Correction of hypertension by partial nephrectomy in segmental renal artery stenosis and electron microscopic studies of renin.

An 18-year-old man had hypertension with hyperreninemia and marked difference in plasma renin activity between both renal veins after tilting. Selective renal arteriography revealed a stenotic lesion in a segmental artery to the upper pole of the left kidney with poststenotic dilatation. The upper pole of the kidney with abnormal arterial segment was resected and the blood pressure returned to normal. Electron microscopically, a large number of mature juxtaglomerular cell granules were associated with many protogranules in the epitheloid cell. These findings suggest that his hypertension was due to overproduction of renin from the upper pole.