KBB-Forum 2004 , Cilt 3, Sayı 4

THE PROTECTIVE ROLE OF TRIMETAZIDINE ON OXIDATIVE SYSTEM AND TEOAEs IN RABBITS EXPOSED TO NOISE

Mustafa Deniz YILMAZ, MD1; Tülay KÖKEN, MD2; Sefa DEREKÖY, MD1; Ahmet KAHRAMAN, MD2; Ali ALTUNTAŞ, MD1; Kürşat DUMAN, MD1; Oktay ÖZEL, MD1
1Department of ENT, University of Kocatepe, Afyon, Turkey
2Department of Biochemistry, University of Kocatepe, Afyon, Turkey Objective: Trimetazidine (TMZ) is an antianginal drug, which has potent antioxidant activity on various tissue. The aims of this study were to uncover the effects of noise exposure on oxidative status and hearing thresholds and to investigate possible protective role of drug TMZ on oxidative system and hearing thresholds.

Materials and Methods: Two groups of rabbits were used in this study and each group had eight rabbits. Eight rabbits in the first group (control group) were not given any treatment whereas TMZ (20 mg/kg p.o, tid, 7 days) was given to the other eight rabbits in the second group. TEOAE’s were recorded in all animals before and after noise exposure. As oxidative stress parameters plasma MDA levels as well erythrocyte GSH, GP and GR enzyme activities were measured in all rabbits. All the rabbits were exposured to noise (100 dB SPL, 1000 Hz, 1 h) and then TEOAEs were recorded again.

Results: In the first group, after noise exposure plasma MDA levels were found to be increased (p<0,05) whereas erythrocyte GSH, erythrocyte GP, erythrocyte GR levels were found to be decreased ( p<0,05). In the second group which was given trimetazidine plasma MDA levels were found to be increased (p<0,05) but erythrocyte GSH, erythrocyte GP, erythrocyte GR levels did not changed ( p>0,05) . TEOAEs after noise exposure were weaker in both groups, but reproducibility and signal noise ratio levels were higher in the second group (p<0.05).

Conclusions: It was shown in this study that cochlear damage due to noise exposure detected by OAE changes was prevented by TMZ in rabbits and this effect of TMZ is possibly mediated via its antioxidant properties. In our opinion, this drug which is used for treatment of ischemic heart diseases and episodic vertigo can play a role in prevention of noise induced hearing loss in people working in hazardous are as. Keywords : Cochlea, hearing loss, noise induced, trimetazidine, antioxidant