[Effects of non-focused ultrasound on the cochlea in guinea pigs]

Guinea pigs with normal preyer's reflex were researched for the morphological and the enzymatic change of cochlea under the influence of 2.5 MHz, 8 MHz non-focused ultrasound irradiation for 3 hours or 6 hours. The results showed that no histopathological changes could be found. But enzyme histochemistry studies showed that 2.5 MHz or 8 MHz non-focused ultrasound irradiation for 6 hours has led to enervation of SDH activity and enhancement of LDH activity of hair cells in the 0.87 +/- 0.20 or 0.80 +/- 0.20 mm areas of the second circle or the first circle respectively. The results suggest that the non-focused ultrasound irradiation for some dose may cause special injury of cochlear hair cells.