부산대학교 도서관

Objective: To study the auditory changes caused by chromium and the possible antagonistic effects of copper and manganese against these changes. Material and method: 20 male and 20 female Wistar rats were randomly divided into four equal groups (control group, Cr poisoning group, and Cu or Mn protective group). After 30d raising, the auditory brainstem responses (ABR) were performed and the level of element Cr in the rat serum was determined. Results: Exposure of rats to K2Cr2O7 provoked auditory damages with the flatness of the ABR waves and a significant prolongation of I and II latencies in ABR waves (p < 0.05). These ABR changes were significantly attenuated in rats of the protective groups. The peaks of ABR waves in the poisoning group were obviously reduced compared with the control group (p < 0.05). The two protective groups showed different recoveries compared with the poisoning group in the wave peaks and the wave latencies. The concentration of serum Cr in the poisoning group (0.3780 mg/I) was about 2.38 times the control group (0.1586 mg/I) and 1.56 and 1 .28 times the protective group respectively. Conclusions: Chromium toxicity made certain damages to the auditory function of rats. The hearing function of copper and manganese protective groups obtained a certain restoration. [ABSTRACT FROM AUTHOR]