Paracrine actions of the stomach-derived leptin

Leptin, a 16 kilodalton protein-encoded by the ob gene, is involved in the regulation of food intake, body composition, and energy expenditure through a central feedback mechanism. Initially thought to be adipocyte-specific, the ob gene, as well as the leptin receptor, has been found in a variety of other tissues. Relevant to this review, the leptin gene and its receptor have been identified in the stomach, intestine, liver, and pancreas. Recent data also suggest that gut leptin may act locally within the gastrointestinal tract to influence intestinal functions such as nutrient absorption and may have a physiopathological implication. This review emphasises the concept that leptin may be a new gastrointestinal hormone.