en Occupational Health Original Article <div style="text-align: justify;"><span style="font-size:10pt"><span style="line-height:150%"><span courier="" new="" style="font-family:"><span style="color:black"><b><span style="font-size:11.0pt"><span style="line-height:150%"><span arial="" style="font-family:">Background: </span></span></span></b><span style="font-size:11.0pt"><span style="line-height:150%"><span arial="" style="font-family:">This study aimed to determine the preventive effect of N-Acetylcysteine (NAC) against continuous noise-induced hearing loss.</span></span></span></span></span></span></span><br> <span style="font-size:10pt"><span style="line-height:150%"><span courier="" new="" style="font-family:"><span style="color:black"><b><span style="font-size:11.0pt"><span style="line-height:150%"><span arial="" style="font-family:">Materials & Methods:</span></span></span></b><span style="font-size:11.0pt"><span style="line-height:150%"><span arial="" style="font-family:"> A total of 24 adult male Wistar rats were randomly assigned into 4 groups of 6 animals: control, noise, noise and NAC, noise and saline. Animals were subjected to 102 dB (102&plusmn;0.5) of continuous, 8 kHz-centered high pass white noise. For two days before to noise, one hour prior to noise for ten days in a row, and two days after noise, NAC (325 mg/kg) was intraperitoneally administered. Temporary and permanent hearing loss were assessed by pre and post noise (1, 7 and 21 days) recordings of distortion product otoacoustic emissions (DPOAEs). </span></span></span></span></span></span></span><br> <span style="font-size:10pt"><span style="line-height:150%"><span courier="" new="" style="font-family:"><span style="color:black"><b><span style="font-size:11.0pt"><span style="line-height:150%"><span arial="" style="font-family:">Results:</span></span></span></b><span style="font-size:11.0pt"><span style="line-height:150%"><span arial="" style="font-family:"> Amplitudes was temporally reduced significantly first day post noise exposure in all groups, and all frequencies (P<0.05). The initial and subsequent recovery was more pronounced in noise-exposed animal treated with NAC compared to those received noise and saline, especially in higher frequencies (P<0.05). Noise and NAC group experienced less permanent hearing loss than noise and saline group (P<0.05). </span></span></span></span></span></span></span><br> <span style="font-size:10pt"><span style="line-height:150%"><span courier="" new="" style="font-family:"><span style="color:black"><b><span style="font-size:11.0pt"><span style="line-height:150%"><span arial="" style="font-family:">Conclusions:</span></span></span></b><span style="font-size:11.0pt"><span style="line-height:150%"><span arial="" style="font-family:"> NAC could partially improve permanent hearing loss after noise exposure However, temporary hearing loss was not affected by NAC.</span></span></span><span style="font-size:11.0pt"><span style="line-height:150%"></span></span></span></span></span></span></div> N-Acetylcysteine,Noise,Temporary,Permanent,Hearing Loss, 114 122 http://johe.rums.ac.ir/browse.php?a_code=A-10-594-1&slc_lang=en&sid=1 Raheleh Hashemi Habybabady habybabady_568@yahoo.com 22400319475328460010772 22400319475328460010772 No Assistant Prof., Health Promotion Research Center, Dept. of Occupational Health Engineering , Zahedan University of Medical Sciences, Zahedan, Iran. Zahedan University of Medical Sciences Mahdi Mohammadi memohammadi@yahoo.com 22400319475328460010773 22400319475328460010773 Yes Professor in Biostatistics, Dept. of Biostatistics & Epidemiology , Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran. Zahedan University of Medical Sciences Hossein Jafari jafari.h3209@gmail.com 22400319475328460010774 22400319475328460010774 No M.Sc in Occupational Health Engineering, Research Assistant, Occupational Health Engineering, Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran. Zahedan University of Medical Sciences Fatemeh Paridokht paridokht6379@gmail.com 22400319475328460010775 22400319475328460010775 No M.Sc in Occupational Health and Safety Engineering, Dept. of Occupational Health and Safety Engineering, Student Research Committee, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran. Isfahan University of Medical Sciences