Relationship between plasma NOx and cardiac and vascular dysfunction after LPS injection in anesthetized dogs

The relationship between plasma nitrite, nitrate, and nitric oxide (NOx), cytokines, and cardiac and vascular dysfunction after lipopolysaccharide (LPS) was studied in chronically instrumented anesthetized dogs. LPS was administered (1 mg/kg iv), and hemodynamics were recorded at baseline, every 15 min for 1 h, and every hour for an additional 14 h. Dramatic reductions in mean arterial pressure (−48 ± 6%), cardiac output (−40 ± 8%), stroke volume (−42 ± 9%), and first derivative of left ventricular pressure (LV dP/dt, −38 ± 7%) were seen within 1 h after injection of endotoxin. Cardiac output was not different from control by 9 h, whereas mean arterial pressure (−19 ± 7%), stroke volume (−32 ± 8%), and LV dP/dt (−21 ± 10%) remained significantly depressed from control. Total peripheral resistance was not significantly different from control. Therefore, the hypotension appears to be due to a reduction in cardiac function and not to vasodilation. Levels of plasma NOx were not different from control until 4 ...