Objective:To explore the preventive and therapeutic mechanism of BX decoction on reflux esophagitis on the basis of esophageal movement.Methods:Sixty rats were randomly divided into 4 groups: sham operation group

model group

cisapride group and BX group.Gastrointestinal reflux models in rats were made.Physiograph was used to observe the contraction of esophageal muscle strips.An RT-PCR based assay was used to detect mRNA expression for calponin and caldesmon in esophageal smooth muscle.Intracellular free calcium was measured by laser scanning confocal microscopy.Results:Compared with that in model group

contractive range of esophageal muscle strips in BX group increased greatly

mRNA expression level for calponin and caldesmon decreased obviously and intracellular free calcium increased significantly.Conclusion: The preventive and therapeutic mechanism of BX decoction on reflux esophagitis may be due to enhancement of contraction of esophageal smooth muscle by downregulating of mRNA expression for calponin and caldesmon and increasing the intracellular free calcium.