摘要
Abstract
Objective To explore the protective effect and possible mechanism of different doses of magnesium sulfate (MgSO4) pretreatment and treatment for cerebral ischemia-reperfusion injury in mice. Method 120 Kunming mice were selected and divided into sham-operated group by simple random sampling, sham-operated group (30 mice), ischemia-reperfusion group (30 mice) and different doses of MgSO4(20, 40, 80 mg/kg) pretreatment group (30 mice, 10 mice per dose) and different doses MgSO4(70, 140, 280 mg/kg) treatment group (30 mice, 10 mice per dose). Mice in pretreatment group were injected intraperitoneally with different doses of MgSO4before ischemia. Mice in treatment group were injected intraperitoneally ismmediately after reperfusion. The pathologic change was observed. The content of nitric oxide (NO), the activity of total nitric oxide synthase (T-NOS) and inducible nitric oxide synthase (iNOS) and ATPase of cerebral tissue were also detected. Animals were assessed and recorded for neurobehavioral scores at 24 hours after cerebral ischemia and reperfusion. Result The pathological change of ischemic impairment in pretreatment and treatment groups were significantly lighter than that of ischemia-reperfusion group. The average survival time of the middle and high dose treatment group and pretreatment group was significantly higher than that of sham-operated group and the ischemia-reperfusion group. The content of NO and the activities of T-NOS and iNOS of cerebral tissue in sham-operated group, pretreatment group and treatment group were all significantly lower than those of ischemia-reperfusion group (P<0.05, P<0.01). There were significant differences in NO content and T-NOS and iNOS activity among different doses treatment group (P<0.05). There was no significant difference in the activity of iNOS in brain tissue of mice among different dose pretreatment group (P>0.05). The activity of Na+-K+-ATPase and Ca2+-Mg2+-ATPase of cerebral tissue were all higher than those of ischemia-reperfusion group (P < 0.05). The activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase in high-dose pretreatment group were significantly higher than those in low-dose pretreatment group, middle-dose pretreatment group, ischemia-reperfusion group and treatment group (P<0.05). The neurobehavioral scores of ischemia-reperfusion group were significantly different from those in sham-operated group, pretreatment group and treatment group (P<0.05, P<0.01).There was no significant difference in the neurological score between high-dose treatment group and sham-operated group (P>0.05), there was significant difference the neurological score between high-dose pretreatment group and sham-operated group in open-field test and suspension test (P<0.01 or P<0.05). Conclusion MgSO4pretreatment and treatment may reduce the degree of neuron injury and have protective effect on ischemia-reperfusion cerebral injury, which may be associated with the decrease of the content of NO and the activities of NOS, iNOS and the increase of the activity of ATPase.关键词
硫酸镁/缺血再灌注损伤/一氧化氮合酶/ATP酶Key words
Magnesium sulfate/Ischemia-reperfusion injury/Nitric oxide synthase/ATPase
