The Changes Of TRPV6 And CLC-2 In Brain Injury Induced By LPS And The Effect Of Panaxadiols

Objective:To investigate the mechanism of PDS on relieving the brain shock injury induced by LPS through observing the changes of TRPV6,CLC-2,BAX and BCL-2 in the brain.Method:1 Forty eight Wistar rats were divided into 6 groups randomly:the experimental control group (Control group);the LPS endotoxic shock model group (LPS group);Dexamethasone administered group (LPS+DEX group) ; PDS low-dose group (LPS+PDSL group, 22.5mg/Kg); PDS mid-dose group (LPS+PDSM group,45.0mg/kg); PDS high-dose group (LPS+PDSH group,90.0mg/kg). Model preparation process:The Wistar rats weren't provided with food but free for water the night before the preparation of the model.On the day of the model preparation,after abdominal cavity injection anaesthesia with 10% hydration trichloroacetaldehyde acetochloral (300mg/kg),the wistar rats were put on the back on the operating board of rat.After segregating the trachea and femoral arteries, the rats were treated with tracheal intubation and femoral artery cannula and connected with pressure transmitter.Take notes of the mean arterial blood pressure(MABP) which was monitored dynamically by the RM6000 4-lead physiologic recording apparatus.With the operation completed,the four lamps were connected with the electrocardio-electrode,and the electrocardiogram(ECG) of the two-leads was recorded.Ten minutes later,we took notes of heart rate(HR),electrocardio and blood pressure(BP).LPS (4mg/kg) was sublingually administered intravenously to build up the animal models of endotoxic shock and the control group which were equally treated with the solution of glucose.In addition,among the PDS-treated groups,PDS was administered before the use of LPS.When blood pressure fell to 2/3 of the baseline,it was regarded as the start point of shock,took notes of the blood pressure at different time point during the procedure of the shock.After four hours of the shock,put the rats to death,sterilized and decapitated,then segregated the cerebral cortex,put them in the liquid nitrogen for quick freezing and then preserved them in the circumstance of subzero 80 degree.2 The dynamic observation of MABP3 Western blotted was used to analyze the expression of BCL-2,BAX,TRPV6 and CLC-2.Results:1 After injection of LPS,the MABP of rats fell to 2/3 of the baseline in all groups after 5 minutes and 10 minutes later,the MABP fell progressively. The MABP had an compensatory restoration from 20min of shock and reached the summit at 30min. From then on,the above index came down constantly again until the models got close to death at 240min.Though the other groups treated with PDS took on the similar effects after injection of LPS,30-60 minutes later they had steady and constant effect of increasing MABP, which is not like that of the groups treated with only LPS. The statistical analysis demonstrated that MABP in the groups treated with PDS was significantly higher than that of LPS groups at the time of 60min,120min,180min and 240min after shock (p<0.05,p<0.01,p<0.001). At the same time,there was no significance of MABP between the three groups of PDS and the Dex group(p>0.05).The LPS endotoxic shock model duplicated successfully on the evidence that the decreasing percentage of MABP at different time is accordance to what of the general MABP. This gave off the individual variance interference and set up a good basis for further study.2 The effect of PDS on the changes of protein BCL-2 and BAX in cerebral cortex of shock induced by LPS.Compared with the control group,the proportionality of BCL-2/BAX decreased in the LPS group;Compared with the LPS group, the proportionality of BCL-2/BAX in the LPS+Dex group and the LPS+PDSL group increased. Anong theoe three LPS+PDS groups,when compared with the LPS group,the proportionality of BCL-2/BAX obviously elevated in the LPS+PDSL group,it almost didn't changed in the LPS+PDSM group and on the contory it decreased in the LPS+PDSH group.3 The effect of PDS on the changes of protein TRPV6 in cerebral cortex of shock induced by LPS.Compared with the control group,the expression of TRPV6 obviously decreased in the LPS group;compared with the LPS group, the expression of TRPV6 obviously increased in the LPS+Dex group;The expression of TRPV6 in all of the three LPS+PDS groups also obviously increased when compared with the LPS group. Among those,Compared with the LPS group,the expression of TRPV6 in LPS+PDSL group increased,and the expression of TRPV6 obviously increased in the LPS+PDSM and LPS+PDSH group,but the LPS+PDSM group was much more significantly.4 The effect of PDS on the changes of protein CLC-2 in cerebral cortex of shock induced by LPS.Compared with control group,four hours latter for injection of LPS the expression of CLC-2 obviouslyb decreased,which made the loss of some capability of the CLC-2 in regulating the stabilization of Chloridion,and induced apoptosis.Interestingly,compared with LPS Group,in adition to the LPS+PDSL group,the expression of CLC-2 reduced in all the LPS+Dex,LPS+PDSM and LPS+PDSH group,and the LPS+PDSH group decreased much more significantly.This indicated that the reduction of the expression of CLC-2 induced by LPS was difficult to elevate by PDS and Dex. Compared with LPS group,the expression of CLC-2 elevated in the LPS+PDSL group,but as the dosage of the PDS increased,the expression of CLC-2 decreased contrarily.Conclusion:1 On the monitoring of the MABP of the Wistar rats,the model of brain shock induced by LPS was made successfully. 2 The shock which was induced by LPS can down regulate the proportionality of BCL-2 and Bax,which promotes the apoptosis and aggravates the brain injury;While given PDS, the proportionality of BCL-2 and Bax rised,which decreased the apoptosis and relieved the brain injury.3 LPS can reduce the expression of TRPV6 in the cerebral cortex,which causes the disequilibrium of the Ca²⁺ between the exterior and interior of the cell and the damage of the brain;Through enhancing the expression of TPRV6 in the cerebral cortex,PDS can relieve the brain injury induced by LPS.4 LPS can reduce the expression of CLC-2 in the cerebral cortex,which causes the disequilibrium of the CL- and the concentration of CL- in the interior of cell elevates,this causes the damage of the brain,the inhibition of proliferation and the promotion of apoptosis in the nerve cell may be the potential mechanism;PDS can enhance the expression of CLC-2 in the cerebral cortex and relieve the brain injury induced by LPS,the reason of which may be the enhancement of proliferation and the inhibition of apoptosis in the nerve cell.