Immunohistochemical localization of renin in end-stage kidneys

Hypertension in chronic renal failure is usually due to excessive accumulation of salt and water. In some cases, sodium and volume depletion by dialysis fail to reduce the high BP, and plasma renin activity tends to be higher. We performed a semiquantitative analysis of the immunohistochemical distribution of renin in the kidneys of ten patients with end-stage renal disease and hypertension using a specific antihuman renin antibody and a peroxidase-antiperoxidase technique on paraffin sections of nephrectomy and/or autopsy specimens. In five cases with severe, dialysis-resistant hypertension, the degree of immunoreactivity was most striking, exceeding that found in renovascular hypertension and present in arterioles at a distance from the glomeruli. Three cases of advanced diabetic glomerulosclerosis consistently showed minimal immunoreactivity. We conclude that renin often can be detected immunologically in the kidney of patients with chronic renal failure and hypertension, but its pathophysiological role will require further study.