Eichhorn I, Fitzner B, Günther J, Pfeiffer C
Acta Biol Med Ger. 1975;34(5):811-9.
D2O decreases the isometric contraction force of papillary muscles from the left ventricle of rats. This effect can be compensated only partially by increasing the calcium content in the perfusion solution. Differences in the effect of D2O under different calcium concentrations point also to an action site other than at the contractile proteins. The enlargement of the restitution of contraction 300 msec after the basic beat, the diminution of the postextrasystolic tiation and the disappearance of postextrasystolic depressions because of high calcium potencontent in the bathing solution make it more probable that the action site lies in cell compartments which may be involved into the supply of activator calcium. The increasing occurrence of aftercontractions alredy at slightly enhanced extracellular calcium is in good agreement with this fact.
重水会降低大鼠左心室乳头肌的等长收缩力。这种效应只能通过增加灌注溶液中的钙含量来部分补偿。不同钙浓度下重水效应的差异也表明其作用位点并非在收缩蛋白处。由于浴液中高钙含量，基础搏动后300毫秒收缩恢复的增大、早搏后强化的减弱以及早搏后凹陷的消失，使得作用位点更有可能位于可能参与活性钙供应的细胞区室。细胞外钙略有增加时后收缩发生率的增加与这一事实高度相符。
