Interaction of heavy metals with membrane Ca^2+ channels

查看全文 作　　者：[1]PengSQ;[2]HajelRK 机构地区：[1]BeijingInstituteofPharmaco-logy&Toxicology,Beijing100850,China;[2]DepartmentofPharmacology&Toxicology,MichiganStateUniversity,EastLansing,USA 出　　处：《中国药理学与毒理学杂志》索引2002年第16卷第6期,共1页 摘　　要：The objective of our study was to determine if specific types of high voltage-activated Ca^2+ channels,typically found in neurons were affected differentially by MeHg,Hg^2+ and Pb^2+.Expression cDNA clones of α1C,α1B or α1E subunits coding for neuronal L-,N- and R- subtypes respectively,were combined with α2b δ and β3 Ca^2+ channel subunits of human neuronal origin to transfect HEK293 cells.Current was measured using whole cell voltage clamp recording techniques.It the present studies,we conclude: (1)neurotoxic heavy metals such as MeHg,Hg^2+ and Pb impair the function of voltage-gated Ca^2+ channels at low μmolar to sub-μmolar concentrations-concentrations in the range of which are pathologically and environmentally relevant; (2)a particular metal,i.e.Pb^2+,may inhibit function of phenotypically distince Ca^2+ channels with variable potency; (3)different metals have differing “orders of potency” at inhibiting defined populations of Ca^2+ channels; (4)for “susceptible populations” of patients with either underlying diseases or genetic alter ations of Ca^2+ channel function,these metals may have heightened effectiveness.As such,for these populations,environmental toxic metals could produce a more dominant neurotoxicity. 关 键 词：重金属 钙离子通道 相互作用