Bodyweight, nutritional status and reproductive function

© 1999 Journals of Reproduction and Fertility 1359-6004/99 $15.00 Leptin is a peptide produced by adipocytes and achieves hormonal status by virtue of its secretion into the bloodstream (Considine et al., 1996). It is a potent satiety factor (Campfield et al., 1995; Halaas et al., 1995) but may serve other functions, such as the regulation of neuroendocrine systems and the gonads. This brief review will outline the sites within the hypothalamo–pituitary axis at which leptin may influence reproductive function, indicating the location of leptin receptors and detailing effects within the hypothalamo–pituitary–gonadal axis (Fig. 1). Since leptin may affect the secretion of various hormones, the way it influences reproduction could either be direct or indirect (Fig. 1). For example, leptin could regulate the secretion of growth hormone (GH) or prolactin (see below), which could have indirect effects on the gonad (Adashi, 1995; Linzer and Arey, 1995).