Differential Expression Of Connexins In Intracranial Aorta And Arteriole After SAH

Objective: To elucidate the temporal changes of four connexins in different parts of the blood vessels and their correlation with the corresponding vasospasm,and to demonstrate the difference of gap junction protein changes in the aorta and arterioles(the pial and parenchymal arteries).To demonstrate that the difference in gap junction protein changes is the reason that the vasospasm inconsistency between the aorta and the arteriole.Methods: Healthy adult male Sprague-Dauley(SD)rats 216 weighing 250-350 g were randomly selected.Rats were divided into three groups: SAH group,Sham group and SAH+18β-GA group(on the basis of SAH group,18β-glycyrrhetinic acid(18β-GA)was intraperitoneally injected once every 24 hours after modeling.The dose was 10 mg/kg.)SAH models were established through double injection of autologous blood into the prechiasmatic cistern of rats.At 24 hours after model establishment,the SAH group and the Sham group were intraperitoneally injected with an equal amount of solvent in the SAH+18β-GA group.Each group of SD rats was subjected to the following experiments on days 1,3,7 and 14.Garcia neurologic scores were used to score the rats in each group.After HE staining,the diameter of rat brain the pial and parenchymal arteries were measured by software system.The diameter of rat basilar artery was measured by Myograph experiments.Western-blot method was used to measure different time points,expression of Cx37,Cx40,Cx43 and Cx45 in brain parenchymal arteries,pial arteries and basilar arteries.The Pearson correlation coefficient was used to study the correlation between vasospasm and connexins.Results: On the 1st day,the 3rd day,the 7th day and the 14 th day of the SAH group,the neurological score was significantly decreased.The diameters of the pial arteries and parenchymal arteries did not change significantly on the 1st day,and began to decline on the 3rd day.The diameter was the lowest on the 7th day and returned to normal on the 14 th day.However,the diameter of the basilar artery began to decrease on the 1st day,and the diameter of the basilar artery was the lowest on the 7th day,and it was relieved on the 14 th day.Cx37 was not detected in the blood vessels at three sites.In the pial arteries and parenchymal arteries,Cx40 in the SAH group did not change significantly on the 1st day,and decreased from the 3rd day,the lowest on the 7th day,no significant change on the 14 th day,and the expression of Cx43 and Cx45 on the1 st day no obvious abnormalities were observed,and the 3rd day,the 7th day and the 14 th day increased significantly;in the basilar artery,the expression of Cx40 in the SAH group decreased significantly on the first day,reached the lowest on the 7th day,and recovered on the 14 th day.The expression of Cx43 and Cx45 was significantly increased at all time points.Correlation studies have shown that connexins are associated with vasospasm at different sites.Conclusions: The role of Cx37 in cerebral vasospasm needs further study.Cx40,Cx43 and Cx45 may be involved in the pathophysiological events of vasospasm after SAH.Cx40 was negatively correlated with CVS at the pial arteries,and Cx43 and Cx45 were positively correlated with CVS.Cx40 was negatively correlated with CVS at the parenchymal artery,Cx43 was not associated with CVS,and Cx45 was positively correlated with CVS.At the basilar artery,Cx40 was negatively correlated with vasospasm,and Cx43 and Cx45 were positively correlated with vasospasm.Connexins may account for the cause of the temporal difference in the vasospasm between the intracranial artery and the arteriole following SAH.