硫酸锌对豚鼠心房肌的负性变力作用

NEGATIVE INOTROPIC EFFECT OF ZINC SULFATE IN ISOLATED GUINEA PIGS ATRIA

硫酸锌(0.1mmol/L)明显抑制豚鼠心房肌收缩性,呈时间依赖性,抑制肾上腺素诱发的自律性,延长功能性不应期。硫酸锌(0.2mmol/L)对左心房能显著抑制频率递增引起的正阶梯现象,明显抑制静息后增强效应。并能非竞争性右移CaCl_2量效曲线,使最大反应压低。结果表明,硫酸锌妨碍豚鼠心房肌钙离子的转运过程。

Zinc sulfate 0.1mmol/L inhibited the frequency dependent positive staircase phenomenon on isolated guinea pig atria. Ten min after adding zinc sulfate 0.1 mmol/L, the contractility of the left atrium decreased. The needed concentration of epinephrine inducing automaticity was increased and the functional refractory period(FRP) was prolonged from 192?5 ms to 247±4 ms ( P<0.01). Ten min after zinc sulfate 0.3 mmol/L was administrated the post-rest potentiation was markedly inhibited, calcium dose-response cur...