Open AccessHemodynamic Effects of Inosine in Combination with Positive and Negative Inotropic Drugs
Author(s) -
Seesko Rc,
HeinzGerd Zimmer
Publication year - 1990
Publication title -
journal of cardiovascular pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.762
H-Index - 100
eISSN - 1533-4023
pISSN - 0160-2446
DOI - 10.1097/00005344-199008000-00011
Subject(s) - chronotropic , inosine , inotrope , verapamil , metoprolol , medicine , cardiac output , blood pressure , adenosine , heart rate , endocrinology , pharmacology , calcium
Inosine applied as a continuous i.v. infusion of 400 mg/kg/h for 20 min had a negative chronotropic and inotropic effect in closed-chest, anesthetized rats. In the presence of adenosine deaminase (ADA, 133 U/kg/h), the reduction in heart rate was abolished indicating that adenosine is responsible for that effect. However, the negative inotropic effect persisted. It was characterized by a 38 and 56% decrease in left ventricular systolic pressure (LVSP) and diastolic aortic pressure, respectively, a 24% decline in LV dp/dtmax and a 16% fall in cardiac output. Total peripheral resistance was diminished by 38%. Inosine in combination with ADA antagonized the noradrenaline-induced positive inotropic effect and the increase in cardiac output. On the other hand, i.v. bolus injection of noradrenaline in rats pretreated with inosine and ADA did not increase blood pressure and total peripheral resistance. Inosine administered in animals pretreated with the beta-receptor blocker metoprolol or with the calcium antagonist verapamil aggravated the negative inotropic effect. Inosine in combination with ADA caused a decline in cardiac output in metoprolol-pretreated rats that was more pronounced than that induced by inosine alone. However, in rats pretreated with verapamil, inosine did not cause a reduction in cardiac output.