RT Journal Article SR Electronic T1 THE DISTRIBUTION OF CHLORCYCLIZINE-14C IN PREGNANT MICE JF Drug Metabolism and Disposition JO Drug Metab Dispos FD American Society for Pharmacology and Experimental Therapeutics SP 598 OP 601 VO 1 IS 3 A1 WILLIAM J. WADDELL YR 1973 UL http://dmd.aspetjournals.org/content/1/3/598.abstract AB The distribution of chlorcyclizine-14C was studied by whole-body autoradiography in pregnant A/JAX mice at 12.5 and 17.5 days of gestation. In the mice at 12.5 days of gestation studied 3, 9, and 24 hr after injection, the amount of radioactivity in the embryos was much less than that in most maternal tissues. Only embryonic central nervous system has a discernible concentration of radioactivity. The concentration of radioactivity is low in maternal blood, but high in maternal liver, bile, intestinal contents, salivary gland. Harder's gland, lung. kidney, bone marrow, follicular walls, corpora lutea, and adrenal cortex. The yolk sac, decidua basalis, endometrium, and uterine lumen contain a high concentration of radioactivity. In the mice at 17.5 days of gestation, the same pattern of distribution of radioactivity is seen in maternal tissues, yolk sac, and uterine lumen as that seen at 12.5 days. However, fetal tissues in late gestation have a higher concentration than in mid-gestation and the pattern of distribution is more nearly similar to that in maternal tissues. Secretion of chlorcyclizine or its metabolites by the fetal yolk sac is a possible explanation for the lower concentration of drug in the embryo and fetus than in the mother at all time intervals after injection. The distribution in adrenal cortex and ovary suggests that chlorcyclizine may interfere with steroid hormone metabolism or action. Copyright © 1973 by The American Society for Pharmacology and Experimental Therapeutics