Abstract
The blood flow in the renal portal system of intact hens was characterized by determining the fractional distribution of 15 μm and 50 μm microspheres in this system after injection into a leg vein. Validation tests showed that only 50 μm spheres gave a reliable estimation of this distribution. The blood flow in the coccy‐geomesenteric vein was directed towards the liver in nearly all cases. On the average 44, 47 and 8% of the portal blood from the external iliac vein perfused the ipsilateral kidney, the liver and the lungs, respectively. However, the distribution of portal blood to these organs varied considerably between individuals and changed appreciably within 35 min in half the animals studied. The reason for these variations is not clear. The portal blood from the right and left external iliac veins was asymmetrically distributed in most animals illustrating the importance of local factors in its regulation. Variation was great in the regional distribution of portal blood within the kidney possibly due to local vasoconstriction of portal vessels. Further information e.g. on the regulation of renal portal blood flow is needed to explain its physiological significance. Microspheres provide a convenient method for such studies. A combination of microsphere and Sperber techniques allows us to determine the renal excretion efficiency of a given substance.

This publication has 25 references indexed in Scilit: