2 . ne - evoked contraction was not significantly changed after the extracellular na + was replaced by choline and c4h12n + , but was relaxed when the extracellular cl - was replaced by glutamate and gluconate . moreover , the vasoconstriction induced by ne was further enhanced with the replacement of the extracellular cl " by br " and scn " , which was still sensitive to either nfa or nppb 用氯化胆碱和四甲基氯化按分别替代灌流液中的氯化钠后血管张力无明显变化,在此基础上nfa 、 nppb仍能抑制血管收缩,引起血管完全舒张;用通透性低的阴离子谷氨酸根和葡萄糖酸根分别替代灌流液中的q后血管发生舒张;用通透性高的阴离子br和scn分别替代灌流液中的ci后血管张力增加,并能被nfa 、 nppb所抑制。
Renin - angiotensin system ( ras ) plays an important role in the regulation of peripheric blood pressure , where angiotensin converting enzyme ( ace ) is considered to be the core of the system . ace plays a key role in increasing the blood pressure by catalyzing the formation of the potent vasopressor angiotensin ii ( ang ii ) from angiotensin i ( ang i ) 在该系统中, ace酶是血压调节过程中一个关键的酶,它可以将无活性的血管紧张素( ang )水解生成具有血管收缩作用的血管紧张素( ang ) ,从而导致血管收缩,机体的血压升高。