TY - JOUR T1 - CONCENTRATION OF FREE AND CONJUGATED MORPHINE IN BRAIN AND OTHER TISSUES OF TOLERANT AND NONTOLERANT RABBITS JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 252 LP - 254 VL - 124 IS - 3 AU - ROBERT SIMINOFF AU - PAUL R. SAUNDERS Y1 - 1958/11/01 UR - http://jpet.aspetjournals.org/content/124/3/252.abstract N2 - Existing methods for the determination of morphine in tissues have been modified to permit the determination of the low concentrations of drug present in the brain after the administration of moderate doses. The method has been applied to a study of the concentration of free morphine in the brain and of free and bound drug in the liver, kidney and blood of tolerant and nontolerant rabbits. No difference was found in the concentration of morphine in tolerant as compared to nontolerant rabbits, at intervals of 1/2, 1, 2, 4 and 8 hours after intraperitoneal administration of the drug. © 1958, by The Williams & Wilkins Company ER -