Nifedipine pretreatment reduces vibration-induced vascular damage.
A rat-tail vibration model of hand-arm vibration was employed to test whether preemptive administration of nifedipine (5 mg/kg) to block vasoconstriction prevents vibration-induced arterial damage. The tails of vibrated and nifedipine-pretreated vibrated Sprague-Dawley rats were exposed continuously to 4 h of 60-HZ vibration at 49 m/s(2) rms. In nonvibrated anesthetized rats, the ventral tail arteries were bathed for 15 min in situ in 1 mM epinephrine or 1 mM norepinephrine to induce structural changes indicative of intense vasoconstriction. Arteries were processed for light and electron microscopy 45 min after treatment. Compared to sham control, 4-h vibration significantly (P < 0.01) reduced lumen size, generated endothelial disruption (7.0 +/- 2.6%), elevated nuclear factor of activated T cells c3 (NFATc3) expression in endothelial and smooth muscle cells, and increased smooth muscle cell vacuolization. The findings demonstrate that blockage of vibration-induced vasoconstriction with nifedipine prevents acute vascular damage. Smooth muscle and endothelial cells structurally altered by vasoconstriction are rendered susceptible to damage by vibration.
Curry
Brian D
BD
Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, 53226, USA.
Govindaraju
Sandya R
SR
Bain
James L W
JL
Zhang
Lin Ling
LL
Yan
Ji-Geng
JG
Matloub
Hani S
HS
Riley
Danny A
DA
D000818:Animals; D001158:Arteries / Q000187:drug effects*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000293:injuries / Q000378:metabolism; D008297:Male; D023421:Models, Animal; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000293:injuries / Q000378:metabolism; D050778:NFATC Transcription Factors / Q000378:metabolism; D009543:Nifedipine / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow / Q000187:drug effects; D013623:Tail / Q000098:blood supply; D014661:Vasoconstriction / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology*; D014732:Vibration / Q000009:adverse effects*
D050778:NFATC Transcription Factors; D014665:Vasodilator Agents; C445503:transcription factor NF-AT c3; D009543:Nifedipine