RT Journal Article
SR Electronic
T1 Blood-Brain Barrier Pharmacoproteomics-Based Reconstruction of the In Vivo Brain Distribution of P-Glycoprotein Substrates in Cynomolgus Monkeys
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 578
OP 588
DO 10.1124/jpet.114.214536
VO 350
IS 3
A1 Uchida, Yasuo
A1 Wakayama, Kentaro
A1 Ohtsuki, Sumio
A1 Chiba, Masato
A1 Ohe, Tomoyuki
A1 Ishii, Yasuyuki
A1 Terasaki, Tetsuya
YR 2014
UL http://jpet.aspetjournals.org/content/350/3/578.abstract
AB The aim of this study was to investigate whether in vivo drug distribution in brain in monkeys can be reconstructed by integrating four factors: protein expression levels of P-glycoprotein (P-gp)/multidrug resistance protein 1 at the blood-brain barrier (BBB), in vitro transport activity per P-gp molecule, and unbound drug fractions in plasma and brain. For five P-gp substrates (indinavir, quinidine, loperamide, paclitaxel, and verapamil) and one nonsubstrate (diazepam), in vitro P-gp transport activities were determined by measuring transcellular transport across monolayers of cynomolgus monkey P-gp–transfected LLC-PK1 and parental cells. In vivo P-gp functions at the BBB were reconstructed from in vitro P-gp transport activities and P-gp expression levels in transfected cells and cynomolgus brain microvessels. Brain-to-plasma concentration ratios (Kp,brain) were reconstructed by integrating the reconstructed in vivo P-gp functions with drug unbound fractions in plasma and brain. For all compounds, the reconstructed Kp,brain values were within a 3-fold range of observed values, as determined by constant intravenous infusion in adult cynomolgus monkeys. Among four factors, plasma unbound fraction was the most sensitive factor to species differences in Kp,brain between monkeys and mice. Unbound brain-to-plasma concentration ratios (Kp,uu,brain) were reconstructed as the reciprocal of the reconstructed in vivo P-gp functions, and the reconstructed Kp,uu,brain values were within a 3-fold range of in vivo values, which were estimated from observed Kp,brain and unbound fractions. This study experimentally demonstrates that brain distributions of P-gp substrates and nonsubstrate can be reconstructed on the basis of pharmacoproteomic concept in monkeys, which serve as a robust model of drug distribution in human brain.