Age-related differences in the beta-adrenergic vasodilator response in rat aortic rings.

Mechanisms underlying age-dependent changes in vasodilator responses to beta-adrenergic drugs are poorly understood. The aim of the current study was to compare responses to isoproterenol (a non-selective beta-adrenergic receptor agonist) in phenylephrine or KCl precontracted aortic rings from 3 week and 3 month old male Wistar rats. Both the mechanism and the subtype of beta-adrenergic receptor underlying the response to isoproterenol in the both age groups were examined.