Age-Related Differences in the P-Adrenergic Vasodilator Response in Rat Aortic Rings

摘要

Mechanisms underlying age-dependent changes in vasodilator responses to (3-adrenergic drugs are poorly understood. The aim of the current study was to compare responses to isoproterenol (a non-selective (3-adrenergic receptor agonist) in phenylephrine or KCI precontracted aortic rings from 3 week and 3 month old male Wistar rats. Both the mechanism and the subtype of (3-adrenergic receptor underlying the response to isoproterenol in the both age groups were examined. Endothelial removal, pre-contraction with KCI (40 mM), pre-treatment with tetraethylammonium or with No-Nitro-L-arginine methyl ester inhibited the vasodilator response to isoproterenol only in aortic rings from older rats.