Strial circulation impairment due to acoustic trauma.

Blood circulation in the cochlear lateral wall after exposure to a non-physiological level of sound (120-125 dB SPL, 3 h) was investigated immunohistologically. Kanamycin (KM), which was expected to function as a tracer of blood flow, was administered to guinea pigs 5 min to 21 h after sound termination. At 5-30 min, KM was scarce in the capillaries of the stria vascularis (CSVs), whereas abundant KM was present in the spiral ligament vessels. These findings differed markedly from those in non-sound-exposed animals. After the initial period, KM gradually did enter into the CSVs, but its pattern of existence there differed from the normal pattern. These observations suggest that acoustic trauma causes blood stagnation in the strial capillaries, leading to strial dysfunction.