Anemia induces 5'-nucleotidase in fibroblasts of cortical labyrinth of rat kidney.
We recently observed a strong increase of 5'-nucleotidase in renal fibroblasts of rats that were anemic due to an immunity against erythropoietin. In order to test if the change of 5'-nucleotidase was related with anemia, we studied the distribution of the enzyme in irradiated rats treated with phenylhydrazine. The hematocrit of these rats decreased to 15% within 4 days and erythropoietin levels were more than 200 times over controls. After 7 days a histochemical study showed that the enzymatic activity and the immunoreactivity for 5'-nucleotidase was markedly enhanced in the fibroblasts of the cortical labyrinth. There was no modification of 5'-nucleotidase in other cell types of the kidney. The 5'-nucleotidase activity of renal fibroblasts in cell culture increased by 72% upon addition of 160 microM 5'-AMP to the culture medium for 8 days. We propose that anemia provokes an energy deficit in some structure in the cortical labyrinth. This might increase the concentration of 5'-AMP which would induce 5'-nucleotidase. An interesting consequence of these events would be an increased production of adenosine in the direct vicinity of some of its putative targets, the glomerular arterioles and the erythropoietin-producing cells.
Le Hir
M
M
Departement Innere Medizin, Kantonsspital, Basel, Schweiz.
Eckardt
K U
KU
Kaissling
B
B
D015720:5'-Nucleotidase / Q000378:metabolism*; D000249:Adenosine Monophosphate / Q000494:pharmacology; D000740:Anemia / Q000139:chemically induced / Q000201:enzymology*; D000818:Animals; D002478:Cells, Cultured; D004921:Erythropoietin / Q000494:pharmacology; D005347:Fibroblasts / Q000201:enzymology*; D005455:Fluorescent Antibody Technique; D006400:Hematocrit; D007672:Kidney Cortex / Q000201:enzymology* / Q000473:pathology; D008297:Male; D010659:Phenylhydrazines / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D010659:Phenylhydrazines; D004921:Erythropoietin; D000249:Adenosine Monophosphate; D015720:5'-Nucleotidase