Objective To investigate the effect of a selective muscarinic receptor antagonist(penehyclidine hydrochloride) on three vessel occlusion model of acute global brain ischemia-reperfusion in rats.Methods One hundred and forty-four SD rats were randomly divided into four groups:sham operated group,vehicle pretreated group(saline 1 ml,i.p.),scopolamine pretreated group(0.01 mg/kg,i.p.) and penehyclidine hydrochloride pretreated group(0.01 mg/kg,i.p.) with drugs injected 40 min before ischemia respectively.The ischemic duration was 10 min.H-E staining,TUNEL staining and immunohistochemical reactions of bax and bcl-2 were carried out at the time points of 2 h,12 h,24 h,3 d and 7 d after reperfusion.Some animals were subjected to TTC staining for assessment of infarction volume 4 d after reperfusion.Results As compared with the vehicle pretreated group,both penehyclidine hydrochloride pretreatment and scopolamine pretreatment accelerated and extended the expression of bcl-2(P<0.01) in the CA1 subfield of hippocampus,meanwhile,penehyclidine hydrochloride pretreatment lowered the expression of bax(P<0.05 or P<0.01).Both of the drug pretreatments increased the survival pyramidal cells,decreased the numbers of apoptotic neurons and attenuated the cerebral infarction volume(P<0.05 or P<0.01).There was a more significant improvement in penehyclidine hydrochloride pretreated group than in scopolamine pretreated group in the same doses(P<0.05).Conclusion Penehyclidine hydrochloride may provide neuroprotection in acute global ischemia-reperfusion injury rats by altering the bcl-2/bax ratio.
