摘要
不同浓度的CdCl_2可使豚鼠右心室乳头肌毒性表现不同。2×10^(-5)M对豚鼠快反应APA及Vmax无显著影响。10^(-4)和5×10^(-4)M可抑制APA、Vmax,缩短APD抑制FC。而在慢反应实验中均呈抑制作用。实验说明低剂量cd使心肌细胞兴奋收缩脱耦联,大剂量对心肌有直接的毒性作用。
0admium chloride(2×10^(-5)M)produced a negative chronotropic action, and a decrease in APD, but did not have an effect on APA and Vraax. CdCl_2 (10^(-4)M)has an inhibition of many parameters of the action potential including APA, Vmax, Fc and APD. The effects of cadmium chloride on slow response potential and contractile force (Fc) of preparations in which thc Na^+ channels were inactived by partial depolarization by increasing the concentration of K^+ 25.4 mM were observed. Many parameters of slow response were also decreased by cadmium chloride. The results reveal that cadmium chloride may make the heart cell excitation-contraction uncouple, and inhibit Ca^(2+) conductance through Ca^(2+) channel and increase K^+ flux o phase 3.
关键词
镉
毒性
心脏
豚鼠
cadmium
fast response
slow response
excitationcontraction uncoupling
toxicological action
