Mechanism of endurance training-induced erythrocyte deformability in rats involves erythropoiesis

Abstract

Higher erythrocyte deformability may reduce the risk of circulatory diseases by enhancing oxygen delivery and reducing the load on the cardiovascular system. The effect of endurance training on erythrocyte deformability is not clear. This study explored the impact of endurance training on erythrocyte deformation and shape and investigated the underlying mechanisms of hemorheological alterations. Forty male Wistar rats were randomly divided into two groups: sedentary (S; n = 21) and exercised (E; n = 19). Hematological indices and erythrocyte shape were measured at the end of the 11th week. The gene expression of erythropoietin (Epo) and the Epo receptor (EpoR) was quantified using reverse transcription-PCR (RT-PCR), and Epo protein expression was analyzed using Western blotting. Endurance training significantly decreased the abnormality ratio of erythrocyte shape (P < 0.01). The deformability indicator (DI) of red blood cells was lower in the E group than in the S group (P < 0.01). Eleven weeks of endurance training increased Epo mRNA and protein expression in the kidney (P < 0.01), EpoR mRNA expression in the bone marrow (P < 0.05), and relative circulating Epo (P < 0.01) compared to the sedentary group. The decrease in the erythrocyte morphological index and the maximum of deformability indicator were associated with an increase in relative circulating Epo. In conclusion, 11 weeks of endurance training increased erythrocyte deformability. Epo and EpoR may contribute to the decreased morphological index and deformability indicator in erythrocytes during endurance training in rats.

Red blood cells in sports: effects of exercise and training on oxygen supply by red blood cells

“…This might be explained by the higher deformability of newly formed red blood cells (Mairbäurl et al, 1983 ; Linderkamp et al, 1993 ). Erythropoietin, which was found slightly elevated (see above) seems to be favorable (Pichon et al, 2013 ; Zhao et al, 2013 ), probably by decreasing the mean red blood cell age and young red blood cells having an improved membrane flexibility (Mohandas and Chasis, 1993 ). In contrast, insulin-like growth factors and growth hormone seem to increase viscosity (Monnier et al, 2000 ; Connes et al, 2007 ).…”

Exercise hemorheology: Classical data, recent findings and unresolved issues

“…The production of RBCs is under the control of erythropoietin (EPO), which is up-regulated with regular exercise training [44]. It is not surprising, therefore, that Zhao et al [99] demonstrated that increased RBC deformability in endurance-trained rats involved erythropoiesis. Specifically, exercise training caused a rise of circulating EPO which was associated with increased RBC deformability.…”

Altitude training induced alterations in erythrocyte rheological properties: A controlled comparison study in rats

“…It was demonstrated that, training under hypoxic conditions causes erythrocyte senescence and erythropoises accompanied by elevated erythropoietin (Epo) concentration has been found after both long-term high altitude exposure and training under hypoxic conditions [14,34]. The influence of EPO on RBC deformability was analyzed recently [25,43,53]. Although neither age distrubition of RBCs nor determination of EPO level were performed in the current study, when our data are evaluated together the increment in RBC deformability observed in both group LHC and LHTH may be explained as increased RBC turnover since young RBCs are known to deform more [37,40,44].…”