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Svorc P, Svorc P. General anesthesia and electrocardiographic parameters in in vivo experiments involving rats. Physiol Res 2022; 71:177-192. [PMID: 35275702 PMCID: PMC9150551 DOI: 10.33549/physiolres.934848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 02/18/2022] [Indexed: 11/25/2022] Open
Abstract
In in vivo cardiovascular or toxicological studies involving rat models, changes in selected electrocardiographic (ECG) parameters are monitored after various interventions to assess the origin and development of heart rhythm disorders. Each ECG parameter has diagnostic significance; as such, commonly evaluated ECG parameters, including heart rate, PR interval, P wave duration, P wave amplitude, QRS complex, QT and QTc interval duration, R wave and T wave amplitude, of rats under various types of general anesthesia were the focus of this study. Studies that performed in vivo cardiovascular or toxicological experiments in rats were retrieved from a search of the Web of Science database for articles published mainly between 2000 and 2021. In total, the search retrieved 123 articles. ECG parameters that were reported as baseline or control values were summarized and averages with ranges were calculated. It is important to be cautious when interpreting results and, in discussions addressing the mechanisms underlying a given type of arrhythmia, acknowledge that initial ECG parameters may already be affected to some extent by the general anesthesia as well as by sex and the time of day the experiments were performed.
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Affiliation(s)
- Pavol Svorc
- Department of Physiology, Medical Faculty, Safarik University, Kosice, Slovak Republic
- Department of Physiology and Patophysiology, Medical Faculty, Ostrava University, Ostrava, Czech Republic
| | - Pavol Svorc
- Department of Physiology and Patophysiology, Medical Faculty, Ostrava University, Ostrava, Czech Republic
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BULDUK B, OTO G, GÜNBATAR N, BULDUK M, KOÇAK Y, ELASAN S. The effect of resveratrol on toxicity caused by cisplatin in rats with experimentally created diabetes by streptozotocin. JOURNAL OF HEALTH SCIENCES AND MEDICINE 2022. [DOI: 10.32322/jhsm.999224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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3
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Hashimoto N, Doki K, Kawano S, Aonuma K, Ieda M, Homma M. Increased serum amiodarone concentration in hypertriglyceridemic patients: Effects of drug distribution to serum lipoproteins. Clin Transl Sci 2021; 15:771-781. [PMID: 34786846 PMCID: PMC8932714 DOI: 10.1111/cts.13199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 11/05/2021] [Accepted: 11/06/2021] [Indexed: 11/29/2022] Open
Abstract
Amiodarone and its main metabolite, desethylamiodarone (DEA), are highly distributed to serum lipoproteins such as very‐low‐density lipoprotein (VLDL) and low‐density lipoprotein (LDL), which are the carriers of triglyceride and cholesterol. This study aimed to investigate the association of serum concentrations of amiodarone and DEA with the levels of serum lipids in terms of drug distribution to lipoprotein fractions in patients with hyperlipidemia. Total serum concentrations of amiodarone and DEA were examined in 116 patients receiving amiodarone for tachyarrhythmias. The concentration‐to‐dose (C/D) ratio of amiodarone positively correlated with the level of serum triglyceride (rs = 0.541, p < 0.001) and was higher in the hypertriglyceridemic state than in normotriglyceridemic state (479 ± 211 vs. 320 ± 161, p < 0.001). No correlation was found between the C/D ratio of DEA and serum triglyceride levels (rs = 0.272), although higher values were observed in the hypertriglyceridemic state (322 ± 125 vs. 285 ± 143, p < 0.001). In the hypertriglyceridemic state, the distribution of amiodarone increased in LDL/VLDL fraction and decreased in high‐density lipoprotein and albumin fractions. The ratio of serum amiodarone to serum DEA, a metabolic ratio of amiodarone, positively correlated with serum triglyceride levels (rs = 0.572, p < 0.001) and was higher in the hypertriglyceridemic state, suggesting that amiodarone metabolism decreased in hyperlipidemia. The results of this study reveal that serum concentrations of amiodarone increase in the hypertriglyceridemic state through the increased lipoprotein‐binding and decreased metabolism of amiodarone.
