[Leptin--missing link between the metabolic state and the reproductive system?].

What is the signal between the metabolic state and reproductive function--it is one of the scientific puzzles in gynecological endocrinology. Previously it was suggested that such substances as insulin, amino acids, IGFBP-I may play a role as a metabolic signal. Leptin a newly discovered hormonal product of obesity (ob) gene is expressed by adipocytes and thought to play a role in the regulation of food intake, metabolism and reproduction. In this article some informations about leptin secretion, its regulation and localization of leptin receptors have been presented. Particular attention to leptin influence on GnRH secretion have been paid. Probably on the base of this mechanism leptin acts as a link between metabolic state and reproductive system. Some data about leptin secretion in obesity, weight loss related amenorrhoea and anorexia nervosa have been discussed. The putative role of leptin in the pathophysiology of polycystic ovary syndrome and initiation of puberty also have been analyzed.