Blood flow in the renal portal circulation of the turkey: effect of epinephrine.

Control of blood flow in the renal portal circulation of turkeys given epinephrine was evaluated by determining the distribution of injected radiopaque contrast medium within the portal circulation. Radiopacity in the region of the renal parenchyma and/or the caudal renal portal vein was increased in each of the 6 birds after epinephrine (4.0 micrograms/kg of body weight) was injected into the wing vein. In 1 bird, the contrast medium also was distributed into the mesenteric vein. Thus, epinephrine not only induced flow of blood from the pelvic limb (leg) to the kidneys, but to the abdominal viscera as well. Regulation of the patency of the renal portal valve is thought to be one means by which renal portal blood flow is controlled. However, epinephrine had no consistent effect on the valve. Thus, epinephrine seemed to control renal portal blood flow and, perhaps, blood flow to other abdominal viscera at sites other than the renal portal valve.