Tubular dimensions and juxtaglomerular granulation index in rat kidneys after unilateral obstruction of the ureter. A study of the morphogenesis of hydronephrosis

Abstract

The effect of ligation of a ureter on the tissues in the kidneys in male Wistar rats was studied by morphometry. Dilation of the lumen in the obstructed kidney persisted after ligation only in distal convolutions and collecting ducts. Swelling of epithelial cells in the obstructed kidney was noted only in the distal convolutions and collecting ducts. The Juxtaglomerular Granulation Index (JGI) in the obstructed kidney increased to a maximum 7 days after ligation of the ureter. In the control kidney the lumen of Bowman's space was expanded, epithelial cells in both proximal and distal parts of the nephron were swollen, and the JGI was increased after ligation of the contralateral ureter. The morphological findings support the assumption that reduced cortical blood flow and decreased intratubular flow are the cause of proximal tubular atrophy rather than a persisting increase of proximal intratubular pressure.