Study On The Effects Of Chronic Renal Failure On Hearing And Its Mechanism

Objective: to observe the effects of chronic renal failure (CRF)on hearing and investigate its mechanism.Methods: twenty-nine male wistar rats were randomly divided into four groups: I the normal rats as control for 12 days (n=6); â…¡ rats given adenine(ig) for 12 days (n=8); â…¢the normal rats as contral for 24 days (n=6);â…£ rats given adenine(ig) for 24 days(n=9). The rat model of CRF was produced by being perfused of adenine [300mg/kg] for 12d and 24d. Brain-stem auditory evoked potential (BAEP) was utilized to evaluate the auditory function and renal tissue morphology was observed; Serum sampling was used to determine the content of Cr, BuN, K+, Na+, Ca2+, P3+, Fe3+, and Zn2+. The expression of NOSâ…¡ in the cochlear was measured by immunohistochemical technique. Results: after adenine given for 12d or 24d, the Cr, BnN, and P3+ were in significant higher level than that in control group. But the level of K+,Ca2+,Fe3+ and Zn2+ was decreased separately. The BAEP thresholds were gradually higher than that in control group, the BAEP delitescence prolonged,and there was asignificant prolonging interval-time of wave between the number I and number â…¤ wave (P<0. 05) .Light microscopic observation of renal tissue showed that the injury became more serious and the degree of fibrosis gradually higher. Data of immune histochemistry about the cochlear tissue showed that the expressions of NOS â…¡ were feebly positive in the cochlear vassal texture, inner-outer hairy cell and helical-ganglion cell,and following functional damage of the kidney, their expressions reinforcedgradually, amongst which the most strong expression was vassal texture, the next helical-ganglion cell, the last inner-outer hairy cell. Conclusion: CRF can result in deafness. It is likely concerned with toxic effects of the metabolizable substance, the metabolizable dysfunction of the electrolyte, shortage of trace elements, et al. One of the important mechanisms of the effects of CRF on hearing is the toxic damage of NO to cochlea.