Long-term effect of food intake on adipose tissue and leptin secretion during long days in Soay rams

Circulating leptin, the obese gene product secreted by adipocytes, is sensitive to short-term (meals, starvation) and long-term (spontaneous food intake, food restriction) changes in energy balance in sheep (Marie et al 2001). The present study aimed to explore relationships between adiposity, adipose tissue from different sites and blood leptin concentrations in rams kept in long days when adiposity is normally high.

Age-related changes in leptin: consequences and mechanisms

ob/ob mice with mutations in the obese gene are extremely obese and hyperphagic and have characteristic neuroendocrine impairments, including impaired reproduction and low sex hormones, low thyroid hormone, low growth hormone, and elevated glucocorticoids, a pattern also observed in fasting mice. The product of the obese gene, called leptin, was originally characterized on the basis of positional cloning. Injections of leptin not only reversed many of the phenotypes of ob/ob mice, many of the neuroendocrine effects of fasting are also reversed by leptin injection.