Savci V, Ulus I H
Department of Pharmacology, Uludag University Medical Faculty, Bursa, Turkey.
Neurochem Res. 1998 May;23(5):733-41. doi: 10.1023/a:1022407409727.
Intracerebroventricular (i.c.v.) choline (50-150 microg) increased blood pressure and decreased heart rate in spinal cord transected, hypotensive rats. Choline administered intraperitoneally (60 mg/kg), also, increased blood pressure, but to a lesser extent. The pressor response to i.c.v. choline was associated with an increase in plasma vasopressin. Mecamylamine pretreatment (50 microg; i.c.v.) blocked the pressor, bradycardic and vasopressin responses to choline (150 microg). Atropine pretreatment (10 microg; i.c.v.) abolished the bradycardia but failed to alter pressor and vasopressin responses. Hemicholinium-3 [HC-3 (20 microg; i.c.v.)] pretreatment attenuated both bradycardia and pressor responses to choline. The vasopressin V1 receptor antagonist, (beta-mercapto-beta,beta-cyclopenta-methylenepropionyl1, O-Me-Tyr2, Arg8)-vasopressin (10 microg/kg) administered intravenously 5 min after choline abolished the pressor response and attenuated the bradycardia-induced by choline. These data show that choline restores hypotension effectively by activating central nicotinic receptors via presynaptic mechanisms, in spinal shock. Choline-induced bradycardia is mediated by central nicotinic and muscarinic receptors. Increase in plasma vasopressin is involved in cardiovascular effects of choline.
脑室内（i.c.v.）注射胆碱（50 - 150微克）可使脊髓横断的低血压大鼠血压升高、心率降低。腹腔注射胆碱（60毫克/千克）也可使血压升高，但幅度较小。脑室内注射胆碱引起的升压反应与血浆血管加压素增加有关。美加明预处理（50微克；脑室内注射）可阻断对胆碱（150微克）的升压、心动过缓和血管加压素反应。阿托品预处理（10微克；脑室内注射）可消除心动过缓，但未能改变升压和血管加压素反应。半胱氨酸胆碱-3 [HC-3（20微克；脑室内注射）]预处理可减弱对胆碱的心动过缓和升压反应。在胆碱注射5分钟后静脉注射血管加压素V1受体拮抗剂（β-巯基-β，β-环戊亚甲基丙酰基1，O-甲基-Tyr2，精氨酸8）-血管加压素（10微克/千克）可消除升压反应并减弱胆碱引起的心动过缓。这些数据表明，在脊髓休克中，胆碱通过突触前机制激活中枢烟碱受体有效恢复低血压。胆碱诱导的心动过缓由中枢烟碱和毒蕈碱受体介导。血浆血管加压素增加参与胆碱的心血管效应。
