The hearing protection of NGF to mimetic aging guinea pigs / 中国耳鼻咽喉头颈外科

ABSTRACT

OBJECTIVE To explore the function and mechanism of the apoptosis in cochlear of mimetic aging guinea pigs treated with NGF. METHODSThe twenty-four four-month-old guinea pigs which auricle reflex were sensitive were divided randomly into three groups A group were injected to abdominal cavity with physiological saline (2 ml/kg) ; B group were injected to abdominal cavity with 5 % D-galactose (300 mg/kg) ; C group were given 5 % D-galactose (300 mg/kg-) and NGF (1000 U/kg) respectively to abdominal cavity. Three groups had been treated two times a day for four consecutive weeks. All the guinea pigs were tested with auditory brainstem response (ABR) before the experiment and twenty-four hours after the last injection. All the guinea pigs were killed by decapitation. The cochlears were removed and fixed in different fixatives. The specimens were treated by a series of special process and the Corti organs were tested with terminal deoxynucleotidy1 transmission-mediated dUTP nick-end-labelling (TUNEL) and transmission electron microscopy respectively. RESULTS The ABR threshold of C group was apparently lower than that of B group (P