Chowdhury P
Department of Physiology/Biophysics, University of Arkansas For Medical Science, Little Rock 72205.
Ann Clin Lab Sci. 1990 Nov-Dec;20(6):415-9.
This study was conducted in male Sprague Dawley rats, maintained chronically on drinking water and on nicotine water at nicotine concentrations of 0.31 and 1.23 mM, to determine the effect of nicotine on body weight regulation and circulating growth hormone levels. The study was repeated to determine the effect of nicotine withdrawal on the same parameters after exposing the animals to high dose of nicotine (1.23 mM) for 12 weeks and then removing the nicotine from water for four weeks. Growth hormone (GH) and insulin levels in the plasma were measured by sensitive radioimmunoassays. The results show that with nicotine treatment the body weight, food and fluid intakes in rats decreased significantly, concomitant with the decrease in plasma glucose and insulin levels while plasma growth hormone levels were increased significantly. A pair-fed study conducted to determine the effect of decreased food intake showed no alteration of metabolic or hormonal parameters. Withdrawal of nicotine for four weeks reversed all of the previously noted parameters including plasma growth hormone levels; however, the body weights were not completely reversed. The data suggest that intake of nicotine affects body weights which appear to be associated with decreased plasma levels of glucose and insulin and release of growth hormone may play a role in that mechanism.
本研究以雄性斯普拉格-道利大鼠为实验对象，大鼠长期饮用普通水以及尼古丁浓度分别为0.31 mM和1.23 mM的尼古丁水，以确定尼古丁对体重调节及循环生长激素水平的影响。在动物暴露于高剂量尼古丁（1.23 mM）12周后，然后在四周内从饮水中去除尼古丁，重复该研究以确定尼古丁戒断对相同参数的影响。通过灵敏的放射免疫分析法测定血浆中的生长激素（GH）和胰岛素水平。结果显示，给予尼古丁处理后，大鼠的体重、食物和液体摄入量显著下降，同时血浆葡萄糖和胰岛素水平降低，而血浆生长激素水平显著升高。一项为确定食物摄入量减少的影响而进行的配对喂养研究表明，代谢或激素参数没有改变。尼古丁戒断四周后，所有先前记录的参数包括血浆生长激素水平均恢复正常；然而，体重并未完全恢复。数据表明，尼古丁摄入会影响体重，这似乎与血浆葡萄糖和胰岛素水平降低有关，生长激素的释放可能在该机制中起作用。
