Growth Hormone Administration Controls Body Composition Associated with Changes of Thermogenesis in Obese KK-Ay Mice

摘要

We investigate the effects of continuous human growth hormone (GH) therapy in young obese mice onthermogenesis. Female KK-Ay obese mice (n=10) were injected subcutaneously with GH (3.5 mg/kg/day) for 30 daysfrom 42 days old. As a control, physiological saline was administered (n=10). At the terminal point (71 days old), GHadministration affected linear growth, and the Lee obesity index (3 square root body weightasoanal length X 1000) wassignificantly decreased. Rates of inguinal and perimetric white adipose pads per body weight also decreased. Free fattyacid levels decreased, while plasma insulin concentrations and homeostasis model assessment insulin resistance wereincreased (P<0.01). Plasma insulin-like growth factor I(IGF-1) levels markedly rose (P<0.00001). Uncoupling protein1(UCP1) and UCP3 mRNA expressions in brown adipose tissue were inhibited (P<0.05). Continuous GH therapy changedobese body composition toward lean, however, the consequence could be the negative regulation of thermogenesis.