), (4 +/- 3), (6.2 +/- 1.7) and (3.0 +/- 0.8) min, T1/2 beta were (262 +/- 125), (416 +/- 131), (285 +/- 50) and (342 +/- 141) min, CL were (17 +/- 4), (21 +/- 12), (1.9 +/- 1.8) and (2.8 +/- 1.1) mL.min-1, Vc were (1.4 +/- 0.5), (1.7 +/- 1.1), (0.24 +/- 0.16) and (0.23 +/- 0.06) L.kg-1, Vd were (6.0 +/- 1.2), (12 +/- 7), (0.8 +/- 0.6) and (1.5 +/- 0.6) L.kg-1, AUC were (57,578 +/- 25,578), (35,240 +/- 15,616), (93,088 +/- 22,375) and (177,712 +/- 120,110) h.microgram.L-1, respectively. CONCLUSION The method is a good reference for pharmacokinetics in human bodies.
Collapse
Affiliation(s)
- Xiao-yue Xu
- Institute for Drug Control of Henan Province, Zhengzhou 450003, China.
| | | | | | | |
Collapse
|
37
|
Abstract
We have evaluated the effects of DMPO, CMPO, EMPO, BMPO, and DEPMPO on functioning CHO cells and the stability of the radical adducts in the presence of cells. The potential toxic effects of the spin traps were measured by two estimates of cell viability (trypan blue exclusion and colony formation) and one of cell function (rate of oxygen consumption). We also studied the effects of the spin traps on colony formation in a second cell line, 9L tumor cells. Toxicity varied with the type of cell line and the parameter that was measured. In aqueous solutions the order of stability for all spin adducts was SO(3) > OH > CH(3), while in cell suspensions it was SO(3) > OH approximately CH(3). The radical adducts of the new spin traps have significantly increased stability as compared to DMPO. These results indicate that the new spin traps potentially offer increased stability of spin adducts in functioning cells. It also is clear that it is necessary to carry out appropriate studies of the stability and toxicity in the system that is to be studied for any particular use of these spin traps. It then should be feasible to select the spin trap(s) best suited for the proposed study.
Collapse
Affiliation(s)
- Nadeem Khan
- Department of Diagnostic Radiology, EPR Center, Dartmouth Medical School, Hanover, NH 03755, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Roffey SJ, Cole S, Comby P, Gibson D, Jezequel SG, Nedderman ANR, Smith DA, Walker DK, Wood N. The disposition of voriconazole in mouse, rat, rabbit, guinea pig, dog, and human. Drug Metab Dispos 2003; 31:731-41. [PMID: 12756205 DOI: 10.1124/dmd.31.6.731] [Citation(s) in RCA: 237] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Voriconazole is a new triazole antifungal agent with potent, wide-spectrum activity. Its pharmacokinetics and metabolism have been studied in mouse, rat, rabbit, dog, guinea pig, and humans after single and multiple administration by both oral and intravenous routes. Absorption of voriconazole is essentially complete in all species. The elimination of voriconazole is characterized by non-linear pharmacokinetics in all species. Consequently, pharmacokinetic parameters are dependent upon dose, and a superproportional increase in area under the curve is seen with increasing dose in rat and dog toxicology studies. Following multiple administration, there is a decrease in systemic exposure. This is most pronounced in mouse and rat, less so in dog, and not observed in guinea pig or rabbit. Repeat-dose toxicology studies in mouse, rat, and dog have demonstrated that induction of cytochrome P450 by voriconazole (autoinduction of metabolism) is responsible for the decreased exposure in these species. Autoinduction of metabolism is not observed in humans, and plasma steady-state concentrations remain constant with time. Voriconazole is extensively metabolized in all species. The major pathways in humans involve fluoropyrimidine N-oxidation, fluoropyrimidine hydroxylation, and methyl hydroxylation. Also, N-oxidation facilitates cleavage of the molecule, resulting in loss of the fluoropyrimidine moiety and subsequent conjugation with glucuronic acid. Major pathways are represented in animal species. The major circulating metabolite in rat, dog, and human is the N-oxide of voriconazole. It is not thought to contribute to efficacy since it is at least 100-fold less potent than voriconazole against fungal pathogens in vitro.
