Orosco M, Rouch C, Nicolaidis S
URA CNRS 1860, Collège de France, Paris.
Appetite. 1994 Dec;23(3):209-18. doi: 10.1006/appe.1994.1054.
In normal rats, hypoglycemic doses of intravenous insulin bring about glucoprivic feeding but the same doses of insulin inhibit feeding when combined with doses of glucose that prevent hypoglycemia. In this study, these effects were compared between obese Zucker rats (fa-fa), known to present several abnormalities related to insulin, and normal Wistar rats by infusion of insulin (1 IU over 1 h), insulin plus glucose (5.1 g over 2 h) or vehicle. Feeding patterns and microstructure were automatically monitored. Contrary to its effect in the normal rats, insulin infusion did not enhance feeding in the Zucker rats but rather slightly decreased total food intake and meal duration. The insulin plus glucose infusion produced a total anorexia in normal rats but only a partial reduction in total food intake and meal duration was observed in Zucker rats. The impaired feeding effect of insulin in the Zucker rat may be related to its peripheral resistance to insulin which prevents a severe hypoglycemia and therefore glucoprivic feeding. The lack of inhibition of feeding when both insulin and glucose are infused may account for the well-known delayed satiation and large meals in the Zucker rats, possibly involving impaired hypothalamic action of insulin.
在正常大鼠中，静脉注射低血糖剂量的胰岛素会引发因血糖缺乏导致的进食，但当相同剂量的胰岛素与能防止低血糖的葡萄糖剂量联合使用时，会抑制进食。在本研究中，通过输注胰岛素（1小时内输注1国际单位）、胰岛素加葡萄糖（2小时内输注5.1克）或赋形剂，比较了已知存在多种与胰岛素相关异常的肥胖 Zucker 大鼠（fa-fa）和正常Wistar大鼠之间的这些效应。自动监测进食模式和微观结构。与对正常大鼠的作用相反，输注胰岛素并未增加 Zucker 大鼠的进食量，反而略微降低了总食物摄入量和进餐持续时间。胰岛素加葡萄糖输注在正常大鼠中导致完全厌食，但在 Zucker 大鼠中仅观察到总食物摄入量和进餐持续时间部分减少。Zucker 大鼠中胰岛素对进食的作用受损可能与其对胰岛素的外周抵抗有关，这种抵抗可防止严重低血糖，从而防止因血糖缺乏导致的进食。同时输注胰岛素和葡萄糖时缺乏对进食的抑制作用，可能解释了 Zucker 大鼠中众所周知的饱腹感延迟和大量进食现象，这可能涉及胰岛素在下丘脑的作用受损。
