OBJECTIVETo investigate the effect of noise on the antioxidant capacity in different regions of brain tissue in guinea pigs.

METHODSThirty male white red-eye guinea pigs were equally and randomly divided into five groups: 1-, 3-, 7-, and 14-day groups after noise exposure and control group. The guinea pigs of the experimental groups were exposed to steady white noise with a sound pressure level at 100 dB for 8 h per day and for 2 consecutive days. The auditory brainstem response (ABR) of guinea pigs, as well as the glutathione (GSH) level, methane dicarboxylic aldehyde (MDA) level, and superoxide dismutase (SOD) activity in the cerebrum, cerebellum, and hippocampus, was determined prior to and 1, 3, 7, and 14 days after noise exposure.

RESULTSAfter noise exposure, the shifts in ABR threshold of the experimental groups were significantly higher than that of the control group (P<0.05). Compared with those in the control group, the SOD activity and GSH level both significantly decreased in the cerebrum tissue of each experimental group after noise exposure (P<0.05) and MDA content significantly increased in the 1-day group (P<0.05). As for cerebellum tissue, the SOD activity and GSH level in the 7-day group were significantly lower than those in the control group (P<0.05), but there was no difference in MDA level between each experimental group and the control group (P>0.05). In comparison with those in the control group, the GSH and MDA levels in the 1-day group after noise exposure were significantly higher, and the GSH and MDA levels in the 3-day group and the MDA level in the 7-day group after noise exposure were significantly lower (all P<0.05).

CONCLUSIONNoise exposure can lead to hearing loss and affect the antioxidant capacity of brain tissue, which indicates that the improvement in antioxidant levels may alleviate noise-induced damage.