Influence of divalent cations on rabbit atria and modification of catecholamine response on pacemaker cells.
Indian J Physiol Pharmacol
;
1985 Oct-Dec; 29(4): 239-44
Article
in English
| IMSEAR
| ID: sea-108023
ABSTRACT
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.
Full text:
Available
Index:
IMSEAR (South-East Asia)
Main subject:
Rabbits
/
Verapamil
/
Catecholamines
/
Epinephrine
/
Cations, Divalent
/
Calcium
/
Cobalt
/
Depression, Chemical
/
Heart
/
Heart Atria
Language:
English
Journal:
Indian J Physiol Pharmacol
Year:
1985
Type:
Article
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