Korean J Anesthesiol.  1999 May;36(5):876-882. 10.4097/kjae.1999.36.5.876.

Effects of L-NAME, Aminoguanidine and Hydroxocobalamin on Aortic Contractile Responses in Endotoxemic Rats during Halothane Administration

• Park JW
• Lim DG
• Seo JK
• Baek WY
• Hang JG
• Kim BK

• KMID: 2240080
• DOI: http://doi.org/10.4097/kjae.1999.36.5.876

Abstract

BACKGROUND: Recent studies demonstrated that volatile anesthetics suppress the NO-cGMP system in the vascular system. It has been known that the hemodynamic changes produced by volatile anesthetics in septic patients are mediated by upregulation of iNOS leading to excessive release of NO. The mechanisms underlying suppression of the NO-cGMP system by anesthetics are still controversial. It has been elucidated that nitric oxide synthase (NOS) plays a major role in the regulatory function in the L-arginine-NO system. So we examined the effects of NOS inhibitor (L-NAME, aminoguanidine) and NO scavenger (hydroxocobalamin) on vascular smooth muscle contractile function in lipopolysaccharide (LPS)-treated rat aorta during halothane administration.
METHODS
Aortic ring preparations were obtained from LPS-treated (1.5 mg/kg, ip, for 18 h) rats. We evaluated the effects of hydroxocobalamin, L-NAME and aminoguanidine on contractile responses to phenylephrine during halothane (1 & 2 MAC) administration respectively. Statistical significances (P<0.05) were analyzed according to data characterictics by repeated measures ANOVA test and student's t-test.
RESULTS
The contractile responses to phenylephrine in LPS-treated rats aorta were significantly (P<0.05) increased in the presence of hydroxocobalamin and L-NAME. During the halothane (1 and 2 MAC) administration, the contractile responses to phenylephrine in LPS-treated rats aorta were increased significantly (P<0.05) in the presence of hydroxocobalamin and L-NAME.
CONCLUSIONS
From these results, it is suggested that hydroxocobalamin and L-NAME may be useful in the therapy of septic shock.

Keyword

Anesthetics, volatile, halothane; Enzymes, nitric oxide synthase inhibitors, L-NAME, aminoguanidine, hydroxocobalamin; Toxicity, lipopolysaccharide

MeSH Terms

Anesthetics
Animals
Aorta
Halothane*
Hemodynamics
Humans
Hydroxocobalamin*
Muscle, Smooth, Vascular
NG-Nitroarginine Methyl Ester*
Nitric Oxide Synthase
Phenylephrine
Rats*
Shock, Septic
Up-Regulation
Anesthetics
Halothane
Hydroxocobalamin
NG-Nitroarginine Methyl Ester
Nitric Oxide Synthase
Phenylephrine