Collapse
Affiliation(s)
- S J Roffey
- Department of Pharmacokinetics, Dynamics and Metabolism (IPC 664), PGRD, Sandwich, Kent CT13 9NJ, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Affiliation(s)
- Christoph Thiemermann
- Department of Experimental Medicine and Nephrology, William Harvey Research Institute, St. Bartholomew's Hospital Medical College, London EC1M6BQ, UK.
| |
Collapse
|
40
|
Ueda A, Nagase S, Yokoyama H, Tada M, Ohya H, Kamada H, Hirayama A, Koyama A. Identification by an EPR technique of decreased mitochondrial reducing activity in puromycin aminonucleoside-induced nephrosis. Free Radic Biol Med 2002; 33:1082-8. [PMID: 12374619 DOI: 10.1016/s0891-5849(02)00997-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The temporal changes in the electron paramagnetic resonance (EPR) signal intensities of a nitroxide radical, 4-hydroxy 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL), in the kidney in rat puromycin aminonucleoside (PAN) nephrosis were investigated in vivo and in vitro. The rats of the PAN nephrosis group received intraperitoneal injections of PAN at 75 mg/kg body weight while those of control group received saline. The in vivo renal half-lives of TEMPOL were calculated from the decay curve of EPR signal intensities after the intravenous injection of the TEMPOL solution. The mitochondrial half-lives were obtained from the decay curve of the EPR signals after mixing the mitochondrial fraction of the kidney and TEMPOL solution. The in vivo half-lives of TEMPOL of the kidney from 7 to 14 d after PAN administration were significantly longer than those of the controls. The mitochondrial half-lives of TEMPOL on the 9th day after the PAN administration prolonged remarkably compared to the controls (378 +/- 69 vs. 676 +/- 183 s, p <.01). These findings indicate that the in vivo and mitochondrial reducing activity in PAN treated rats decreased markedly, because the half-life of TEMPOL in the kidney reflects the renal reducing activity.
Collapse
Affiliation(s)
- Atsushi Ueda
- Department of Internal Medicine, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Kamataria M, Yasui H, Ogata T, Sakurai H. Local pharmacokinetic analysis of a stable spin probe in mice by in vivo L-band ESR with surface-coil-type resonators. Free Radic Res 2002; 36:1115-25. [PMID: 12516884 DOI: 10.1080/1071576021000028352] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In vivo ESR spectroscopy using a low frequency microwave of approximately 1 GHz has been developed to measure non-invasive ESR spectra in animals given paramagnetic compounds, in which a loop-gap-type resonator was used and ESR spectra were measured at the animal's head or abdomen. Therefore, the concentrations of paramagnetic species in both the blood and organs were compositely contributed to the spectra. When we understand the kinetics of paramagnetic species in detail, it is essentially important to know how these kinetics are expressed in each organ. For this purpose, a surface-coil-type resonator, which enabled local ESR measurement in specific organs, has been developed. By using this method, we studied the real-time pharmacokinetics of spin clearance curves detected in the organs of mice given 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4-hydroxy-TEMPO) intravenously (i.v.), by monitoring the inferior vena cava, liver and kidney. Quantified dearance curves in the organs were analyzed on the basis of a two-compartment model, and pharmacokinetic parameters were estimated based on the curve-fitting. The obtained pharmacokinetic parameters were found to depend on the measurement site, and the distribution and elimination processes of the spin probe were successfully separated between the blood and organs of mice.
Collapse
Affiliation(s)
- Masayuki Kamataria
- Department of Analytical and Bioinorganic Chemistry, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto 607-8414, Japan
| | | | | | | |
Collapse
|
42
|
Billah M, Cooper N, Cuss F, Davenport RJ, Dyke HJ, Egan R, Ganguly A, Gowers L, Hannah DR, Haughan AF, Kendall HJ, Lowe C, Minnicozzi M, Montana JG, Naylor R, Oxford J, Peake JC, Piwinski JJ, Runcie KA, Sabin V, Sharpe A, Shih NY, Warneck JBH. Synthesis and profile of SCH351591, a novel PDE4 inhibitor. Bioorg Med Chem Lett 2002; 12:1621-3. [PMID: 12039576 DOI: 10.1016/s0960-894x(02)00225-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The syntheses and pharmacological profiles of some 2-trifluoromethyl-8-methoxyquinoline-5-carboxamides are described. SCH351591 is a potent selective inhibitor of phosphodiesterase type 4 (PDE4).
