Rowe B P, Noble A R, Munday K A
Pflugers Arch. 1979 May 15;380(1):13-7. doi: 10.1007/BF00582606.
The effect of tachyphylaxis to angiotensin II amide on the pressor potency of angiotensin I, II and III and noradrenaline was investigated in conscious rabbits with indwelling cannulae. No significant difference was observed between the reduction in responses to angiotensin II (58 +/- 4%) and angiotensin III (42 +/- 6%) but angiotensin I (15 +/- 5 %) and noradernaline (17 +/- 10%) responses were less markedly inhibited. If all angiotensin I pressor activity was mediated through its conversion to angiotensin II one would expect an equivalent degree of cross-tachyphylaxis to occur with the two peptides. Our results suggest that angiotensin I may have significant inherent pressor activity of its own, independent of conversion. This compound is already known to have activity at other target tissues. The absence of a significant difference in the degree of tachyphylaxis with angiotensin II and III may indicate they have substantially common pathways as pressor agents.
在留置套管的清醒家兔中，研究了速发耐受对血管紧张素II酰胺对血管紧张素I、II、III及去甲肾上腺素升压效能的影响。血管紧张素II（58±4%）和血管紧张素III（42±6%）反应的降低之间未观察到显著差异，但血管紧张素I（15±5%）和去甲肾上腺素（17±10%）的反应受抑制程度较轻。如果所有血管紧张素I的升压活性都是通过其转化为血管紧张素II介导的，那么可以预期这两种肽会出现同等程度的交叉速发耐受。我们的结果表明，血管紧张素I可能具有自身显著的固有升压活性，与转化无关。已知该化合物在其他靶组织中具有活性。血管紧张素II和III在速发耐受程度上没有显著差异，这可能表明它们作为升压剂具有基本相同的途径。
