1.
Indian J Physiol Pharmacol
;
1985 Oct-Dec; 29(4): 239-44
Artículo
en Inglés
| IMSEAR
| ID: sea-108023
RESUMEN
Spontaneously beating isolated atria of rabbits responded to Mn++ and Co++ with a progressively increasing negative chronotropism and inotropism, which was reversible by washout and by elevating the bath concentration of Ca++. The cumulative dose response curve for adrenaline for chronotropic response was markedly shifted to the right in the presence of Mn++ or Co++. This effect was also reversible. Verapamil produced only a moderate decline in spontaneous rate and contractility and did not block the chronotropic response to adrenaline. It is concluded that Mn++ and Co++ block the action of catecholamine on the pacemaker cells and they differ at least in part from organic calcium channel antagonists in their mechanism of action.