Do the central beta-adrenoceptors play any role in the genesis of centrogenic cardiac arrhythmias in anesthetized rats ?

In urethan-anesthetized rats, the intracerebroventricular (ICV) administration of salbutamol induced cardiac arrhythmias, but only in very large doses and in only a few experiments. The ICV microinjection of ICI 118551, a specific beta-adrenoceptor blocking agent, failed to affect the arrhythmogenic action of ICV sodium glutamate. From these results, it may be concluded that the central beta2-adrenoceptors are not involved in the genesis of cardiac arrhythmias induced by ICV administration of sodium glutamate.