Korean J Anesthesiol.  1995 Mar;28(3):376-384. 10.4097/kjae.1995.28.3.376.

Effects of Calcium and Potassium Channel Blockers on Local Anesthetics-Induced Relaxation in Rat Thoracic Aortic Rings

• Kim HG
• Park SS
• Park JW

• KMID: 1934355
• DOI: http://doi.org/10.4097/kjae.1995.28.3.376

Abstract

This study was designed to evaluate the effects of calcium and potassium channel blockers on local anesthetics-induced vascular relaxation of isolated rat thoracic aorta. In the presence of lidocaine and bupivacaine, the aortic rings previously contracted with phenylephrine(10(-4)M) were slightly contracted at the beginning of the administration of local anesthetics. But in the presence of tetracaine, aortic rings were not contracted at the beginnings. Verapamil, diltiazem and nifedipine in concentration of 10(-9)M to 10(-5)M produced cumulative concentration-dependent vasorelaxation significantly in the aortic rings previously contracted with phenylephrine(10(-4)M). In the presence of lidocaine, bupivacaine and tetracaine, verapamil, diltiazem and nifedipine in concentration of 10(-9)M to 10(-5)M caused dose-dependent vasorelaxation in aortic rings significantly. Tetraethylammonium HCl(TEA) in concentration of 10(-9)M to 10(-5)M did not produce dose-dependent vasorelaxation but slight contraction showed at the beginning of the administration. In the presence of lidocaine, bupivacaine, TEA in concentration of 10(-9)M to 10(-5)M did not produce vasorelaxation remarkably. But in the presence of tetracaine, TEA in concentration of 10(-9)M to 10(-5)M produced cumuIative concentration-dependent vasorelaxation significantly. These findings suggest that local anesthetics, especially tetracaine, which interact with calcium and potassium channel bleckers, lead to blockade of the sodium and calcium channels as well as potassium channels.

Keyword

Local anesthetics; Calcium channel blockers; Potassium channel blockers; Aortic rings

MeSH Terms

Anesthetics, Local
Animals
Aorta, Thoracic
Bupivacaine
Calcium Channel Blockers
Calcium Channels
Calcium*
Diltiazem
Lidocaine
Nifedipine
Potassium Channel Blockers*
Potassium Channels*
Potassium*
Rats*
Relaxation*
Sodium
Tea
Tetracaine
Tetraethylammonium
Vasodilation
Verapamil
Anesthetics, Local
Bupivacaine
Calcium
Calcium Channel Blockers
Calcium Channels
Diltiazem
Lidocaine
Nifedipine
Potassium
Potassium Channel Blockers
Potassium Channels
Sodium
Tea
Tetracaine
Tetraethylammonium
Verapamil