Anti-oxidant Mechanism Of TMP On Cochlea Hair Cell Damaged By Gentamycin

Objective To observe the effect of anti-oxidant of tetraethylplyrazine(TMP)on cochlea hair cell damaged by gentamycin(GM)and explore the protein expression and activity of Cu/Zn superoxide dismutase(Cu/Zn SOD or SOD1)Mn-superoxide dismutase(Mn SOD or SOD2)and ECSOD(SOD3)to discuss Anti-Oxidant mechanism.Methods 60 healthy guinea pigs were divided randomly into four groups:model group(GM group),therapy group(GM+TMP group),TMP group and normal control group,15 in each group.GM group:intramuscular injection of Gentamycin sulfate 120 mg-kg-1·d-1 for 12 days.TMP group:TMP 30 mg-kg-1·d-1 intraperitoneal injection for 12 days.GM+TMP group:intramuscular injection of Gentamycin sulfate 120 mg-kg-1·d-1,intraperitoneal injection of TMP 30 mg-kg-1·d-1 for 12 days.The normal control group:daily intramuscular injection of saline 2.5 ml·kg-1·d-1 for 12 days.The observation indexes were as follows:auditory brainstem response(ABR).HE stain.Immunohistochemical method and Western blot to test protein expression of SOD1,SOD2,SOD3.T-SOD,SOD1,SOD2 activity and MDA determination of Value.Results(1)The result of ABR show that:before treatment ABR threshold in each group showed no significant difference(P>0.05),after treatment,GM group ABR threshold is significantly higher than GM+TMP group(P<0.01),TMP group and the normal control group in the ABR threshold before and after treatment did not change significantly(P>0.05).(2)HE stain show:the normal control group cochlea tissue normomorph,model group cochlea has different degrees pathological injury,therapy group pathological injury is ligher than the model group,TMP group cochlea tissue is complete.(3)Immunohistochemical method show:on spiral ganglion,the protein expressi-on of SOD1,SOD2,SOD3 has no significant difference between model group an-d therapy group(P>0.05).On hair cells,therapy group has higher protein expression of SOD1,SOD2 than model group(P<0.05),and SOD3 protein exp-ression has no significant di-fference between each group(P>0.05).(4)Weste blot show;the height order of the protein expression of SOD1,SOD2,SO-D3:GM+TMP group>GM group>normal control group≈TMP group.(5)T-SOD,SOD1,SOD2 activity and MDA determination of Value:after treatment G-M group MDA significantly increased,compared with control group,GM+TMP group,TMP group(P<0.05).Control group,GM+TMP group and TM-P group has no signif-icant difference(P>0.05).T-SOD,SOD1,SOD2 activity in the cochlear tissue decreas-ed significantly in GM+TMP group,and higher than that in GM group(P<0.05),GM group is lower than control group(P>0.05).Conclusions GM can induce ototoxicity,and cause guinea pig’s cochlea hair cell damage.TMP can realize the anti-oxidant effect through adjust the protein expression of SOD1,SOD2,SOD3and the activity,and reduce MDA determinationof Value.