title: Haemodynamic effects of Ro 13-6438, a new inotropic agent with vasodilating properties.
abstract: The chemical class 1,5 dihydroimidazo (2,1-6) guinazolin-2(3H)ones has been shown to have positive inotropic activity, some of its members displaying a favourable ratio between positive inotropic and chronotropic activity. This study was designed to determine the cardiovascular properties of Ro 13-6483, a non-glycoside, non-catechol positive inotropic agent, in anaesthetized, open chest mongrel dogs. Ro 13-6483 (1 mg/kg) was administered intravenously over a 5-min period to 6 dogs. Haemodynamic changes were measured continuously over a period of 45 min. Ro 13-6438 increased stroke volume by 61.9% (p less than 0.001) and cardiac output by 53.3% (p less than 0.001). Systolic and diastolic blood pressure decreased significantly (p less than 0.01). Heart rate did not change. The lowering of the blood pressure, without a significant increase in heart rate, observed after Ro 13-6483 administration might prove to be of value in patients with congestive heart failure, since Ro 13-6483 would reduce afterload and improve the competency of the heart, in addition to the positive inotropic effects.
mesh_terms: D000818:Animals; D004285:Dogs; D004353:Drug Evaluation, Preclinical; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D011799:Quinazolines / Q000494:pharmacology*; D013268:Stimulation, Chemical; D014665:Vasodilator Agents
chemical_list: D011799:Quinazolines; D014665:Vasodilator Agents; C040850:quazinone