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Mechanism of vibration‐induced vascular damage in rat‐tail artery
Author(s) -
Govindaraju Sandya Rani,
Bain James,
Riley Danny
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a33
Subject(s) - vacuole , vasoconstriction , vascular smooth muscle , lumen (anatomy) , chemistry , anatomy , extracellular , cytoplasm , medicine , biology , microbiology and biotechnology , smooth muscle
Years of powered tool use can lead to hand‐arm vibration syndrome, a vasospastic and neurodegenerative disease of the fingers. In our rat‐tail vibration model, vascular smooth muscle cells (VSMC) are injured in 4 hrs. They exhibit cell surface protrusions which appear as vacuoles at the light microscopic level. The mechanism of vibration‐induced VSMC injury was examined in the current study. Tails of male Sprague‐Dawley rats (292 ± 11 g) were vibrated for 4 hrs with or without general anesthesia. Vibration without anesthesia caused significant vasoconstriction (20% reduction in lumen size compared to sham vibrated without anaesthesia), and the contracting VSMC formed 44.8 ± 7.0 vacuoles. Anesthesia prevented vasoconstriction and vacuole formation during vibration. Additional rats had their tail arteries treated for 15 min with 1 mM norepinephrine in situ to induce vasoconstriction (44% reduction in lumen size compared to sham treated) and extensive vacuolation (112.4 ± 20.6). The anesthetized rats were then vibrated for 4 hrs to determine whether the vacuoles would be disrupted. In toluidine‐blue stained semithin sections, the VSMC lacked vacuoles and exhibited light and dark intracellular banding patterns. The extracellular matrix was filled with particulate material, which was confirmed to be cellular debris by electron microscopy. The present findings suggest that vibration damages vasoconstricted arteries by dislodging and fragmenting the VSMC protrusions. Loss of cell membrane and cytoplasm in these vacuoles may compromise VSMC function. Supported by Medical College of Wisconsin and in part by NIOSH grant R01 OH003493.