Nuclear Factor Kappa B/Cyxlooxygenase-2 And Necrotizing Enterocolitis Relativity Research

Objective To explore the effect of nuclear factor kappa B ( NF- κ B) / cyxlooxygenase-2 ( COX-2) signal pathway in neonatal necrotizing enterocolitis (NEC), so as to provide the experimental base for corresponding clinical treatment of the NEC.Methods The NEC model was established in newborn rats by anoxia and high oxygen as followed:One-day old Wistar rats were put into 100% nitrogen for 7 minutes and then 100% oxygen for 7 minutes.After that,they were returned to their mothers.① Flow Cytometer (FCM) method was used to observe the expression of NF- κ B in intestine mucosa of newborn rats with normal and NEC (1.5,3,4,5.5,7,24h); ② Immunohisochemistry method was used to observe the expression of COX-2 in intestine mucosa of newborn rats with normal and NEC (1,3,4,6,7d); ③The anti-oxidant pyrrolidine dithiocarbamate (PDTC) was used to observe its effect on NF-κ B activity of intestine mucosa in NEC ; ④ The anti-oxidant pyrrolidine dithiocarbamate (PDTC) was used to observe its effect on COX-2 activity of intestine mucosa in NEC.Results ①NF-κ B was strongly expressed in the epithelial cells of NEC, while detectable in low level in normal intestinal tissue, in newborn rats with NEC, the NF-κ B activity in intestine mucosa was enhanced at the 1.5h and reached to the peak level at the 4^th hour; then , it was weakened gradually and the level at the 7^th hour was similar to the 1.5h; the level at the 24^th hour was similar to the normal; PDTC had an inhibitive effect on the expression of intestine mucosa NF- κ B used in the dosage of 200mg/kg. ②COX-2 protein was strongly expressed in the epithelial cells of NEC, while detectable in low level in normal intestinal tissue, in newborn rats with NEC, the COX-2 activity in intestine mucosa was enhanced at the 1^st day and reached to the peak level at the 4^th day; then , it was weakened gradually and the level at the 7^th day was similar to the 1^st day; PDTC had an inhibitive effect on the expression of intestinemucosa COX-2 protein used in the dosage of 200mg/kg.Conclusion In newborn rats with NEC , the NF- k B and COX-2 of intestine mucosa were activated, and indicate a peak; The anti-oxidant PDTC can inhibit the expression of NF- k B and COX-2. It suggested that the NF- k B/ COX-2 expression may contribute to the development of NEC.