Endocrine Abstracts

One of the hallmarks of parturition in most mammals is a dramatic drop in plasma levels of progesterone (P4), which promotes myometrial relaxation, prior to labor. In humans and some other primates however, the opposite occurs and placental P4 production increases with advancing pregnancy. The expression of nuclear progesterone receptor (PR)-responsive genes is decreased in the primate uterus at term, which suggests ‘functional’ progestin withdrawal involves repressi...

3beta-hydroxysteroid dehydrogenase (3beta-HSD) expression is essential for the synthesis of all classes of steroid hormones, converting delta5-3beta-hydroxysteroids into hormonally active delta4-3-ketosteroids in NAD+-dependent reactions. A variety of 3beta-HSD isoforms have been described in primate, rodent and other mammals, often exhibiting distinct kinetic properties, preferential subcellular localization, as well as alternative substrate s...