Gastric Electrical Stimulation-induced Entrainment Of Gastric Slow Waves(GSWs) In Rats: Roles Of Synapses And ICC

Objective: To explore the role of synapses in gastric pacing-induced entrainment of gastric slow waves in rats.Methods: The Wistar rat models with two pairs of electrodes were established by operation , and were divided into two groups of rats included the pacing group(GES,n=10) and control group(n=6). Using immunohistochemistry, reverse transcription polymerase chain reaction (RT-PCR) and western blot analysis, synaptophysin(Syn) expression were measured in the antral myenteric plexus in GES group and control.β-actin,a steadily expressed gene ,was used as the internal reference . The ratio of Syn mRNA,Syn protein toβ-actin mRNA,β-actin protein in the integrated optical density was calculated to represent the relative expression amount of Syn mRNA and Syn protein in the tissues.Results: Syn immunoreactivity in the antral myenteric plexus in GES group was more abundant than that of control(806.421±342.135vs448.3±261.467, P<0.05; 0.019±0.008vs0.010±0.005, P<0.05); In the antral myenteric plexus,the expressions of Syn mRNA and protein were increased in GES group as compared with that of control (0.082±0.025.vs 0.146±0.0 28; 0.298±0.018 vs 0.502±0.098, P< 0.05 ,respectively).Conclusion: The synapses maybe play important roles in the mechanisms of gastric electrical pacing. Objective:To investigate the effect of gastric electrical stimulation(GES) of different durations on interstitial cells of Cajal (ICC) in the antral myenteric plexus in rats.Methods: The Wistar rat models with two pairs of electrodes were established by operation,and were divided into three groups : GES1 group(were given long pulse GES for 1 hour daily for 1d,n=8), GES2 group(were given long pulse GES for 1 hour daily for 20d,n=8), control group(no GES,n=8). After GES of different durations finished, all the rats of the three groups were sacrificed respectively. The number of ICC in the antral myenteric plexus was counted after immunohistochemical staining for c-Kit. C-kit protein expression was studied by western blot analysis.β-actin,a steadily expressed protein ,was used as the internal reference , and the C-kit protein toβ-actin protein in the integrated optical density was calculated to represent the relative expression amount of C-kit protein.Results: C-kit immunoreactivity in the antral myenteric plexus in GES2 group was more abundant than that of control(2066.3124±226.70 vs 1154.24±593.43, P<0.05 ,0.20±0.05 vs 0.13±0.05, P<0.05); GES1 group was not different from that of control (1280.44+442.72 vs 1154.24±593.43 P>0.05;0.15±0.03 vs 0.13±0.05, P>0.05 ); the expressions of C-kit protein were increased in GES2 group as compared with that of control (0.50±0.09vs0.29±0.02, P<0.05),GES1 group was not different from that of control(0.31±0.04vs0.29±0.02,P>0.05 ). Conclusion: With the prolongation of the GES duration,chronic GES can alter the number of ICC in the antral myenteric plexus in rats,which maybe play a important role in the mechanisms of GES.