Felix D, Harding J W
J Hypertens Suppl. 1986 Dec;4(6):S398-401.
During a recent comparison of iontophoretically applied angiotensin II (ANG II) and angiotensin III (ANG III) in the paraventricular nucleus of the rat we observed that ANG III was more potent than ANG II. This suggested that ANG II may have to be converted to ANG III before it becomes active. To test this hypothesis we performed two experiments. Firstly, we examined the effects of bestatin, an aminopeptidase B inhibitor, on the activity of applied ANG II and ANG III. Next, we monitored the effects of amastatin, a specific aminopeptidase A inhibitor, on the action of coapplied ANG II or ANG III. Bestatin, while having no activity of its own, dramatically enhanced the actions of both ANG II and ANG III. Amastatin, on the other hand, had little effect on ANG III's action and diminished or totally blocked ANG II-dependent activity. Like bestatin, amastatin had no effects alone. In total these results strongly support the notion that ANG II must be converted to ANG III in the brain before it is activated.
在最近一项对大鼠室旁核中离子导入法应用的血管紧张素II（ANG II）和血管紧张素III（ANG III）的比较中，我们观察到ANG III比ANG II更有效。这表明ANG II可能必须先转化为ANG III才能变得活跃。为了验证这一假设，我们进行了两项实验。首先，我们研究了氨肽酶B抑制剂贝司他汀对应用的ANG II和ANG III活性的影响。接下来，我们监测了特异性氨肽酶A抑制剂抑氨肽酶对共同应用的ANG II或ANG III作用的影响。贝司他汀本身没有活性，但显著增强了ANG II和ANG III的作用。另一方面，抑氨肽酶对ANG III的作用影响很小，却减弱或完全阻断了ANG II依赖性活性。与贝司他汀一样，抑氨肽酶单独使用没有效果。总体而言，这些结果有力地支持了ANG II在大脑中被激活之前必须先转化为ANG III这一观点。
