TY - JOUR T1 - THE DISTRIBUTION OF METHADONE IN THE NONPREGNANT, PREGNANT AND FETAL RAT AFTER ACUTE METHADONE TREATMENT JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 273 LP - 278 VL - 181 IS - 2 AU - MARVIN A. PETERS AU - MARILYN TURNBOW AU - DORIS BUCHENAUER Y1 - 1972/05/01 UR - http://jpet.aspetjournals.org/content/181/2/273.abstract N2 - The 14C-labeled methadone administered to female rats was found to be distributed differently in the pregnant as compared with nonpregnant female control animals. The liver of the pregnant rat showed a 50% decrease in the concentration of methadone whereas a 3-fold increase in the concentration of methadone was found in the uterus. The concentrations in some of the other tissues studied varied to some extent; however, no significant differences were observed. The concentration of methadone in the fetal tissues was significantly lower than that found in the maternal tissues in all cases with the exception of the brain. The concentration of methadone in the brain of the fetus was 2 to 3 times the concentration present in the maternal brain. The three methods used in this study all gave similar values and comparisons with regard to the distribution of methadone in the nonpregnant, pregnant and fetal tissues. © 1972 by The Williams & Wilkins Co. ER -