The pathophysiology of paraquat nephrotoxicity in the sheep

The effect of intravenous paraquat on ovine renal function was examined at four dose schedules. Paraquat caused dose dependent reduction in ovine glomerular and tubular function, but glomerular filtration rate increased at a low dose. The earliest reduction in function involved the major energy dependent processes of the kidney to inhibit sodium reabsorption. There were marked shifts in fluid balance to which the kidney initially responded. As nephrotoxicity progressed the homeostatic response failed. Paraquat which is a quaternary amine may mimic the pharmacological behaviour of similar compounds which are ganglion blocking agents. Paraquat causes hyperglycaemia in sheep.