Objective To observe the expression of catechol-O-methyltransferase(COMT)in inferior colliculus and auditory cortex of guinea pigs with age-related hearing loss(AHL)induced by D-galactose

so as to explore the possible mechanism of electroacupuncture(EA)underlying preventing AHL.Methods Thirty 3-month-old guinea pigs were randomly divided into control group

model group and EA group(n=10in each group)

and ten 18-month-old guinea pigs were allocated as elderly group.The AHL model was established by subcutaneous injection of D-galactose.EA was applied to bilateral"Yifeng"(SJ 17)and"Tinggong"(SI 19)for 15 min in the EA group while modeling

once daily for 6weeks.After treatment

the latency of auditory brainstem response(ABR)Ⅲ wave was measured by a brain-stem evoked potentiometer.The expressions of COMT in the inferior colliculus and auditory cortex were detected by Western blot.Results Compared with the control group

the latencies of ABRⅢwave were significantly prolonged and the expressions of COMT in the inferior colliculus and auditory cortex were significantly decreased in the model group and the elderly group(P<0.05).After the treatment

the latency of ABRⅢ wave was significantly shortened and the expressions of COMT in the inferior colliculus and auditory cortex were significantly increased in the EA group in comparison with the model group(P<0.05).Conclusion EA at"Yifeng"(SJ 17)and "Tinggong"(SI 19)can improve the hearing of age-related deafness in guinea pigs

which may contribute to its effect in up-regulating the expression of COMT in the inferior colliculus and auditory cortex.