CIRCULATING LEVELS OF ACTIVE, TOTAL AND INACTIVE RENIN (PRORENIN), ANGIOTENSIN-I AND ANGIOTENSINOGEN IN CARBON TETRACHLORIDE-TREATED RATS

1. Plasma renin activity (PRA), plasma angiotensin I concentration (AN G I), plasma angiotensinogen concentration (PAC) and the plasma levels of active, total and inactive renin (prorenin) were measured in rats with carbon tetrachloride (CCl4)-induced acute renal failure. Rats wer e treated with a single oral dose of CCl4 (2.5 mL/kg) and killed 1, 2, 3 and 7 days later. 2. On days 1-3 PRA, ANG I and PAC decreased and i ncreased on day 7. Active renin fell on days 2 and 3, total renin (try psin treatment) augmented on day 1 and diminished on day 3, prorenin a nd per cent prorenin increased on days 1 and 2. Angiotensin I concentr ation paralleled PRA and PAC. The CCl4-induced decrease in PRA was sec ondary to the fall in active renin and in PAC. Total renin augmented a s a consequence of the elevation of prorenin. Renal function, evaluate d by serum urea, serum creatinine and creatinine clearance, decreased on days 1 and 2 when PRA was low and plasma prorenin was high. 3. Thes e data do not support the involvement of the circulating active renin- angiotensin system (RAS) in the pathophysiology of acute renal failure induced by CCl4, however, increased prorenin levels were associated w ith the decrease in renal function.