title: [Effect of vasoactive intestinal peptide on defecation and VIP-cAMP-PKA-AQP3 signaling pathway  in rats with constipation].
abstract: To observe the effect of vasoactive intestinal peptide (VIP) on the metabolism of intestinal fluid and cyclic AMP protein kinase A signaling pathway (cAMP-PKA) and water channel protein 3 (AQP3) in rats with constipation, and to explore the mechanism of VIP in the treatment of constipation.  Methods: A total of 45 healthy adult rats were randomly divided into a control group, a model group, a model +VIP group. After 4 weeks of VIP treatment, the first black stool time were examined with the ink gastric method; the water content in feces was calculated; the morphological changes in colonic tissues were observed by HE staining. The expression of VIP and AQP3 protein levels in colon tissues were detected by Western blot; and the cAMP, PKA, AQP3 mRNA expression levels were detected by quantitative real time polymerase chain reaction (qPCR).   Results: Compared with the control group, the first black stool time was prolonged, the water content of fecal decreased significantly (both P<0.01); part of the colon mucosa epithelial cells were destructed; the goblet cell volume decreased and quantity was reduced; the contents of AQP3 and VIP in colon tissues were significantly decreased, and the cAMP, PKA and AQP3 mRNA levels were decreased in the model group (all P<0.05). Compared with the model group, the first black stool time in the model +VIP group was shortened, the fecal water content increased significantly (both P<0.05); the mucosal epithelium integrity improved, the number of goblet cells increased; the content of AQP3 and VIP in colon tissues was increased, and the cAMP, PKA, and AQP3 mRNA levels were elevated (all P<0.05).  Conclusion: Intravenous injection of VIP can regulate intestinal fluid metabolism and improve the symptoms of constipation in rats, which might be related to the regulation of VIP-cAMP-PKA-AQP3 signaling pathway.
authors.affiliation: Department of Basic Medical Sciences, Shaanxi University of Traditional Chinese Medicine, Xianyang Shaanxi 712046, China.
authors.forename: Yongxue
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Basic Medical Sciences, Shaanxi University of Traditional Chinese Medicine, Xianyang Shaanxi 712046, China.
authors.forename: Yujin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Basic Medical Sciences, Shaanxi University of Traditional Chinese Medicine, Xianyang Shaanxi 712046, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Basic Medical Sciences, Shaanxi University of Traditional Chinese Medicine, Xianyang Shaanxi 712046, China.
authors.forename: Shuguang
authors.initials: S
authors.lastname: Yan
authors.affiliation: Department of Personnel, Shaanxi University of Traditional Chinese Medicine, Xianyang Shaanxi 712046, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.affiliation: Department of Collaborative Innovation Center, Shaanxi University of Traditional Chinese Medicine, Xianyang Shaanxi 712083, China.
authors.forename: Pei
authors.initials: P
authors.lastname: Xie
mesh_terms: D000818:Animals; D051400:Aquaporin 3 / Q000502:physiology*; D020346:Aquaporins; D015153:Blotting, Western; D003106:Colon / Q000737:chemistry* / Q000473:pathology*; D003248:Constipation / Q000503:physiopathology / Q000628:therapy; D000242:Cyclic AMP / Q000502:physiology*; D003672:Defecation; D004847:Epithelial Cells / Q000473:pathology; D005243:Feces / Q000737:chemistry; D020397:Goblet Cells / Q000473:pathology; D007413:Intestinal Mucosa / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger; D051381:Rats; D015398:Signal Transduction; D014660:Vasoactive Intestinal Peptide / Q000008:administration & dosage / Q000502:physiology* / Q000627:therapeutic use
chemical_list: C496029:Aqp3 protein, rat; D020346:Aquaporins; D012333:RNA, Messenger; D051400:Aquaporin 3; D014660:Vasoactive Intestinal Peptide; D000242:Cyclic AMP