Collapse
Affiliation(s)
- Motasim Billah
- Schering-Plough Corporation, Galloping Hill Road, Kenilworth, NJ 07033-0530, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Leonard SS, Mowrey K, Pack D, Shi X, Castranova V, Kuppusamy P, Vallyathan V. In vivo bioassays of acute asbestosis and its correlation with ESR spectroscopy and imaging in redox status. Mol Cell Biochem 2002; 234-235:369-77. [PMID: 12162455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
In vivo electron spin resonance (ESR) spectroscopy and whole body imaging were used to investigate the toxicity of biological reactions and organ specific oxidative changes associated with the development of acute asbestosis. Pathogen-free mice were exposed to 100 microg of crocidolite asbestos suspended in 50 microL of a 0.9% NaCl solution by aspiration. The bio-assay group had broncho-alveolar lavage (BAL) and serum draws performed on control and treated mice at 1, 3, and 7 days post-instillation. The ESR spectroscopic measurements and whole body imaging were performed with a separate group of mice at the same time points. Bio-assays included measurements of albumin, lactate dehydrogenase (LDH), N-acetyl-beta-D-glucoaminidase (NAG), and catalase in acellular lavage fluids, and total antioxidants status in blood serum. ESR spectroscopic and imaging measurements were performed after intraperitoneal injection of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-15N-1-oxyl (TEMPOL) or 3-carbamoylproxyl (3-CP) nitroxides at a final concentration of 344 mg/kg body weight. Albumin showed a significant increase in BAL fluid at the 3 day exposure time point. The presence of this protein in lavage fluid indicates that the gas/blood barrier has been damaged in the lung. LDH in BAL fluid also exhibited a significant increase at 3 days post-exposure, an indication of enhanced cell membrane damage in the lung. Similar results were observed for NAG, a lysosomal enzyme, implying activation of phagocytic cells. Contemporaneously with the development of acute asbestosis at day 3 post-exposure, there were significant increases in the levels of total antioxidants in the serum and catalase in the BAL fluid. Significant impairment in the ability of asbestos exposed animals to clear TEMPOL radical during acute disease progression was evident at days 1 and 3 post exposure. ESR image measurements provided information on the location and distribution of the 3-CP label within the lungs and heart of the mouse and its clearance over time. Bioassays in concert with ESR spectroscopy and imaging presented in this study provide congruent data on the early acute phase of pulmonary injury and oxidant generation in response to asbestos exposure and their decline after 7 days. The increased levels of total antioxidants in the serum and catalase in BAL fluid correlated with the reduction in the clearance rate for TEMPOL, suggesting that a change in the redox status of the lung is associated with lung injury induced by asbestos.
Collapse
Affiliation(s)
- Stephen S Leonard
- Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505-2888, USA
| | | | | | | | | | | | | |
Collapse
|
44
|
Yokoyama H, Itoh O, Aoyama M, Obara H, Ohya H, Kamada H. In vivo temporal EPR imaging of the brain of rats by using two types of blood-brain barrier-permeable nitroxide radicals. Magn Reson Imaging 2002; 20:277-84. [PMID: 12117610 DOI: 10.1016/s0730-725x(02)00491-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In vivo temporal EPR imaging was conducted on the brain of rats that received one of two kinds of blood-brain barrier-permeable nitroxide radicals via the tail vein-one is a water-soluble 3-hydroxymethyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (hydroxymethyl-PROXYL); and the other is a non-water-soluble 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (PCAM). From temporal EPR imaging data, temporal changes in the distribution of the nitroxide radical in the cerebral cortex, striatum, and hippocampus in the brain were investigated. It was found that the half-lives of the three parts in the brain of hydroxymethyl-PROXYL are longer and their EPR signal intensities are greater than those of PCAM.
Collapse
|
45
|
Ueda A, Yokoyama H, Nagase S, Hirayama A, Koyama A, Ohya H, Kamada H. In vivo temporal EPR imaging for estimating the kinetics of a nitroxide radical in the renal parenchyma and pelvis in rats. Magn Reson Imaging 2002; 20:77-82. [PMID: 11973032 DOI: 10.1016/s0730-725x(02)00467-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The kinetics of a nitroxide radical in the renal parenchyma and pelvis in rats were investigated by employing an in vivo EPR imaging system equipped with a surface-coil-type resonator (SCR). The exposed kidney of a living rat was inserted into the single-turn coil of the SCR, with the renal major axis aligned with the direction of alternative magnetic field (B(1)). After the injection of nitroxide radical via the tail vein, EPR measurements were repeated. From the temporal EPR images of the kidney on the 2-D projection to the plane which is perpendicular to the direction of B(1,) the decay rate of nitroxide radical in the renal parenchyma and pelvis was estimated. The parenchymal decay rate was found to be significantly shorter than that for the pelvis.
