Unilateral renal hypoplasia with associated venous anomaly and hypertension. A study of the juxtaglomerular cells.

A child with unilateral renal hypoplasia, high plasma renin levels and hypertension was found to have large numbers of juxtaglomerular granular cells in the affected kidney. They were seen adjacent to and sometimes in the interior of hyalinized glomeruli or, in loose nests scattered in the interstitium. Ultrastructurally they contained large numbers of crystalline protogranules in the Golgi region and also displayed other features suggestive of hyperactivity. Atrophic tubules, smooth muscle and mast cells were present in considerable numbers. Well-preserved renal cortex remained in the affected kidney with no demonstrable juxtaglomerular granularity. After unilateral nephrectomy the patient became normotensive and plasma renin levels became normal. Thus it appears that the juxtaglomerular cells are able to produce and release renin independent of the structural integrity of the juxtaglomerular apparatus and renal glomerulus.