期刊名称：Journal of Clinical Biochemistry and Nutrition
印刷版ISSN：0912-0009
电子版ISSN：1880-5086
出版年度：1999
卷号：26
期号：2
页码：77-84
DOI：10.3164/jcbn.26.77
出版社：The Society for Free Radical Research Japan
摘要：The recent discovery of the positional cloning of the mouse obese ( ob ) gene has resulted in renewed attention to the scientific study of obesity and body weight regulation. It was further discovered that the ob gene encodes for a circulating hormone, ob protein or leptin, secreted by adipose tissue. In the ob/ob mouse model which becomes very obese, there is a complete leptin deficiency. As such, if leptin is administered to these animals, food intake and body weight decrease significantly. The db/db mouse also becomes obese, but it has high levels of circulating leptin. Thus it is believed that this animal model cannot respond to leptin because of an altered leptin receptor. Because humans appear to have serum leptin levels in proportion to the level of body fat mass it is speculated that “leptin resistance” may also be involved, at least in part, in the development of human obesity. However, it is also proposed that for “normal” body weight regulation, leptin may act like a lipostat in response to changes in energy balance and fat stores and that exogenous leptin could possibly reset the lipostat. Serum leptin levels were measured in three groups of women: those who had lost ≥20% of their body weight and maintained the weight loss; those who lost ≥20% of their body weight and regained it; and weight stable controls who had never dieted. The maintainers and controls had similar leptin levels at 10.2±7.0 and 7.5±3.8ng/ml respectively. Those who had regained the weight had higher leptin levels than the other two groups at 20.8±8.4ng/ml ( p <0.05). Body mass index (BMI) was also significantly higher in this group ( p <0.001) at 34.1±6.4 compared to 24.0±2.0 in the maintainers and 21.3±2.5 in the controls. Leptin has also been shown to influence resting metabolic rate (RMR). Thus, serum leptin levels were measured in women who were similar in height, weight and age but had a low (≤85% predicted) or high (>100% predicted) RMR. No relationship between leptin and RMR was observed. There appear to be many unanswered questions about the mechanisms of action of leptin in humans.
