Jun Takagi (1) and Norifumi Yonehara (2,*)
Departments of (1) Dental Anesthesiology and (2) Dental Pharmacology, Osaka University Faculty of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan
(*) To whom correspondence should be addressed.
Abstract: We examined the effects of intravenous injection of several serotonin (5-HT) antagonists on the inhibitory action of electro-acupuncture (EAP) against the nociceptive responses in the trigeminal nucleus caudalis in rabbits. The inhibitory effect of EAP was suppressed by pindolol, methysergide and ICS 205-930, whereas NAN-190 and ketanserin amplified the EAP effect. These results suggest that 5-HT1, except 5-HT1A; 5-HT2, except 5-HT2A; and 5-HT3 receptors are positively involved in EAP-induced analgesia, whereas the activation of 5-HT1A and 5-HT2A receptors suppressively act on EAP-induced analgesia.
Keywords: Electro-acupuncture, Evoked potential, Serotonin receptor subtype