论文部分内容阅读
本文对猫脑动脉的胆碱能神经冲动传递的离体研究结果进行如下两方面的探讨:1)在乙酰胆碱亚舒张浓度下的反应;2)在阿托品敏感性神经源性血管舒张的可能性上的争议. 观察结果表明,55％的脑动脉血管条对0.1～3nmol·L~(-1)浓度的乙酰胆碱(ACh)产生了收缩反应,高于上述浓度的乙酰胆碱引起了血管内皮依赖性的舒张反应.进一步提高乙酰胆碱浓度则导致直接的血管平滑肌的收缩反应,0.1～3 nmol·L~(-1)亚舒张浓度乙酰胆碱引起的血管收缩反应以及高于此浓度乙酰胆碱所致的血管内皮依赖性舒张反应仅发生干预先已收缩而有张力的脑血管,亚舒张浓度乙酰胆碱(0.1～3nmol·L~(-1))所致的收缩反应并不依赖于血管内皮的存在,在Krebs溶液4℃条件下保存5d的同样脑血管对亚舒张浓度乙酰胆碱(0.1～3nmol·L~(-1))所致的收缩反应频率下降至13％,但血管内皮依赖性舒张反应或直接的血管平滑肌收缩反应在如此条件下保存的脑血管上依然完好. 以上结果与乙酰胆碱作为脑血管神经末梢递质导致神经源性血管舒张的假说是不相符合的。
In this paper, the in vitro studies of cholinergic nerve impulse transmission in the cerebral arteries of cats were explored in two ways: 1) their response to acetylcholine at diastolic concentrations; 2) on the possibility of atropine-induced neurogenic vasodilation The results showed that 55% of cerebral arterial vascular strips contracted acetylcholine (ACh) concentration of 0.1 ~ 3nmol·L ~ (-1), while acetylcholine above the above concentration caused endothelium-dependent relaxation The further increase of acetylcholine concentration resulted in direct vascular smooth muscle contraction, vasoconstriction induced by acetylcholine at sub-diastolic concentrations of 0.1-3 nmol·L -1 and endothelium-dependent relaxation induced by acetylcholine at this concentration The reaction only took place in the cerebral blood vessels that had been contracted and had tension. The contractile response induced by acetylcholine (0.1 ~ 3 nmol·L -1) was not dependent on the existence of vascular endothelium. Under the condition of 4 ℃ in Krebs solution The frequency of contractile response to sub-diastolic concentrations of acetylcholine (0.1-3 nmol·L -1) in the same cerebrovascular-vasa vasorum stored for 5 days decreased to 13%, but the endothelium-dependent vasodilation or direct The reaction is still intact smooth muscle contraction on cerebrovascular stored under such conditions. These results as cerebral acetylcholine neurotransmitter nerve endings leading to neurogenic vasodilation hypothesis is not consistent.