Barrios V, Rodriguez-Sanchez M N, Colas B, Arilla E
Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Alcalá de Henares, Madrid, Spain.
Eur J Pharmacol. 1990 Apr 25;179(3):263-70. doi: 10.1016/0014-2999(90)90164-2.
Since nicotine and somatostatin have regulatory effects on locomotor activity it was of interest to determine whether the receptors for somatostatin are modulated by the cholinergic nicotine-like effects. An i.v. dose of 0.3 mg/kg nicotine induced an increase in the concentrations of somatostatin-like immunoreactivity at 4 min in the parietal cortex and at 15 min in the hippocampus. These changes were associated with a significant increase in the total number of specific somatostatin receptors in the parietal cortex at 15 min and in the hippocampus at 30 min following injection. To determine if the above mentioned changes are related to the nicotine activation of central nicotine-like acetylcholine receptors, a cholinergic nicotinic blocking agent, mecamylamine, was administered before the nicotine injection. Pretreatment with mecamylamine (5.0 mg/kg i.v.) prevented the nicotine-induced changes in somatostatin level and binding in both brain areas. Mecamylamine alone had no observable effect on the somatostatinergic system. These results suggest that the somatostatinergic system can be regulated by nicotine-like acetylcholine receptors and may be involved in some of the behavioral central effects of nicotine.
由于尼古丁和生长抑素对运动活动具有调节作用，因此确定生长抑素受体是否受胆碱能尼古丁样效应的调节很有意义。静脉注射0.3mg/kg尼古丁可使顶叶皮质在4分钟时以及海马体在15分钟时的生长抑素样免疫反应浓度增加。这些变化与注射后15分钟时顶叶皮质以及30分钟时海马体中特异性生长抑素受体总数的显著增加有关。为了确定上述变化是否与尼古丁对中枢尼古丁样乙酰胆碱受体的激活有关，在注射尼古丁前给予了一种胆碱能烟碱阻断剂美加明。用美加明（静脉注射5.0mg/kg）预处理可防止尼古丁诱导的两个脑区生长抑素水平和结合的变化。单独使用美加明对生长抑素能系统没有明显影响。这些结果表明，生长抑素能系统可受尼古丁样乙酰胆碱受体调节，并可能参与尼古丁的一些行为中枢效应。
