Frequency dependent effects of vibration on nerve function, oxidative stress and inflammation.
Pacurari-M; Johnson-C; Krajnak-K
FASEB J 2010 Apr; 24(Meeting Abstracts):1054.2
Prolonged occupational exposure to hand-held vibrating tools leads to pain and reductions in tactile sensitivity, grip strength and manual dexterity. The goal of the current study was to use a rat-tail model to determine if vibration frequency influences factors related to sensorineural dysfunction. We tested the hypothesis that exposure to tail vibration (4 hr/day for 3 days) at a high frequency (250 Hz) would result in sensorineural dysfunction and greater increases in oxidative stress and inflammation in tail nerves than exposure to vibration at a lower frequency (62.5 Hz). Nerve function was assessed using transcutaneous electrical stimulation. Exposure to 250-Hz, but not 62.5-Hz vibration, resulted in an increased sensitivity of Aß- and A-nerve fibers to electrical stimulation. These changes in nerve fiber sensitivity were associated with increased expression of interleukin (IL)-1ß and tumor necrosis factor - in tail nerves, and a moderate increase in cyclooxygenase-2 gene expression. Circulating concentrations of IL-1 ß were also increased. Vibration exposure at both frequencies resulted in reductions in glutathione and glutathione peroxidase 3 levels in tail nerves. However gene expression for other oxidative factors and nitrotyrosine protein levels were significantly increased after exposure to vibration at 62.5 Hz, but not 250 Hz. These results demonstrate that the effects of vibration on sensorineural function and physiology are frequency dependent, and that changes in nerve function may be related to increases in inflammation and oxidative activity.
Exposure-assessment; Exposure-levels; Exposure-methods; Hand-tools; Laboratory-testing; Nerve-function; Nerves; Neurological-diseases; Neurological-reactions; Neuromotor-disorders; Neuromotor-system; Neuromotor-system-disorders; Occupational-diseases; Occupational-exposure; Occupational-hazards; Oxidative-metabolism; Oxidative-processes; Sensitivity-testing; Sensory-disorders; Sensory-motor-system; Vibration-disease; Vibration-effects; Vibration-exposure
Issue of Publication
The FASEB Journal. Experimental Biology 2010, April 24 - 28, 2010, Anaheim, California