Collapse
Affiliation(s)
- Atsushi Ueda
- Institute for Life Support Technology, Yamagata Public Corporation for the Development of Industry, Yamagata, Japan
| | | | | | | | | | | | | |
Collapse
|
46
|
Strizki JM, Xu S, Wagner NE, Wojcik L, Liu J, Hou Y, Endres M, Palani A, Shapiro S, Clader JW, Greenlee WJ, Tagat JR, McCombie S, Cox K, Fawzi AB, Chou CC, Pugliese-Sivo C, Davies L, Moreno ME, Ho DD, Trkola A, Stoddart CA, Moore JP, Reyes GR, Baroudy BM. SCH-C (SCH 351125), an orally bioavailable, small molecule antagonist of the chemokine receptor CCR5, is a potent inhibitor of HIV-1 infection in vitro and in vivo. Proc Natl Acad Sci U S A 2001; 98:12718-23. [PMID: 11606733 PMCID: PMC60120 DOI: 10.1073/pnas.221375398] [Citation(s) in RCA: 255] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2001] [Indexed: 11/18/2022] Open
Abstract
We describe here the identification and properties of SCH-C (SCH 351125), a small molecule inhibitor of HIV-1 entry via the CCR5 coreceptor. SCH-C, an oxime-piperidine compound, is a specific CCR5 antagonist as determined in multiple receptor binding and signal transduction assays. This compound specifically inhibits HIV-1 infection mediated by CCR5 in U-87 astroglioma cells but has no effect on infection of CXCR4-expressing cells. SCH-C has broad and potent antiviral activity in vitro against primary HIV-1 isolates that use CCR5 as their entry coreceptor, with mean 50% inhibitory concentrations ranging between 0.4 and 9 nM. Moreover, SCH-C strongly inhibits the replication of an R5-using HIV-1 isolate in SCID-hu Thy/Liv mice. SCH-C has a favorable pharmacokinetic profile in rodents and primates with an oral bioavailability of 50-60% and a serum half-life of 5-6 h. On the basis of its novel mechanism of action, potent antiviral activity, and in vivo pharmacokinetic profile, SCH-C is a promising new candidate for therapeutic intervention of HIV infection.
Collapse
Affiliation(s)
- J M Strizki
- Schering-Plough Research Institute, Kenilworth, NJ 07033, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Palani A, Shapiro S, Clader JW, Greenlee WJ, Cox K, Strizki J, Endres M, Baroudy BM. Discovery of 4-[(Z)-(4-bromophenyl)- (ethoxyimino)methyl]-1'-[(2,4-dimethyl-3- pyridinyl)carbonyl]-4'-methyl-1,4'- bipiperidine N-oxide (SCH 351125): an orally bioavailable human CCR5 antagonist for the treatment of HIV infection. J Med Chem 2001; 44:3339-42. [PMID: 11585437 DOI: 10.1021/jm015526o] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Structure-activity studies on piperidino-piperidine 3 led to the discovery of SCH 351125 (1), a selective CCR5 antagonist with potent activity against RANTES binding (K(i) = 2 nM), which possesses subnanomolar activity in blocking viral entry and has excellent antiviral potency versus a panel of primary HIV-1 viral isolates. Compound 1, which has good oral bioavailability in rats, dogs, and monkeys, is proposed as a potential therapeutic agent for the treatment of HIV-1 and has entered human clinical trials.
Collapse
Affiliation(s)
- A Palani
- Chemical Research, Drug Safety and Metabolism, and Antiviral Research, Schering-Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, USA.
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Tagat JR, Steensma RW, McCombie SW, Nazareno DV, Lin SI, Neustadt BR, Cox K, Xu S, Wojcik L, Murray MG, Vantuno N, Baroudy BM, Strizki JM. Piperazine-based CCR5 antagonists as HIV-1 inhibitors. II. Discovery of 1-[(2,4-dimethyl-3-pyridinyl)carbonyl]-4- methyl-4-[3(S)-methyl-4-[1(S)-[4-(trifluoromethyl)phenyl]ethyl]-1-piperazinyl]- piperidine N1-oxide (Sch-350634), an orally bioavailable, potent CCR5 antagonist. J Med Chem 2001; 44:3343-6. [PMID: 11585438 DOI: 10.1021/jm0155401] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Truncation of the original piperidino-2(S)-methyl piperazine lead structure 2, from a family of muscarinic antagonists, gave compound 8 which has improved selectivity for the HIV-1 co-receptor CCR5 over muscarinic receptors. Further optimization for pharmacokinetic properties afforded Sch-350634 (1), a prototypical piperazine-based CCR5 antagonist, which is a potent inhibitor of HIV-1 entry and replication in PBMCs. The title compound (1) has excellent oral bioavailability in rat, dog, and monkey.
