Increased oxidant activity mediates vascular dysfunction in vibration injury

Area of Science:

• Vascular physiology
• Occupational health
• Biomedical engineering

Background:

• Hand-arm vibration syndrome (HAVS) results from occupational exposure to vibrating tools.
• Vibration exposure can cause vascular, neurological, and musculoskeletal damage.
• The precise mechanisms of vibration-induced vascular dysfunction require further elucidation.

Purpose of the Study:

• To investigate the effects of acute vibration exposure on digital artery function.
• To explore the roles of nitric oxide (NO) and reactive oxygen species (ROS) in vibration-induced vascular changes.
• To identify potential therapeutic targets for mitigating vibration-induced vascular damage.

Main Methods:

• Rat paws were exposed to controlled vibration (125 Hz, 49 m/s²).
• Digital artery function was assessed in vitro using a pressure myograph system.
• Vascular responses were measured after exposure to agonists, endothelium denudation, and pharmacological interventions (L-NAME, catalase).
• Nitric oxide (NO) and reactive oxygen species (ROS) levels were quantified using fluorescent probes.

Main Results:

• Vibration exposure reduced digital artery constriction to phenylephrine and 5-hydroxytryptamine.
• This impairment was endothelium-dependent and linked to increased ROS levels and reduced NO activity.
• Inhibition of nitric-oxide synthase (NOS) or degradation of ROS with catalase restored normal vascular function.
• Increased ROS levels were associated with endothelial NOS (eNOS) uncoupling.

Conclusions:

• Acute vibration induces digital artery dysfunction by increasing ROS, likely via endothelial NOS uncoupling.
• Therapeutic strategies aimed at reducing ROS or boosting NO bioavailability may be beneficial for HAVS.
• This study provides insights into the pathophysiology of vibration-induced vascular injury.