Glomerular Endothelial Cells in Uranyl Nitrate-induced Acute Renal Failure in Rats

P. S. Avasthi; A. P. Evan; D. Hay

doi:10.1172/JCI109641

Glomerular Endothelial Cells in Uranyl Nitrate-induced Acute Renal Failure in Rats

P. S. Avasthi, A. P. Evan, and D. Hay

Published January 1, 1980 - More info

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Abstract

In uranyl nitrate (UN)-induced acute renal failure (ARF) glomerular ultrafiltration coefficient (K_f) decreases because of unknown reasons. Since transport of water across the glomerular capillary wall occurs predominantly extracellularly through the endothelial fenestrae (EF), a reduction in the diameter and/or the density of EF can reduce the extracellular filtration area and the glomerular K_f. To examine this possibility, ARF was induced in rats by intravenous administration of UN in low (15 mg/kg) and high doses (25 mg/kg). Fenestral density (¯x±SEM) per 5 cm² from the scanning electron micrographs (×30,000) was 107±10, 103±9, and 101±11 at 2, 7, and 17 h after the intravenous administration of bicarbonate saline to the control rats. In the low-dose UN group the EF density was 91±2, 52±8, and 45±11 at 2, 7, and 17 h after the injection, whereas for the high-dose group at corresponding time intervals the EF density was 95±3, 54±9, and 44±10. Fenestral diameters, in Angstrom units (¯x±SEM), were 751±53, 765±43, and 764±37 at 2, 7, and 17 h after the injection of bicarbonate saline to control rats. At corresponding intervals after the administration of UN, the fenestral diameters were 501±61, 472±28, and 438±98 for the low-dose group and 525±43, 470±39, and 440±56 for the high-dose group. 2, 7, and 17 h after the injection of UN, fenestral area of the low-dose group decreased to 52.1, 30.1, and 24.6% of the controls, whereas in the high-dose group, the fenestral area declined to 54.3, 30.2, and 23.6% of the controls. Administration of UN (15 mg/kg) to sodium-loaded rats did not alter renal function or endothelial cell morphology. It is suggested that in UN-induced ARF the morphological alterations in endothelial cells reduce the K_f of glomerular capillaries by reducing the filtration area.

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