Harris R B
Monell Chemical Senses Center, Philadelphia, PA 19104-3308.
Int J Obes. 1989;13(5):647-60.
Hypophysectomized (hypox) rats were fed ad libitum or were tube-fed increasing levels of their normal food intake. Sham operated (sham) rats were tube-fed to maintain their normal rate of growth or were fed 150 percent of their ad libitum food intake. This was equivalent to the highest intake of hypox rats. Overfeeding continued for 20 days. Overfeeding hypox rats increased body weight almost entirely by hypertrophy and hyperplasia of body fat depots. Overfeeding did not promote growth of lean tissue in hypox rats. Serum insulin increased with higher levels of food intake and extreme overfeeding resulted in hyperinsulinemia and hyperglycemia in hypox rats. Serum thyroid hormones and corticosterone were lower in hypox than sham rats and were not significantly changed by overfeeding. Adipose and hepatic fatty acid synthesis and esterification and adipose glycerol release were measured in vitro. Although serum insulin increased, peripheral tissue of overfed hypox rats remained insulin resistant. Rates of hepatic and adipose lipid synthesis and adipose lipolysis appeared to be determined by nutrient availability rather than being dependent upon pituitary factors.
对垂体切除的（垂体切除组）大鼠不限量喂食，或通过管饲法逐渐增加其正常食物摄入量。对假手术（假手术组）大鼠进行管饲以维持其正常生长速度，或按其自由摄食量的150%喂食。这相当于垂体切除组大鼠的最高摄入量。过度喂食持续20天。过度喂食垂体切除组大鼠几乎完全通过体脂库的肥大和增生使体重增加。过度喂食并未促进垂体切除组大鼠瘦组织的生长。随着食物摄入量增加，垂体切除组大鼠血清胰岛素升高，极端过度喂食导致垂体切除组大鼠出现高胰岛素血症和高血糖。垂体切除组大鼠血清甲状腺激素和皮质酮水平低于假手术组大鼠，且过度喂食对其无显著影响。在体外测量脂肪组织和肝脏的脂肪酸合成、酯化以及脂肪组织甘油释放。尽管血清胰岛素升高，但过度喂食的垂体切除组大鼠外周组织仍存在胰岛素抵抗。肝脏和脂肪组织的脂质合成及脂肪组织脂解速率似乎由营养物质供应决定，而非依赖于垂体因素。
