LEP and hyperinsulinemic hypoglycemia, familial, 4: In leptin-deficient ob/ob mice, loss of Mchr1 reduced adiposity (although body weights were not statistically different), improved the response in an oral glucose tolerance test (OGTT), increased spontaneous movement, and improved thermoregulation upon exposure to cold, suggesting that MCH is an important mediator of the response to leptin deficiency (Bjursell et al., 2006).