1
|
Chen X, Slättengren T, de Lange ECM, Smith DE, Hammarlund-Udenaes M. Revisiting atenolol as a low passive permeability marker. Fluids Barriers CNS 2017; 14:30. [PMID: 29089037 PMCID: PMC5664587 DOI: 10.1186/s12987-017-0078-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 10/13/2017] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Atenolol, a hydrophilic beta blocker, has been used as a model drug for studying passive permeability of biological membranes such as the blood-brain barrier (BBB) and the intestinal epithelium. However, the extent of S-atenolol (the active enantiomer) distribution in brain has never been evaluated, at equilibrium, to confirm that no transporters are involved in its transport at the BBB. METHODS To assess whether S-atenolol, in fact, depicts the characteristics of a low passive permeable drug at the BBB, a microdialysis study was performed in rats to monitor the unbound concentrations of S-atenolol in brain extracellular fluid (ECF) and plasma during and after intravenous infusion. A pharmacokinetic model was developed, based on the microdialysis data, to estimate the permeability clearance of S-atenolol into and out of brain. In addition, the nonspecific binding of S-atenolol in brain homogenate was evaluated using equilibrium dialysis. RESULTS The steady-state ratio of unbound S-atenolol concentrations in brain ECF to that in plasma (i.e., Kp,uu,brain) was 3.5% ± 0.4%, a value much less than unity. The unbound volume of distribution in brain (Vu, brain) of S-atenolol was also calculated as 0.69 ± 0.10 mL/g brain, indicating that S-atenolol is evenly distributed within brain parenchyma. Lastly, equilibrium dialysis showed limited nonspecific binding of S-atenolol in brain homogenate with an unbound fraction (fu,brain) of 0.88 ± 0.07. CONCLUSIONS It is concluded, based on Kp,uu,brain being much smaller than unity, that S-atenolol is actively effluxed at the BBB, indicating the need to re-consider S-atenolol as a model drug for passive permeability studies of BBB transport or intestinal absorption.
Collapse
Affiliation(s)
- Xiaomei Chen
- Department of Pharmaceutical Biosciences, Translational PKPD Research Group, Uppsala University, Box 591, SE-75124, Uppsala, Sweden.,Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Tim Slättengren
- Department of Pharmaceutical Biosciences, Translational PKPD Research Group, Uppsala University, Box 591, SE-75124, Uppsala, Sweden
| | - Elizabeth C M de Lange
- Department of Pharmacology, Leiden Academic Centre for Drug Research, Leiden, The Netherlands
| | - David E Smith
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Margareta Hammarlund-Udenaes
- Department of Pharmaceutical Biosciences, Translational PKPD Research Group, Uppsala University, Box 591, SE-75124, Uppsala, Sweden.
| |
Collapse
|
2
|
Hammarlund-Udenaes M. Microdialysis as an Important Technique in Systems Pharmacology—a Historical and Methodological Review. AAPS JOURNAL 2017; 19:1294-1303. [DOI: 10.1208/s12248-017-0108-2] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Accepted: 06/01/2017] [Indexed: 01/03/2023]
|
3
|
Gustafsson S, Eriksson J, Syvänen S, Eriksson O, Hammarlund-Udenaes M, Antoni G. Combined PET and microdialysis for in vivo estimation of drug blood-brain barrier transport and brain unbound concentrations. Neuroimage 2017; 155:177-186. [DOI: 10.1016/j.neuroimage.2017.04.068] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 04/26/2017] [Accepted: 04/27/2017] [Indexed: 12/24/2022] Open
|
4
|
Zestos AG, Kennedy RT. Microdialysis Coupled with LC-MS/MS for In Vivo Neurochemical Monitoring. AAPS JOURNAL 2017; 19:1284-1293. [PMID: 28660399 DOI: 10.1208/s12248-017-0114-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 06/13/2017] [Indexed: 10/19/2022]
Abstract
Microdialysis is a powerful sampling technique used to monitor small molecules in vivo. Despite the many applications of microdialysis sampling, it is limited by the method of analyzing the resulting samples. An emerging technique for analysis of microdialysis samples is liquid chromatography-tandem mass spectrometry (LC-MS/MS). This technique is highly versatile, allowing multiplexed analysis of neurotransmitters, metabolites, and neuropeptides. Using LC-MS/MS for polar neurotransmitters is hampered by weak retention reverse phase LC columns. Several derivatization reagents have been utilized to enhance separation and resolution of neurochemicals in dialysate samples including benzoyl chloride (BzCl), dansyl chloride, formaldehyde, ethylchloroformate, and propionic anhydride. BzCl reacts with amine and phenol groups so that many neurotransmitters can be labeled. Besides improving separation on reverse phase columns, this reagent also increases sensitivity. It is available in a heavy form so that it can be used to make stable-isotope labeled internal standard for improved quantification. Using BzCl with LC-MS/MS has allowed for measuring as many as 70 neurochemicals in a single assay. With slightly different conditions, LC-MS/MS has also been used for monitoring endocannabinoids. LC-MS/MS is also useful for neuropeptide assay because it allows for highly sensitive, sequence specific measurement of most peptides. These advances have allowed for multiplexed neurotransmitter measurements in behavioral, circuit analysis, and drug effect studies.
