title: Alpha- and beta-adrenergically mediated responses in isolated lung strips of guinea pigs.
abstract: Thin strips of lung parenchyma from guinea pigs were mounted in an isolated tissue bath and placed under an initial tension of 1.2 gm. Drug-induced changes in resting tension were recorded isometrically upon the addition of representative alpha- and beta-adrenergic agonists. Lung strips relaxed following challenge with isoproterenol, 10(-9) to 10(-6)M (beta-adrenergic agonist), and contracted following challenge with phenylephrine, 10(-6) to 10(-4)M (alpha-adrenergic agonist). The responses of lung strips to norepinephrine, 10(-8) to 10(-4)M (mixed alpha- or beta-agonist) were influenced by the presence of either an alpha- or beta-adrenergic antagonist: pretreatment with phentolamine, 10(-5)M (alpha-antagonist) resulted in relaxant responses to norepinephrine, whereas pretreatment with propranolol, 10(-5)M (beta-antagonist) resulted in contractile responses. Cocaine, an uptake-1 inhibitor, potentiated the contractile effect of norepinephrine but not the relaxant effect of isoproterenol or norepinephrine. These data support the existence of alpha- and beta-adrenergic receptors mediating contraction and relaxation, respectively, in guinea pig lungs.
mesh_terms: D000818:Animals; D003042:Cocaine / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008168:Lung / Q000502:physiology*; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology; D011941:Receptors, Adrenergic / Q000502:physiology*; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*; D011943:Receptors, Adrenergic, beta / Q000502:physiology*
chemical_list: D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D003042:Cocaine; D007545:Isoproterenol; D009638:Norepinephrine