The effect of acetylsalicylic acid on renal function in the Pekin duck.

The acute effects of intravenously administered lysine-acetylsalicylic acid (ASA) on renal function in the Pekin duck have been studied with special reference to possible interactions with the antidiuretic hormone, arginine vasotocin (AVT), in the control of renal water and solute output. ASA produces an immediate increase in urine flow rate which is dose-related in the range 25 to 100 mg kg-1 and is associated with a slight reduction in urine osmolality, but an overall increase in renal osmolal excretion affecting Na+, Cl- and K+ to approximately equal extents. The effects, which are similar in both saltwater and freshwater adapted ducks infused with hyposmotic saline or glucose solution, can also be produced by similar doses of sodium salicylate (SA). The mechanism of action is probably not related to inhibition of prostaglandin synthetases. There is no change in the glomerular filtration rate or peripheral blood pressure following the ASA injection. There is no change in the circulating level of AVT; however, preliminary studies do not exclude the possibility of a partial antagonism of salicylate to AVT at the renal level.