Abstract
The effect of acoustic trauma on cochlear strial circulation was investigated immunohistologically in the guinea pig. Kanamycin was used as a tracer of blood flow. Moreover, histochemical examinations were made to reveal the emergence of free radicals in the cochlea following acoustic trauma. At 5 min (5 min after intense sound exposure 120–125 dB SPL, 3 h) the blood flow in the stria vascularis was greatly diminished. At 2 h the strial blood flow started to recirculate and at 6 h it appeared to have returned to normal. Superoxide anion radicals (O−2) emerged along the luminal membrane of the marginal cells of the stria vascularis at 5 min. O−2 disappeared at 30 min, but reappeared at 2 h. The cause of its emergence at 5 rnin was obscure. However, the strange phenemenon that O−2 emerged again at 2 h seemed ascribable to the re-circulation of strial blood flow after sound exposure.