摘要
采用常规麦氏浴槽灌流法 ,研究了外源性γ -氨基丁酸 (GABA)及其类似物对离体小鼠十二指肠活动的影响 ,结果显示 :GABA明显抑制了离体小鼠十二指肠的自发活动 ,并明显存在剂量依赖性。GABAA 受体阻断剂印防己毒素和GABAB 受体激动剂巴氯芬均明显模拟此效应 ,增强阿托品对十二指肠的抑制作用 ,并逆转酚妥拉明对小鼠离体十二指肠的增强作用 ,所有的药物对肠段的活动频率均无影响。这些结果表明GABA对小鼠离体十二指肠的抑制作用是由GABAA 受体正性作用与GABAB 受体负性作用共同调节的 ,在生理状态下 ,以GABAB 受体的作用为主。GABAB 受体的这种作用可能是通过肠胆碱能系统介导来完成 ,也可能是独立的GABA能系统和 (或 )非胆碱能系统来完成 。
The purpose of this study was to examine the effect of GABA and it's analogs on the isolated mouse duodenum.The isolated segments was maintained in a bath containing Tyrode's Solution (37℃).The spontaneous contractile-relaxation of duodenum was measured by normal method on physiological recorder.The results showed that GABA could inhibit significantly the spontaneous contraction of the mouse duodenum dose dependently.The analogs of GABA,picrotoxin and baclofen could mimic this effect.The antagonism of atropine on contraction of the mouse duodenum was promoted by baclofen in contract,Picrotoxin could overturn the phentolamine-induced contraction.These agents had no effect at the contractile rate of the isolated segment.The results suggest that GABA induced depress response of the mouse duodenum was common regulated by positive role of GABA A receptor and negative role of GABA B receptor.The depression through GABA B receptor was main factor under normal physiological condition.This depression mediated GABA B receptor was likely to inhibit the release of acetylcholine,and acted of a autonomous GABA ergic-noadrenergic mechanism.
出处
《湖北农业科学》
北大核心
2003年第1期84-87,共4页
Hubei Agricultural Sciences
