TY - JOUR
T1 - Creatine and tempol attenuate noise-induced hearing loss
AU - Minami, Shujiro B.
AU - Yamashita, Daisuke
AU - Ogawa, Kaoru
AU - Schacht, Jochen
AU - Miller, Josef M.
N1 - Funding Information:
Supported by NIH DC 04058 and DC 05188, General Motors Corp., United Autoworkers Union, and the Ruth and Lynn Townsend Professorship of Communication Disorders. We wish to thank Hollie Valentine for her technical assistance.
PY - 2007/5/7
Y1 - 2007/5/7
N2 - To define the role of free radical formation and potential energy depletion in noise induced hearing loss (NIHL), we measured the effectiveness of tempol (free radical scavenger) and creatine (enhances cellular energy storage) alone and in combination to attenuate NIHL. Guinea pigs were divided into four treatment groups: controls, 3% creatine diet (2 weeks prior to noise exposure), tempol (3 mM in drinking water 2 weeks prior to exposure), and creatine plus tempol and exposed to 120 dB SPL one-octave band noise centered at 4 kHz for 5 h. The noise-only control group showed frequency-dependent auditory threshold shifts (measured by auditory brainstem response, ABR) of up to 73 dB (16 kHz) on day 1, and up to 50 dB (8 kHz) on day 10. Creatine-treated subjects had significantly smaller ABR threshold shifts on day 1 and on day 10. Tempol alone significantly reduced ABR threshold shifts on day 10 but not on day 1. ABR shifts after combination treatment were similar to those in the creatine group. Hair cell loss on day 10 was equally attenuated by creatine and tempol alone or in combination. Our results indicate that the maintenance of ATP levels is important in attenuating both temporary and permanent NIHL, while the scavenging of free radicals provides protection from permanent NIHL.
AB - To define the role of free radical formation and potential energy depletion in noise induced hearing loss (NIHL), we measured the effectiveness of tempol (free radical scavenger) and creatine (enhances cellular energy storage) alone and in combination to attenuate NIHL. Guinea pigs were divided into four treatment groups: controls, 3% creatine diet (2 weeks prior to noise exposure), tempol (3 mM in drinking water 2 weeks prior to exposure), and creatine plus tempol and exposed to 120 dB SPL one-octave band noise centered at 4 kHz for 5 h. The noise-only control group showed frequency-dependent auditory threshold shifts (measured by auditory brainstem response, ABR) of up to 73 dB (16 kHz) on day 1, and up to 50 dB (8 kHz) on day 10. Creatine-treated subjects had significantly smaller ABR threshold shifts on day 1 and on day 10. Tempol alone significantly reduced ABR threshold shifts on day 10 but not on day 1. ABR shifts after combination treatment were similar to those in the creatine group. Hair cell loss on day 10 was equally attenuated by creatine and tempol alone or in combination. Our results indicate that the maintenance of ATP levels is important in attenuating both temporary and permanent NIHL, while the scavenging of free radicals provides protection from permanent NIHL.
KW - ATP
KW - Antioxidant
KW - Guinea pig
KW - Hair cell
KW - Inner ear
KW - Reactive oxygen specie
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U2 - 10.1016/j.brainres.2007.02.021
DO - 10.1016/j.brainres.2007.02.021
M3 - Article
C2 - 17359945
AN - SCOPUS:34247142458
VL - 1148
SP - 83
EP - 89
JO - Molecular Brain Research
JF - Molecular Brain Research
SN - 0006-8993
IS - 1
ER -