Document Detail


Evaluation of the permeation characteristics of a model opioid peptide, H-Tyr-D-Ala-Gly-Phe-D-Leu-OH (DADLE), and its cyclic prodrugs across the blood-brain barrier using an in situ perfused rat brain model.
MedLine Citation:
PMID:  12388672     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The permeation characteristics of a model opioid peptide, H-Tyr-D-Ala-Gly-Phe-D-Leu-OH (DADLE), and its cyclic prodrugs [acyloxyalkoxy-based cyclic prodrug of DADLE (AOA-DADLE), coumarinic acid-based cyclic prodrug of DADLE (CA-DALE), and oxymethyl-modified coumarinic acid-based cyclic prodrug of DADLE (OMCA-DADLE)] across the blood-brain barrier (BBB) were determined using an in situ perfused rat brain model. The rat brains were perfused with Krebs-bicarbonate buffer containing test compounds in the absence or presence of a specific P-glycoprotein inhibitor (GF-120918). Brain samples were collected after perfusion and processed by a capillary depletion method. After liquid phase extraction with acetonitrile, samples were analyzed using high-performance liquid chromatography with tandem mass spectrometric detection. Linear uptake kinetics of DADLE and its cyclic prodrugs was observed within the range of 60 to 240 s of perfusion. The apparent permeability coefficient (P(app)) of DADLE across the BBB was very low (<10(-7) cm/s), probably due to its unfavorable physicochemical properties (e.g., charge, hydrophilicity, and high hydrogen-bonding potential). All three cyclic prodrugs, however, also exhibited low membrane permeation (P(app) <10(-7) cm/s) in spite of their more favorable physicochemical properties (e.g., no charge, high hydrophobicity, and low hydrogen-bonding potential). Inclusion of GF-120918 (10 microM) in the perfusates fully inhibited the P-gp activity in the BBB and dramatically increased the P(app) values of AOA-DADLE, CA-DADLE, and OMCA-DADLE by approximately 50-, 460-, and 170-fold, respectively. In contrast, GF-120918 had no effect on the P(app) value of DADLE. In addition, the observed bioconversions of the prodrugs to DADLE in the rat brains after 240-s perfusion were very low (5.1% from AOA-DADLE, 0.6% from CA-DADLE, and 0.2% from OMCA-DADLE), which was consistent with the in vitro bioconversion rates determined previously in rat brain homogenates.
Authors:
Weiqing Chen; Jerry Z Yang; Rikke Andersen; Lisbeth H Nielsen; Ronald T Borchardt
Publication Detail:
Type:  In Vitro; Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The Journal of pharmacology and experimental therapeutics     Volume:  303     ISSN:  0022-3565     ISO Abbreviation:  J. Pharmacol. Exp. Ther.     Publication Date:  2002 Nov 
Date Detail:
Created Date:  2002-10-21     Completed Date:  2002-11-22     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0376362     Medline TA:  J Pharmacol Exp Ther     Country:  United States    
Other Details:
Languages:  eng     Pagination:  849-57     Citation Subset:  IM    
Affiliation:
Department of Pharmaceutical Chemistry, The University of Kansas, 2095 Constant Avenue, Lawrence, KS 66047, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Acridines / pharmacology
Algorithms
Animals
Biotransformation
Blood-Brain Barrier / drug effects*
Brain Chemistry / drug effects
Chromatography, High Pressure Liquid
Diazepam / pharmacology
Enkephalin, Leucine-2-Alanine / analogs & derivatives,  pharmacokinetics*
GABA Modulators / pharmacology
Isoquinolines / pharmacology
Kinetics
Male
Mass Spectrometry
P-Glycoprotein / metabolism
Perfusion
Prodrugs / pharmacokinetics*
Quinidine / pharmacology
Rats
Rats, Sprague-Dawley
Tetrahydroisoquinolines*
Grant Support
ID/Acronym/Agency:
DA 09315/DA/NIDA NIH HHS
Chemical
Reg. No./Substance:
0/Acridines; 0/GABA Modulators; 0/Isoquinolines; 0/P-Glycoprotein; 0/Prodrugs; 0/Tetrahydroisoquinolines; 143664-11-3/GF 120918; 439-14-5/Diazepam; 56-54-2/Quinidine; 63631-40-3/Enkephalin, Leucine-2-Alanine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  In vitro stability and in vivo pharmacokinetic studies of a model opioid peptide, H-Tyr-D-Ala-Gly-Ph...
Next Document:  The identification and characterization of the marine natural product scytonemin as a novel antiprol...