Coexistence of Hyperplasia of Renomedullary Interstitial Cells and Juxtaglomerular Cells after Acute Occlusion of Renal Artery

A left renal artery aneurysm was found in a 45-year-old normotensive man. In an attempt to evade the possible occurrence of aneurysmal rupture, aneurysmectomy in addition to left renal biopsy (first surgery) was performed. This vascular operation led to a virtually complete renal artery stenosis concomitant with the development of hypertension. The renin-angiotensin-aldosterone system and levels of plasma prostaglandins were also increased following this failed surgery. Reconstruction of the affected renal artery was technically so difficult that left nephrectomy was carried out (second surgery). Renal specimens obtained at the first surgery revealed no histological abnormalities. Discriminating histological findings of the kidney obtained at the second surgery were remarkable; hyperplasia of the juxtaglomerular cells producing renin and hyperplasia of the renomedullary interstitial cells which had pecularities similar to cells known to secrete renal prostaglandins. High levels of the renin-angiotensin-aldosterone system and plasma prostaglandins after the first surgery were reduced following the second surgery. It is suggested that acute constriction of the renal artery led to a hyperplastic change of the the juxtaglomerular cells and the renomedullary interstitial cells and stimulated an inappropriate release of renin and renal prostaglandins.