Gonadal steroids and energy homeostasis in the leptin era

Gonadal steroids influence food intake-and body weight. Although the specif ic mechanisms underlying these effects are not clear, a consideration of th eir effects in the context of current models of energy homeostasis may ulti mately lead to the identification of these mechanisms. When compared with l eptin, the prototypical humoral signal of energy balance, sex steroids shar e many common properties related to food intake and body weight. Specifical ly, gonadal steroids circulate in proportion to fat mass and current energy balance, and administration of these compounds influences food intake, ene rgy expenditure, body weight, and body composition. Moreover,;both estrogen s and androgens modulate central nervous system effecters of energy homeost asis that are targets for the action of leptin, including pathways that con tain neuropeptide Y, pro-opiomelanocortin, or melanin-concentrating hormone . Sex steroids and leptin: also regulate one another's production. Although gonadal steroids, unlike leptin, are clearly not critical to the maintenan ce of normal energy homeostasis, they do appear to function as physiologic modulators bf this process. Identifying the specific central mediators of t heir effects will contribute to our understanding of their role in energy h omeostasis. Nutrition 2000;16:937-946. (C) Elsevier Science Inc. 2000.