<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Misra, A L</style></author><author><style face="normal" font="default" size="100%">Bloch, R</style></author><author><style face="normal" font="default" size="100%">Vardy, J</style></author><author><style face="normal" font="default" size="100%">Mulé, S J</style></author><author><style face="normal" font="default" size="100%">Verebely, K</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Disposition of (15,16-3H)naltrexone in the central nervous system of the rat.</style></title><secondary-title><style face="normal" font="default" size="100%">Drug Metab Dispos</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Drug Metab. Dispos.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Animals</style></keyword><keyword><style  face="normal" font="default" size="100%">Blood-Brain Barrier</style></keyword><keyword><style  face="normal" font="default" size="100%">Brain</style></keyword><keyword><style  face="normal" font="default" size="100%">Chromatography, Thin Layer</style></keyword><keyword><style  face="normal" font="default" size="100%">Male</style></keyword><keyword><style  face="normal" font="default" size="100%">Naloxone</style></keyword><keyword><style  face="normal" font="default" size="100%">Naltrexone</style></keyword><keyword><style  face="normal" font="default" size="100%">Rats</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1976</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1976 May-Jun</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">4</style></volume><pages><style face="normal" font="default" size="100%">276-80</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;After injection of (15,16-3H)naltrexone (10 mg/kg s.c.) in male Wistar rats, peak concentrations of drug occurred in brain and plasma within 0.5 hr. Levels of naltrexone were sustained in brain between 2 and 24 hr and were barely detectable at 48 hr. Significant amounts of metabolities were present in brain and plasma at longer time periods. The t1/2 of naltrexone in brain and plasma were approximately 8.0 and 11.4 hr. respectively. The brain/plasma ratios of naltrexone at earlier times (0.5-1 hr) were higher than those at later times. The binding of naltrexone in vitro with rat plasma proteins in concentrations of 1-10 mug/ml ranged between 41 and 59% 6beta-Naltrexol was present in very small amounts in brain but not in plasma. In addition to 7,8-dihydro-14-hydroxynormophinone and 7,8-dihydro-14-hydroxynormophine, tentative evidence was obtained for three other metabolites of naltrexone in brain. These metabolites were also present in plasma in addition to free and conjugated naltrexone and its N-dealkylated metabolites.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/6233?dopt=Abstract</style></custom1></record></records></xml>