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Affiliation(s)
- Naoaki Hashimoto
- Department of Pharmacy, University of Tsukuba Hospital, Tsukuba, Japan.,Department of Pharmaceutical Sciences, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Kosuke Doki
- Department of Pharmacy, University of Tsukuba Hospital, Tsukuba, Japan.,Department of Pharmaceutical Sciences, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Satoru Kawano
- Department of Cardiology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Kazutaka Aonuma
- Department of Cardiology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Masaki Ieda
- Department of Cardiology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Masato Homma
- Department of Pharmacy, University of Tsukuba Hospital, Tsukuba, Japan.,Department of Pharmaceutical Sciences, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
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Bin Jardan YA, Ahad A, Raish M, Ahmad A, Alam MA, Al-Mohizea AM, Al-Jenoobi FI. Assessment of glibenclamide pharmacokinetics in poloxamer 407-induced hyperlipidemic rats. Saudi Pharm J 2021; 29:719-723. [PMID: 34400867 PMCID: PMC8347666 DOI: 10.1016/j.jsps.2021.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 05/11/2021] [Indexed: 11/19/2022] Open
Abstract
The aim of the present research was to describe the consequences of hyperlipidemia (HL) on the pharmacokinetics of glibenclamide (Gb) in poloxamer 407-induced hyperlipidemic rats. Rats were given intraperitoneal dose of poloxamer 407 to cause hyperlipidemia. A single oral dose of Gb (10 mg/Kg) was given to normal and HL rats. The Cmax and tmax after oral dose of Gb in normal rats were 340.10 µg/ml and 3.67 h, respectively. Whereas, the Cmax and tmax after oral dose of Gb in HL rats were noted as 773.39 µg/ml and 2.50 h respectively. The AUC value of Gb was found considerably higher in the HL rats. While the plasma clearance (CL) after oral dose of Gb was 2.53 ml/h and 1.39 ml/h in normal and HL rats respectively. The improved plasma concentration of Gb following oral dosing in rats with HL seems to be due to a direct influence on hepatic clearance or metabolizing enzymes. In conclusion, the Gb pharmacokinetics was considerably affected by the HL in rats. Such findings play an important role for predicting the alterations in the pharmacokinetics of drugs including GB, in cases having hyperlipidemia.
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Affiliation(s)
- Yousef A. Bin Jardan
- Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
- Corresponding author.
| | - Abdul Ahad
- Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
| | - Mohammad Raish
- Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
| | - Ajaz Ahmad
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
| | - Mohd Aftab Alam
- Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
| | - Abdullah M. Al-Mohizea
- Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
| | - Fahad I. Al-Jenoobi
- Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
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Elsherbiny ME. Hyperlipidemia: Insights into Mechanisms Involved in Modulation of Drug Pharmacokinetics and Response. EGYPTIAN JOURNAL OF BASIC AND CLINICAL PHARMACOLOGY 2020. [DOI: 10.32527/2020/101456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Botelho AF, Joviano-Santos JV, Santos-Miranda A, Menezes-Filho JE, Soto-Blanco B, Cruz JS, Guatimosim C, Melo MM. Non-invasive ECG recording and QT interval correction assessment in anesthetized rats and mice. PESQUISA VETERINARIA BRASILEIRA 2019. [DOI: 10.1590/1678-6160-pvb-6029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
ABSTRACT: Rats and mice are the most common species used in experimental cardiac electrophysiology studies. Electrocardiogram (ECG) recording shows paramount importance for monitoring arrhythmias and cardiac function in several disease models, including QT syndrome. However, the lack of standardized reference values and QT correction formula for different animal species and lineages represent a challenge for ECG interpretation. The aim of this study is to provide an improved method for ECG recording, establishing reference range values and determine the QT formulas with higher correlation to heart rate (HR). A total of 10 Wistar rats, 10 Swiss mice, 10 C57BL/6 mice and 10 FVB/NJ mice were used in the study. Animals were submitted to anesthesia with isoflurane and ECG recording was performed using a six-channel non-invasive electrocardiograph. QT was corrected using the following formulas: Bazzett, Fridericia, Mitchell, Hodges, Van der Water and Framingham. Normal range values for ECG parameters were established in all animals studied. Pearsons’ correlation defined Hodges formula as the most suitable for QT correction. This study demonstrated an improved method of ECG recording with reference values for Swiss, FVB/NJ, C57BL/6 mice, and Wistar rats. Hodges’ formula was the most effective formula for QT correction in rodents, whereas Bazett’s and Friderica formulas were ineffective for such animals. The present work contributes to arrhythmias investigation in experimental cardiology and may reduce misinterpretations in rodents’ ECG.
