The Effects Of The Activation Of Complement System And AQP4 On Intra Cerebral Ischemia And Reperfusion Of The Rats

Objective The activation of the complement system and aquaporin-4 act importent roles in injures after intra cerebral ischemia and reperfusion.We try to investigate intravenous immune globlin and AQP4 inhibitor—allyl chloride on the cerebral artery ischemia-reperfusion model(MCAIR) of rats and obverse the activation of complement system , the expression of AQP4mRNA and other correlated intexes。To provide the usages of the activation of the complement system and aquaporin-4 and the relationship between them.Methods 192 rats were randomly assigned to sham operate group,control group ,intravenous immune globlin injected group(IVIG group)and allyl chloride intragastric administration group(allyl chloride group). MCAIR was established by nylon monofilament occlusion method in rats .After operations,the sham operate group were injected 5% D-sorbitol solution(1g/kg) into vena caudalisfor one time.After cerebral artery ischemia-reperfusion , the control group were injected 5% D-sorbitol solution(1g/kg) into vena caudalisfor one time, the IVIG group were injected IVIG(1g/kg) into vena caudalis for one time.The allyl chloride group were injected 5% D-sorbitol solution(1g/kg) into vena caudalis for one time and irrigated allyl chloride (200mg/kg) into stomachonce once a day.We graded the neurological deficts, examined the brain water content and expression of AQP4mRNA by methods of RT-PCR at the different time(12h,,1d,3d,5d,7d).Determined the changes of complement C3 and C5a in Immunohistochemical method.Evans blue fluorescence was used to evaluat the permeability of blood-brain barrier (BBB) and enhanced computerized tomography(CT) was used to measure the infract volume. we analyse the changes and the connection between them.Result (1)After intra cerebral ischemia and reperfusion ,the scores of the motor functions of the rats in operated groups followded same tendency.The scores of the IVIG and allyl chloride group were lower than the control group on 1th,3th and 5th day,and the IVIG group was lower than the allyl chloride group in the same time.(2)The AQP4mRNA increased on the operated side of the operated group and achived the peak on 1th and 3th.Both of the IVIG and allyl chloride group were lower than the control group,and the allyl chloride group was lower than the control group each time.(3)After intra cerebral ischemia and reperfusion for 12 hours,the water content of the brain tissue incread,and achived the peak on 1th day,then decread.The IVIG and allyl chloride group were lower than the control group each time,and the IVIG group was lower than the allyl chloride group on 1th,3th and 5th day.(4)Completment C3 expressed on both side of the cerebral hemisphere.After intra cerebral ischemia and reperfusion in 12h,the operate groups increased and achived the peak on 3th day.In the operate groups,the operated side increased more than the other side.On the operated side,there was no difference in 12h(P>0.05).The IVIG and allyl chloride group were lower than the control group after the 1th day,and the allyl chloride group was lower than the IVIG group.Complement C5a only expressed on the operated side of the operated group,it incread on the1th day,and achived the peak on 3th day,then decreased.On 7th day,there was still some to express.After 1 day,the IVIG and allyl chloride group were lower than the control group,and the IVIG group was lower than the allyl chloride group .(5)The permeability of blood-brain barrier of the IVIG and allyl chloride group are lower than the control group,and the IVIG group was lower than the allyl chloride group each time.(6)After intra cerebral ischemia and reperfusion,the infract volumes were highest on 1th day.the IVIG and allyl chloride group are lower than the control group on 5th and 7th day,and the IVIG group was lower than the allyl chloride group.Conclusion (1)The activation of the complement system and the exp- ression of AQP4 after intra cerebral cerebral ischemia and reperfusion avate brain damage.(2)Both of IVIG and allyl chloride can effectually reduce brain damage.The cheif role of IVIG was the inhibitor of complement system and allyl chloride was the inhibitor of AQP4.