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.
Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, 53226, USA.
Brian D
BD
Curry
Sandya R
SR
Govindaraju
James L W
JL
Bain
Lin Ling
LL
Zhang
Ji-Geng
JG
Yan
Hani S
HS
Matloub
Danny A
DA
Riley
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