title: Stimulation of erythropoietin in renal insufficiency by hypobaric hypoxia.
abstract: Patients with renal anaemia show inadequate levels of immunoreactive erythropoietin (Epo) related to the degree of anaemia. The purpose of our study is to compare the degree of stimulation of Epo by means of hypobaric hypoxia in normal controls and patients with renal anaemia. Baseline Epo concentrations were found to be 11.1 +/- 2.0 U/l in 10 healthy volunteers and 11.4 +/- 4.6 U/l in six patients with renal anaemia. After exposure to hypobaric hypoxia equivalent to 4560 m above sea level for a duration of 3.5 h, we observed a significant increase in serum Epo in healthy volunteers to 22.8 +/- 9.1 U/l (P < 0.005), while there was no increase in patients with renal anaemia: 12.3 +/- 5.2 U/l (P < 0.2). Our results show that in patients with renal anaemia serum Epo concentrations are comparable to those of normal controls, but inadequate in view of the concomitant degree of anaemia. Stimulation by acute hypobaric hypoxia was not possible in patients with renal insufficiency as opposed to normal controls. From these data it can be concluded that either Epo production is working at maximum capacity under baseline conditions, or an additional hybobaric stimulus is not able to influence a disturbed set point of the oxygen sensor regulating Epo synthesis.
authors.affiliation: Section of Nephrology, University Hospital, Zurich, Switzerland.
authors.forename: J
authors.initials: J
authors.lastname: Quick
authors.forename: A
authors.initials: A
authors.lastname: Eichenberger
authors.forename: U
authors.initials: U
authors.lastname: Binswanger
mesh_terms: D000328:Adult; D000531:Altitude; D000740:Anemia / Q000097:blood; D004921:Erythropoietin / Q000096:biosynthesis* / Q000097:blood; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*
chemical_list: D004921:Erythropoietin; D010100:Oxygen