ACE IN 3-TUNICAE OF RAT AORTA - EXPRESSION IN SMOOTH-MUSCLE AND EFFECT OF RENOVASCULAR HYPERTENSION
ACE IN 3-TUNICAE OF RAT AORTA - EXPRESSION IN SMOOTH-MUSCLE AND EFFECT OF RENOVASCULAR HYPERTENSION
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DOI：
10.1152/ajpheart.1994.267.5.h1777
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发表时间：
1994-11-01
影响因子：
4.8
通讯作者：
ALHENCGELAS, F
中科院分区：
文献类型：
--
作者：
ARNAL, JF;BATTLE, T;ALHENCGELAS, F
血管紧张素转换酶(ACE)存在于血管内皮细胞表面和大血管外膜。血管平滑肌中是否存在血管紧张素转换酶仍然存在争议。我们从没有侧支动脉的区域显微解剖了有或没有内皮的外膜和中膜的部分。膜结合型血管紧张素转换酶活性平均为全主动脉的41%(pmol[甘氨酸-1-C-14]马尿酰-L-组氨酸-L亮氨酸水解酶组织(-1)·分(-1))，而外膜仅为6%。免疫印迹法检测培养上清液中的血管紧张素转换酶免疫反应。分离培养上清进行聚合酶链式反应，检测血管紧张素转换酶基因的表达。血管紧张素I和血管紧张素II同样能够收缩内侧环，依那普利拉阻断了对血管紧张素I的反应。在两肾一夹高血压大鼠，夹闭后15d、1mo和3mo，核糖核酸酶保护试验显示血管紧张素转换酶基因表达增加(P=0.02)，血管紧张素转换酶活性升高。与假手术组大鼠相比，中膜和外膜血管紧张素转换酶活性均增加1.5~2倍(P<0.02)。因此，血管紧张素转换酶基因的表达存在于大鼠主动脉的血管内膜，血管紧张素转换成血管紧张素II。肾性高血压时，血管中层和外膜的ACE表达上调。
Angiotensin I-converting enzyme (ACE) is known to be present at the surface of endothelial cells and also in the adventitia in large vessels. The presence of ACE in the vascular smooth muscle remains controversial. We microdissected segments of adventitia and media with or without endothelium from a region devoid: of collateral arteries. The membrane-bound ACE activity in the media averaged 41% (pmol [glycine-1-C-14]hippuryl-L-histidyl-L-leucine hydrolyzed.g tissue(-1).min(-1)) of the values found in the whole aorta, whereas the adventitia contained only 6%. Immunoreactive ACE in media was characterized by Western blotting. ACE mRNAs were detected and characterized after polymerase chain amplification in isolated media. Angiotensin I and angiotensin II were equally able to contract medial rings, and the response to angiotensin I was blocked by enalaprilat. In aortas of two-kidney, one-clip hypertensive rats, there was an increase in ACE mRNA estimated by ribonuclease protection assay (P = 0.02) and in ACE activity at 15 days and 1 and 3 mo after clipping. This corresponded to a 1.5- to 2-fold increase in the ACE activity of both the media and the adventitia compared with sham-operated rats (P less than or equal to 0.02). Thus ACE gene expression occurs in smooth muscle of rat aorta, which contains roughly the same amount of enzyme as the endothehum and readily converts angiotensin I to angiotensin II. ACE in the medial layer and the adventitia is upregulated in renovascular hypertension.