Collapse
Affiliation(s)
- Alexander G Zestos
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, Michigan, 48109-1055, USA.,Department of Pharmacology, University of Michigan, 2301 MSRB III, 1150 W. Medical Center Dr., Ann Arbor, Michigan, 48109-1055, USA.,Department of Chemistry, American University, 4400 Massachusetts Avenue, NW, Washington, District of Columbia, 20016, USA
| | - Robert T Kennedy
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, Michigan, 48109-1055, USA. .,Department of Pharmacology, University of Michigan, 2301 MSRB III, 1150 W. Medical Center Dr., Ann Arbor, Michigan, 48109-1055, USA.
| |
Collapse
|
5
|
Intracerebral microdialysis in blood-brain barrier drug research with focus on nanodelivery. DRUG DISCOVERY TODAY. TECHNOLOGIES 2016; 20:13-18. [PMID: 27986218 DOI: 10.1016/j.ddtec.2016.07.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 07/13/2016] [Indexed: 01/09/2023]
Abstract
Microdialysis has contributed significantly to advance the understanding of BBB transport of drugs and to reveal key aspects of BBB transport, including quantifying active efflux and active uptake. Microdialysis studies on pharmacokinetic-pharmacodynamic relationships have given in-depth understanding of the processes involved. Recently, nanodelivery to the brain has been investigated with microdialysis, contributing to nanodelivery science by giving quantitative information on the possible success of different delivery vehicles and how they are involved in BBB transport.
Collapse
|
6
|
Lindqvist A, Jönsson S, Hammarlund-Udenaes M. Exploring Factors Causing Low Brain Penetration of the Opioid Peptide DAMGO through Experimental Methods and Modeling. Mol Pharm 2016; 13:1258-66. [DOI: 10.1021/acs.molpharmaceut.5b00835] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Annika Lindqvist
- Translational
PKPD Group, Department of Pharmaceutical Biosciences, Associate Member
of SciLife Lab, Uppsala University, Box 591, Uppsala, SE-75124, Sweden
| | - Siv Jönsson
- Pharmacometrics
Group, Department of Pharmaceutical Biosciences, Uppsala University, Box 591, Uppsala, SE-75124, Sweden
| | - Margareta Hammarlund-Udenaes
- Translational
PKPD Group, Department of Pharmaceutical Biosciences, Associate Member
of SciLife Lab, Uppsala University, Box 591, Uppsala, SE-75124, Sweden
| |
Collapse
|
7
|
Gharavi R, Hedrich W, Wang H, Hassan HE. Transporter-Mediated Disposition of Opioids: Implications for Clinical Drug Interactions. Pharm Res 2015; 32:2477-502. [PMID: 25972096 DOI: 10.1007/s11095-015-1711-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 05/06/2015] [Indexed: 01/08/2023]
Abstract
Opioid-related deaths, abuse, and drug interactions are growing epidemic problems that have medical, social, and economic implications. Drug transporters play a major role in the disposition of many drugs, including opioids; hence they can modulate their pharmacokinetics, pharmacodynamics and their associated drug-drug interactions (DDIs). Our understanding of the interaction of transporters with many therapeutic agents is improving; however, investigating such interactions with opioids is progressing relatively slowly despite the alarming number of opioids-mediated DDIs that may be related to transporters. This review presents a comprehensive report of the current literature relating to opioids and their drug transporter interactions. Additionally, it highlights the emergence of transporters that are yet to be fully identified but may play prominent roles in the disposition of opioids, the growing interest in transporter genomics for opioids, and the potential implications of opioid-drug transporter interactions for cancer treatments. A better understanding of drug transporters interactions with opioids will provide greater insight into potential clinical DDIs and could help improve opioids safety and efficacy.
