Renin excretion in patients with renal disease.

The renal handling of renin was studied in normal subjects and in patients with predominant tubular and glomerular damage. The renin in plasma and urine was assayed in the blood pressure preparation of the rat. Excessive renin excretion occurred only in patients with proximal tubular dysfunction and was not related to creatinine clearance, proteinuria or plasma renin levels. However, a significant correlation was found between renin clearance and clearances of other low molecular weight proteins which pass freely through the glomerular membrane and are normally reabsorbed by the tubules. All the evidence points to the important role played by tubular reabsorption in the control of renin urinary excretion. ADDITIONAL