title: [Cardiovascular effects of MY-5116 and MY-1250].
abstract: The effects of MY-5116, isoamyl 5,6-dihydro-7,8-dimethyl-4,5-dioxo-4H-pyrano [3,2-c]quinoline-2-carboxylate, an anti-allergic drug, and MY-1250, an active metabolite of MY-5116, on the cardiovascular system were studied in dogs, rats and guinea pigs. Orally administered MY-5116 (300 mg/kg) had no effect on the cardiovascular system in anesthetized dogs and conscious rats. In anesthetized dogs, MY-1250 and disodium cromoglycate (DSCG) caused hypotension, bradycardia and reduction of respiration rate from the doses of 3 and 10 micrograms/kg, i.v., respectively. Both drugs showed a tachyphylaxic phenomena which was crossed with each other. MY-1250-induced cardiovascular effects were abolished by bilateral vagotomy. MY-1250 (3-30 micrograms/kg, i.v.) caused a decrease of carotid blood flow, a transient decrease followed by a slight increase of renal blood flow, and a transient increase followed by a slight decrease of femoral blood flow in anesthetized dogs. MY-1250 had no effect on sympathetic ganglion, but increased the contractile force of isolated left atria from guinea pigs at 10(-5) g/ml and increased its rate at 10(-4) g/ml. These positive inotropic and chronotropic effects were not influenced by reserpinization. MY-1250 had no effect on the norepinephrine-induced dose-response curve in isolated rat aorta.
mesh_terms: D000818:Animals; D001158:Arteries / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002319:Cardiovascular System / Q000187:drug effects*; D004205:Cromolyn Sodium / Q000494:pharmacology; D004285:Dogs; D004562:Electrocardiography; D005260:Female; D005728:Ganglia, Sympathetic / Q000187:drug effects; D006168:Guinea Pigs; D006339:Heart Rate / Q000187:drug effects; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D008297:Male; D009541:Nictitating Membrane / Q000187:drug effects; D011804:Quinolines / Q000494:pharmacology*; D015363:Quinolones; D051381:Rats; D011919:Rats, Inbred Strains; D012119:Respiration / Q000187:drug effects
chemical_list: D007166:Immunosuppressive Agents; D011804:Quinolines; D015363:Quinolones; C048522:repirinast; C049488:MY 1250; D004205:Cromolyn Sodium