摘要
采用常规离体蟾蜍心脏灌流法 ,通过生理记录仪经张力换能器系统描记心脏活动 ,探讨氨酪酸(GABA)对离体蟾蜍心脏活动的影响 ;结果表明 ,GABA明显增强了蟾蜍离体心脏收缩和舒张活动 ,并在一定范围内存在剂量依赖性 ;GABAA 受体阻断剂印防己毒素和GABAB 受体激动剂巴氯酚对心脏的收缩和舒张均有抑制作用 ;GABA能够加强肾上腺素对离体蟾蜍心脏的增强作用 ,而逆转乙酰胆碱的抑制作用 ;在酚妥拉明存在的条件下 ,GABA的正性肌力作用受到抑制 ;而在普萘洛尔和阿托品分别存在的条件下 ,GABA能够逆转普萘洛尔对离体蟾蜍心脏的抑制作用 ,而加强阿托品对离体蟾蜍心脏的增强作用 ;以上这些药品对心率均无明显影响。GABA对离体蟾蜍心脏的增强作用是通过GABAA 受体正性肌力作用和GABAB 受体负性肌力作用共同调节的 ,在生理状态下 ,以GABAA 受体作用为主 ,GABA的正性肌力作用可能是通过肾上腺素能系统中的α1 受体介导来完成的 。
To study the effects of GABA on the activity of isolated toad hearts The isolated toad heart was conducted by means of perfusing apparatus Heart contractions were recorded by tonotransducer and LMS-2B recorder GABA could significantly strengthen the activity of contraction and diastole of isolated hearts of toad Both of GABA A receptor the blocker picrotoxin, and the agonist of GABA B, Baclofen had inhibitory effects on the activity of contraction and diastole of the hearts GABA could strengthen the action of adrenaline on the isolated hearts, and inhibit the action of Ach The positive role of GABA was inhibited with phentolamine GABA could also deterorate the inhibition of propranolol on the isolated heart when there was propranolol, and enhance the positive role of Atropine on the hearts within Atropine All the medicines mentioned above had no effect on the rate of heart GABA-increased response of the isolated toad hearts was commonly regulated by positive role of GABA A receptor and negative role of GABA B receptor The depression through GABA B receptor was the main factor under normal physiological condition The positive role of GABA A was likely conducted by the α 1-receptor of adrenergic system , and likely had no contact with the cholinergic system
出处
《湖北农业科学》
北大核心
2003年第4期86-89,共4页
Hubei Agricultural Sciences
基金
海南省教育厅自然科学基金资助项目(HJSK990 9- 1)
