三七总苷对应激大鼠胃黏膜褪黑素受体mRNA表达的影响

Effect of Total Saponins from Panax notoginseng on Expession of Melatonin Receptor mRNA in Gastric Mucosa of Stress Rats

目的:观察三七总苷对应激大鼠胃黏膜组织中褪黑素受体(MR)表达以及含量的影响。方法:采用经典的水浸-束缚应激模型,总RNA提取产物应用RevertAid First Strand cDNA Synthesis Kit进行逆转录,PCR产物进行琼脂糖电泳,经KODAK1D Image成像系统分析,以目的基因(MT1受体)与内参(GAPDH)光密度比值表示MT1受体mRNA的相对表达水平。结果:水浸-束缚应激6 h后,所有以MT1为引物的RT-PCR产物中,均可见大小为360bp的阳性条带;模型组MR的相对含量比正常组略低,三七总苷组、雷尼替丁组与正常组和模型组比较,MR的相对含量均升高(P<0.05或P<0.01)。结论:应激大鼠胃黏膜中确实存在MT1受体mRNA的表达,三七总苷组通过上调MR表达而发挥胃黏膜保护作用,其机理可能是三七总苷促进褪黑素分泌或提高其与受体结合容量所表现的MR高表达。

Objective： To observe the effect of total saponins from Panax notoginseng （PNS） on melatonin receptor （MR） expression and its content in gastric mucosa of stress rats. Methods： Waterimmersion restraint stress （WRS） was used to induce stress rat models. RevertAid First Strand cDNA Synthesis Kit was used for the reverse transcription of the total RNA from gastric mucosa of stress rats. The PCR product was analyzed by agarose gel electrophoresis firstly and then by KODAK 1D Image system. The expression level of melatonin 1 （ MT1 ） receptor mRNA was calculated with the optimal density of ratio of MT1 receptor and GAPDH. Results ： Six hours after WRS, there were 360 bp positive bands in RT-PCR product of MT1. The relative content of MR was lower in the model group than that in the normal group. MR content in PNS group and ranitidine group were both higher than that in the normal group and the model group （P 〈 0. 05 or P 〈 0. 01 ）. Conclusion ： There is mRNA expression of MT1 receptor in gastric mucosa of stress rats indeed. PNS has protective effect on gastric mucosa of stress rats by up-regulating MR expression, and its protective mechanism may be related to promoting melatonin secretion or increasing the binding capacity of melatonin to its receptor.