Collapse
Affiliation(s)
- Robert Gharavi
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 N Pine Street, Rooms: N525 (Office), Baltimore, Maryland, 21201, USA
| | | | | | | |
Collapse
|
8
|
Rottbøll LAH, Skovgaard K, Barington K, Jensen HE, Friis C. Intrabronchial Microdialysis: Effects of Probe Localization on Tissue Trauma and Drug Penetration into the Pulmonary Epithelial Lining Fluid. Basic Clin Pharmacol Toxicol 2015; 117:242-50. [PMID: 25827198 DOI: 10.1111/bcpt.12403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 03/24/2015] [Indexed: 11/29/2022]
Abstract
Recent intrabronchial microdialysis data indicate that the respiratory epithelium is highly permeable to drugs. Of concern is whether intrabronchial microdialysis disrupts the integrity of the respiratory epithelium and thereby alters drug penetration into the pulmonary epithelial lining fluid (PELF). The objective of this study was to investigate the effect of intrabronchial microdialysis on the integrity of the bronchial epithelium. Microdialysis sampling in PELF in proximal (n = 4) and distal bronchi (n = 4) was performed after intravenous inulin and florfenicol administration in anaesthetized pigs. Inulin was used as a marker molecule of permeability of the epithelium, and florfenicol was used as test drug. Bronchial tissue was examined by histopathology (distal and proximal bronchi) and gene expression analysis (RT-qPCR, proximal bronchi) at the termination of the experiment (6.5 hr). The microdialysis probe caused overt tissue trauma in distal bronchi, whereas no histopathological lesions were observed in proximal bronchi. A moderate up-regulation of the pro-inflammatory cytokines IL1B, IL6 and acute-phase reactant serum amyloid A was seen in proximal bronchi surrounding the microdialysis probes suggesting initiation of an inflammatory response. The observed up-regulation is considered to have limited impact on drug penetration during short-term studies. Inulin penetrated the respiratory epithelium in both proximal and distal bronchi without any correlation to histopathological lesions. Likewise, florfenicol penetration into PELF was unaffected by bronchial histopathology. However, this independency of pathology on drug penetration may not be valid for other antibiotics. We conclude that short-term microdialysis drug quantification can be performed in proximal bronchi without disruption of tissue integrity.
