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 (ANG 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 were 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 increased on day 7. Active renin fell on days 2 and 3, total renin (trypsin treatment) augmented on day 1 and diminished on day 3, prorenin and per cent prorenin increased on days 1 and 2. Angiotensin I concentration paralleled PRA and PAC. The CCl₄-induced decrease in PRA was secondary to the fall in active renin and in PAC. Total renin augmented as a consequence of the elevation of prorenin. Renal function, evaluated by serum urea, serum creatinine and creatinine clearance, decreased on days 1 and 2 when PRA was low and plasma prorenin was high. 3. These 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 with the decrease in renal function.