Hypoxia promotes apoptosis of germ cells in rat testes / 中华男科学杂志

<p><b>OBJECTIVE</b>To explore the effects of hypobaric hypoxia on the apoptosis of germ cells in male rats.</p><p><b>METHODS</b>Adult male Wistar rats were randomly divided into four groups: a control group raised at sea level; a 5 d, a 15 d and a 30 d hypoxic group raised in a hypobaric chamber simulating 5000 m altitude for 5 days, 15 days and 30 days respectively. Flow cytometry and TUNEL were used to evaluate the apoptosis of germ cells in the testis. Bax and Bcl-2 in the testis were measured by Western blot.</p><p><b>RESULTS</b>Seminiferous tubules with apoptotic germ cells were significantly more in the hypoxic groups than in the control (P < 0.01). Most apoptotic germ cells were spermatogonia and spermatocytes. Compared with the control group, apoptotic germ cells detected by PI flow cytometry were significantly increased in the hypoxic 15 d and 30 d groups (P < 0.05); Bax was significantly higher (P < 0.05), and so was the ratio of Bax to Bcl-2 in the hypoxic 30 d group (P < 0.01).</p><p><b>CONCLUSION</b>Hypoxia promotes apoptosis of testicular germ cells in male rats. Chronic hypoxia increases Bax expression in the rat testis.</p>

Isolation and identification of differentially expressed proteins in hippocampus of mice during hypobaric hypoxic delayed preconditioning / 中国应用生理学杂志

<p><b>AIM</b>To explore the differentially expressed proteins between hypobaric hypoxic delayed preconditioning (HHDP) and normal mouse hippocampus.</p><p><b>METHODS</b>After the animal model of HHDP was constructed, hippocampal proteins were obtained by a series of abstraction with lysis solution containing high concentration urea. As soon as isoelectric focusing and SDS-PAGE was performed. The resolved proteins in the 2-DE gels were visualized by Coomassie blue R-250. The gels were scanned, and the images were processed with PDQuest software. Differential proteins were exactly excised from the gels, destained and digested with trypsin. The peptides were isolated and sent for MALDI-TOF-MS testing. Database searching was performed using peptide masses obtained from MALDI-TOF-MS.</p><p><b>RESULTS</b>Averages of 481 +/- 38 and 477 +/- 21 protein spots were detected in control gels and preconditioning gels, respectively. 169 +/- 6 protein spots were matched between these two types of gels. Among the matched spots, while the quantities of 21 +/- 12 spots in control gels increased by above 2 times than that in preconditioning one, the quantities of 33 +/- 10 spots in preconditioning gels increased by the same times than that in control one. The correlation coefficient between these two patterns were 0.7748 +/- 0.0267. 12 spots in preconditioning gels significantly increased compared with the control (P < 0.05, n = 4). Among 12 spots excised from the gels, perfect peptide mass fingerprinting spectrums of 8 spots were acquired. The results showed that one protein was fructose biphosphate aldolase A. Three proteins matched nothing might be new proteins. The other four proteins just matched the partial sequences of the proteins of database were no coincidence to it's isoelectric point and molecular weight. So they might be homological proteins.</p><p><b>CONCLUSION</b>Many proteins, for example fructose biphosphate aldolase A, has been differentially expressed in hippocampus of mice during HHDP. This may be one of the molecule mechanisms of HHDP.</p>

Effect of hypoxia on expression of iNOS mRNA in cultured rat astrocytes / 中国应用生理学杂志

<p><b>AIM</b>To explore the effects of hypoxia on expression of inducible nitric oxide synthase (iNOS) mRNA in cultured rat astrocytes.</p><p><b>METHODS</b>Cultured rat astrocytes were randomly divided into 4 groups: glutamate group (G), hypoxic group (H), hypoxia + glutamate group (H + G) and the control (C). Cells of control group were exposed to normoxic (95% air, 5% CO2) condition, and cells of G and H + G were incubated with 100 micromol/L L-glutamate, cells of H and H + G exposed to hypoxic conditions (5% CO2, 95% N2) at 37 degrees C. Each group had five timepoints which included 0 h, 3 h, 6 h, 12 h, 24 h, respectively. Expression of mRNAs of iNOS were detected with reverse transcription polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>Expression of iNOS mRNA was not detectable in G and C, while it increased dramatically and continuously from 6 h to 24 h in H and G + H. Expression of iNOS mRNA was significantly higher in H than both in G and C at 6 h, 12 h and 24 h, and expression of iNOS mRNA was the highest of all groups in G + H.</p><p><b>CONCLUSION</b>Hypoxia upregulates the expression of iNOS mRNA in cultured astrocytes. Glutamate does not induce the expression of iNOS mRNA but enhance the effect of hypoxia, which is maybe one of the adaptive mechanisms of hypoxia-induced cerebral dilation.</p>