HEMODYNAMIC-EFFECTS OF PYRUVATE INFUSION IN DOGS

Purpose: Although pyruvate supplementation enhances endurance in human s and increases cardiac output in dogs, its effects on cardiac and per ipheral vascular function are not known. Thus, we assessed the cardiov ascular effects of pyruvate infusion. Materials and Methods: Aortic, l eft ventricular (LV), and pulmonary (Ppa) pressures and LV stroke volu me (SVlv; derived from aortic flow probe) were measured after thoracot omy in eight anesthetized dogs. LV area or volume changes were measure d using either an epicardial echocardiography (n = 6) or a conductance catheter (n = 2). LV end-systolic elastance (Ees(lv)) and preload rec ruitable stroke force (PRSF(lv)) relations, as estimates of contractil ity, were generated by transient inferior vena cava occlusion. Simulta neous stroke volume to arterial pressure relations during the occlusio ns were used to measure arterial elastance (Ea), and steady-state syst emic and pulmonary vascular resistances were used as measures of arter ial tone. Graded doses of pyruvate (8, 16, and 32 mg/kg/min), dobutami ne mine (positive control) and propranolol (negative control) and plac ebo (volume control) were sequentially given. Results: Dobutamine incr eased Ees(lv), PRSF(lv), whereas propranolol had the opposite effect o n Ees(lv) and PRSF(lv). Pyruvate at 32 mg/kg/min increased heart rate, Ppa, and SVlv and decreased LV end-diastolic area, and systemic vascu lar resistance without changing arterial pressure, Ees(lv), PRSF(lv), or Ea. Conclusions: We conclude that pyruvate infusion in normal dogs induces venodilation but does not alter either cardiac contractility o r arterial tone. Copyright (C) 1995 by W.B. Saunders Company