tailieunhanh - báo cáo hóa học: " N-Acetyl L-Cysteine does not protect mouse ears from "

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: N-Acetyl L-Cysteine does not protect mouse ears from | Davis et al. Journal of Occupational Medicine and Toxicology 2010 5 11 http content 5 1 11 JOURNAL OF OCCUPATIONAL MEDICINE ANDTOXICOLOGY RESEARCH Open Access N-Acetyl L-Cysteine does not protect mouse ears from the effects of noise Rickie R Davis 1 2 David A Custer2 Edward Krieg3 and Kumar Alagramam4 Abstract Background Noise-induced hearing loss NIHL is one of the most common occupational injuries in the United States. It would be extremely valuable if a safe inexpensive compound could be identified which protects worker hearing from noise. In a series of experiments Kopke has shown that the compound N-acetyl-L-cysteine L-NAC can protect the hearing of chinchillas from the effects of a single exposure to noise. L-NAC is used in clinical medicine and is very safe. Although L-NAC was reported to be promising it has not been successful in other studies Kramer et al. 2006 Hamernik et al. 2008 . The present study was undertaken to determine if L-NAC could protect C57BL 6J B6 mice from the permanent effects of noise. Method Two groups of five B6 mice were injected with either 300 or 600 mg kg L-NAC approximately 1 hr prior to a 104 dB broadband noise exposure and again immediately after the exposure. A control group N 7 was exposed to the same noise level but injected with vehicle sterile saline . Auditory brainstem response measurements were made at 4 8 16 and 32 kHz one week prior to and 12 days after exposure. Conclusions There were no statistically significant differences in ABR threshold shifts between the mice receiving L-NAC and the control mice. This indicates that L-NAC was not effective in preventing permanent threshold shift in this mouse model of NIHL. Background The inbred mouse strain C57BL 6J B6 has been shown to be more susceptible to noise-induced hearing loss NIHL than the CBA CaJ strain 1 . This phenotype has been traced to a mutation of the gene coding for cadherin 23 Cdh23 2 . Staecker et al. 3 demonstrated that the antioxidant .