Interaction of Nonpeptidic δ Agonists with P‐Glycoprotein by In Situ Mouse Brain Perfusion: Liquid Chromatography–Mass Spectrometry Analysis and Internal Standard Strategy

• Published in: Journal of pharmaceutical sciences Vol. 91; no. 1; pp. 244 - 252
• Main Authors: Dagenais, Claude, Ducharme, Julie, Pollack, Gary M.
• Format: Journal Article
• Language: English
• Published: New York Elsevier Inc 01.01.2002; John Wiley & Sons, Inc; Wiley; American Pharmaceutical Association
• Subjects: Analysis; Animals; ATP Binding Cassette Transporter, Subfamily B - deficiency; ATP Binding Cassette Transporter, Subfamily B - metabolism; ATP Binding Cassette Transporter, Subfamily B, Member 1 - deficiency; ATP Binding Cassette Transporter, Subfamily B, Member 1 - genetics; ATP Binding Cassette Transporter, Subfamily B, Member 1 - metabolism; ATP-Binding Cassette Transporters - metabolism; Biological and medical sciences; blood-brain barrier; Brain - blood supply; Brain - metabolism; Calcium Channel Blockers - pharmacokinetics; Chromatography, Liquid - methods; Chromatography, Liquid - statistics & numerical data; General pharmacology; Male; Mass Spectrometry - methods; Mass Spectrometry - statistics & numerical data; Medical sciences; Mice; Mice, Knockout; Neuropharmacology; Neurotransmitters. Neurotransmission. Receptors; opioids; P-glycoprotein; Peptidergic system (neuropeptide, opioid peptide, opiates...). Adenosinergic and purinergic systems; Perfusion - methods; Pharmacology. Drug treatments; Receptors, Opioid, delta - agonists; Receptors, Opioid, delta - metabolism; verapamil; Verapamil - pharmacokinetics; P‐glycoprotein; blood–brain barrier; verapamil; opioids; Agonist; Rodentia; Calcium antagonist; P Glycoprotein; Central nervous system; HPLC chromatography; Non peptide compound; Molecular interaction; Antiarrhythmic agent; δ Opioid receptor; Blood brain barrier; Vertebrata; Biological fixation; Mammalia; Mouse; Animal; Aralkylamine; Verapamil; Mass spectrometry; Quantitative analysis; Brain (vertebrata)
• ISSN: 0022-3549; 1520-6017
• DOI: 10.1002/jps.1175

Many opioids are substrates of the efflux transporter P‐glycoprotein (P‐gp) in the blood–brain barrier (BBB). In situ brain perfusion in wild‐type and mdr 1a(−/−) P‐gp‐deficient mice was utilized to investigate potential P‐gp‐mediated transport of novel nonpeptidic δ agonists (AR‐M δ compounds). Because radioactive compounds were not available for this series, liquid chromatography–mass spectrometric detection (LC–MS) was the assay methodology of choice. Verapamil in the perfusion buffer (0.5 μM) served as a positive control for P‐gp‐mediated efflux and as an experimental internal standard for P‐gp modulation by AR‐M δ compounds. LC–MS provided excellent assay sensitivity with no significant interferences. In P‐gp‐competent mice, the brain extraction of AR‐M δ compounds ranged from 1.1 to 96%. The ratio of initial brain uptake clearances (Clup) in P‐gp‐deficient and wild‐type mice (P‐gp effect) ranged from 0.96 to 4.91. Some compounds increased the Clup of verapamil in P‐gp‐competent mice, consistent with P‐gp inhibition. These results demonstrate that LC–MS is an appropriate assay methodology for mouse brain perfusion samples, that AR‐M δ compounds may interact with P‐gp in the BBB, and that the internal strategy can provide useful information concerning P‐gp modulation by compounds of interest. © 2002 Wiley‐Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91:244–252, 2002