ABSTRACT
To examine the significance of heat shock protein 70 mRNA in ototoxicity resulted from gentamicin (GM), twenty healthy albino guinea pigs (200-250 g) of either sex with a positive Prier reflex were divided into two groups randomly. In GM group the animals received 100 mg/kg GM daily by intraperitoneal injection for 10 d. In saline control group the animals received 2.5 ml/kg saline daily by intraperitoneal injection for 10 d. Auditory brainstem response (ABR) thresholds were recorded in each animal before and 1 d after GM or saline administration. After the second ABR measurement, the expression of HSP70 mRNA in guinea pig cochlea was observed with in situ hybridization and image quantitative analysis system. The results showed that the threshold of ABR in the GM group was significantly higher than that of the saline control (P< 0.001). The expression of HSP70 mRNA was more intensive in stria vascularis, spiral ligament and spiral ganglion cells in the GM group than that of the saline control group. These results suggest that administration of gentamicin can induce the expression of HSP 70 mRNA in guinea pig cochlea, and that this effect may protect hearing function from ototoxicity.
Subject(s)
Animals , Female , Male , Cochlea , Metabolism , Evoked Potentials, Auditory, Brain Stem , Physiology , Gentamicins , Toxicity , Guinea Pigs , HSP70 Heat-Shock Proteins , Genetics , RNA, Messenger , Genetics , Random AllocationABSTRACT
<p><b>AIM</b>To explore the effects of gentamicin ototoxicity on the expression of heat shock protein 70 in guinea pigs cochlea.</p><p><b>METHODS</b>We used immunohistochemistry staining and image quantitative analysis system, combined with auditory brainstem response (ABR) measurement to investigate the change on the expression of HSP70 in guinea pigs cochlea of gentamicin ototoxicity.</p><p><b>RESULTS</b>The levels of HSP70 immunoreactivity in guinea pigs cochlea of experimental animals were high including Corti's organ, stria vascularis, medial spiral limbus, spiral ganglion cells and the threshold of ABR was in high correlation with the expression of HSP70 ([ r] > 0.8, P < 0.01).</p><p><b>CONCLUSION</b>Gentamicin can induce expression of HSP 70 in guinea pigs cochlea and protect hearing function.</p>