大黄不同途径给药对小鼠胃肠动力影响及作用机制的实验研究

Experimental Study on the Effect of Rheum Officinale by Different Routes of Administration on Gastroin testinal Motility of Mice and Its Underlying Mechanism

目的:采用灌胃及灌肠途径给药,观察不同浓度大黄液在不同时相点对小鼠胃肠动力的影响,探讨大黄对小鼠胃肠动力影响的作用机制。方法:健康清洁级ICR小鼠240只,随机分为灌胃组、灌肠组,每组120只。灌胃组予高(25%)、中(12.5%)、低(6.25%)浓度的大黄液灌胃,灌肠组予高(25%)、中(12.5%)、低(6.25%)浓度的大黄液灌肠,分别在给药后0.5、1、3、6h等四个时相点脱颈椎处死小鼠,取胃及小肠组织,计算胃内残留率、小肠推进率,放射免疫法测定胃窦组织胃动素表达水平。结果:25%、12.5%、6.25%大黄液给药0.5、1、3、6h后灌肠组的胃内残留率均比灌胃组显著降低(P<0.05或P<0.01),且以给药后1、3h最为显著(P<0.01);两组小肠推进率比较,差异无统计学意义(P>0.05);灌肠组胃窦组织胃动素(MTL)含量比灌胃组显著升高(P<0.05);小鼠胃内残留率与胃窦组织MTL含量呈显著负相关性(P<0.01)。结论:大黄灌肠可明显减轻其对小鼠胃动力的抑制作用,但不影响其对肠道传输的促进作用,其作用机制可能与增加胃窦组织胃动素含量有关。

Objective： To observe the effect of rhubarb by gavage and enema administration on gastrointestinal mobility in mice and explore the underlying mechanism. Methods： A total of 240 healthy ICR mice were randomly divided into 2 groups based on different routes of administration. Mice were intragastrically given high-rhubarb （25%）, medium-rhubarb（12.5%）, and low-rhubarb（6.25%） in gavage group（n=120）, while the same doses of rhu- barb were intracolonically given in enema group（n=120）. Mice were sacrificed in 0.5, 1, 3, and 6 h after administration to harvest stomach and intestinal tissues for calculating gastric remnant rate and intestinal propulsive rate and determining the expression of motilin in gastric antrum. Results： Three enema subgroups had lower gastric remnant rates than the 3 gavage subgroups did at each time point（P〈0.05 or P〈0.01）. No significant difference in intestinal propulsive rate was seen between the enema and gavage groups at each time point, no matter which dose of rhubarb（P〉0.05）. The expression of motilin was increased in enema groups than that in gavage groups（P〈 0.05）. Spearman nonparametric correlation analysis showed that a negative association between the gastric remnant rate and motilin in gastric antrum（r=- 0.426, P〈0.01）. Conclusions： Rhubarb can mitigate their effects on inhibition of gastric motility through enema administration, but does not affect its role in promoting intestinal transit. This may be related to the increase of motilin.