地黄活性成分梓醇对转基因CHO细胞M_2受体的调节作用

目的探讨地黄活性成分梓醇对转染M2受体亚型基因的CHO细胞系(CHOm2细胞)M2受体密度作用。方法采用衰老CHOm2细胞,常规培养后加入不同浓度梓醇及对照生理盐水,放射配基结合分析测定M2受体密度,Lowry法测定蛋白含量;同时观察了梓醇与M受体结合位点的关系及对乙酰胆碱酯酶的作用。结果梓醇在终浓度10-5、10-4mol.L-1明显升高衰老CHOm2细胞M2受体密度(P<0.01),但不占领M受体结合位点,也不抑制乙酰胆碱酯酶活性(P>0.05)。结论梓醇能上调衰老CHOm2细胞M2受体密度,可能是地黄治疗AD的主要有效成分。

Regulatory effect of catalpol from Radix Rehmanniae on M2 receptor density in M2 receptor transfected CHO cells

Aim To investigate the effect of catalpol from Radix Rehmanniae on M_2 receptor density in CHO cells transfected with gene of M_2 receptors(CHO m2).Methods Cultured CHOm2 cells were randomly divided into 4 groups:three concentrations of catalpol :10-6、10-5、10-4 mol·L-1,and saline control.After addition of catalpol and saline for 72 h,M_2 Receptor density was measured by single point 3H-NMS binding assay,the content of protein was measured with Lowry's method.Competitive binding assay using the binding system of 3H-NMS was performed to address the question about whether catalpol could occupy the M receptor binding site.Addition of catapol to brain homogenate and measuring the enzyme activity with the Ellman's colorimetric method were performed to address the question about whether catalpol could in-hibit acetylcholinesterase activity.Results Catalpol can elevate the M_2 receptor density in CHO m2 cells significantly at the doses of 10-5、10-4 mol·L-1(P<0.01),but not at 10-6 mol·L-1.On the other hand,catalpol did not occupy the M receptor binding site,nor did it inhibit the activity of acetylcholinesterase.Conclusion Catalpol has up-regulation effect on M_2 Receptor density in a dose-dependent manner,and may be the active component of Radix Rehmanniae in treating diseases with memory impairment.