Effect of Gastric Electrical Stimulation on Ultrastructure of Interstitial Cells of Cajal in Antral Myenteric Nerve Plexus in Rats

Background:Previous study demonstrated that increase of interstitial cells of Cajal in antral myenteric nerve plexus (ICCs-MY) is involved in the modulatory effect of long-term,long pulse gastric electrical stimulation(GES) on gastric slow wave.Aims:To investigate the effect of long pulse GES with different time course on number and ultrastructure of antral ICCs-MY in rats for studying the possible mechanism of GES in modulating gastric slow wave.Methods:GES model was established in Wistar rats.The model rats were divided into three groups:GES1 group,GES2 group and control group. Optimal GES parameters were selected to entrain gastric slow wave in GES1 and GES2 groups.Rats in GES1 group were given GES once,and those in GES2 group were given GES daily for 20 days;rats in control group did not receive GES. Then all the rats were sacrificed,and the antral tissues were prepared and examined by transmission electron microscopy. Results:Number of antral ICCs-MY in GES2 group was significantly higher than that in GES1 group and control group, while no significant difference was seen between the latter two groups.Cytoplasmic mitochondria and ribosomes were more abundant in GES1 and GES2 groups than in control group.Direct connection between ICCs processes and surrounding smooth muscle cells(SMCs) could be visualized in GES1 group,tight connection was visualized between ICCs and SMCs in GES2 group,and no obvious connection was seen between ICCs and SMCs in control group.Conclusions:Changes of number and ultrastructure of antral ICCs-MY might be involved in the modulation of gastric slow wave by long-term,long pulse GES.