RT Journal Article SR Electronic T1 SELECTIVITY OF ESTROGEN DISTRIBUTION IN TISSUES JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 469 OP 475 VO 150 IS 3 A1 Eisenfeld, Arnold J. A1 Axelrod, Julius YR 1965 UL http://jpet.aspetjournals.org/content/150/3/469.abstract AB Circulating estradiol is selectively accumulated by the anterior pituitary, uterus, vagina, hypothalamus, septum and preoptic region. Pretreatment with the progestin norethynodrel reduced the H3-estradiol concentrations in the anterior pituitary, uterus, vagina, heart, adrenal, hypothalamus, preoptic region and septum. Treatment with norethynodrel after H3-estradiol administration reduced the radioactive concentration only in the uterus and vagina. Norethynodrel appeared to function as a competitive inhibitor of estradiol for binding. Evidence has been presented for an estradiol saturable binding mechanism in the anterior pituitary, uterus, vagina, and hypothalamus. The Williams & Wilkins Comapny