Collapse
Affiliation(s)
| | - Kerstin Skovgaard
- Section for Immunology and Vaccinology, National Veterinary Institute, Technical University of Denmark, Copenhagen, Denmark
| | - Kristiane Barington
- Department of Veterinary Disease Biology, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Elvang Jensen
- Department of Veterinary Disease Biology, University of Copenhagen, Copenhagen, Denmark
| | - Christian Friis
- Department of Veterinary Disease Biology, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
9
|
Chen X, Loryan I, Payan M, Keep RF, Smith DE, Hammarlund-Udenaes M. Effect of transporter inhibition on the distribution of cefadroxil in rat brain. Fluids Barriers CNS 2014; 11:25. [PMID: 25414790 PMCID: PMC4237734 DOI: 10.1186/2045-8118-11-25] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 10/18/2014] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Cefadroxil, a cephalosporin antibiotic, is a substrate for several membrane transporters including peptide transporter 2 (PEPT2), organic anion transporters (OATs), multidrug resistance-associated proteins (MRPs), and organic anion transporting polypeptides (OATPs). These transporters are expressed at the blood-brain barrier (BBB), blood-cerebrospinal fluid barrier (BCSFB), and/or brain cells. The effect of these transporters on cefadroxil distribution in brain is unknown, especially in the extracellular and intracellular fluids within brain. METHODS Intracerebral microdialysis was used to measure unbound concentrations of cefadroxil in rat blood, striatum extracellular fluid (ECF) and lateral ventricle cerebrospinal fluid (CSF). The distribution of cefadroxil in brain was compared in the absence and presence of probenecid, an inhibitor of OATs, MRPs and OATPs, where both drugs were administered intravenously. The effect of PEPT2 inhibition by intracerebroventricular (icv) infusion of Ala-Ala, a substrate of PEPT2, on cefadroxil levels in brain was also evaluated. In addition, using an in vitro brain slice method, the distribution of cefadroxil in brain intracellular fluid (ICF) was studied in the absence and presence of transport inhibitors (probenecid for OATs, MRPs and OATPs; Ala-Ala and glycylsarcosine for PEPT2). RESULTS The ratio of unbound cefadroxil AUC in brain ECF to blood (Kp,uu,ECF) was ~2.5-fold greater during probenecid treatment. In contrast, the ratio of cefadroxil AUC in CSF to blood (Kp,uu,CSF) did not change significantly during probenecid infusion. Icv infusion of Ala-Ala did not change cefadroxil levels in brain ECF, CSF or blood. In the brain slice study, Ala-Ala and glycylsarcosine decreased the unbound volume of distribution of cefadroxil in brain (Vu,brain), indicating a reduction in cefadroxil accumulation in brain cells. In contrast, probenecid increased cefadroxil accumulation in brain cells, as indicated by a greater value for Vu,brain. CONCLUSIONS Transporters (OATs, MRPs, and perhaps OATPs) that can be inhibited by probenecid play an important role in mediating the brain-to-blood efflux of cefadroxil at the BBB. The uptake of cefadroxil in brain cells involves both the influx transporter PEPT2 and efflux transporters (probenecid-inhibitable). These findings demonstrate that drug-drug interactions via relevant transporters may affect the distribution of cephalosporins in both brain ECF and ICF.
Collapse
Affiliation(s)
- Xiaomei Chen
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Mi 48109 USA ; Department of Pharmaceutical Biosciences, Translational PKPD Research Group, Uppsala University, Box 591, SE-75124 Uppsala, Sweden
| | - Irena Loryan
- Department of Pharmaceutical Biosciences, Translational PKPD Research Group, Uppsala University, Box 591, SE-75124 Uppsala, Sweden
| | - Maryam Payan
- Department of Pharmaceutical Biosciences, Translational PKPD Research Group, Uppsala University, Box 591, SE-75124 Uppsala, Sweden ; Biopharmaceutics and Pharmacokinetic Division, Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan Health System, Ann Arbor, MI 48109 USA
| | - David E Smith
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Mi 48109 USA
| | - Margareta Hammarlund-Udenaes
- Department of Pharmaceutical Biosciences, Translational PKPD Research Group, Uppsala University, Box 591, SE-75124 Uppsala, Sweden
| |
Collapse
|
10
|
Hershey ND, Kennedy RT. In vivo calibration of microdialysis using infusion of stable-isotope labeled neurotransmitters. ACS Chem Neurosci 2013; 4:729-36. [PMID: 23374073 PMCID: PMC3656751 DOI: 10.1021/cn300199m] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Accepted: 01/12/2013] [Indexed: 11/29/2022] Open
Abstract
In vivo calibration of microdialysis probes is required for interpreting measured concentrations. The most popular method of in vivo calibration is no-net-flux (NNF), which requires infusing several concentrations of neurotransmitters to determine in vivo recoveries (extraction fraction or Ed) and extracellular concentrations. A new method for in vivo calibration of microdialysis of neurotransmitters using glutamate (GLU) and dopamine (DA) as model analytes is reported. (13)C6-DA and (13)C5-GLU were perfused through microdialysis probes as internal calibrators. Using liquid chromatography with mass spectrometry, it was possible to distinguish the (13)C-forms from the endogenous forms of each neurotransmitter. Ed was directly calculated by measuring the loss of the (13)C-forms during infusion. The measured endogenous (12)C forms of the neurotransmitters could be corrected for Ed to give calibrated extracellular concentrations in vivo. Retrodialysis of stable-isotope-labeled (SIL) neurotransmitters gave Ed and extracellular concentrations of (13)C5-GLU and (13)C6-DA that matched no-net-flux measurements; however, the values were obtained in a fraction of time because no added measurements were required to obtain the calibration. Ed was reduced during uptake inhibition for GLU and DA when measured by SIL retrodialysis. Because Ed is directly measured at each microdialysis fraction, it was possible to monitor changes in Ed under transient conditions created by systemic injection of uptake inhibitors. The results show that DA and GLU concentrations are underestimated by as much as 50% if not corrected for Ed during uptake inhibition. SIL retrodialysis provides equivalent information to NNF at much reduced time and animal use.
