Scholz H, Hackbarth I, Schmitz W, Wetzel E
Basic Res Cardiol. 1980 May-Jun;75(3):418-22. doi: 10.1007/BF01908404.
Ammonium vanadate (NH4VO3; 50-1000 microM) increases the force of contraction of isolated electrically driven cat papillary muscles in a concentration-dependent manner. The positive inotropic effect (PIE) of NH4VO3 became significant at 50 microM and was maximal at 500 to 1000 microM. It was accompanied by an increase in the rate of force development, in the rate of relaxation and in relaxation time of the isometric contraction. Similar results as with NH4VO3 were also observed in the presence of 1 microM propranolol, 5 microM phentolamine or after reserpine-pretreatment (5 mg/kg i.p.). These results indicate that vanadate produces a direct PIT in ventricular cardiac muscle which is unlikely to be mediated by alpha- or beta-adrenoceptor stimulation. In cat left atrial strips, however, vanadate ions produced a negative inotropic effect through a hitherto unknown mechanism. Vanadate effects similar to those observed in the cat heart were obtained in ventricular and atrial preparations from bovine hearts.
钒酸铵（NH4VO3；50 - 1000微摩尔）以浓度依赖的方式增加离体电驱动猫乳头肌的收缩力。NH4VO3的正性肌力作用（PIE）在50微摩尔时变得显著，在500至1000微摩尔时达到最大。它伴随着等长收缩的力量发展速率、松弛速率和松弛时间的增加。在存在1微摩尔普萘洛尔、5微摩尔酚妥拉明或利血平预处理（腹腔注射5毫克/千克）的情况下，也观察到了与NH4VO3类似的结果。这些结果表明，钒酸盐在心室心肌中产生直接的正性肌力作用（PIT），这不太可能由α或β肾上腺素能受体刺激介导。然而，在猫左心房条带中，钒酸根离子通过一种迄今未知的机制产生负性肌力作用。在牛心脏的心室和心房制剂中获得了与在猫心脏中观察到的类似的钒酸盐效应。
