Protective effect of clonidine against the cardiotoxic effects of ouabain in cat

Cardiac arrhythmias and cardiac arrest were induced in pentobarbitone anaesthetised cats by slow intravenous infusion of ouabain. The dose of ouabain required for the induction of the stages of arrhythmias and cardiac arrest and the maximum pressor effect induced by ouabain were assessed in control and clonidine pretreated cats. Clonidine caused significant delay in the onset of cardiotonic effects of ouabain and inhibition of the maximum pressor effect of ouabain. The inhibition of cardiotoxic and pressor effects of ouabain may be the result of clonidine's effect on the neural components of ouabain action.