慢性持续性低氧对大鼠海马CaMKⅡ的影响

Effects of chronic normobaric hypoxia on T-CaMKⅡ and p-CaMKⅡ levels in hippocampus of rats

目的探讨慢性持续性低氧对大鼠海马钙调蛋白依赖性蛋白激酶Ⅱ(CaMKⅡ)表达量及其磷酸化水平的影响。方法选取清洁级SD成年雄性大鼠,随机分为6组每组6只。正常对照组(C组),低氧1d组(H1),低氧3d组(H3),低氧7d组(H7),低氧14d组(H14),低氧21d组(H21)。建立慢性持续性低氧模型。测量右心室收缩压,计算右心室肥厚指数,即右心室重量与左心室加室间隔重量比值[RV/(LV+S)]。断头取海马组织,应用10%SDS-PAGE和Western blot技术及GelDoc凝胶成像系统半定量检测T-CaMKⅡ和p-CaMKⅡ水平。结果与C组(100%)相比,H1[(77.6±14.9)%]、H3[(66.7±19.3)%]、H7[(79.6±21.7)%]、H14[(75.7±14.2)%]、H21[(78.8±12.9)%]组大鼠海马p-CaMKⅡ水平显著下降(P<0.05)。同时与C组(100%)相比,H1[(67.9±25.3)%]、H3[(74.1±23.2)%]、H7[(72.2±25.1)%]、H14[(75.3±12.4)%]、H21[(73.3±16.1)%]组大鼠海马CaMKⅡ蛋白表达量显著下降(P<0.05)。结论慢性持续性低氧可使大鼠海马组织内CaMKII活性下降,并抑制该蛋白的正常表达。

Objective To explore the effects of chronic normobaric hypoxia （10% oxygen environment） on T-CaMK Ⅱ and p-CaMKⅡ levels of hippocampus of rats.Methods Male SD rats were randomly divided into six groups （n=6 each）：control group, group H1 in which rats were in chronic normobaric hypoxia for 1 day, group H3 in which rats were in chronic normobaric hypoxia for 3 days, group H7 in which rats were in chronic normobaric hypoxia for 7 days, group H14 in which rats were in chronic normobaric hypoxia for 14 days, group H21 in which rats were in chronic normobaric hypoxia for 21days.The ratios of right ventricle （RV）/left ventricle＋ ventricular septum （LV＋VS） were calculated and the right ventricular systolic pressure was measured.The rats were sacrificed by decapitation and the hippocampus were dissected.T-CaMKⅡ and p-CaMKⅡ were examined by 10% SDS-PAGE and western blot analysia and GelDoc system.Results Compared with control group（100%）, the T-CaMKⅡ levels decreased in the hippocampus in H1（77.6±14.9%）、H3（66.7±19.3%）、H7（79.6±21.7%）、H14（75.7±14.2%）、H21（78.8±12.9%）group （P0.05）.And compared with control group（100%）, the p-CaMKⅡ levels decreased in hippocampus in H1 （67.9±25.3%）、H3 （74.1±23.2%）、H7 （72.2±25.1%）、H14 （75.3± 12.4%）、H21（73.3±16.1%） group （P0.05）.Conclusions Chronic normobaric hypoxia decreases CaMKⅡ activity in rats and could inhibit the CaMKⅡ expression.