Leptin and the gastrointestinal tract

The discovery of leptin in 1990 was the culmination of earlier work which r ecognized that communication between the adipocyte and the hypothalamus was important in maintaining body weight. Leptin, which is a 16 kilodalton pro tein-encoded by the OB gene, is involved in the regulation of food intake, body composition, and energy expenditure through a central feedback mechani sm. initially thought to be adipocyte-specific, the OB gene, as well as the leptin receptor, have been found in a variety of other tissues. Relevant t o this review, the leptin gene and its receptor have been identified in the stomach, intestine, fiver, and pancreas. Recent data also suggest that lep tin may act locally within the gastrointestinal tract to influence intestin al function. This review emphasizes the concept that leptin may be a new gastrointestina l hormone and the need to expand the focus of leptin research to include ai l phases of weight maintenance, such as nutrient absorption and utilization , in addition to food intake. (C) 2000 Lippincott Williams & Wilkins, Inc.