Chapter 135 - Leptin and the Regulation of Feeding

Abstract

This chapter discusses the role of leptin in the regulation of feeding behavior. Leptin is an adipocyte-derived polypeptide hormone that acts in the central nervous system via the long form of its receptor (LRb) to inhibit feeding. Alterations in leptin levels during chronic changes in nutritional status regulate feeding and energy expenditure, increasing feeding and decreasing energy expenditure in low leptin states such as starvation. The major sites of leptin action are in the brain, and leptin regulates melanocortin and neuropeptide Y (NPY) tone in the hypothalamus. The activation of PI 3-kinase and STATS by LRb mediate specific aspects of leptin action. Alterations in central-nervous-system leptin action may contribute to the development of obesity. Much of the action of leptin is attributable to effects in the central nervous system (CNS). CNS administration of leptin recapitulates the anorectic and neuroendocrine effects of peripherally applied leptin. Leptin action on the hypothalamic neurons also regulates the activity of the autonomic nervous system, although direct leptin action on brainstem LRb-expressing neurons may play a role in this and other leptin actions.