Prostaglandins maintain renal microvascular blood flow during hyperdynamic bacteremia

Any beneficial effects of prostaglandin synthesis inhibitors on systemic hemodynamic derangements during sepsis may be offset by the effect of these inhibitors to reduce renal blood flow. To determine the specific role of prostaglandins in maintaining renal perfusion during hyperdynamic live Escherichia coli bacteremia in rats, we used in vivo video-microscopy and optical doppler velocimetry to quantitate changes in renal microvascular blood flow, and to determine if endogenous prostaglandins participate in these responses. E. coli infusions constricted preglomerular arterioles and decreased renal microvascular blood flow in decerebrate animals without drug anesthesia but dilated pre- and postglomerular arterioles in urethane-anesthetized rats. Local inhibition of renal prostaglandin production with mefenamate after E. coli infusion caused renal arteriolar constriction in both groups and decreased renal blood flow to indicate that renal prostaglandin production is an important mechanism for maintenance of renal microvascular blood flow during high cardiac output sepsis.