论文部分内容阅读
肾素-血管紧张素-醛固酮系统(R-A-A系统)是血压调节的三个主要生理控制机理之一。肝脏合成并分泌血管紧张素原,它是一种α_2球蛋白,分子量为6万,结构如下:Asp~1-Arg~2-Val~3-Tyr~4-Ile~5-His~6-Pro~7-Phe~8-His~9-Leu~(10)-Leu~(11)-Val~(12)-Tyr~(13)-Ser~(14)。在血浆中,它被由肾小球旁体产生的肾素选择性地切断Leu~(10)-Leu~(11)肽键生成无生理活性的十肽,即血管紧张素I。血管紧张素I在血管紧张素转化酶作用下,脱去羧基端的组氨酰一亮氨酸生成血管紧张素II。血管紧张素II在血管紧张素酶A的作用下,失去氨基端的门冬氨酸成为血管紧张素III。血管紧张素II具有多种生理活性。它能引起血管收缩,是已
The renin-angiotensin-aldosterone system (R-A-A system) is one of the three major physiological mechanisms of blood pressure regulation. The liver synthesizes and secretes angiotensinogen, an α 2 -globulin with a molecular weight of 60,000 and has the following structure: Asp1-Arg2-Val3-Tyr4-Ile5-His6-Pro 7-Phe 8-His 9 -Leu 10 -Leu 11 -Val 12-Tyr 13 -Ser 14. In plasma, it is selectively cleaved by Leu ~ (10) -Leu ~ (11) peptide bonds by renin produced by glomerular parallels to generate physiologically inactive decapeptide, angiotensin I. Angiotensin I removes the carboxyl-terminal histidyl-leucine to angiotensin II by the action of angiotensin-converting enzyme. Angiotensin II loses the amino-terminal aspartate to angiotensin III under the action of angiotensin A. Angiotensin II has a variety of physiological activities. It can cause vasoconstriction, yes