Effects of morplune preconditiolung on oxygen-glucose deprivation and restoration induced-PKC.EPSILON. membrane translocation in hippocampal slices of mice

：Objective To investigatethe effects of morphine preconditioning on oxygen-glucose deprivation andrestoration(OGD/R)-induced PKCe membrane translocation inhippocampal slices of mice.Methods Hippocampi were isolated from adult BALB/C mice ofeither sex weighing 18-22 g and sliced(400 μm thick)and incubated innormal artificial cerebro-spinal fluid(nACSF).The hippocampal slices were divided into5groups(n = 40 each): group Ⅰ control(group C);groupⅡ morphine preconditioning(group M);group Ⅲmorphine+naloxone(groupN+M);group Ⅳ naloxone(group N)and groupⅤ OGD/R.The slices were incubated in nACSF in thepresence or absence of morphine 3.0 μmol/L for 30 min(group M andC).In group N+M,before being incubated with morphine the slices were incubated withnaloxone 50μmol/L for 30 min.In group Ⅳ the slices were incubated with naloxone 50 μmol/L alone for 1 h.Sliceswere subjected to OGD for20 min followed by restoration of O2-glucose supply for 2 h ingroup Ⅱ-Ⅴ.Theslices were homogenized,sonicated and centrifuged to separate the protein of particulatefraction from that of soluble fraction.SDS-PAGE Western blot was used to detect the PKCe membrane translocation in hippocampal slices.Results The PKCemembranetranslocation was significantly increased during OGD/R in OGD/R groups than in controlgroup.Morphine preconditioning significantly decreased the PKCe membrane translocation during OGD/R.Naloxone completely blocked the inhibition ofPKCe membrane translecationinduced by morphine preconditioning but naloxone alone had no effect on PKCe membrane translocation induced by OGD/R.Conclusion Inhibition of PKCemembrane translocation may beinvolved in the morphine preconditioning-induced cerebral ischemic tolerance. Key words: Morphine; Ischemic preconditioning; Protein kinaseC-epsilon; Reperfusion injury; Hippocampus