Effects of indomethacin on intrarenal blood flow and medullary osmolality in dogs.

The effects of indomethacin on renal blood flow (RBF) and its distribution were measured during control, during hemorrhage to 70 mm Hg and during refractory shock. Outer and inner cortical blood flow and outer medullary blood flow were measured with a freeze-dissection 133Xe disappearance technique. Control dogs treated with indomethacin exhibited a loss of blood flow to the outer medulla as well as decreases in both cortical blood flows. Hemorrhage caused the expected redistribution of RBF, the greatest part going to the inner cortex and outer medulla. Hemorrhaged dogs pretreated with indomethacin exhibited no difference from hemorrhage alone in freeze-dissection measured cortical flows, but again had marked ischemia of the outer medulla. Refractory shocked dogs treated with indomethacin also exhibited significantly decreased outer medullary flow. The osmolality of the renal papilla appeared to increase with indomethacin treatment in all three conditions (control, hemorrhage, shock).