title: Effects of the new calcium antagonist monatepil on cardiac function and myocardial oxygen supply and demand in animals.
abstract: The effects of monatepil ([(+/-)-N-(6,11-dihydrodibenzo[b,e]thiepin-11-yl)-4-(p-fluor ophenyl)-1- piperazinebutyramide]maleate, AJ-2615, CAS 103377-41-9), a new calcium antagonist, on cardiac function and myocardial oxygen supply and demand were examined. 1. Monatepil reduced the spontaneous beats of isolated rabbit atria at the concentration of 3 x 10(-6) and 10(-5) mol/l. Monatepil decreased the contractile force of papillary muscles in a concentration-dependent manner (3 x 10(-8)-10(-5) mol/l). 2. Monatepil (0.3 mg/kg i.v.) slightly decreased heart rate in anesthetized open-chest dogs. This drug (0.1, 0.3 mg/kg i.v.) increased cardiac output and decreased blood pressure and total peripheral resistance. Monatepil decreased left ventricular dP/dtmax and slightly increased left ventricular end-diastolic pressure. 3. Monatepil (0.1-1.0 mg/kg i.v.) did not affect the PR interval, QRS duration and QTc interval of electrocardiograms in anesthetized dogs, whereas diltiazem (0.3 and 1.0 mg/kg i.v.) markedly prolonged the PR interval. 4. Monatepil (0.1-0.3 mg/kg i.v.) increased coronary blood flow (CoBF) and decreased myocardial oxygen consumption (MOC) and extraction. 5. Monatepil and diltiazem showed almost the same effects on cardiac function and myocardial oxygen supply and demand, but the negative chronotropic and negative dromotropic effects of monatepil were less potent than those of diltiazem.
authors.affiliation: Department of Pharmacology, Dainippon Pharmaceutical Co., Ltd., Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kataoka
authors.forename: I
authors.initials: I
authors.lastname: Nose
authors.forename: Y
authors.initials: Y
authors.lastname: Honda
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.forename: N
authors.initials: N
authors.lastname: Hatano
authors.forename: Y
authors.initials: Y
authors.lastname: Masuda
authors.forename: K
authors.initials: K
authors.lastname: Hosoki
authors.forename: T
authors.initials: T
authors.lastname: Karasawa
mesh_terms: D000758:Anesthesia; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D003326:Coronary Circulation / Q000187:drug effects; D003988:Dibenzothiepins / Q000494:pharmacology*; D004110:Diltiazem / Q000494:pharmacology; D004285:Dogs; D004562:Electrocardiography / Q000187:drug effects; D005260:Female; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects*; D010210:Papillary Muscles / Q000187:drug effects / Q000378:metabolism; D010879:Piperazines / Q000494:pharmacology; D011817:Rabbits; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D000889:Anti-Arrhythmia Agents; D002121:Calcium Channel Blockers; D003988:Dibenzothiepins; D010879:Piperazines; D004110:Diltiazem; C067818:monatepil