Collapse
Affiliation(s)
- Neil D. Hershey
- Department of Chemistry and Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109,
United States
| | - Robert T. Kennedy
- Department of Chemistry and Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109,
United States
| |
Collapse
|
11
|
In vitro, in vivo and in silico models of drug distribution into the brain. J Pharmacokinet Pharmacodyn 2013; 40:301-14. [DOI: 10.1007/s10928-013-9303-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Accepted: 01/31/2013] [Indexed: 10/27/2022]
|
12
|
de Lange ECM. Utility of CSF in translational neuroscience. J Pharmacokinet Pharmacodyn 2013; 40:315-26. [PMID: 23400635 PMCID: PMC3663203 DOI: 10.1007/s10928-013-9301-9] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 01/30/2013] [Indexed: 01/19/2023]
Abstract
Human cerebrospinal fluid (CSF) sampling is of high value as the only general applicable methodology to obtain information on free drug concentrations in individual human brain. As the ultimate interest is in the free drug concentration at the CNS target site, the question is what CSF concentrations may tell us in that respect. Studies have been performed in rats and other animals for which concentrations in brain extracellular fluid (brain ECF) as a target site for many drugs, have been compared to (cisterna magna) CSF concentrations, at presumed steady state conditions,. The data indicated that CSF drug concentrations provided a rather good indication of, but not a reliable measure for predicting brain ECF concentrations. Furthermore, comparing rat with human CSF concentrations, human CSF concentrations tend to be higher and display much more variability. However, this comparison of CSF concentrations cannot be a direct one, as humans probably had a disease for which CSF was collected in the first place, while the rats were healthy. In order to be able to more accurately predict human brain ECF concentrations, understanding of the complexity of the CNS in terms of intrabrain pharmacokinetic relationships and the influence of CNS disorders on brain pharmacokinetics needs to be increased. This can be achieved by expanding a currently existing preclinically derived physiologically based pharmacokinetic model for brain distribution. This model has been shown to successfully predict data obtained for human lumbar CSF concentrations of acetaminophen which renders trust in the model prediction of human brain ECF concentrations. This model should further evolute by inclusion of influences of drug properties, fluid flows, transporter functionalities and different disease conditions. Finally the model should include measures of target site engagement and CNS effects, to ultimately learn about concentrations that best predict particular target site concentrations, via human CSF concentrations.
