Chlorzoxazone inhibits contraction of rat thoracic aorta.

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Dong DL, Luan Y, Feng TM, Fan CL, Yue P, Sun ZJ, Gu RM, Yang BF

Chlorzoxazone inhibits contraction of rat thoracic aorta.

Eur J Pharmacol. 2006 Sep 18;545(2-3):161-6. Epub 2006 Jun 29.

PubMed ID

16859676 [ View in PubMed

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Abstract

Chlorzoxazone has been reported to activate the intermediate-conductance, Ca(2+)-activated K(+) channels in aortic endothelial cells and to relax the artery. The aim of the present study was to characterize the chlorzoxazone-induced relaxation of rat thoracic artery. Chlorzoxazone did not affect the tension of the thoracic artery rings at rest, but relaxed the precontraction induced by 1 muM noradrenaline in an endothelium independent manner. Preincubation with chlorzoxazone also antagonized the contraction induced by 1 microM noradrenaline or 25 mM KCl. The chlorzoxazone-induced relaxation of the thoracic artery pre-contracted by noradrenaline was suppressed by 5 mM tetraethylammonium, 75 mM ethanol and 2 microM paxilline, but not by 2 microM clotrimazole. Chlorzoxazone relaxed the 4-aminopyridine-induced contraction. The pattern of chlorzoxazone-induced relaxation was different from that of verapamil, the L-type Ca(2+) channel blocker. The inhibition of the noradrenaline-induced contraction by chlorzoxazone was attenuated when chlorzoxazone treatment was prolonged to 4 h. No difference in the contraction-relaxation was found between the artery rings from normal rats and those from rats that received 100 mg/kg chlorzoxazone for 7 days. We conclude that chlorzoxazone abolishes the contraction of rat thoracic artery induced by noradrenaline and that the effect of chlorzoxazone is endothelium independent and also not mediated by intermediate-conductance, Ca(2+)-activated K(+) channels.

DrugBank Data that Cites this Article

Drugs

Chlorzoxazone

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Chlorzoxazone	Calcium-activated potassium channel subunit alpha-1	Protein	Humans	Yes	Not Available	Details