[Erythropoietin secretion in patients with chronic obstructive lung diseases during normobaric oxygen inhalation]. / Sekrece erytropoetinu u nemocných s chronickou obstrukcní chorobou plicní po normobarické inhalaci kyslíku.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) are characterized by compensatory polycythaemia probably induced by increased erythropoietin (EPO) secretion in the kidneys. METHODS AND RESULTS: As the regulatory mechanisms of erythropoietin secretion in chronic obstructive pulmonary disease are scarcely known we studied plasma EPO levels in 14 patients with COPD (pO2 = 61.9 +/- 1.4 mm Hg, Hct = 47.8 +/- 1.1%) under basal conditions, after two hours of isobaric oxygen breathing and two and four hours after discontinued oxygen breathing. The control group consisted of 12 healthy subjects (pO2 = 87.5 +/- 2.2 mm Hg, Hct = 43.7 +/- 1.6%). Under basal conditions patients with COPD showed significantly higher plasma erythropoietin levels as compared with healthy controls. Oxygen breathing was followed by a significant decline of plasma EPO levels both in patients with COPD as in the control group. This decline was significantly more marked and of longer duration in COPD patients than in healthy controls. CONCLUSIONS: 1. Patients with chronic obstructive pulmonary disease are characterized by significantly higher plasma EPO levels as compared with healthy subjects. 2. The renal oxygen sensor function involved in the regulation of EPO secretion seems to be altered in COPD patients.