【摘要】 目的　探讨侧脑室注射 (icv)组胺 (HA)对升高血压、减慢心率的作用机制。方法　实验用乌拉坦麻醉、肌肉松弛、人工呼吸的家兔 ,观察在icvHA之前和之后血压和心率的变化。结果　icvHA (5 0 μg)可引起血压升高、心率减慢。预先icvH1受体阻断剂扑尔敏或α1受体阻断剂哌唑嗪 ,或静脉注射酚妥拉明或六甲双铵均可阻断HA的中枢升压反应。预先icvH2 受体阻断剂甲氰咪胍 ,或α2 受体阻断剂Yohinbin(育亨宾 )对HA的中枢心血管效应均无影响。切断两侧颈部迷走神经 ,再icvHA ,心率减慢作用消失。结论　家兔icvHA后 ,可通过交感神经使血压升高 ,通过迷走神经使心率减慢 ,并与中枢H1受体有关。此外 ,在中枢HA能的升压作用中也有α1肾上腺素能受体的参与。更多还原

【Abstract】 Objective To investigate the effect of histamine （ HA ） on cardiovascular system through injection into intracerebroventricular （icv） and to explore its mechanism.Methods Observing the alteration of blood pressure and heart rate bef ore and after icv HA in rabbits anaesthetized with urethane, immobilized and ass i sted by artificial respiration.Results Adiministration HA （50 μg） in to ventricule could increased blood pressure and decreased heart rate. Pretreat ment with H₁ receptor blocker, chlorpheniramine, of α₁ receptor blocker, p razosin into ventricule or intravenous injection of phentolamine or hexamethoniu m could block the central pressor response to HA. The effect of HA was not disap peared by pretreatment with H₂ receptor blocker, cimitidine or α₂ receptor b locker, yohimbine into ventricule. The bradycardic response of HA was disappeare d after bilateral cervial vagotomy.Conclusion The blood pressure to HA was mediated by central H₁ rece ptor which involved in sympathetic nervous system, while heart rate response was mediated by vagus nerve. The α₁ adrenergic receptor is also involved in the central HA pressor response.更多还原