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Lee U, Kwon MH, Kang HE. Pharmacokinetic alterations in poloxamer 407-induced hyperlipidemic rats. Xenobiotica 2018; 49:611-625. [PMID: 29658375 DOI: 10.1080/00498254.2018.1466212] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
1. Plasma lipid profile abnormalities in hyperlipidemia can potentially alter the pharmacokinetics of a drug in a complex manner. To evaluate these pharmacokinetic alterations in hyperlipidemia and to determine the underlying mechanism(s), poloxamer 407-induced hyperlipidemic rats (HL rats), a well-established animal model of hyperlipidemia have been used. 2. In this review, we summarize findings on the pathophysiological and gene expression changes in drug-metabolizing enzymes and transporters in HL rats. We discuss pharmacokinetic changes in drugs metabolized primarily via hepatic cytochrome P450 (CYPs) in terms of alterations in hepatic intrinsic clearance (CL'int), free fraction in plasma (fu) and hepatic blood flow rate (QH), depending on the hepatic excretion ratio, as well as drugs eliminated primarily by mechanisms other than hepatic CYPs. 3. For lipoprotein-bound drugs, increased binding to lipoproteins resulted in lower fu values and volumes of distribution, with some exceptions. Generally, slower non-renal clearance (or total body clearance) of drugs that are substrates of hepatic CYP3A and CYP2C is well explained by the following factors: alterations in CL'int (due to down-regulation of hepatic CYPs), decreased fu and/or possible decreased QH. 4. These consistent findings across studies in HL rats suggest more studies are needed at the clinical level for optimal pharmacotherapies for hyperlipidemia.
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Affiliation(s)
- Unji Lee
- a Department of Pharmacy , Ewha Womans University Medical Center , Seoul , South Korea
| | - Mi Hye Kwon
- b College of Pharmacy and Integrated Research Institute of Pharmaceutical Sciences , The Catholic University of Korea , Bucheon , South Korea
| | - Hee Eun Kang
- b College of Pharmacy and Integrated Research Institute of Pharmaceutical Sciences , The Catholic University of Korea , Bucheon , South Korea
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Hyperlipidemia Alters the Pharmacokinetics of Posaconazole and Vincristine Upon Co-Administration in Rats. Drugs R D 2017; 17:287-296. [PMID: 28299646 PMCID: PMC5427049 DOI: 10.1007/s40268-017-0178-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Objectives Co-administration of posaconazole (PSZ) and vincristine (VCR) in the treatment of patients with acute lymphoblastic leukemia increases the neurotoxicity of VCR. Our aim is to study the effect of increased lipoprotein levels on the pharmacokinetics of PSZ and VCR upon co-administration in rats. Methods Rats were assigned to three groups, normolipidemic (NL), intermediate hyperlipidemic (IHL), and extreme hyperlipidemic (HL) groups. All rats were administered PSZ orally followed by VCR intravenously 4 h later. For the pharmacokinetic study, serial plasma samples were collected over 96 h and for tissue distribution study; plasma, lung, and liver tissues were collected over 48 h post oral dosing. Results Posaconazole showed higher plasma concentrations than VCR at all time points. Co-administration of VCR with PSZ reduced PSZ weight normalized oral clearance, increased PSZ area under the plasma concentration–time curve (AUC) from time zero to infinity, showed higher PSZ liver concentrations, and increased VCR volume of distribution of the central compartment. Upon increasing the lipoprotein levels, PSZ showed higher plasma availability and delayed tissue distribution, whereas VCR had shown a significant decrease in PSZ AUC0-24h, AUC0-tlast, and AUCo-inf (NL = IHL > HL) and a significant increase in the volume of distribution (NL = IHL < HL). Vincristine has shown higher tissue uptake and concentrations. Conclusion Monitoring cholesterol and triglyceride levels in patients with acute lymphoblastic leukemia is advisable to decrease VCR neurological side effect incidences and delay the activity of both PSZ and VCR.
