Hypoxia-induced renal and extrarenal erythropoietin production in posthypoxic or hypertransfused polycythemic rats.
The erythropoietic response, measured as 59Fe uptake by RBC, and the erythropoietin content of kidney tissue after exposure to hypobaric hypoxia were determined in both posthypoxic (PH) and hypertransfused (HT) rats. Plasma Ep titers were also measured in both PH and HT nephrectomized rats treated similarly. PH and HT rats with similar degrees of polycythemia greatly differed in their responses to hypoxia, with radioiron uptake by RBC about six times higher in the former than in the latter. Kidney Ep titers were significantly enhanced after exposure to hypoxia in either normal or polycythemic rats. However, kidney Ep titers in PH rats were significantly higher than the values found in normal or HT rats. Plasma Ep titers in both PH and HT nephrectomized rats exposed to hypoxia were similar and significantly lower than the plasma values of normal or nephrectomized, nonpolycythemic rats treated similarly. These results suggest that exposure to hypoxia induces sensitization of the renal, but not extrarenal, mechanism involved in Ep production.
R M
RM
Alippi
A C
AC
Barceló
J A
JA
Kofoed
C E
CE
Bozzini
D000818:Animals; D001803:Blood Transfusion; D004909:Erythrocyte Indices; D004921:Erythropoietin / Q000032:analysis / Q000096:biosynthesis*; D000860:Hypoxia / Q000503:physiopathology*; D007668:Kidney / Q000378:metabolism* / Q000502:physiology; D008297:Male; D009392:Nephrectomy; D011086:Polycythemia / Q000097:blood / Q000503:physiopathology*; D051381:Rats; D011919:Rats, Inbred Strains
D004921:Erythropoietin