calcium and ouabain acted synergistically.5 increasing calcium concentrations inhibited the positive chronotropic effect of noradrenaline in a manner similar to increasing ouabain concentrations.6 a hypothesis is proposed which explains the chronotropic effect of ouabain on the basis of two mechanisms : ( 1 ) increase of the catecholamine concentration affecting the pacemaker ;
C1372804
positive
C0028351
noradrenaline