RT Journal Article SR Electronic T1 SUBCELLULAR DISTRIBUTION OF 4-14C-DIPHENYLHYDANTOIN IN RAT BRAIN JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 342 OP 349 VO 177 IS 2 A1 KEMP, JOHN W. A1 WOODBURY, DIXON M. YR 1971 UL http://jpet.aspetjournals.org/content/177/2/342.abstract AB The subcellular distribution of 4-14C-diphenylhydantoin in cerebral cortex after injection into the cisterna magna of male Sprague-Dawley rats has been studied. Diphenylhydantoin readily penetrated into the cerebral cortex and was localized in the major subcellular fractions. The nuclear fraction and supernatant fluid contained the greatest quantity of radioactive drug 15 minutes after injection; the microsomal fraction contained the least. By 12 hours postinjection, the microsomal fraction had retained the drug to a greater extent; approximately 38% of the total radioactivity in the cerebral cortex was bound by these particles. The supernatant fluid contained about 44%, and the mitochondrial and nuclear fractions contained approximately 2% each. Binding of the drug by the microsomal and nuclear fractions was firm and could be released only upon alkaline hydrolysis. From the data presented, it appears that the microsomal fraction is the major binding site for diphenylhydantoin in the cerebral cortex. © 1971 by The Williams & Wilkins Co.