Published online Jun 21, 2016. doi: 10.3748/wjg.v22.i23.5353
Peer-review started: March 3, 2016
First decision: April 1, 2016
Revised: April 14, 2016
Accepted: May 4, 2016
Article in press: May 4, 2016
Published online: June 21, 2016
AIM: To investigate the effects of different parameters of gastric electrical stimulation (GES) on interstitial cells of Cajal (ICCs) and changes in the insulin-like growth factor 1 (IGF-1) signal pathway in streptozotocin-induced diabetic rats.
METHODS: Male rats were randomized into control, diabetic (DM), diabetic with sham GES (DM + SGES), diabetic with GES1 (5.5 cpm, 100 ms, 4 mA) (DM + GES1), diabetic with GES2 (5.5 cpm, 300 ms, 4 mA) (DM + GES2) and diabetic with GES3 (5.5 cpm, 550 ms, 2 mA) (DM + GES3) groups. The expression levels of c-kit, M-SCF and IGF-1 receptors were evaluated in the gastric antrum using Western blot analysis. The distribution of ICCs was observed using immunolabeling for c-kit, while smooth muscle cells and IGF-1 receptors were identified using α-SMA and IGF-1R antibodies. Serum level of IGF-1 was tested using enzyme-linked immunosorbent assay.
RESULTS: Gastric emptying was delayed in the DM group but improved in all GES groups, especially in the GES2 group. The expression levels of c-kit, M-SCF and IGF-1R were decreased in the DM group but increased in all GES groups. More ICCs (c-kit+) and smooth muscle cells (α-SMA+/IGF-1R+) were observed in all GES groups than in the DM group. The average level of IGF-1 in the DM group was markedly decreased, but it was up-regulated in all GES groups, especially in the GES2 group.
CONCLUSION: The results suggest that long-pulse GES promotes the regeneration of ICCs. The IGF-1 signaling pathway might be involved in the mechanism underlying this process, which results in improved gastric emptying.
Core tip: Gastric electrical stimulation (GES) regulates gastric motility and protects the interstitial cells of Cajal (ICCs). However, the mechanisms underlying these processes have not been determined. In this study, we report that long-pulse GES with three different parameters protected ICCs and that the insulin-like growth factor 1 signaling pathway is probably involved in this process. One GES parameter (5.5 cpm, 300 ms, 4 mA) showed immense potential as a clinical application for applying long-pulse GES as the optimal parameter.