Pregnancy Maintenance in Ovariectomized Rats with 16α, 17αDihydroxyprogesterone Derivatives and Other Progestogens

Abstract

The acetophenone and acetonide derivatives of 16α,17α-dihydroxyprogesterone were compared with several other progestational steroids for maintenance of pregnancy activity in rats ovariectomized on day 8 of pregnancy. Both of these derivatives of 16α,17α-dihydroxyprogesterone, progesterone and 6α-methyl-17α-hydroxyprogesterone acetate, maintained pregnancy. 17α-Ethinyl-19- nortestosterone and 17α-hydroxyprogesterone caproate did not sustain gestation. Estrone enhanced the maintenance of pregnancy activity of progesterone and the acetophenone derivative of 16α,17α-dihydroxyprogesterone, the augmentation being greater in the latter compound. The acetophenone derivative of 16α,17α-dihydroxyprogesterone and 6α-methyl- 17α-hydroxyprogesterone acetate were orally active in preventing termination of pregnancy in castrated rats.