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[Effect of different altitudes on telomere length of rat peripheral blood leukocyte].

The present study was aimed to investigate the effect of different altitudes on telomere length of rat peripheral blood leukocyte and possible mechanism. Sixty male rats were randomly divided into three groups, lower altitude control group (10 m), moderate altitude group (2 260 m) and very high altitude group (simulated 5 000 m). The moderate altitude group and very high altitude group rats were transported to Xining and hypobaric chamber in Qinghai University, respectively. The peripheral blood specimens were extracted 30 d after the transportation. By means of real-time PCR, automatic blood cell analyzer, ELISA, TBA and WST-1 methods, the telomere lengths of blood leukocyte, the hemoglobin (Hb) contents, the plasma levels of telomerase reverse transcriptase (TERT) and hypoxia-inducible factor 1α (HIF-1α), the plasma content of malondialdehyde (MDA) and superoxide dismutase (SOD) activity were measured, respectively. The results showed that the telomere lengths of peripheral blood leukocyte in moderate altitude group were longer than those in control group and very high altitude group. The changes of TERT were compatible with the telomere length of peripheral blood leukocyte under different altitudes. The levels of HIF-1α in moderate altitude group and very high altitude group were higher than that of control group. The very high altitude group showed decreased SOD activities and increased level of MDA, compared with the other two groups. These results suggest that the telomere lengths of rat peripheral blood leukocyte in moderate altitude are elongated, and that the telomere-elongating effect is lost under very high altitude. The changes of HIF-1α, TERT and oxidative stress damage are the main mechanisms of telomere length changes. Moderate altitude living might be beneficial to increasing the life span in mammals.