title: Influence of some antidepressant drugs on the circulatory system: II. Action of amitriptyline and nortriptyline on basic circulatory parameters.
abstract: Amitriptyline and nortriptyline in doses higher than 0.5 mg/kg exert a hypotensive action, and doses of less than 0-5 mg/kg have no characteristic effect on blood pressure. Both drugs diminished amplitude of cardiac contractions in situ in experimental animals. Low doses increased frequency and amplitude of respirations, and higher doses paralyzed respiratory function. Animals died as a result of paralysis of the respiratory center. In decapitated animals both drugs exhibited activity similar to that in animals with intact central nervous system, but their hypotensive effect was less pronounced. Blockade of the sympathetic and parasympathetic systems and of vegetative ganglia had no influence on the action of amitriptyline and nortriptyline on blood pressure. In low doses both amitriptyline and nortriptyline potentiated, and in high doses weakened the hypertensive effect of noradrenaline.
mesh_terms: D000639:Amitriptyline / Q000494:pharmacology*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002415:Cats; D004087:Dihydroergotamine / Q000494:pharmacology; D006439:Hemodynamics / Q000187:drug effects*; D066298:In Vitro Techniques; D009130:Muscle, Smooth / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology; D009661:Nortriptyline / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D011817:Rabbits; D012119:Respiration / Q000187:drug effects
chemical_list: D000644:Quaternary Ammonium Compounds; D000639:Amitriptyline; D004087:Dihydroergotamine; D001285:Atropine; D011433:Propranolol; D009661:Nortriptyline; D009638:Norepinephrine