抄録
In the living hair cells of the inner ears in anesthetized guinea pigs, Nitro-BT and phosphate buffer mixture can penetrate into the hair cells and undergoes reduction in absence of the specific substrate, resulting in the production of formazan. This Nitro-BT reducibility of the hair cells is demonstrated in the inner ears taken from guinea pigs immediately after decapitation, too. In the present study, effect of freezing to temperatures from 0° to -30°C for 5 and 20 minutes followed by thawing on the Nitro-BT reducibility and SDH activity of the hair cells were investigated histochemically by perfusion with incubation medium. Freezing at -10°C and below for 20 minutes affected severely the Nitro-BT reducibility of the hair cells in the vestibular organs, resulting in conspicuous decrease in the formazan production. There was slight to moderate decrease in SDH activity of the hair cells in the vestibular organs after freezing to 0°C and below for 20 minutes. The present study suggests that the activities of the electron transport system and related dehydrogenase system in the hair cells of the vestibular organs are more sensitive to freezing injury than in the hair cells of the organ of Corti.
