Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.1.3.5 (
5'-nucleotidase
)
3,167
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The kidney is the main site of
erythropoietin
(
EPO
) formation. Oxygen sensing in the kidney itself plays a major role in the control of
EPO
synthesis. By in situ hybridization it has been established that the
EPO
-producing cells are situated in the interstitium of the cortical labyrinth, but they have not been precisely identified. Morphological findings provide new insights into the location and mechanism of oxygen sensing in the kidney. In addition to causing an increase in the number of cells containing
EPO
messenger RNA, anemia provokes structural changes exclusively in the cortical labyrinth. Specifically, the fibroblasts become enlarged and show increased activity of
5'-nucleotidase
, and the S1 segment of the proximal tubule shows similar alterations as in various models of hypoxia. Thus, structures that are situated in the close vicinity of the
EPO
-producing cells appear to be sensitive to decreased oxygen delivery.
...
PMID:Structure-function correlations in erythropoietin formation and oxygen sensing in the kidney. 175 79
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.
...
PMID:Anemia induces 5'-nucleotidase in fibroblasts of cortical labyrinth of rat kidney. 256 Feb 35
