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EPO, red cells, and serum transferrin receptor in continuous and intermittent hypoxia

2000; Lippincott Williams & Wilkins; Volume: 32; Issue: 4 Linguagem: Inglês

10.1097/00005768-200004000-00012

1530-0315

P. Koistinen, H. Rusko, Kerttu Irjala, ALLAN RAJAM KI, KENNETH PENTTINEN, VESA-PEKKA SARPARANTA, J Karpakka, JUHANI LEPP LUOTO,

Thermal Regulation in Medicine

KOISTINEN, P. O., H. RUSKO, K. IRJALA, A. RAJAMÄKI, K. PENTTINEN, V-P. SARPARANTA, J. KARPAKKA, and J. LEPPÄLUOTO. EPO, red cells, and serum transferrin receptor in continuous and intermittent hypoxia. Med. Sci. Sports Exerc., Vol. 32, No. 4, pp. 800–804, 2000. Purpose: Erythropoietic response in 10 healthy nonsmoking volunteers exposed to normobaric hypoxia continuously or intermittently 12 h daily for 7 d was evaluated in a randomized cross-over study. Methods: An oxygen content of 15.4% corresponding to an altitude of 2500 m was created by adding nitrogen into room air in a flat. Venous blood samples for hemoglobin (Hb), hematocrit (Hct), reticulocytes, serum erythropoietin (S-EPO), red cell 2,3-diphosphoglycerate (2,3-DPG), serum ferritin (S-Ferrit), and serum soluble transferrin receptor (S-TransfR) were drawn at 8:00 a.m. Results: S-EPO was increased from baseline values of 22.9 ± 9.6 and 20.5 ± 10.1 U·L−1 to 40.7 ± 12.9 (P < 0.05) and 35 ± 14.3 U·L−1 (P < 0.05) after the first night in continuous and intermittent hypoxia, respectively, and remained elevated throughout both exposures. Hb and Hct values did not show any significant changes. Red cell 2,3-DPG rose from baseline a value of 5.0 ± 0.8 to 5.9 ± 0.7 mmol·L−1 (P < 0.05) after the first day in continuous hypoxia and from 5.2 ± 0.7 mmol·L−1 to 6.1 ± 0.5 mmol·L−1 on day 3 (P < 0.05) during intermittent hypoxia. The reticulocyte count rose significantly (P < 0.05) after 5 d in both experiments. S-transferrin receptor level rose significantly from 2.2 ± 0.4 and 2.1 ± 0.5 mg·L−1 to 2.6 ± 0.5 mg·L−1 and 2.3 ± 0.6 mg·L−1 on day 5 (P < 0.05), to 2.7 ± 0.5 mg·L−1 and 2.5 ± 0.6 mg·L−1 on day 7 (P < 0.05) under continuous and intermittent hypoxia, respectively. Conclusions: We suggest that intermittent exposure to moderate normobaric hypoxia 12 h daily for 1 wk induces a similar stimulation of erythropoiesis as continuous exposure.