Effects of exhaustive exercise-induced oxidative stress on red blood cell deformability / 中国应用生理学杂志

<p><b>OBJECTIVE</b>The aim of the present study is to explore the effects of exhaustive exercise-induced oxidative stress on the antioxidant capacity and diformability of rat red blood cells.</p><p><b>METHODS</b>Rats were divided into three group (n = 10): sedentary control (C), exhaustive running exercise (ERE) and moderate running exercise (MRE) groups. Animals in the ERE group started treadmill running at a speed of 20 m/min speed with a 5% gradient, and reached a speed of 25 m/min with gradient 15% in 20 min. Running was continued until exhaustion. MRE group rats running at a speed of 20 m/min with a 5% gradient for 40 min. The levels of free thiol in erythrocyte membrane protein, lipidperoxidation levels and membrane protein components were analyzed. The red blood cell deformability of different groups was also observed.</p><p><b>RESULTS</b>The results showed that red blood cells were damaged by severe oxidative stress and the anti-oxidative capacity decreased significantly under exhaustive exercise conditions. Besides, lipid peroxidation and protein sulfhydryl cross-link based clustering of membrane were found after exhaustive exercise, and polymers high molecular weight (HMW) was formed. The elongation index (EI) was found to decline significantly in the ERE group compared with the C and MRE groups under shear stress (control group, 0.41 +/- 0.01 at 3 Pa and 0.571 +/- 0.008 at 30 Pa; ERE group, 0.314 +/- 0.013 at 3 Pa and 0.534 +/- 0.009 at 30 Pa; P < 0.05 and P < 0.01, respectively).</p><p><b>CONCLUSION</b>These exercise-induced oxidative injure result in a significant decrease in deformability of rat erythrocytes, which in turn leads to dysfunction in the microcirculatory.</p>

Effect of HIF-1alpha on sex hormone levels and germ cell apoptosis of mice / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To study the effect of hypoxia on hypothalamus-adenohypophysis-testis axis hormone levels, germ cell apoptosis and hypoxia-inducible factor-1alpha (HIF-1alpha) expression in testis of adolescent mice, and explore HIF-1alpha regulation on the reproductive function of male mice.</p><p><b>METHODS</b>Eighty SPF grade adolescent C57BL/6 mice were randomly divided into normoxia group, hypoxia 3, 7, 14 and 28 d groups. The level of serum testosterone (T), free testosterone (FT), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) was analyzed by ELISA. Detected the sperm count, motility rate and abnormal sperm rate of epididymal sperm suspension. The apoptosis cells in testis were determined using TUNEL method. The expression of HIF-1alpha was analyzed using Western blot.</p><p><b>RESULTS</b>Compared with corresponding normoxia group, serum T, FT, FSH and LH concentrations in hypoxia 3 d group were significantly higher (P < 0.05); T and LH concentrations in hypoxia 14 d group were significantly lower (P < 0.05). Sperm count and motility rate in hypoxia 7 and 14 d groups significantly declined (P < 0.05); abnormal sperm rate in all hypoxia groups significantly increased (P < 0.05). The apoptosis index (AI) of germ cells in hypoxia 7, 14 and 28 d groups significantly increased (P < 0.05), and the levels of HIF-1alpha protein expression were significantly higher (P < 0.05).</p><p><b>CONCLUSION</b>HIF-1alpha protein highly expressed in mice testis could induce germ cell apoptosis increased in chronic hypoxia environment.</p>