Sodium Excretion after Renal Vasodilation by Papaverine in Conscious and Anesthetized Sheep 1

Summary

Ten conscious and ten chlorolose-anesthetized sheep were studied while either 0.9% NaCl solution or 7 mg/min papaverine HCl solution was infused into the renal artery of a sole remaining kidney. During saline infusion, conscious sheep had significantly higher renal blood (RBF) and glomerular filtration rate (GFR) than anesthetized animals (P < 0.01 and < 0.05 respectively). Renal resistance (RR) was significantly greater in the anesthetized animals (P < 0.01) but arterial blood pressure (BP), absolute (U_NaV) and fractional Na excretion (FE_Na) were not different between the two groups. Infusion of 7 mg/min papaverine for 20 min resulted in an increase in RBF in both groups but this was statistically significant (P < 0.01) only in the conscious sheep. BP declined significantly in both groups (P < 0.02) but GFR fell only in the conscious animals (P < 0.01). Papaverine had very little effect on FE_Na and U_NaV of conscious sheep but produced dramatic rises in both variables when the animals were anesthetized (P < 0.02).