Collapse
|
13
|
Hammarlund-Udenaes M. In Vivo Approaches to Assessing the Blood–Brain Barrier. TOPICS IN MEDICINAL CHEMISTRY 2013. [DOI: 10.1007/7355_2013_27] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
14
|
Gottas A, Oiestad E, Boix F, Ripel A, Thaulow C, Pettersen B, Vindenes V, Morland J. Simultaneous measurement of heroin and its metabolites in brain extracellular fluid by microdialysis and ultra performance liquid chromatography tandem mass spectrometry. J Pharmacol Toxicol Methods 2012; 66:14-21. [DOI: 10.1016/j.vascn.2012.04.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Accepted: 04/19/2012] [Indexed: 11/24/2022]
|
15
|
Kuhnline Sloan CD, Nandi P, Linz TH, Aldrich JV, Audus KL, Lunte SM. Analytical and biological methods for probing the blood-brain barrier. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2012; 5:505-31. [PMID: 22708905 PMCID: PMC3744104 DOI: 10.1146/annurev-anchem-062011-143002] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The blood-brain barrier (BBB) is an important interface between the peripheral and central nervous systems. It protects the brain against the infiltration of harmful substances and regulates the permeation of beneficial endogenous substances from the blood into the extracellular fluid of the brain. It can also present a major obstacle in the development of drugs that are targeted for the central nervous system. Several methods have been developed to investigate the transport and metabolism of drugs, peptides, and endogenous compounds at the BBB. In vivo methods include intravenous injection, brain perfusion, positron emission tomography, and microdialysis sampling. Researchers have also developed in vitro cell-culture models that can be employed to investigate transport and metabolism at the BBB without the complication of systemic involvement. All these methods require sensitive and selective analytical methods to monitor the transport and metabolism of the compounds of interest at the BBB.
Collapse
|
16
|
Sadiq MW, Borgs A, Okura T, Shimomura K, Kato S, Deguchi Y, Jansson B, Björkman S, Terasaki T, Hammarlund-udenaes M. Diphenhydramine Active Uptake at the Blood–Brain Barrier and Its Interaction with Oxycodone in vitro and in Vivo. J Pharm Sci 2011; 100:3912-23. [DOI: 10.1002/jps.22567] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Revised: 03/15/2011] [Accepted: 03/15/2011] [Indexed: 02/06/2023]
|
17
|
Sadiq MW, Salehpour M, Forsgard N, Possnert G, Hammarlund-Udenaes M. Morphine Brain Pharmacokinetics at Very Low Concentrations Studied with Accelerator Mass Spectrometry and Liquid Chromatography-Tandem Mass Spectrometry. Drug Metab Dispos 2010; 39:174-9. [DOI: 10.1124/dmd.110.036434] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
18
|
Bengtsson J, Ederoth P, Ley D, Hansson S, Amer-Wåhlin I, Hellström-Westas L, Marsál K, Nordström CH, Hammarlund-Udenaes M. The influence of age on the distribution of morphine and morphine-3-glucuronide across the blood-brain barrier in sheep. Br J Pharmacol 2009; 157:1085-96. [PMID: 19438510 DOI: 10.1111/j.1476-5381.2009.00242.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE The effect of age on the distribution of morphine and morphine-3-glucuronide (M3G) across the blood-brain barrier (BBB) was studied in a sheep model utilizing intracerebral microdialysis. The effect of neonatal asphyxia on brain drug distribution was also studied. EXPERIMENTAL APPROACH Microdialysis probes were inserted into the cortex, striatum and blood of 11 lambs (127 gestation days) and six ewes. Morphine, 1 mg x kg(-1), was intravenously administered as a 10 min constant infusion. Microdialysis and blood samples were collected for up to 360 min and analysed using liquid chromatography-tandem mass spectrometry. The half-life, clearance, volume of distribution, unbound drug brain : blood distribution ratio (K(p,uu)) and unbound drug volume of distribution in brain (V(u,brain)) were estimated. KEY RESULTS Morphine K(p,uu) was 1.19 and 1.89 for the sheep and premature lambs, respectively, indicating that active influx into the brain decreases with age. Induced asphyxia did not affect transport of morphine or M3G across the BBB. Morphine V(u,brain) measurements were higher in sheep than in premature lambs. The M3G K(p,uu) values were 0.27 and 0.17 in sheep and premature lambs, indicating a net efflux from the brain in both groups. CONCLUSIONS AND IMPLICATIONS The morphine K(p,uu) was above unity, indicating active transport into the brain; influx was significantly higher in premature lambs than in adult sheep. These results in sheep differ from those in humans, rats, mice and pigs where a net efflux of morphine from the brain is observed.
Collapse
Affiliation(s)
- J Bengtsson
- Division of Pharmacokinetics and Drug Therapy, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala SE-751 24, Sweden
| | | | | | | | | | | | | | | | | |
Collapse
|