[Effects of acetamidophenol on auditory in mice].

OBJECTIVE: The purpose of this investigation was to observe the effects of the Acetaminophen on auditory in mice.

METHOD: Regardless of male and female mice, healthy seven-year-old C57 mice were randomly divided into Acetaminophen low-dose group (150 mg/kg), Acetaminophen medium-dose group (300 mg/kg), Acetaminophen high-dose group(600 mg/kg) and control group. Then mice were tested for ABR to observe the changes of ABR's threshold in the zero, second, fourth and ninth day separately. The change of cochlea hair cells morphology was studied by immunofluorescent labeling. And HPLC detects the concentration of Acetaminophen in endolymph of mice cochlea.

RESULT: After 30 minutes following administration, the Acetaminophen in endolymph of mice cochlear can be assayed by high performance liquid chromatography (HPLC). Acetaminophen increased the hearing thresholds compared to the control group. Hearing thresholds increased significantly in the Acetaminophen at 9 d,compared to the control group (P < 0.05). After administered medium-dose and high-dose of Acetaminophen, on the 9th day with the time of giving medicine to all the groups strengthens, the ABR thresholds heightens. And the average threshold is (44.75 +/- 16.00) dB, (50.00 +/- 11.00) dB respectively. Hair cells damages could be observed in experimental group after operations.

CONCLUSION: Acetaminophen can pass through blood-labyrinth barrier to the inner ear. These data demonstrate that taking certain acetaminophen can induce hearing impairment in mice.