Effect of nerve growth factor on guinea pig with hearing loss induced by noise

Objective To explore the therapeutic effect of nerve growth factor(NGF)in guinea pig with hearing loss caused by noise.Methods Forty-eightmale guinea pigs were randomly divided into four groups:control group,hearing impairment model group,acupuncture point injection group,and intraperitoneal injection group.Except for the control group,the rest groups were exposed to 100dB white noise for a whole week.The acupuncture point-injection group and the in traperitoneal injection group were injected with NGF into their acupuncture points and abdominal cavities separately.In the hearing impairment model groups,physiological saline was injected and the control group was with noinjection.The injections were once of each two-day for 4 weeks.Distortion product otoacoustic emission(DPOAE)was applied to observe the amplitude value before and after the noise exposure and the injections.Results The amplitude and signal to noise of DPOAE in hearing impairment model group were lower than that of the other groups obviously.The treamtent effects of the acupuncture point injection group was better than the in traperitoneal injection group,and the amplitude and signal-to-noiseratio of the acupuncture point injection group was significantly different after the treamtent(P<0.01).Conclusion NGF point injection is a newe ffective approach for the treatment of hearing impairment caused by noise.