Leptin and the gastrointestinal tract.

Summary The number of publications on leptin and its effects areincreasing exponentially. Initial studies focused onleptin secretion from adipocytes and its effect on foodintake and energy metabolism. However, the nascentstudies discussed in this review indicate that leptin mayhave important physiologic and pathophysiologic effectsin the gastrointestinal system as well. They also empha-size the need for future work to explore the role ofleptin in orchestrating the interaction between thecentral and peripheral nervous system in controllinggastrointestinal physiology. Acknowledgement The authors were supported in part by National Institutes of Health Grant AA 10445. References and recommended reading Papers of particular interest, published within the annual period of review,have been highlighted as: • Of special interest•• Of outstanding interest 1 Zhang Y, Proenca R, Maffei M, Barone M, Leopold L, Friedman JM:Positional cloning of the mouse obese gene and its human homologue.Nature 1994, 372:425–432.2 Friedman JM: Leptin, leptin receptor and the control of body weight. NutrRev 1998, 56:S38–S46.3 Pelleymounter MA, Cullen MJ, Baker MB, Hecht R, Winters D, Boone T,Collins F: Effects of the obese gene product on body weight regulation inob/ob mice. Science 1995, 269:540–543.•4 Morton NM, Emilsson V, Liu YL, Cawthorne MA: Leptin action in intestinalcells. J Biol Chem 1998, 273:26194–26201.This study identified the presence of the leptin receptor in the jejunum.5 O’Doherty RM, Anderson PR, Zhao AZ, Bornfeldt KE, Newgard CB:Sparing effect of leptin on glycogen stores in rats during the fed -to-fasttransition. Am J Physiol 1999, 277:E544–E550.6 Aiston S, Agius L: Leptin enhances glycogen storage in hepatocytes byinhibition of phosphorylase and exerts an additive effect with insulin.Diabetes 1999, 48:15–20.7 Zhou YT, Shimabukuro M, Koyama K, Lee K, Wang F, Trieu CB, Newgard,Under RU: Induction by leptin of uncoupling protein-2 and enzymes of fattyacid oxidation. Proc Natl Acad Sci USA 1997, 94:6386–6390.8 Seeley RJ, Van Dijk G, Campfield LA, Smith FJ, Burn P, Nelligan JA, et al.:Intraventricular leptin reduces food intake and body weight of lean rats butnot obese Zucker rats. Horm Metab Res 1996, 28:664–668.