正加速度适应性训练对大鼠胃黏膜PGI_2、TXA_2含量及TXA_2/PGI_2比值的影响

Effect of positive accelerationadaptive training on PGI_2 and TXA_2 contents and TXA_2/PGI_2 ratio in the gastric mucosa of rats

目的:研究正加速度(+Gz)适应性训练对大鼠胃黏膜前列环素(prostacyclin,PGI2)、血栓素A2(thromboxane A2,TXA2)含量及TXA2/PGI2比值变化的影响.方法:40只♂SD大鼠随机分为5组,每组8只,分别标记为为A、B、C、D、E组.A组大鼠为空白对照,不做处理,B组大鼠+5 Gz值暴露5 min,1次/d,连续暴露5 d,C组大鼠+10 Gz值暴露5 min,1次/d,连续暴露5 d,D组大鼠适应性训练(即+4 Gz值暴露3 min,1次/d,连续暴露5 d)后+5 Gz值暴露5 min,1次/d,连续暴露5 d,E组大鼠适应性训练(即+4 Gz值暴露3 min,1次/d,连续暴露5 d)后+10 Gz值暴露5 min,1次/d,连续暴露5 d.试验结束后肉眼和光学显微镜下观察胃黏膜损伤情况,计算损伤指数,ELISA法检测胃黏膜内TXB2、6-酮-前列腺素F1?(6-keto-prostaglandin F1?,6-K-PGF1?)的含量,并计算TXB2/6-K-PGF1?的比值.结果:肉眼和光学显微镜下观察,除A组外,其余各组胃黏膜均有损伤,D组损伤轻于B组,E组损伤轻于C组.适应性训练后,D组损伤指数小于B组(0.875±0.641 vs 1.750±0.707,P<0.05),E组损伤指数小于C组(2.250±1.035 vs 5.625±1.767,P<0.05);D组TXB2低于B组(159.588 pg/m L±36.216 pg/m L vs251.018 pg/m L±50.845 pg/m L,P<0.01),E组TXB2低于C组(150.476 pg/m L±48.589p g/m L v s 331.538 p g/m L±79.102 p g/m L,P<0.01);D组6-K-P G F1?高于B组(72.242p g/m L±12.413 p g/m L vs 52.015 p g/m L±11.827 pg/m L,P<0.01),E组6-K-PGF1?高于C组(87.426 pg/m L±15.833 pg/m L vs 44.726pg/m L±18.867 pg/m L,P<0.01);D组TXB2/6-K-PGF1?比值小于B组(2.283±0.705 vs 5.128±1.788,P<0.01),E组TXB2/6-K-P G F1?比值小于C组(2.250±1.035 vs 8.599±4.157,P<0.01).结论:适应性训练可明显减轻持续+Gz暴露带来的胃黏膜损伤,其机制与PGI2含量升高、TXA2含量降低以及TXA2/P G I2比值降低有关.

AIM：To assess the effect of positive acceleration adaptive training on prostacyclin（PGI2） and thromboxane A2（TXA2） contents and TXA2/PGI2 ratio in the gastric mucosa of rats.METHODS：Forty male SD rats were randomly divided into five groups：A,B,C,D and E.Group A did not undergo any treatment.Group B was exposed to ＋5 Gz for 5 min per day over 5 consecutive days.Group C was exposed to ＋10 Gz for 5 min per day over 5consecutive days.Group D was exposed to ＋4Gz for 3 min per day over 5 consecutive days and ＋5 Gz for 5 min per day over another 5consecutive days.Group E was exposed to ＋4Gz for 3 min per day over 5 consecutive days and ＋10 Gz for 5 min per day over another 5consecutive days.The damage to the gastric mucosa was then observed grossly and under a microscope to calculate the damage index.The TXB2 and 6-keto-prostaglandin F（1α）（6-K-PGF（1α））contents in the gastric mucosa were detected by ELISA,and the TXB2/6-K-PGF（1α） ratio was calculated.RESULTS：On unaided visual and microscopic observations,all groups developed mucosa damage,with the exception of group A.The damage to the gastric mucosa was less in group D than in group B,and in group E than in group C.The harm index was significantly lower in group D than in group B（0.875 ± 0.641 vs 1.750 ± 0.707,P〈0.05）,and in group E than in group C（2.250±1.035 vs 5.625±1.767,P〈0.05）.The content of TXB2 was significantly lower in group D than in group B（159.588pg/mL±36.216 pg/mL vs 251.018 pg/mL±50.845 pg/mL,P〈0.01）,and in group E than in group C（150.476 pg/mL±48.589pg/mL vs331.538 pg/mL±79.102 pg/mL,P〈0.01）.The content of 6-K-PGF（1α） was significantly higher in group D than in group B（72.242 pg/mL±12.413 pg/mL vs 52.015 pg/mL±11.827 pg/mL,P〈0.01）,and in group E than in group C（87.426 pg/mL±15.833 pg/mL vs 44.726pg/mL±18.867 pg/mL,P〈0.01）.The ratio of TXB2/6-K-PGF（1α） was significantly lower in group D than in group B（2.283±0.705 vs 5.128±1.788,P〈0.01）,and in group E than in group C（2.250±1.035 vs 8.599±4.157,P〈0.01）.CONCLUSION：Adaptive training can significantly reduce the gastric mucosal damage caused by high ＋Gz via mechanisms possibly related to the increase in PGI2 content,decrease in TXA2 content and reduction of the TXA2/PGI2 ratio.