Early effects of ethylene glycol on the ultrastructure of the renal cortex in dogs

Abstract

SUMMARY A sublethal dose of ethylene glycol was administered orally to 3 groups of dogs; dogs of a control group were given distilled water instead. Renal cortical biopsy samples were obtained from dogs of experimental and control groups at various times after treatment. Tissue was examined by use of light microscopy and transmission electron microscopy. In dogs of the control group, the light and electron microscopic appearances of tissue were within normal limits at all sample collection hours. In dogs of the experimental groups, renal corpuscular structure remained within normal limits by use of light and electron microscopy throughout the study, though morphologic change was seen in other structures of the cortex. Light microscopic lesions first appeared at 12 hours, and were similar to those reported in the literature. Ultrastructural lesions were first observed in the 5-hour samples, and similar to the light microscopic lesions, were most common in the proximal convoluted tubules (pct). Initial pct cellular changes included vacuolization of cells and distention of the parabasal extracellular spaces; pct cellular lesions seen in later-hour samples included formation of apical buds and cellular rupture. Internalization or sloughing of the pct brush border was not observed. Distal convoluted tubules (dct) were frequently dilated and/or packed with cellular debris. A few dct cells had degenerative or necrotic changes. In pct and dct, abnormal cells were frequently flanked by normal or nearly normal cells. During later hours, a few cells with types of changes first observed in early hours continued to be observed, implying ongoing response of cells to the toxin.