Experimental Study On The Change Of NF-κB In The Hypoxic-ischemic Reperfusion Model Of Bilirubin Intervention Newborn Rats

Objective To study the protective effect of bilirubin in the hypoxic-ischemic myocardial injury through establishing the classic HIR model as the degree of asphyxia.Bilirubin and PNS intervention in the newborn SD rats of the classic model of HIR,NF-κB expression were determined.Comparing the protective effect of Bilirubin and PNS,in order to verify the protective effect and mechanism of bilirubin in hypoxic—ischemic myocardial injury,To seek a new theoretical foundation for the treatment of hypoxic—ischemic myocardial injury.Methods 7-day-old newborn SD rats 72(Kunming Medical College Animal Center) were randomly divided into 5 groups,groupⅠ:Normal control group,groupⅡ:HIR model + Nature saline group,groupⅢ:HIR model + bilirubin intervention group,groupⅣ:HIR model + PNS intervention group,groupⅤ:HIR model + saline + Znpp group.GroupⅠ,without any deal,only to do the incision in the middle of the neck,free the common carotid artery.GroupⅡ,the newborn rats were given normal saline by intraperitoneal injection as soon as the HIR model were established.GroupⅢ,the newborn rats were given 10mg/kg bilirubin by intraperitoneal injection as soon as the HIR model were established.GroupⅣ,the newborn rats were given 100mg/kg PNS by intraperitoneal injection as soon as the HIR model were established,the same dose of PNS was repeated by intraperitoneal injection after 12 hours.GroupⅤ,the newborn rats were given the same volume of normal saline by intraperitoneal injection,24-hour before establishing HIR model,the rats of groupⅤmade by the way of peritoneal injection of Znpp 25mg/kg,the other dealing was the same as groupⅡ.The rats of every group were killed after establishing HIR model 6 hours,24-hour.8 animals were killed in corresponding time pionts.Their myocardium tissues were fixed,they were made into paraffin section,then,treated with immunohistochemisty.Use cell count evaluation of positive cell and semi-quantitative evaluation of positive intensity.AT last the data were processed with SPSS11.5 statistical methodResults(1) Compared groupⅠwith groupⅡ,the expression of NF-κB of groupⅡsignificantly higher(P＜0.01).And the expression of NF-κB of groupⅡwere decreased in comparing groupⅡ6h with groupⅡ24h.(2) The expression of NF-κB in groupⅢ,groupⅣwere significantly decreased,comparing with groupⅡ(P＜0.01).(3)Compared groupⅢand groupⅣ,there were no significant difference(P＞0.05).(4) The expression of NF-κB of groupⅤwere higher than groupⅡ(P＜0.05).Conclusions The mechanism of the protective effect of bilirubin in hypoxic—ischemic myocardial damage may be related to inhibiting NF-κB activation and reducing the inflammatory response.