Korean J Anesthesiol.  2001 Mar;40(3):384-388. 10.4097/kjae.2001.40.3.384.

The Effect of Halothane and Enflurane on the Aorta Contracted with Phenylephrine in Rabbits

• Kwon OK
• Choi JH
• Kim ES
• Lee DW
• Shim JY

• KMID: 2236809
• DOI: http://doi.org/10.4097/kjae.2001.40.3.384

Abstract

BACKGROUND: Inhalation anesthetics have been known as vasodilators, but there are several reports that halothane and enflurane have different effects on vascular smooth muscles. Vasodilatation and vasoconstriction were observed in different vessels in the same animal. We tried to observe the effect of halothane and enflurane on the contraction of the aorta in rabbits.
METHODS
Isolated tracheal preparations of rabbits were used. Halothane (1.4%) and enflurane (1.4%, 2.8% and 5%) were administered after contractions induced by phenylephrine (10(-7) M), and verapamil (10(-7), 10(-6), 10(-5), 10(-4), and 10(-3) M) was administered. In the verapamil pretreated group, after a phenylephrine (10(-7) M) induced contraction, verapamil (10(-7) M) and enflurane (2.8% and 5%) were administered. The percentile contraction to the contraction induced by phenylephrine was evaluated.
RESULTS
The potentiation of the contration by phenypephrine was observed by halothane and enflurane administration and these potentiations disappeared with the adminstration of verapamil. With prior administration of verapamil, there was no potentiation of the contraction by enflurane.
CONCLUSIONS
Halothane and enflurane potentiates the contraction induced by phenylephrine in rabbit aortas. In addition, the influx of extracellular calcium seems to play a role in this potentiation of the contraction.

Keyword

Anesthetics gases; enflurane; halothane; Arteries: aorta

MeSH Terms

Anesthetics, Inhalation
Animals
Aorta*
Calcium
Enflurane*
Halothane*
Muscle, Smooth, Vascular
Phenylephrine*
Rabbits*
Vasoconstriction
Vasodilation
Vasodilator Agents
Verapamil
Anesthetics, Inhalation
Calcium
Enflurane
Halothane
Phenylephrine
Vasodilator Agents
Verapamil