Purple noise-induced changes in the expression of SLC26A4 gene in cochlear tissue of rat

As one of the most important physical detrimental factors, purple noise can be considered similar to sounds that a wide range of people are exposed to in their workplaces. Also, cochlear tissue samples are the best tissue samples to evaluate gene expression and pathologic studies following noise exposure. Therefore, the aim of this study was to investigate the effects of purple noise on the expression of SLC26A4 gene in cochlear tissue. Methods & material: Totally, 10 male Wistar rats were used in this experimental study. Both N1 and N2 exposure groups were exposed to purple noise with sound pressure level of 115-120 dB and frequency range of 4-20 kHz. Histological tests were performed for pathological studies. Finally, the relative expression of SLC26A4 gene was determined by qRT-PCR technique. All experiments were conducted according to ethical standards of working with laboratory animals.

The results showed that the expression of SLC26A4 gene decreased significantly compared to the normal level in both N1 and N2 groups. The results of cochlear tissue pathology showed that the group exposed to purple noise for 6 days had more mechanical damage 7 days after cessation of exposure.

Significant decreased expression in SLC26A4 gene and permanent damage to the Reissner and Basal lamina membranes in the cochlear tissue and the auditory nerve ganglion leads to strengthening the incidence of advancing sensorineural hearing impairment and increases the likelihood of metastasis in cochlear tissue.