Regulatory effect of catalpol from Radix Rehmanniae on M_2 receptor density in M_2 receptor transfected CHO cells / 中国药理学通报

ABSTRACT

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 groupsthree concentrations of catalpol10-6、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