The effect of indomethacin, 6-hydroxydopamine, saralasin, and hemorrhage on renal hemodynamics.

This report describes the response of the renal circulation to prolonged hemorrhagic hypotension and reinfusion of blood, and to the effect of a variety of drugs (saralasin, indomethacin, and 6-hydroxydopamine, 6-OH-DA). Plastic microspheres were used to measure blood flow perfusing the entire kidney and also the outer cortex, inner cortex, and medulla of the kidney. Cardiac output was determined with a Doppler flow probe, and total and regional flows were calculated. Redistribution of blood flow from outer cortex to inner cortex and medulla occurred during hemorrhage and after administration of saralasin and 6-hydroxy-dopamine, while indomethacin did not alter intrarenal flow distribution. Total renal flow increased after reinfusion of blood and saralasin, but decreased after indomethacin. It did not change after 6-hydroxydopamine. The results demonstrate that changes in total and intrarenal flow occur independently and are probably due to different mechanisms.