Progesterone induces incubatory changes in the brooding pouch of the frog Gastrotheca riobambae (Fowler)

Progesterone induces closure, vascularization, and the formation of embryonic chambers around inert beads in the brooding pouch of the frog Gastrotheca riobambae (Fowler). These changes of the pouch resemble those occurring during normal reproduction. In contrast to progesterone, human chorionic gonadotropin induces pouch closure only in females with large ovaries. The results suggest that pituitary gonadotropin indirectly induces the incubatory changes of the pouch by stimulating the secretion of a progesterone-like hormone from the ovary.