Collapse
Affiliation(s)
- J R Tagat
- Departments of Chemical Research, Drug Metabolism & Pharmacokinetics, and Antiviral Therapy, Schering-Plough Research Institute, K-15-2B-2800, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Togashi H, Matsuo T, Shinzawa H, Takada Y, Watanabe H, Saito T, Oikawa K, Kamada H, Takahashi T. In vivo imaging of increased oxidative stress in the liver by electron spin resonance-computed tomography. Res Commun Mol Pathol Pharmacol 2001; 107:197-217. [PMID: 11484875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
The aim of this study was to investigate whether increased hepatic oxidative stress could be visualised in living animals before the onset of obvious liver injury. Acute hepatic injury was induced in mice by priming with heat-killed Corynebacterium parvum followed by injection of a low dose of lipopolysaccharide (LPS). Low frequency band electron spin resonance-computed tomography (ESR-CT) with 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (carbamoyl-PROXYL) was used to visualize hepatic oxidative stress. Biochemical and histological investigations performed 3 h after injection of LPS revealed no obvious injury to the liver. Conversely, significant hepatic oxidative stress could be detected at this time. Nitroxides such as carbamoyl-PROXYL are rapidly reduced to the corresponding hydroxylamine in vivo. resulting in the disappearance of their ESR signals. The kinetic clearance of carbamoyl-PROXYL after intravenous administration was delayed significantly in mice that had received LPS, due to impairment of the reduction system by hepatic oxidative stress. ESR-CT of the murine abdomen revealed a high intensity area of carbamoyl-PROXYL which consisted mainly of the liver and enlarged spleen. Time-course observations with ESR-CT using carbamoyl-PROXYL showed that the high intensity area in the liver disappeared rapidly due to reduction of carbamoyl-PROXYL. Three hours after LPS injection into the same mouse, ESR-CT images were obtained again by intravenous injection of carbamoyl-PROXYL. The ESR-CT images of the mouse with hepatic oxidative stress clearly showed that the high intensity area of carbamoyl-PROXYL in the liver persisted for a long period of time. This study is the first report to describe the use of in vivo ESR-CT for visualizing the state of increased oxidative stress in the liver before the onset of obvious hepatic injury.
Collapse
Affiliation(s)
- H Togashi
- The Second Department of Internal Medicine, Yamagata University School of Medicine, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Abstract
While the exact mechanism of H2O2-induced cytotoxicity is unknown, there is considerable evidence implicating DNA as a primary target. A recent study showed that a cell-impermeable nitroxide protected mammalian cells from H2O2-induced cell killing and suggested that the protection was mediated through cell membrane-bound or extracellular factors. To further define the protective properties of nitroxides, Chinese hamster V79 cells were exposed to H2O2 with or without cell-permeable and impermeable nitroxides and selected metal chelators. EPR spectroscopy and paramagnetic line broadening agents were used to distinguish between intra- and extracellular nitroxide distribution. To study the effectiveness of nitroxide protection, in the absence of a cell membrane, H2O2-mediated damage to supercoiled plasmid DNA was evaluated. Both deferrioxamine and Tempol cross the cell membrane, and inhibited H2O2-mediated cell killing, whereas the cell-impermeable DTPA and nitroxide, CAT-1, failed to protect. Similar protective effects of the chelators and nitroxides were observed when L-histidine, which enhances intracellular injury, was added to H2O2. In contrast, when damage to plasmid DNA was induced (in the absence of a cell membrane), both nitroxides were protective. Collectively, these results do not support a role for membrane-bound or extracellular factors in mediating H2O2 cytotoxicity in mammalian cells.
Collapse
Affiliation(s)
- A M Samuni
- Radiation Biology Branch, Division of Clinical Sciences, Bldg. 10 Rm B3B69, National Cancer Institute, NIH, Bethesda, MD 20892-1002, USA
| | | | | | | |
Collapse
|