摘要
本文报告了氟化钠(NaF)对离体兔左房肌具有浓度依赖性和时间依赖性的正性肌力作用;能抑制由Ba^(2+)诱发的左房自律性;能使左房功能不应期缩短、兴奋性提高;一定浓度的NaF亦能使右房肌的收缩频率降低、收缩力增强。NaF的这些作用,可能与其能改变细胞内、外的Ca^(2+)浓度有关。实验进一步表明,F^-与Ca^(2+)在心房肌上可能有相同的作用方式,提示:NaF是一种钙通道激动剂。
Sodium fluoride (NaF) is a plasma toxin. It is highly toxic to cardiovascular system. A scries of tests were performed to study the physiologic properties of NaF on isolated rabbit atria muscles and the effects of propranolol and MnCl2 on dose-response curve of NaF.
When NaF 32-1000 μM was added, the contractility of the left and right atria muscles was increased. After addition of NaF 3162 μM, the functional refractory period (FRP) was shortened from 160±9mS to 120± 10mS (n= 14, P<0.0t) while BaCl2-induccd auiomaticily was decreased to 50% (n = 9, P<0.01) compared with the control. The NaF concentration shifting the duration-intensity curve to the left was 1000μM. With the NaF 1000μM, the contractile frequency of rabbit right atria muscles was decreased to 68% (n = 13, P<0.01). Propranolol (26μM) antagnized the positively inotropic action of NaF and CaCl2 non-specifically, while MnCl2 (0.12mM) antagonized them specifically.
出处
《地方病通报》
1990年第4期50-54,共5页
Endemic Diseases Bulletin
关键词
心房肌
生理特性
氟化钠
毒理学
Sodium fluoride
Contractility
Excitability
Functional refractory period
Dose-response curve
Automaticity
