[Antihypertensive activity of monoclonal antibody to angiotensin II].

The antihypertensive effect of monoclonal antibody to angiotensin II (MAAII) was studied in renovascular hypertensive (RVH) rats. We found that MAAII could antagonize the pressor effect of exogenous angiotensin II but not of vasopressin in vivo. Five minutes after the administration of MAAII (15 mg/kg, i.v.), plasma angiotensin II could not be detected by radioimmunoassay and the mean blood pressure (MBP) decreased in RVH rats more than in normotensive rats (delta MBP: -5.33 +/- 0.12 and -1.17 +/- 0.29 kPa, respectively, P less than 0.01). The hypotensive effect of captopril was markedly inhibited by prior administration of MAAII, while that of nitroprusside and phentolamine was not. The results suggest that the antihypertensive effect of MAAII is mainly due to its specific binding to circulating angiotensin II.