Pregnancy without progesterone in horses defines a second endogenous biopotent progesterone receptor agonist, 5α-dihydroprogesterone.

ABSTRACT: One of the most widely accepted axioms of mammalian reproductive biology is that pregnancy requires the (sole) support of progesterone, acting in large measure through nuclear progesterone receptors (PRs) in uterine and cervical tissues, without which pregnancy cannot be established or maintained. However, mares lack detectable progesterone in the latter half of pregnancy. Instead of progesterone, several (mainly 5α-reduced) pregnanes are elevated and have long been speculated to provide progestational support in lieu of progesterone itself. To the authors' knowledge, evidence for the bioactivity of a second potent endogenously synthesized pregnane able to support pregnancy in the absence of progesterone has never before been reported. The 5α-reduced progesterone metabolite dihydroprogeste

SUBMITTER: Scholtz EL 

PROVIDER: S-EPMC3948269 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature