Cyclobenzaprine, a centrally acting muscle relaxant, acts on descending serotonergic systems.

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Kobayashi H, Hasegawa Y, Ono H

Cyclobenzaprine, a centrally acting muscle relaxant, acts on descending serotonergic systems.

Eur J Pharmacol. 1996 Sep 5;311(1):29-35.

PubMed ID

8884233 [ View in PubMed

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Abstract

The centrally acting muscle relaxant cyclobenzaprine was thought to be an alpha 2-adrenoceptor agonist that reduced muscle tone by decreasing the activity of descending noradrenergic neurons. In the present study, we examined the effects of cyclobenzaprine on descending neurons by measuring the monosynaptic reflex in rats. Cyclobenzaprine reduced the monosynaptic reflex amplitude dose dependently and this effect was not inhibited by the alpha 2-adrenoceptor antagonists idazoxan and yohimbine. Cyclobenzaprine-induced monosynaptic reflex depression was not attenuated by noradrenergic neuronal lesions produced by 6-hydroxydopamine. However, cyclobenzaprine inhibited monosynaptic reflex facilitation induced by (+/-)-1-(4-iodo-2,5-dimethoxyphenyl)-2-aminopropane, a 5-HT2 receptor agonist, in spinalized rats markedly, and 5-HT depletion by DL-p-chlorophenylalanine inhibited the depressive effect of cyclobenzaprine on the monosynaptic reflex. These results suggest that cyclobenzaprine is a 5-HT2 receptor antagonist and that its muscle relaxant effect is due to inhibition of serotonergic, not noradrenergic, descending systems in the spinal cord.

DrugBank Data that Cites this Article

Drugs

Cyclobenzaprine

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Cyclobenzaprine	5-hydroxytryptamine receptor 2A	Protein	Humans	Yes	Antagonist	Details