First Author | Mizuno TM | Year | 1998 |
Journal | Diabetes | Volume | 47 |
Issue | 2 | Pages | 294-7 |
PubMed ID | 9519731 | Mgi Jnum | J:45531 |
Mgi Id | MGI:1195579 | Doi | 10.2337/diab.47.2.294 |
Citation | Mizuno TM, et al. (1998) Hypothalamic pro-opiomelanocortin mRNA is reduced by fasting in ob/ob and db/db mice, but is stimulated by leptin. Diabetes 47(2):294-7 |
abstractText | Reduction in the activity of the alpha-melanocyte-stimulating hormone (alpha-MSH) system causes obesity, and infusions of alpha-MSH can produce satiety, raising the possibility that alpha-MSH may mediate physiological satiety signals. Since alpha-MSH is coded for by the pro-opiomelanocortin (POMC) gene, we examined if POMC gene expression would be inhibited by fasting in normal mice or in models of obesity characterized by leptin insufficiency (ob/ob) or leptin insensitivity (db/db). In wild-type mice, hypothalamic POMC mRNA was decreased > 60% after a 2-day fast and was positively correlated with leptin mRNA. Similarly, compared with controls, POMC mRNA was decreased by at least 60% in both db/db and ob/ob mice. POMC mRNA was negatively correlated with both neuropeptide Y (NPY) and melanin-concentrating hormone (MCH) mRNA. Finally, treatment of both male and female ob/ob mice with leptin stimulated hypothalamic POMC mRNA by about threefold. These results suggest that impairment in production, processing, or responsiveness to alpha-MSH may be a common feature of obesity and that hypothalamic POMC neurons, stimulated by leptin, may constitute a link between leptin and the melanocortin system. |