Jpn. J. Pharmacol. 82 (3), 261-264 (2000)

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

Katsuyuki Miura¹, Shinya Yamanaka¹, Tsuneyuki Ebara¹, Michiaki Okumura²,
Masahito Imanishi², Shokei Kim¹, Tatsuya Nakatani³ and Hiroshi Iwao<sup>1


1</sup>Departmentﾊof Pharmacology and ³Department of Urology, Osaka City University Medical School, Osaka 545-8585, Japan
²OsakaﾊCity General Hospital, Osaka 534-0021, Japan

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) (10ﾊmg/kg,ﾊi.v.) decreased systemic blood pressure and cardiac output with transient increases in hematocrit and total vascular resistance. Administration of carboxy-PTIO (1.7ﾊmgﾊ睫kg^-1ﾊ睫min^-1,ﾊi.v. for 60ﾊmin) at 90ﾊmin 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.

Keywords: Endotoxic shock, Nitric oxide, Carboxy-PTIO