论文部分内容阅读
在培养的单个ＳＤ乳鼠心肌细胞，观察了牛磺酸对ＫＣｌ，去甲肾上腺素（ＮＥ）和毒毛花苷Ｇ引起的胞浆游离Ｃａ２＋浓度（［Ｃａ２＋］ｉ）变化的影响．当细胞外ＣａＣｌ２浓度为１．３ｍｍｏｌ·Ｌ－１时，牛磺酸１０，２０ｍｍｏｌ·Ｌ－１不影响心肌细胞静息［Ｃａ２＋］ｉ；但能浓度依赖性地抑制３５ｍｍｏｌ·Ｌ－１ＫＣｌ和１μｍｏｌ·Ｌ－１毒毛花苷Ｇ升高［Ｃａ２＋］ｉ的作用．１０μｍｏｌ·Ｌ－１ＮＥ在含Ｃａ２＋的缓冲液中能引起双相的［Ｃａ２＋］ｉ变化，即快速升高相和持续升高相．牛磺酸２０ｍｍｏｌ·Ｌ－１能抑制ＮＥ引起的［Ｃａ２＋］ｉ持续升高，而对快速升高相无显著影响．在无Ｃａ２＋的缓冲液中，牛磺酸不影响ＮＥ升高［Ｃａ２＋］ｉ的作用．结果提示牛磺酸可能通过减少心肌细胞电压依赖性Ｃａ２＋内流和Ｎａ＋／Ｃａ２＋交换而抑制ＫＣｌ，ＮＥ和毒毛花苷Ｇ引起的［Ｃａ２＋］ｉ升高．
The effects of taurine on the changes of cytosolic free Ca2 + concentration ([Ca2 +] i) induced by KCl, NE and tocinolide G were observed in cultured SD rat neonatal cardiomyocytes. When the concentration of extracellular CaCl2 was 1.3mmol·L-1, taurine 10,20mmol·L-1 did not affect cardiomyocytes resting [Ca2 +] i but inhibited the concentration of 35mmol·L-1 KCl and 1μmol L-1 ouabain increases the effect of [Ca2 +] i. 10μmol·L-1NE can cause biphasic change of [Ca2 +] i in Ca2 + -containing buffer, ie, rapidly rising phase and continuously rising phase. Taurine 20mmol·L-1 can inhibit NE-induced [Ca2 +] i continued to rise, while the rapid increase had no significant effect. In Ca2 + -free buffer, taurine did not affect NE’s effect of increasing [Ca2 +] i. The results suggest that taurine may inhibit the increase of [Ca2 +] i induced by KCl, NE and ouabain by reducing the cardiomyocyte voltage-dependent Ca2 + influx and Na + / Ca2 + exchange.