A role for renin in rebound hypertension and encephalopathy after infusion of saralasin acetate (Sar1-Ala8-angiotensin II).

Blood-pressure reduction by specific angiotensin II inhibition with Sar1-Ala8-angiotensin II (saralasin acetate, P113) has been extensively employed to identify renin-dependent forms of hypertension.1 2 3 4 Stimulation of the renin-angiotensin system by treatment with diuretics1 2 3 4 or dietary sodium depletion increases the frequency and the amplitude of the depressor response to saralasin. These procedures have been advocated and extensively used as a preparative step in saralasin testing. To date, in a rather wide experience with saralasin, the drug has not produced any serious untoward effects, although undue hypotension has occasionally been reported.5 The four patients described below had alarming and dangerous rebound . . .