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Khalil HA, Belal TS, El-Yazbi AF, Hamdy DA. The effect of increased lipoproteins levels on the disposition of vincristine in rat. Lipids Health Dis 2016; 15:152. [PMID: 27613245 PMCID: PMC5017019 DOI: 10.1186/s12944-016-0318-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 08/30/2016] [Indexed: 11/10/2022] Open
Abstract
Background Vincristine (VCR), an antineoplastic agent, is a key component in the treatment of acute lymphoblastic leukemia, lymphomas, rhabdomyosarcoma, neuroblastoma, and Wilms’ tumor diseases. Recently, high incidence of hyperlipidemia was reported to be associated with allogenic hematopoietic stem cell transplantation and VCR/L-asparaginase therapy. The aim of this study is to test the effects of incremental increase in lipoproteins levels on vincristine disposition in rat. Method To study VCR pharmacokinetics and protein binding, rats (n = 25) were assigned to three groups, normal lipidemic (NL), intermediate (IHL) and extreme hyperlipidemic (HL). Hyperlipidemia was induced by ip injection of (1 g/Kg) poloxamer 407 in rats. Serial blood samples were collected using the pre-inserted jugular vein cannula for 72 h post VCR (0.15 mg/Kg) i.v. dose. VCR unbound fractions in NL, IHL and HL plasma were determined using ultrafiltration kits. Results VCR demonstrated a rapid distribution phase (6–8 h) followed by a slower elimination phase with a mean elimination t½ of ~ 14 h. VCR exhibited moderate binding to plasma proteins ~ 83 %. It showed a relatively small Vc (~0.17 L/Kg) and a larger Vβ (1.53 L/Kg) indicating good tissue distribution. As the lipoproteins levels were increased, no significant changes were noted in VCR unbound fraction, plasma concentration, or volume of distribution indicating low affinity to lipoprotein binding. Induced HL also did not affect VCR elimination where similar VCR AUC0-∞, Cl and elimination phase t½ were reported along the different lipemic groups. Conclusion Incremental increase in lipoprotein levels resulted in no significant effect on VCR disposition as such ALL malignant lymphoma and allogenic hematopoietic stem cell transplantation patients need not to worry about HL-VCR interaction. Whether, HL can potentiate another drug-drug or drug-disease interaction involving VCR warrants further studying and monitoring to ensure therapeutic safety and efficiency.
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Affiliation(s)
- Hadeel A Khalil
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Alexandria University, 1 El Khartoum Square, Alexandria, 21521, Egypt
| | - Tarek S Belal
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Alexandria University, 1 El Khartoum Square, Alexandria, 21521, Egypt
| | - Ahmed F El-Yazbi
- Department of Pharmacology & Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, 21521, Egypt.,Faculty of Medicine, the American University of Beirut, Lebanon, Alexandria, Egypt
| | - Dalia A Hamdy
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Alexandria University, 1 El Khartoum Square, Alexandria, 21521, Egypt.
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Jardan YAB, Brocks DR. The pharmacokinetics of dronedarone in normolipidemic and hyperlipidemic rats. Biopharm Drug Dispos 2016; 37:345-51. [DOI: 10.1002/bdd.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 03/11/2016] [Accepted: 05/14/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Yousef A. Bin Jardan
- Faculty of Pharmacy & Pharmaceutical Sciences; University of Alberta; Edmonton Alberta Canada
| | - Dion R. Brocks
- Faculty of Pharmacy & Pharmaceutical Sciences; University of Alberta; Edmonton Alberta Canada
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11
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The effect of hyperlipidemia on the pharmacokinetics, hepatic and pulmonary uptake of posaconazole in rat. Eur J Pharm Sci 2016; 91:190-5. [DOI: 10.1016/j.ejps.2016.05.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 05/09/2016] [Accepted: 05/09/2016] [Indexed: 11/21/2022]
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Abstract
Electrocardiography (ECG) in rats is a widely applied experimental method in basic cardiovascular research. The technique of ECG recordings is simple; however, the interpretation of electrocardiographic parameters is challenging. This is because the analysis may be biased by experimental settings, such as the type of anesthesia, the strain or age of animals. Here, we aimed to review electrocardiographic parameters in rats, their normal range, as well as the effect of experimental settings on the parameters variation. Furthermore, differences and similarities between rat and human ECG are discussed in the context of translational cardiovascular research.
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Affiliation(s)
- P Konopelski
- Department of Experimental Physiology and Pathophysiology, Medical University of Warsaw, Warsaw, Poland.
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13
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Brocks DR, Hamdy DA, Ben-Eltriki M, Patel JP, El-Kadi AO. Effect of rat serum lipoproteins on mRNA levels and amiodarone metabolism by cultured primary rat hepatocytes. J Pharm Sci 2012; 102:262-70. [PMID: 23132435 DOI: 10.1002/jps.23348] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 10/02/2012] [Accepted: 10/04/2012] [Indexed: 01/12/2023]
Abstract
Hyperlipidemia can significantly increase amiodarone (AM) in vivo liver uptake and decrease its velocity of microsomal metabolism. Here, hepatocytes isolated from normolipidemic (NL) and hyperlipidemic rats were incubated with AM in the presence or absence of diluted NL or hyperlipidemic serum. The serum was added either as preincubation before drug, or concurrently with drug; incubations without rat serum were used as controls. The hepatocyte levels of mRNA for several proteins and enzymes were also measured. Disappearance of AM was seen up to 72 h. There was little difference between hepatocytes from NL or hyperlipidemic animals in intrinsic clearance (CL(int) ) of AM. The effect of hyperlipidemic rat serum, either before or with AM, was profound, causing a significant reduction in the CL(int) . Reductions were seen in mRNA for cytochrome P450 1A1, 3A2, and 2D1, some transporters, and low-density lipoprotein receptors after exposure of hepatocytes to lipoprotein-rich sera. In conclusion, exposure of isolated hepatocytes to hyperlipidemic serum caused decreases in AM CL(int) and lower mRNA levels for some proteins involved in the uptake and metabolism of AM. When coincubated with serum, an additional effect of increased binding to lipoproteins seemed to further contribute to a reduced CL of AM.
