title: Long-pulse gastric electrical stimulation protects interstitial cells of Cajal in diabetic rats via IGF-1 signaling pathway.
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Hai Li, Yan Chen, Shi Liu, Xiao-Hua Hou, Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province, China.
authors.forename: Hai
authors.initials: H
authors.lastname: Li
authors.affiliation: Hai Li, Yan Chen, Shi Liu, Xiao-Hua Hou, Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Hai Li, Yan Chen, Shi Liu, Xiao-Hua Hou, Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province, China.
authors.forename: Shi
authors.initials: S
authors.lastname: Liu
authors.affiliation: Hai Li, Yan Chen, Shi Liu, Xiao-Hua Hou, Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province, China.
authors.forename: Xiao-Hua
authors.initials: XH
authors.lastname: Hou
mesh_terms: D000818:Animals; D015153:Blotting, Western; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000139:chemically induced / Q000150:complications*; D004599:Electric Stimulation Therapy / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay; D005746:Gastric Emptying; D005767:Gastrointestinal Diseases / Q000209:etiology / Q000628:therapy*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis / Q000378:metabolism*; D056885:Interstitial Cells of Cajal / Q000378:metabolism*; D016173:Macrophage Colony-Stimulating Factor / Q000378:metabolism; D008297:Male; D032389:Myocytes, Smooth Muscle / Q000378:metabolism; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D011706:Pyloric Antrum / Q000166:cytology / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D017526:Receptor, IGF Type 1 / Q000378:metabolism; D015398:Signal Transduction; D013311:Streptozocin
chemical_list: C548904:insulin-like growth factor-1, rat; D013311:Streptozocin; D007334:Insulin-Like Growth Factor I; D016173:Macrophage Colony-Stimulating Factor; D019009:Proto-Oncogene Proteins c-kit; D017526:Receptor, IGF Type 1
keywords: Diabetes mellitus; Gastric emptying; Gastrointestinal motility disorders; IGF-1 pathway; Interstitial cells of Cajal; Long-pulse gastric electrical stimulation