Luteolysis

Luteolysis is the process by which steroid production ceases and the cells that comprise the corpus luteum (CL) undergo cell death. In many, but not all, animals, luteolysis is initiated by uterine release of prostaglandin F2a (PGF2A). There are multiple biochemical pathways that are activated by PGF2A that result in inhibition of progesterone production and initiation of apoptosis. In species that rely on PGF2A to initiate luteolysis as well as those that do not, a common feature of luteolysis is the recruitment and activation of immune cells. Cytokines produced by these cells participate in promoting luteolysis. For pregnancy to succeed, the CL must be maintained, requiring signals from the embryo to rescue the CL from undergoing luteolysis.