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Hamdy DA, Brocks DR. Effect of hyperlipidemia on ketoconazole–midazolam drug–drug interaction in rat. J Pharm Sci 2011; 100:4986-92. [DOI: 10.1002/jps.22675] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 04/13/2011] [Accepted: 06/03/2011] [Indexed: 11/06/2022]
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Patel JP, Brocks DR. Effect of experimental hyperlipidaemia on the electrocardiographic effects of repeated doses of halofantrine in rats. Br J Pharmacol 2011; 161:1427-40. [PMID: 20698852 DOI: 10.1111/j.1476-5381.2010.00983.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Halofantrine can cause a prolongation of the cardiac QT interval, leading to serious ventricular arrhythmias. Hyperlipidaemia elevates plasma concentration of halofantrine and may influence its tissue uptake. The present study examined the effect of experimental hyperlipidaemia on QT interval prolongation induced by halofantrine in rats. EXPERIMENTAL APPROACH Normolipidaemic and hyperlipidaemic rats (induced with poloxamer 407) were given 4 doses of halofantrine (i.v., 4-40 mg·kg(-1)·d(-1)) or vehicle every 12 h. Under brief anaesthesia, ECGs were recorded before administration of the vehicle or drug and 12 h after the first and last doses. Blood samples were taken at the same time after the first and last dose of halofantrine. Hearts were also collected 12 h after the last dose. Plasma and heart samples were assayed for drug and desbutylhalofantrine using a stereospecific method. KEY RESULTS In the vehicle group, hyperlipidaemia by itself did not affect the ECG. Compared to baseline, QT intervals were significantly higher in both normolipidaemic and hyperlipidaemic rats after halofantrine. In hyperlipidaemic rats, plasma but not heart concentrations of the halofantrine enantiomers were significantly higher compared to those in normolipidaemic rats. Despite the lack of difference in the concentrations of halofantrine in heart, QT intervals were significantly higher in hyperlipidaemic compared to those in normolipidaemic rats. CONCLUSIONS AND IMPLICATIONS The unbound fraction of halofantrine appeared to be the controlling factor for drug uptake by the heart. Our data suggested a greater vulnerability to halofantrine-induced QT interval prolongation in the hyperlipidaemic state.
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Affiliation(s)
- Jigar P Patel
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada
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Hamdy DA, Brocks DR. The effect of increased lipoprotein levels on the pharmacokinetics of ketoconazole enantiomers in the rat. Xenobiotica 2010; 41:137-43. [DOI: 10.3109/00498254.2010.529178] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Gershkovich P, Sivak O, Sharma A, Barr AM, Procyshyn R, Wasan KM. Effect of hypertriglyceridemia on the pharmacokinetics and blood-brain barrier penetration of clozapine and norclozapine following administration to rats. Eur Neuropsychopharmacol 2010; 20:545-52. [PMID: 20163937 DOI: 10.1016/j.euroneuro.2010.01.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2009] [Revised: 12/31/2009] [Accepted: 01/21/2010] [Indexed: 10/19/2022]
Abstract
There is a long-term discussion in the literature concerning the possible link between the improved efficacy of clozapine treatment and elevated plasma triglyceride levels, but no mechanistic studies have been performed to date. The aim of this work was to investigate whether the postprandial hypertriglyceridemia affects the pharmacokinetics and brain distribution of clozapine and norclozapine. Experimental hypertriglyceridemia in rats was induced by oral administration of peanut oil and the pharmacokinetic parameters and brain penetration of clozapine and norclozapine following administration of clozapine were compared to normotriglyceridemic control animals. Moderately increased clearance of clozapine was found in hypertriglyceridemic animals compared to control group. No changes were found in penetration of compounds across the blood-brain barrier (BBB). Taken together, the results do not support the hypothesis that hypertriglyceridemia improves the effect of clozapine by altered pharmacokinetics of clozapine and norclozapine and their increased penetration across the BBB.
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Affiliation(s)
- Pavel Gershkovich
- Division of Pharmaceutics and Biopharmaceutics, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada.
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