毒毛旋花子苷原对正常和心衰心肌单细胞收缩力和钙瞬变的作用

目的检测毒毛旋花子苷原(Str)对正常和心衰心肌单细胞收缩力和钙瞬变的作用。方法采用降主动脉缩窄建立豚鼠慢性充血性心力衰竭模型,酶解法急性分离左室心肌细胞,同步检测Str对单个正常细胞(NC)和心衰细胞(FC)收缩力和钙瞬变的影响,并检测Str是否具有钙增敏作用。结果0.1、1、10、25μmol.L-1Str可使NC和FC收缩幅度、钙瞬变幅度呈剂量依赖性增大;同剂量时,Str对FC的作用比NC更明显;但Str对NC和FC收缩时程及钙瞬变时程均无影响。Str对NC具有钙增敏作用,而对FC没有。结论Str增加FC的收缩力和钙瞬变作用比NC更明显,而Str仅对NC具有钙增敏作用。

The effects of strophanthidin on the contractility and calcium transient of a single normal or failure ventricular myocyte

Aim To detect the effects of strophanthidin(Str)on the contractility and calcium transient properties of normal or failure ventricular myocytes.Methods The guinea pig chronic congestive heart failure model was produced by constricting descent aorta.The left ventricular myocytes were enzymatically isolated.The effects of Str on contractility and calcium transient of normal ventricular myocytes(NC)or failure ventricular myocytes(FC)were assessed simultaneously.At the same time,the calcium sensitivity induced by Str was examined.Results Str 0.1,1,10,25 μmol·L-1 increased the extent of cell shortening and the calcium transient amplitude on NC and FC in a concentration-dependent manner individually.At the same concentration,effect of Str was more potent in FC than in NC.Both in NC and FC,Str at any concentration had no effect on the systolic time and the calcium transient time.In addition,Str increased calcium sensitivity in NC,but not in FC.Conclusions The increments in contractility and calcium transient induced by Str in FC are more potent than in NC,Only in NC Str increases calcium sensitivity.