Agonistic and antagonistic actions of 3,4-dihydroxy-substituted phenoxypropanolamines in guinea-pig atria and trachea.
1. Racemic mixtures of noradrenaline, adrenaline, isoprenaline, N-t-butylnor-adrenaline and their corresponding derivatives containing an oxymethylene (OM) link between the phenyl ring and ethanolamine side-chain have been tested for their effects on beta-adrenoceptors in isolated guinea-pig atrial and tracheal preparations. 2. In atrial and in spontaneously contracted tracheal preparations both the parent catecholamines and their corresponding OM-derivatives had a similar order of potency as beta-receptor agonists. 3. In carbachol-stimulated tracheal preparations the OM-derivatives were shown to have partial agonistic actions. 4. As in other phenylethanolamines and phenoxypropanolamines, both the agonistic and antagonistic potency of the OM-derivatives increased with increasing amine substitution.
D000403:Airway Resistance / Q000187:drug effects*; D000818:Animals; D002217:Carbachol / Q000037:antagonists & inhibitors; D004837:Epinephrine / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D009200:Myocardial Contraction / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D011412:Propanolamines / Q000494:pharmacology*; D014132:Trachea / Q000187:drug effects
D011412:Propanolamines; D002217:Carbachol; D007545:Isoproterenol; D009638:Norepinephrine; D004837:Epinephrine