Objective: To observe the effect of electroacupuncture(EA) of acupoints on experimental cutaneous pruritus induced by intradermal injection of hydroxytryptamine(5-HT) in rats.Methods: For establishing cutaneous pruritus model

14 male Spraque-Dawley rats were randomly divided into normal saline(NS) group(n=6) and model group(n=8).Pruritus model was established by intradermal injection of(10 μL) of NS or 2% 5-HT at the nape of the neck.After injection

the rats were quickly put into an observation chamber and videotaped for(60 min).The scratching response toward the injected site was counted by playing back the video.Thereafter

other 48 rats were randomly allocated to post-anesthetization model(PAM) group(n=12)

EA-I group(n=12)

EA-II group(n=12) and sham-EA group(n=12).For rats of PAM group

pentobarbital sodium((40 mg/kg)) was injected intraperitoneally (2.5 h) prior to the injection of 5-HT.EA(4-(16 Hz)

1-(3 V)) was applied to unilateral "Quchi"(LI 11) and "Hegu"(LI 4) for EA-I group

"Zusanli"(ST 36) and "Sanyinjiao"(SP 6) for EA-II group

and "nonacupoints" nearby the above-mentioned 4 acupoints for sham-EA group after the rats were anesthetized.When the rats in EA and sham-EA groups regained consciousness from anesthesia

5-HT was injected intradermally.Results: Compared with NS group

the scratching times in model group increased significantly after injection of 5-HT(P<0.001).There was no significant difference between model group and PAM group in the scratching times(P>0.05).EA of LI11 and LI-4 or ST-36 and SP-6 could significantly reduce the rats' scratching times(P<0.01

0.05) in comparison with PAM group

and no statistical difference was found between two EA groups(P>0.05).Compared with PAM group

the scratching times of sham-EA had no marked changes

suggesting no inhibitory role of sham-EA on 5-HT induced itching reaction(P>0.05).Conclusion: Intradermal injection of 5-HT induces itching response

and EA can relieve the itching reaction and EA of acupoints has a special effect.