Effects of Nitric Oxide Scavenger, Carboxy-PTIO on Endotoxin-Induced Alterations in Systemic Hemodynamics in Rats

Abstract

The present experiments were conducted to clarify the mode of cardiovascular action of carboxy-2-phenyl-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide(carboxy-PTIO), a nitric oxide(NO)scavenger, during rat endotoxic shock by determining cardiac output and systemic arterial tone simultaneously.Lipopolysaccharide(LPS)(10mg/kg, i.v.) decreased systemic blood pressure and cardiac output with transient increases in hematocrit and total vascular resistance.Administration of carboxy-PTIO(1.7mg·kg^-1·min^-1, i.v.for 60min) at 90min after LPS attenuated further decline in blood pressure and cardiac output without affecting changes in hematocrit or total vascular resistance.It is concluded that carboxy-PTIO attenuates endotoxin-induced hypotension predominantly by maintaining cardiac output in rat experimental endotoxic shock.