title: Somatostatin inhibits the production of interferon-γ by intestinal epithelial cells during intestinal ischemia-reperfusion in macaques.
abstract: BACKGROUND
  Our previous study found that somatostatin (SST) inhibited the intestinal inflammatory injury in a macaque model of intestinal ischemia-reperfusion (IIR); however, the underlying mechanism was unclear.
  
  
  OBJECTIVE
  The present study was aimed to investigate the effects of SST on IFN-γ and the systemic inflammatory response after IIR.
  
  
  METHODS
  Fifteen macaques were randomly divided into controls, IIR and SST+ IIR groups. ELISA was performed to measure IFN-γ in ileum tissues, ileac epithelial cells (IECs) and ileal lymphocytes, as well as the systemic levels of IL-6, IL-1β, TNF-α and IFN-γ in the peripheral circulation and the portal vein. HE staining was performed to evaluate morphological changes in vital organs. Immunohistochemistry was performed to identify the distribution of IFN-γ, CD4, CD8 and CD57 in the ileum.
  
  
  RESULTS
  After IIR, IFN-γ level was significantly increased in the IECs. IL-6, IL-1β and TNF-α were significantly increased in both the portal vein and the peripheral circulation; in contrast, IFN-γ level was increased in the portal vein alone. Prophylactic SST reversed the change in IFN-γ in the IECs and portal vein. SST led to an alleviation of the pathological changes in systemic vital organs. The distribution of CD4(+), CD57(+) and CD8(+) cells was not positively correlated with the secretion of IFN-γ.
  
  
  CONCLUSIONS
  IECs are the main source of IFN-γ production after IIR. SST may indirectly lead to mast cell deactivation through the inhibition of IFN-γ production by IECs. Pretreatment with SST may be beneficial for preventing a massive systemic inflammatory response in vital organs after IIR.
authors.affiliation: Department of Gastroenterology, West China Hospital, Sichuan University, Guoxue Lane 37#, Chengdu, 610041, People's Republic of China.
authors.forename: Ling
authors.initials: L
authors.lastname: Liu
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Tan
authors.forename: Bin
authors.initials: B
authors.lastname: Hu
authors.forename: Hao
authors.initials: H
authors.lastname: Wu
authors.forename: Chunhui
authors.initials: C
authors.lastname: Wang
authors.forename: Chengwei
authors.initials: C
authors.lastname: Tang
mesh_terms: D000818:Animals; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D006728:Hormones / Q000494:pharmacology*; D007371:Interferon-gamma / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000378:metabolism; D008253:Macaca mulatta; D008297:Male; D009102:Multiple Organ Failure / Q000503:physiopathology; D015427:Reperfusion Injury / Q000378:metabolism*; D013004:Somatostatin / Q000494:pharmacology*
chemical_list: D006728:Hormones; D013004:Somatostatin; D007371:Interferon-gamma