Torlińska T, Nowak K W, Kozlik J, Paluszak J
Dept. of Physiology, University School of Medical Sciences, Poznań, Poland.
J Physiol Pharmacol. 1993 Dec;44(4):399-408.
The aim of the study was to estimate the effect of hypothermia on (125J)-iodoinsulin binding to liver plasma membranes. Rat liver membranes were prepared from control, normothermic rats (Tr = 35.6 +/- 0.3 degrees C) and hypothermic rats (Tr = 26.5 +/- 0.9 degrees C) and purified according to Havrankowa. In addition, serum insulin and glucagon levels by means of RIA and glucose concentration using the glucose oxidase method were measured. Scatchard analysis was used to determine the kinetic parameters of the hormone receptor interaction. The data showed no significant differences in the affinity of the binding sites but indicated a decrease in receptor concentrations in liver plasma membranes from hypothermic rats. In contrast to changes in serum insulin level which was decreased by about 50% in hypothermic rats blood glucose concentrations did not significantly differ between the hypothermic and normothermic ones. Our results show that in hypothermic rats the hormonal adaptation operates on the level of the number of liver receptors whereas the insulin receptor affinity remains unaffected.
本研究的目的是评估低温对（125J）-碘胰岛素与肝细胞膜结合的影响。从对照常温大鼠（Tr = 35.6 +/- 0.3摄氏度）和低温大鼠（Tr = 26.5 +/- 0.9摄氏度）制备大鼠肝细胞膜，并根据哈夫兰科娃方法进行纯化。此外，通过放射免疫分析法测定血清胰岛素和胰高血糖素水平，使用葡萄糖氧化酶法测定葡萄糖浓度。采用斯卡查德分析来确定激素受体相互作用的动力学参数。数据显示结合位点的亲和力无显著差异，但表明低温大鼠肝细胞膜中受体浓度降低。与低温大鼠血清胰岛素水平降低约50%的变化相反，低温大鼠和常温大鼠的血糖浓度无显著差异。我们的结果表明，在低温大鼠中，激素适应性作用于肝受体数量水平，而胰岛素受体亲和力不受影响。
