Structure:
Progesterone, the major steroid hormone produced by the corpus
luteum, is regulated by LH. If conception
occurs in viviparous animals, progesterone is strongly stimulated by gonadotrophins
secreted by the chorionic cells of the placenta.
Function:
Progesterone is a key hormone of the reproductive
cycles, preparing estrogen-stimulated tissues for secretory cellular
changes, termed luteinization, that support nidation and placentation in
vivaparous animals. Progesterone acts as a weak anti-estrogen, reducing
the mRNA synthesis response to estradiol.
