Effects of glucagon on diuresis, renal plasma flow and glomerular filtration in sheep

The effects of intravenous infusion of glucagon (100 ng.kg-1.min-1) on diuresis, renal plasma flow and glomerular filtration rate were studied in conscious sheep. Diuresis began to decrease upon initiation of glucagon infusion, down to 50% of its baseline value at the end of glucagon infusion. Glomerular filtration rate was also decreased by 75%. With regard to renal plasma flow, the decrease started at the beginning of glucagon infusion, but remained restricted. It was not possible, from these results, to explain the reduced diuresis by a decrease in renal plasma flow; the observed anti-diuretic effect could be the consequence of a modification of either the filtration coefficient or water tubular reabsorption.