[Direct effects of prostaglandin E1 on renal blood flow and renal function during acute reduction of cardiac output in dogs]

Abstract

During low cardiac output state induced by inflating the balloons inserted into both superior and inferior caval veins, direct effects of PGE1 (10 ng.kg-1.min-1, infused into renal artery) on renal blood flow and renal function were investigated. In control group, acute reduction of cardiac output resulted in decrease of renal blood flow (RBF) and significant increase of filtration fraction (FF), suggesting tight constriction of the efferent arteriole by activation of renin-angiotensin system and sympathetic nervous system. In PGE1 group, glomerular filtration rate (GFR) and FF decreased significantly although there was no decrease in RBF. No significant change was seen in distribution of intrarenal blood flow during low cardiac output state in both groups. These results indicate that decrease in GFR by direct infusion of PGE1 into renal artery during low cardiac output state is probably due to reduction of glomerular filtration pressure produced by dominant inhibition of the efferent arteriole constriction rather than the inhibition of the afferent arteriole by PGE1.