Central effects of alpha-adrenoceptor agonist drugs on a cardiovascular reflex evoked by stimulation of somatic afferents.
Further studies were undertaken on the effects of intracisternally administered alpha-adrenoceptor agonists and antagonists on the cardiovascular response to electrical stimulation of somatic afferent nerves in cats. It was found that oxymetazoline and adrenaline both caused hypotension and bradycardia, while phenylephrine was inactive. Adrenaline and phenylephrine reduced the size of the reflex pressor response, while oxymetazoline markedly prolonged it without affecting its magnitude. Intracisternal piperoxan antagonized these effects. It is suggested that these drugs may act at functionally independent sites within the central nervous system.
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D001921:Brain / Q000187:drug effects*; D002415:Cats; D004558:Electric Stimulation; D004837:Epinephrine / Q000494:pharmacology; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D008297:Male; D010656:Phenylephrine / Q000494:pharmacology; D012018:Reflex / Q000187:drug effects*
D000316:Adrenergic alpha-Agonists; D010656:Phenylephrine; D004837:Epinephrine