RUOLO DEL PATHWAY L-ARGININA/OSSIDO DI AZOTO NELL'IPOREATTIVITA VASCOLARE IN CORSO DI SHOCK SETTICO. STUDIO FARMACOLOGICO IN RATTI TRATTATI CON ENDOTOSSINA BATTERICA

Translated title of the contribution: The role of pathway L-arginine/nitric oxide on vascular hyporeactivity in septic shock. Pharmacological study of endotoxin-injected rats

M. A. Potenza, M. Serio, M. Montagnani, G. Mansi, S. Pece, D. Mitolo-Chieppa

Research output: Contribution to journalArticle

Abstract

Recent studies have provided evidence that administration of E. coli lipopolysaccharides (LPS) to rats produces vascular hyporeactivity to catecholamines and other vasoconstrictor agents. The present study was carried out ex vivo on mesenteric vascular bed from LPS-injected rats in order to investigate the causes of vascular hyporesponsiveness as well as the role of L-arg/NO pathway in resistance blood vessels, during septic shock syndrome. The involvement of L-arg/NO pathway was evaluated by administration of L-arg, which produced a decrease of perfusion pressure in LPS-treated rats, whereas it was ineffective in control rats. Under these experimental conditions, L-NAME or L-NNA, inhibitors of NO production were unable to prevent L-arg vasorelaxation. Furthermore, dexamethasone pretreatment in endotoxaemic rats significantly reduced the vasorelaxation by L-arg, whereas it was ineffective to reverse vascular hyporeactivity occurring in septic shock; moreover, dexametasone significantly increased initial contraction peak induced by NA. In order to evaluate whether vascular hyporeactivity could be due to defects in calcium-dependent mechanisms, we tested the effect of ET-1, a vasoconstrictor peptide released by endothelium. In LPS-treated rats, ET-1 was able to enhance the contractile response to NA much more than in control rats. Our findings suggest that hyporesponsiveness in septic shock syndrome may depend on both activation of the L-arg/NO pathway and alterations in post-receptor mechanisms involving calcium handling.

Translated title of the contributionThe role of pathway L-arginine/nitric oxide on vascular hyporeactivity in septic shock. Pharmacological study of endotoxin-injected rats
Original languageItalian
Pages (from-to)70-80
Number of pages11
JournalRivista Italiana di Biologia e Medicina
Volume15
Issue number3-4
Publication statusPublished - 1995

ASJC Scopus subject areas

  • Medicine(all)

Fingerprint Dive into the research topics of 'The role of pathway L-arginine/nitric oxide on vascular hyporeactivity in septic shock. Pharmacological study of endotoxin-injected rats'. Together they form a unique fingerprint.

  • Cite this