EFFECTS OF ANEMIA ON MORPHOLOGY OF RAT RENAL-CORTEX

Information on morphological and functional effects of anemia in kidne y is scarce, although this organ plays a major role in erythropoietin production, which is strongly stimulated in anemia. We undertook a mor phological study of kidneys of anemic rats. Anemia was induced by X-ir radiation and subsequent injection of a hemolytic drug. The most strik ing effects of anemia on renal morphology were damages in the proximal tubule and a volume increase of the peritubular space. These effects were evident only in the cortical labyrinth. Morphometry showed that t he enlargement of the peritubular space reflected an increase of the v olumes of both capillaries and interstitium. The structural changes in the cortical interstitium were associated with increased activity of the ecto-5'-nucleotidase in the fibroblasts. We suggest that hypoxia a ccounts for most of the observed alterations. The hypoxic proximal tub ule might release the nucleotide AMP, which would be hydrolyzed to ade nosine by the ecto-5'-nucleotidase in the interstitium. Adenosine has been reported to trigger the synthesis of erythropoietin and the growt h of blood capillaries.