The basement membrane of the atrophic kidney tubule. An electron microscopic study of changes in rats

In a light and electron microscopic study of the rat's kidney after obstruction of the renal vein or after subtotal nephrectomy the tubular basement membrane changes occurring during the ensuing atrophy of the tubules have been examined. Characteristically, they consist of diffuse widening, focal thickening with vesicular and granular inclusions, circumscribed dissolution, or reduplication of this structure. These observations have led to the conclusion that the tubular basement membrane is formed by both interstitial and tubular cells, although the interstitial cells contribute the greater share to its formation, maintenance and renewal. The thickening of the basement membrane taking place in tubular atrophy must, however, be attributed entirely to the interstitial cells.