Expressions Of TGF-β1 And Its Receptors In Frontal Lobe Following Subarachnoid Hemorrhage In Rats And Neuroprotection Of Nimodipine

Objective To investigate the expressions of TGF-β1 and its receptors (TβRⅠ, TβRⅡ) in frontal lobe following subarachnoid hemorrhage (SAH) in rats and to investigate the neuroprotection of nimodipine.Methods 72 health male Sprague-dawley (SD) rats were assigned randomly into following groups:Normal group, Control group, Experimental group. Experimental group were assigned randomly into 2 subgroups:SAH subgroup and ND subgroup (The ND subgroup were injected ND). The both subgroups were assigned randomly into 5 groups:Id group,3d group,5d group,7d group and 14d group (n=6). The pathological changes of basilar artery (BA) were examined, and the expressions of TGF-β1 and TβR I, TβR II in frontal lobe following SAH at defferent time point were detected by immunohistochemistry method.Results Since 1st day after SAH, the pathological changes including thickness of arterial wall, arterial narrowing, and such changes were more obvious on 5th day and 7th day. The expression of TGF-β1 incresed on 1st day in SAH subgroup, and reached to the peak on 3rd day, and deceased on 5th and 7th day, and the level on 14th day was similar to the control group. The expressions of TβR I incresed on 1st day in SAH subgroup, and reached to the peak on 5th and 7th day, and decreased on 14th day. The expression of TβR II incresed since 1st day, reached the peak on 3rd day, decresed on 5th and 7th day, and the level on 14th day was similar to the control group. No significant difference of pathological changes between SAH subgroup and ND subgroup can be seen. But compared with SAH subgroup, on 5th day and 7th day the expression of TGF-β1 in ND subgroup was more obvious, and the expression of TβR I decresed obviously, while the expression of TβR II increased; There was no significant difference of TGF-β1, TβR I and TβR II on 1st,3rd and 14th day between SAH subgroup and ND subgroup.Conclusions 1. The pathological changes including thickness of arterial wall, arterial narrowing suggests that CVS happens after SAH.2. The expressions of TGF-β1 and TβRⅠ,Ⅱin frontal lobe after SAH have changed and been concerned with CVS suggests that TGF-β1 and TβR I, TβR II may paticipate the patho-process of vasospasm.3. There was no significant effect of ND on the pathological changes of BA. But ND may play neuroprotective role in ischemic brain tissue by increasing the expression of TGF-β1 to inhibit the overload of Ca2+. The adjustment of ND on the expression proportion of TβR I and TβR II may be one of the mechanism of its neuroprotection.