Role of leptin in physiology of animal reproduction-A review

Abstract

Leptin a multifarious hormone was discovered in 1994, a protein synthesized and secreted by adipose tissue has been shown to regulate feed intake in several species of animals. Although, a nimiety of information exists regarding the physiological role of leptin in animals, but the regulation and action of leptin in reproductive aspects of domestic animals is still naive. Emerging evidence in several species indicates that leptin may also affect the hypothalamo-pituitary-gonadal axis thus augmenting various reproductive processes. Leptin mRNA receptors are present in the anterior pituitary and hypothalamus of several species. Evidence to support direct action of leptin at the level of the gonad indicates that the leptin receptor and its mRNA are present in ovarian tissues of several species, including cattle. These leptin receptors are functional, since leptin inhibits insulin-induced steroidogenesis of both granulosa and thecal cells of cattle in vitro. Leptin receptors are present in buffalo corpus luteum in different stages of the estrous cycle. In both primates and animals, leptin receptors exist in placental tissues and may regulate metabolism of the fetal-placental unit. During pregnancy, placental production of leptin may be a major contributor for the increase in maternal leptin in primates. Leptin association can be made for body energy stores, dietary energy intake and reproductive functions in animals.