A microradiographic study of nephrons in mercuric chloride-induced acute renal failure in the rabbit

Microradiography of nephrons was performed on glutaraldehyde-perfusion-fixed kidneys from rabbits injected with mercuric chloride. Kidneys were studied at intervals after injection of the toxin and compared with controls. All mercury-injected animals developed acute renal failure, determined by a rise in serum creatinine. At 6 hours, small filling defects were seen in proximal straight tubules, arising from the wall, and by 24 hours, widespread tubular obstruction was noted. By 12 hours, dilatation of Bowman's space and compression of the glomerular tuft were seen. At 18 hours, preferential channels in the glomerular capillary loops were found, and by 24 hours, there was paraglomerular shunting. No changes were noted in afferent or efferent arterioles. These findings may be related to the decreased glomerular filtration rate seen in acute nephrotoxic renal failure and suggest a role for tubular obstruction in the pathophysiology of this disorder.