四君子汤对脾虚证胃肠动力障碍大鼠胃平滑肌CaM-MLCK信号通路的机制探讨

Objective: To explore the pathogenesis of gastrointestinal dysfunction (GID) in spleen deficiency syndrome and the mechanism of action of Sijunzi Decoction intervention through experiments. Methods: 36 SD rats were randomly divided into a blank group, a model group, a traditional Chinese medicine group and a western medicine group. The animal model of GID in spleen deficiency syndrome was established by intragastric administration of iodoacetamide + standing on a small platform + abnormal hunger and satiety. Subsequently, the traditional Chinese medicine group was given Sijunzi Decoction at 6.3 g·kg⁻¹ and the western medicine group was given mosapride at 0.45 mg·kg⁻¹ by gavage. The gastric emptying rate and the changes in the calmodulin (CaM)-myosin light chain kinase (MLCK) pathway in each group of rats were detected by gastric emptying measurement, Western blot, immunohistochemistry, real-time fluorescence quantitative PCR (Real-time PCR) and Mg²⁺-ATPase activity detection. Results: The gastric emptying rate of rats in the model group was lower than that of normal rats (P < 0.01), and the protein expression levels of smooth muscle CaM and MLCK, MLCK mRNA and MLCK activity increased (P < 0.05, P < 0.01); after the intervention of Sijunzi Decoction, the gastric emptying rate of rats increased (P < 0.05), and the protein expression levels of smooth muscle CaM and MLCK, MLCK mRNA expression and MLCK activity increased (P < 0.05, P < 0.01). Conclusion: There are changes in the CaM-MLCK signaling pathway in rats with GID in spleen deficiency syndrome. Sijunzi Decoction may indirectly promote gastrointestinal motility by regulating this signaling pathway to relieve the high tension of gastric smooth muscle.

目的:通过实验探讨脾虚证胃肠动力障碍（gastrohitestinal dysfunction,GID）的发病及四君子汤干预的作用机制。方法:将36只SD大鼠随机分为空白组、模型组、中药组和西药组,运用碘乙酰胺灌服+小平台站立+饥饱失常法塑造脾虚证GID动物模型,随后给予中药组四君子汤6.3 g·kg-1和西药莫沙必利0.45 mg·kg-1灌胃,通过胃排空测定、蛋白免疫印迹法（Western blot）、免疫组化法、实时荧光定量PCR法（Real-time PCR）及Mg2+-ATPase活性检测对各组大鼠胃排空率及钙调素（CaM）-肌球蛋白轻链激酶（MLCK）通路改变进行检测。结果:模型组大鼠胃排空率较正常大鼠低（P<0.01）,平滑肌CaM,MLCK蛋白表达量,MLCK mRNA及MLCK活性升高（P<0.05,P<0.01）;四君子汤干预后大鼠胃排空率升高（P<0.05）,平滑肌CaM,MLCK蛋白,MLCK mRNA表达量及MLCK活性升高（P<0.05,P<0.01）。结论:脾虚证GID大鼠存在CaM-MLCK信号通路改变,四君子汤可能通过调节该信号通路舒缓胃平滑肌高张力而间接促进胃肠动力。