Ikemoto F, Tanaka M, Itoh S, Song G B, Tominaga M, Hiruma M, Takada T, Nakamura N, Yamamoto K
J Cardiovasc Pharmacol. 1986;8 Suppl 10:S69-74.
With regard to the concept of the local action of the renin angiotensin system (RAS) involved in blood pressure regulation, the presence of angiotensin converting enzyme (ACE) in a variety of organs suggests that locally produced angiotensin II (ANG II) shares, at least to some extent, the actions of this peptide on respective target organs of ANG II. However, renal ACE is less well understood for its relationship between blood pressure and enzyme activity. In our present studies, with a single oral administration of enalapril to spontaneously hypertensive rats, the inhibition of renal cortical and aortic ACE, but not plasma ACE, coincided with a reduction in blood pressure. Development of high blood pressure in stroke-prone, spontaneously hypertensive rats (SHRSP) from 7 to 22 weeks of age was accompanied by an increase in ACE activity in the renal cortex. Aortic and pulmonary ACE also tended to increase with age, but was less prominent. Isolated brush-border membranes contained abundant ACE, both in Wistar-Kyoto rats and SHRSP, and the levels of ACE in renal cortical homogenates closely correlated to the levels of brush-border ACE. Thus, changes in renal cortical ACE activity in response to the ACE inhibition and in cases of SHRSP in relation to aging are apparently associated with changes in blood pressure. It is likely that renal cortical ACE activity reflects the enzyme activity in the brush borders. Thus, brush-border ACE should probably be taken into account when discussing possible roles of renal ACE.
关于肾素血管紧张素系统（RAS）局部作用参与血压调节的概念，多种器官中存在血管紧张素转换酶（ACE）表明，局部产生的血管紧张素II（ANG II）至少在一定程度上与该肽对ANG II各自靶器官的作用相同。然而，肾ACE与其血压和酶活性之间的关系尚不清楚。在我们目前的研究中，对自发性高血压大鼠单次口服依那普利后，肾皮质和主动脉ACE受到抑制，但血浆ACE未受抑制，同时血压降低。易中风自发性高血压大鼠（SHRSP）从7周龄到22周龄高血压的发展伴随着肾皮质ACE活性的增加。主动脉和肺ACE也随年龄增长而有增加趋势，但不明显。在Wistar-Kyoto大鼠和SHRSP中，分离的刷状缘膜均含有丰富的ACE，肾皮质匀浆中ACE水平与刷状缘ACE水平密切相关。因此，ACE抑制后肾皮质ACE活性的变化以及SHRSP衰老过程中肾皮质ACE活性的变化显然与血压变化有关。肾皮质ACE活性可能反映了刷状缘中的酶活性。因此，在讨论肾ACE的可能作用时，可能应考虑刷状缘ACE。
