Role of endothelium-derived relaxing factor on vascular reactivity in endotoxin-induced shock.

Abstract

Role of endothelium-derived relaxing factor on vascular reactivity in endotoxin-induced shock. Chinese J. Physiol. The present study showed that E. coli lipopolysaccharide (LPS; 5 mg/kg, i.v.) produced a maximal and significant reduction in mean arterial blood pressure in the anesthetized rat. Pretreatment with N omega-nitro-L-arginine (50 mg/kg, i.v.) produced an increase in mean arterial blood pressure and completely abolished the LPS-induced hypotension. In vitro, it was designed to analyse the mechanisms underlying the LPS-induced hypotension by using various contractile and relaxant agents. Phenylephrine and high-K(+)-induced contraction was less in mesenteric arterial rings from LPS-treated rats than in rings from control rats. The removal of endothelium significantly enhanced the contraction induced by phenylephrine and high-K+ in LPS-treated rats, whereas in control rats, only the contraction induced by phenylephrine was enhanced. In contrast, the relaxation elicited by acetylcholine, A23187, L-arginine and nitroglycerin was greater in mesenteric arterial rings from LPS-treated rats than those from control rats. However, the greater relaxation induced by acetylcholine in LPS-treated rats was completely abolished by N omega-nitro-L-arginine or methylene blue. Additionally, the acetylcholine-induced relaxation was absent by removal of the endothelium. These results suggest that LPS treatment induces the production of nitric oxide from vascular endothelial cells and/or smooth muscle cells then impair the contractile response to vasoconstrictors and enhance the relaxation to vasodilators in small mesenteric arteries.

• Authors: M H Yen, S J Chen, C C Wu
• Journal: The Chinese journal of physiology (Chin J Physiol) Vol. 36 Issue 4 Pg. 225-31 ( 1993) ISSN: 0304-4920 [Print] India
• PMID: 8020337 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Lipopolysaccharides
• Vasoconstrictor Agents
• Vasodilator Agents
• Nitroarginine
• Nitric Oxide
• Arginine

Topics

• Animals
• Arginine (analogs & derivatives, pharmacology)
• Blood Pressure (drug effects)
• Blood Vessels (drug effects, physiopathology)
• Endothelium, Vascular (physiology)
• In Vitro Techniques
• Lipopolysaccharides (antagonists & inhibitors, pharmacology)
• Male
• Mesenteric Arteries (drug effects)
• Muscle Contraction (drug effects)
• Muscle Relaxation (drug effects)
• Muscle, Smooth, Vascular (drug effects, metabolism, physiology)
• Nitric Oxide (biosynthesis, physiology)
• Nitroarginine
• Rats
• Rats, Sprague-Dawley
• Shock, Septic (physiopathology)
• Vasoconstrictor Agents (pharmacology)
• Vasodilator Agents (pharmacology)