目的研究尾悬吊模拟失重对大鼠血清GAS含量和腺胃区黏膜组织中Hsp70及其基因表达的影响。方法健康雄性Wistar大鼠64只,随机分成8组(n=8),按模拟失重时相分别为6h、12h、1d、2d、3d、5d、7d和0h(地面对照组)。采用尾吊法建立模拟失重动物模型。应用放免法检测各组大鼠血清GAS含量,免疫组化法和RT-PCR技术分别检测大鼠胃黏膜组织中Hsp70蛋白及Hsp70mRNA表达。结果与对照组相比,实验组大鼠血清GAS含量在模拟失重早期(6～12h)明显升高(P<0.05),随着尾悬吊时相的延长,血清GAS含量呈逐渐下降趋势。免疫组化染色结果显示,实验各组大鼠胃黏膜组织中均有Hsp70阳性表达;悬吊6h～2d各组大鼠胃黏膜组织中着色明显变深,尤其胞核在模拟失重早期即深染,期间胞浆染色亦增强;悬吊3～7d组大鼠的胞核染色逐渐变浅,部分胞核中染色消失,但细胞浆内仍有比较明显的Hsp70染色。RT-PCR结果显示,模拟失重6h大鼠胃黏膜组织中Hsp70mRNA表达水平即明显上调(P<0.05)。12h、1d、2d各组的Hsp70mRNA表达逐渐回落,3d组降至接近对照组水平,其后又出现一短时相升高现象。结论尾悬吊模拟失重可导致大鼠血清GAS含量波动和腺胃区胃黏膜组织中Hsp70及其基因表达明显改变,提示GAS和Hsp70在失重条件下胃黏膜应激反应及适应耐受过程中可能发挥重要作用。 Objective To investigate the effect of simulated weightlessness on the content of serum GAS and the expression of Hsp70 and its gene in the gastric mucosa of rats with tail suspension. Methods Sixty-four healthy male Wistar rats were randomly divided into 8 groups (n = 8). The simulated weightlessness phases were 6h, 12h, 1d, 2d, 3d, 5d, 7d and 0h respectively. Animal model of simulated weightlessness was established by tail-hanging method. Serum GAS levels were detected by radioimmunoassay. The expression of Hsp70 protein and Hsp70 mRNA in gastric mucosa were detected by immunohistochemistry and RT-PCR. Results Compared with the control group, serum GAS level in the experimental group was significantly increased at 6-12 h (P <0.05), and the serum GAS level gradually decreased with the extension of the tail suspension phase. The results of immunohistochemistry showed that the expression of Hsp70 was positive in gastric mucosa of rats in each group. The staining of gastric mucosa of rats in 6h ~ 2d suspension was obviously darker, especially in early stage of simulated weightlessness , During the cytoplasm staining also increased; suspended 3 ~ 7d group, the nucleus stained lighter, some of the nucleus disappeared, but the cytoplasm still more obvious Hsp70 staining. The results of RT-PCR showed that the expression of Hsp70mRNA in gastric mucosa of rats with simulated weightlessness was significantly increased (P <0.05). The expression of Hsp70mRNA gradually decreased at 12h, 1d and 2d, and decreased to the level of the control group in the 3d group, followed by a short-term phase increase. CONCLUSIONS: Simulated weightlessness in tail suspension can cause fluctuations in serum GAS content and significant changes in Hsp70 and its gene expression in gastric mucosa, suggesting that GAS and Hsp70 may respond to gastric mucosal stress and to adapt to tolerance during weightlessness Play an important role.