Skeggs L T, Dorer F E, Kahn J R, Lentz K E, Levine M
Am J Med. 1976 May 31;60(6):737-48. doi: 10.1016/0002-9343(76)90888-3.
The renin-angiotensin system has an important role in maintaining elevated blood pressure levels in certain forms of experimental and human hypertension. Renin, an enzyme produced by the juxtaglomerular cells of the kidney, acts on a protein substrate found in the alpha 2-globulin fraction of the plasma to produce a decapeptide, angiotensin I. This decapeptide is not directly pressor, but on passage through the pulmonary circulation is converted to an octapeptide, angiotensin II, a very potent pressor substance which acts by causing constriction of arteriolar smooth muscle. In addition to its direct action which increases blood pressure, angiotensin II acts on the adrenal cortex to cause the release of the sodium-retaining hormone aldosterone. Recent evidence suggests that this action may be mediated by the heptapeptide, angiotensin III. Both renin and its protein substrate exist in multiple forms and renin may also exist as a high molecular-weight "pro-hormone," although the physiologic significance of these forms is not clear. The elucidation of the biochemistry of the renin-angiotensin system has provided us with inhibitors which allow the system to be blocked effectively in vivo. Thus, angiotensin antagonists such as Sar 1, IIe 8-angiotensin II and converting enzyme inhibitors such as BPP 9a (SQ 20881) have proved useful in the study of experimental and human hypertension.
肾素-血管紧张素系统在某些实验性高血压和人类高血压中，对于维持血压升高起着重要作用。肾素是一种由肾脏近球细胞产生的酶，作用于血浆α2球蛋白部分中的一种蛋白质底物，产生一种十肽，即血管紧张素I。这种十肽本身并无直接升压作用，但在通过肺循环时会转变为一种八肽，即血管紧张素II，这是一种非常强效的升压物质，其作用机制是引起小动脉平滑肌收缩。除了直接升高血压的作用外，血管紧张素II还作用于肾上腺皮质，促使潴留钠的激素醛固酮释放。最近的证据表明，这一作用可能是由七肽血管紧张素III介导的。肾素及其蛋白质底物均有多种形式，肾素也可能以高分子量“前激素”的形式存在，尽管这些形式的生理意义尚不清楚。肾素-血管紧张素系统生物化学的阐明为我们提供了抑制剂，可在体内有效阻断该系统。因此，诸如Sar 1、Ile 8-血管紧张素II之类的血管紧张素拮抗剂以及诸如BPP 9a（SQ 20881）之类的转化酶抑制剂已被证明在实验性高血压和人类高血压的研究中很有用。
