The effect of age on  -adrenoceptor activity in tracheal smooth muscle.
There was an age-related reduction of the sensitivity of rat and guinea-pig isolated tracheal smooth muscles to stimulation of beta-adrenoceptors, but the ability of tracheal smooth muscle to relax to isoprenaline was not completely lost.
D000375:Aging; D000818:Animals; D006168:Guinea Pigs; D007545:Isoproterenol / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D051381:Rats; D011941:Receptors, Adrenergic / Q000187:drug effects*; D014132:Trachea / Q000187:drug effects / Q000502:physiology
D011941:Receptors, Adrenergic; D007545:Isoproterenol