Species-related differences in the mechanism of apoptosis during structural luteolysis

Luteolysis is defined as the loss of function and subsequent involution of the luteal structure. The luteolytic process is usually subdivided, whereby the decline in progesterone is described as functional luteolysis and the structural involution is described as structural luteolysis. After the corpus luteum ceases to produce progesterone, it decreases in size, experiences a loss of cellular integrity, and then disappears from the ovary as a result of apoptosis of luteal cells. However, the control mechanisms responsible for initiating and mediating apoptosis during structural luteolysis seem more complex than originally envisioned. Furthermore, efforts to elucidate the apoptotic mechanisms have been complicated by the fact that different mammalian species have different mechanisms for controlling luteal function. Therefore, it is of interest to know whether different mammalian species have different apoptotic mechanisms. The goal of this review was to focus on species-related differences in the mechanism of apoptosis during structural luteolysis in rodents, cattle and humans, the species that are used most for luteolysis research.