Interactions of calcium and amrinone on norepinephrine induced contractions of isolated rabbit aortic strips

ABSTRACT

In the present study, the interaction of calcium and amrinone was examined on isolated rabbit aorta by using different calcium concentrations in the bathing solution. Norepinephrine-induced contractions were then recorded both in the absence and in the presence of amrinone. The present data show that the responses of rabbit aortic strips to each of NE and amrinone depended not only on ambient Ca2+ concentration, but also on the sequence of exposure of the vessel to the different drugs. This may have implications in clinical practice in cardiac patients with hypocalcemia who require both calcium and amrinone infusions; the resultant hemodynamic effect would depend on which of the infusions was started first