title: Vibration disrupts vascular function in a model of metabolic syndrome.
abstract: Vibration-induced white finger (VWF) is a disorder seen in workers exposed to hand-transmitted vibration, and is characterized by cold-induced vasospasms and finger blanching. Because overweight people with metabolic syndrome are pre-disposed to developing peripheral vascular disorders, it has been suggested that they also may be at greater risk of developing VWF if exposed to occupational vibration. We used an animal model of metabolic syndrome, the obese Zucker rat, to determine if metabolic syndrome alters vascular responses to vibration. Tails of lean and obese Zucker rats were exposed to vibration (125 Hz, 49 m/s(2) r.m.s.) or control conditions for 4 h/d for 10 d. Ventral tail arteries were collected and assessed for changes in gene expression, levels of reactive oxygen species (ROS) and for responsiveness to vasomodulating factors. Vibration exposure generally reduced the sensitivity of arteries to acetylcholine (ACh)-induced vasodilation. This decrease in sensitivity was most apparent in obese rats. Vibration also induced reductions in vascular nitric oxide concentrations and increases in vascular concentrations of ROS in obese rats. These results indicate that vibration interferes with endothelial-mediated vasodilation, and that metabolic syndrome exacerbates these effects. These findings are consistent with idea that workers with metabolic syndrome have an increased risk of developing VWF.
authors.affiliation: Engineering and Controls Technology Branch, National Institute for Occupational Safety and Health, 1095 Willowdale Rd, Morgantown, WV 26505, USA. kkrajnak@cdc.gov
authors.forename: Kristine
authors.initials: K
authors.lastname: Krajnak
authors.forename: Stacey
authors.initials: S
authors.lastname: Waugh
authors.forename: Claud
authors.initials: C
authors.lastname: Johnson
authors.forename: Roger
authors.initials: R
authors.lastname: Miller
authors.forename: Megan
authors.initials: M
authors.lastname: Kiedrowski
mesh_terms: D000818:Animals; D004198:Disease Susceptibility; D004730:Endothelium, Vascular / Q000503:physiopathology; D053421:Hand-Arm Vibration Syndrome / Q000503:physiopathology*; D008297:Male; D024821:Metabolic Syndrome / Q000503:physiopathology*; D009569:Nitric Oxide / Q000097:blood; D011897:Random Allocation; D051381:Rats; D011924:Rats, Zucker; D017382:Reactive Oxygen Species / Q000097:blood; D013623:Tail / Q000098:blood supply / Q000378:metabolism; D014664:Vasodilation
chemical_list: D017382:Reactive Oxygen Species; D009569:Nitric Oxide