褪黑素对心理应激大鼠胃黏膜SOD、MDA和胃黏膜损伤的影响

目的　探讨褪黑素 (MT)对心理应激性胃黏膜损伤的保护作用及其机制。方法　 48只雄性SD大鼠随机分为对照组 (C组 )、规则光组 (R组 )、不规则光组 (I组 )和褪黑素组 (M组 )。检测大鼠胃黏膜损伤指数 (UI) ,胃黏膜超氧化物歧化酶 (SOD)活性、丙二醛 (MDA)含量及血清皮质醇浓度。结果　C组大鼠胃黏膜光整完好 ,肉眼未见糜烂及溃疡。R和I组UI均高于C组 (P <0 .0 5) ,M组UI低于I组 (P <0 .0 5)。R、I组胃黏膜SOD活性降低 ,I组降低更明显 (P <0 .0 5) ;R、I组胃黏膜MDA含量升高 ,I组升高明显 (P <0 .0 5) ,但M组SOD升高 ,MDA含量下降 (P <0 .0 5)。R、I组大鼠血清皮质醇升高 ,I组明显升高 (P <0 .0 5) ;而M组血清皮质醇较I组降低 (P <0 .0 5)。结论　褪黑素通过其抗氧化及抑制血清皮质醇水平的作用对心理应激性胃黏膜损伤起保护作用

Effects of melatonin on gastric mucosa lesions in rats with psychlological stress

Objective To investigate the protective effects a nd mechanism of melatonin on the gastric mucosa lesions induced by psychlologica l stress in rats. Methods A total of 48 adult male rats wer e divided randomly into control group (C), regular stress group (R), irregular s tress group (I) and melatonin group (M). The gastric ulcer index (UI), level of serum cortisol, MDA and SOD activity were examined. Results The mean UI in M group was less than that of I and R groups. The level of seru m cortisol increased in R and I groups. It was decreased in M group significantl y ( P < 0.05 ). The activity of SOD in M group was higher than that of R and I groups ( P < 0 .05 ).The amount of MDA in R and I groups was higher than that of C group. It was decreased in M group ( P< 0.05 ). Conclusion Gastric mucosa lesion induced by psychological s tress can be significantly prevented by melatonin. The protection of melatonin a gainst gastric mucosal lesion by stress is due to antioxidant activity and the l owered level of serum cortisol.