Effect of ascorbic acid on the numerical hair cell loss in noise exposed guinea pigs.

Two groups of guinea pigs were exposed to 1/3 octave band noise centered at 4 kHz, 113-118 dB SPL, for 2 h. The animals of the first group were treated with ascorbic acid (AA), 0.5 mg per 1 g of body mass injected intraperitoneally before noise exposure. The second group (control) was exposed without being treated. By means of the surface specimen method and consequent assessment of numerical atrophy of cochlear hair cells it was found that application of ascorbic acid before the noise exposure resulted in a lower or no loss of hair cells especially within the respective frequency segment of the basilar membrane. Possible protective effect of AA and/or the negative effect of hypovitaminosis "C" are discussed.