The effects of repetitive vibration on sensorineural function: biomarkers of sensorineural injury in an animal model of metabolic syndrome

Abstract

Exposure to hand-transmitted vibration in the work-place can result in the loss of sensation and pain in workers. These effects may be exacerbated by pre-existing conditions such as diabetes or the presence of primary Raynaud's phenomena. The goal of these studies was to use an established model of vibration-induced injury in Zucker rats. Lean Zucker rats have a normal metabolic profile, while obese Zucker rats display symptoms of metabolic disorder or Type II diabetes. This study examined the effects of vibration in obese and lean rats. Zucker rats were exposed to 4 h of vibration for 10 consecutive days at a frequency of 125 Hz and acceleration of 49 m/s2 for 10 consecutive days. Sensory function was checked using transcutaneous electrical stimulation on days 1, 5 and 9 of the exposure. Once the study was complete the ventral tail nerves, dorsal root ganglia and spinal cord were dissected, and levels of various transcripts involved in sensorineural dysfunction were measured. Sensorineural dysfunction was assessed using transcutaneous electrical stimulation. Obese Zucker rats displayed very few changes in sensorineural function. However they did display significant changes in transcript levels for factors involved in synapse formation, peripheral nerve remodeling, and inflammation. The changes in transcript levels suggested that obese Zucker rats had some level of sensory nerve injury prior to exposure, and that exposure to vibration activated pathways involved in injury and re-innervation.

Changes in the expression of calcitonin gene-related peptide after exposure to injurious stretch-shortening contractions

“…The rate of axonal transport of CGRP from the DRG to the nerve terminal might also be slower in aged rats, or there may be a change in nerve conduction and release a of peptides from sensory neurons (Bergman and Ulfhake 2002). In a model of vibration-induced injury, the myelin sheath surrounding sensory nerves show signs of injury and changes in 2,3-cyclic nucleotide phosphatase (CNPase) suggesting that injury may affect myelin-nerve communication (Kiedrowski and others 2015). …”

Biomarkers in Patients with Hand-Arm Vibration Injury Entailing Raynaud’s Phenomenon and Cold Sensitivity, Compared to Referents

“…Data suggest there is an individual susceptibility to HAVS, possibly due to contributions from coexisting medical conditions, for e.g., diabetes neuropathy [2]. Different pathophysiological mechanisms such as localized structural injuries affecting peripheral nerves and blood vessels and systemic inflammatory processes may exist [3][4][5][6][7]. Elevated plasma levels of thrombomodulin (TM), a marker for endothelial damage, are higher in vibration-exposed than in non-exposed workers [8,9].…”