Nagata M, Osumi Y
Department of Pharmacology, Kochi Medical School, Japan.
Eur J Pharmacol. 1989 Apr 12;163(1):85-90. doi: 10.1016/0014-2999(89)90398-1.
Intracerebroventricularly (i.c.v.) administered nicotine 50 and 100 nmol produced dual changes, an early decrease and a successive increase in gastric motility in urethane-anesthetized rats in which an intragastric balloon had been placed. These dual effects of nicotine were significantly antagonized by simultaneously administered hexamethonium i.c.v. but not by splanchnicectomy or by pretreatment with reserpine. Both atropine pretreatment and vagotomy abolished the stimulating effect of nicotine on gastric motility. Nicotine administered i.c.v. to bilaterally vagotomized rats did not affect gastric motility which was however enhanced by electrical stimulation of the vagus nerve. These observations suggest that central activation of the vagal cholinergic component results in excitation and central activation of the vagal non-adrenergic inhibitory component with i.c.v. administered nicotine results in inhibition of gastric motility. Sympathoadrenal systems and central monoaminergic mechanisms are probably not involved in the inhibitory effect of i.c.v. administered nicotine on gastric motility.
在已植入胃内气囊的氨基甲酸乙酯麻醉大鼠中，脑室内（i.c.v.）注射50和100 nmol尼古丁会产生双重变化，即胃动力先下降，随后升高。尼古丁的这种双重作用可被同时脑室内注射六甲铵显著拮抗，但不能被内脏神经切除术或利血平预处理所拮抗。阿托品预处理和迷走神经切断术均可消除尼古丁对胃动力的刺激作用。对双侧迷走神经切断的大鼠脑室内注射尼古丁不影响胃动力，但电刺激迷走神经可增强胃动力。这些观察结果表明，迷走胆碱能成分的中枢激活导致兴奋，而迷走非肾上腺素能抑制成分的中枢激活与脑室内注射尼古丁导致胃动力抑制有关。交感肾上腺系统和中枢单胺能机制可能不参与脑室内注射尼古丁对胃动力的抑制作用。
