独一味对蟾蜍离体心脏功能的影响

目的 研究独一味对蟾蜍离体心脏的作用及其相关机制.方法 采用离体蛙心灌流法观察独一味提取物对离体心脏的收缩力、心输出量和心率的影响.结果 ①独一味提取物使蟾蜍离体心脏的收缩力减弱,心输出量减少,心率略有减慢.在0.01～2.0 mg·ml~(-1)浓度范围内,独一味提取物抑制心肌收缩力的作用与剂量之间呈现明显的量效关系,最大效应可使心肌收缩力降低36.4%.②随灌流液中钙离子浓度增加,独一味对心脏的抑制作用增强;另外,独一味的心脏抑制作用可部分被阿托品拮抗.结论 独一味可抑制蟾蜍离体心脏的功能,其作用可能与抑制细胞外的钙离子内流,减少细胞内钙有关,而与心肌细胞受体的关系有待进一步研究.

Effects of Herba Lamiophlomis on the Cardiac Function of Isolated Toad Hearts

Objective To investigate the effects of Herba Lamiophlomis on the isolated toad hearts and the underlying mechanism. Methods With isolated heart irrigation technique, the effects of Herba Lamiophlomis extract on the cardiac contractility, cardiac output and heart rate were investigated.Rusults ①Herba Lamiophlomis had the inhibitory effects on the isolated toad hearts, could attenuate the cardiac contractility, decrease the cardiac output and reduce the heart rate.It had an obvious dose-effect rela-tionship within the concentration of (0.01～2.0)mg·ml~(-1).The maximal inhibitory effect on the cardiac contractility was near by 36.4%.②The inhibition of Herba Lamiophlomis on cardiac contractility became stronger along with the increase of [Ca~(2+)] in the perfusion solution.Besides,the effect of Herba Lamiophlomis on the cardiac function could be partially antagonized by atropine. Conclusion Herba Lamiophlomis can inhibit the function of isolated toad hearts.The mechanism may be that Herba Lamiophlomis blocks Ca~(2+) channel on the cell membrane,and inhibit the flowing of Ca~(2+) from extracell to intercell, thus reduce the intracellular concentration of Ca~(2+). While the interaction of Herba Lamiophlomis and receptor on the cell membrane is worth further research.