Two methods for determination of renin secretion rates in rats.

1. Renin secretion rates in normal rats were determined with two different methods: (a) the product of renal plasma flow as measured by sodium p-aminohippurate and the difference between renal and peripheral vein renin activity; (b) the product of this latter difference and the renal plasma flow as calculated from the clearance and extraction of inulin. 2. The renin secretion rates, as calculated by these two methods, were not significantly different (P greater than 0-1) and were found to be highly correlated (r = 0-943; P less than 0-001).