Role of sex steroids and prostaglandins during the luteal life cycle in domestic cats and lynxes.

Although lynxes and domestic cats are both felids, their luteal life cycles differ. As in many species, corpora lutea (CLs) of domestic cats regress after pregnancy or pseudopregnancy. By contrast, CLs of lynxes do not functionally regress following the cycle of their formation. They stay physiologically active and persist for several years. To obtain an improved understanding of the life cycle of both species, we comparatively studied the CLs of these species in detail. In this review, we summarize the similarities and differences of their CLs regarding sex steroid and prostaglandin generation and receptors. The most evident differences were visible in the CLs of lynxes, which persist from previous cycles, compared with CLs of lynxes and domestic cats from the recent luteal cycle. We assume that these differences could indicate processes ensuring long-term luteal survival and functionality, for example, by high estrogen production/metabolism or by antioxidative effects.