Alpha-receptor subsensitivity of isolated atria from rats following physical training or repeated ACTH-injections.
Decreased chronotropic and inotropic sensitivity of isolated atria to phenylephrine but not to isoprenaline was found in rats following repeated physical training by swimming or repeated ACTH-injections. These changes were induced within a week of subjection of animals to these treatments. It is concluded, that these effects are mediated by increased adrenergic activity which results in this subsensitivity of alpha-receptors.
D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D006325:Heart Atria / Q000294:innervation*; D007545:Isoproterenol / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D010656:Phenylephrine / Q000008:administration & dosage / Q000494:pharmacology*; D005082:Physical Exertion; D051381:Rats; D011919:Rats, Inbred Strains; D011941:Receptors, Adrenergic / Q000187:drug effects*; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects*
D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D010656:Phenylephrine; D000324:Adrenocorticotropic Hormone; D007545:Isoproterenol