Structure, Function, and Regulation of the Corpus Luteum

The corpus luteum is a transient endocrine gland in the adult ovary that differentiates from the follicle wall after ovulation. It is vital to mammalian reproduction as it produces the steroid hormone, progesterone, which acts on the reproductive tract to permit embryo implantation and to support a maternal environment that sustains intrauterine pregnancy. This chapter will review the remarkable species differences in endocrine and local control of the development (luteinization), functional lifespan, and regression (luteolysis) of the corpus luteum. The review will focus on luteotropic and luteolytic factors that regulate the structure and function of the corpus luteum during the ovarian cycle, and in some species extend the luteal lifespan if pregnancy occurs.