Control of the corpus luteum: a model system for toxicology research.

The rodent corpus luteum is an ephemeral structure releasing progesterone for only a few hours rather than several days. However, in response to the mating stimulus, sufficient prolactin is released from the pituitary gland in a unique pattern to activate the corpus luteum and maintain it in a secretory state for several days. Progesterone, secreted from the corpus luteum, prolongs the secretion of prolactin, while the uterus may secrete a substance which terminates the functional life of the corpus luteum directly and also acts upon he prolactin secretory apparatus within the hypothalamopituitary axis to terminate prolactin secretion.