Korean J Anesthesiol.  1994 Oct;27(10):1229-1236. 10.4097/kjae.1994.27.10.1229.

Effects of Volatile Anesthetics on Isolated Rings of Thoracic Aorta in Rats

• Cho YH
• Baek WY
• Hong JG
• Park JW
• Kim BK

• KMID: 2240492
• DOI: http://doi.org/10.4097/kjae.1994.27.10.1229

Abstract

Halothane, enflurane, and isoflurane are generally regarded as vasodilators. This property has been attributed to a direct action on vascular smooth muscle or the inhibition of vasoconstricition by endogenous neurohumoral substances. Because of the importance of the endothelium in determining of modulating the vascular responses of a wide vareity of agents, vascular effects of halothane, enflurane and isoflaurane on isolated rings of thoracic aorta in Sprague-Dawley rats were studied in the presence and absence of intact endothelium. Halothane, enflurane and isoflurane induced relaxation on thoraeic aortic rings precan-tracted with 50mM KCl both with and without endothelium. Halothane also induced vasodilation in both aortic rings precontracted with 10-6 M phenylephrine. And enflurane and isoflurane induced vasodilation in denuded aortic rings precontracted with phenylephrine. But endothelium intact rings demonstrsted significant(p<0.05) vasoconstriction at low concentrations of both enflurane and isoflurane followed by vasodilation at higher concentra- tion precontracted with phenyephrine. These results suggest that at low concentration and intact rings, enflurane and isoflurane eause vasoconstriction through inhibition of basal EDRF production and /or stimulation of the release of an endothelium derived constricting factor. At higher concentration, a direct vasodilating effect of the anesthetic predominance.

Keyword

Inhalation anesthetics; vasorelaxation; EDRF

MeSH Terms

Anesthetics*
Anesthetics, Inhalation
Animals
Aorta, Thoracic*
Endothelium
Enflurane
Halothane
Isoflurane
Muscle, Smooth, Vascular
Phenylephrine
Rats*
Rats, Sprague-Dawley
Relaxation
Vasoconstriction
Vasodilation
Vasodilator Agents
Anesthetics
Anesthetics, Inhalation
Enflurane
Halothane
Isoflurane
Phenylephrine
Vasodilator Agents