Insidious Cerebral Capillary Trauma from Motor Vehicle-Induced Vibration

Abstract

Cumulative cerebral injury from motor vehicle-induced whole body vibration has not been demonstrated thus far. Our lab has demonstrated isolated cerebral injury from whole body vibration and we believe that repetitive vibration can cause cumulative insults, impairing cerebral function. A simulated motor vehicle-induced whole body vibration study was conducted with fifty-six Sprague-Dawley rats divided into seven groups (N=8): (1) 8-week control group; (2) 8-week vibration group (exposed to whole body vibration at 30 Hz and 0.5g acceleration for 4 hours/day, 5 days/week for 8 weeks); (3) 8-week vibration group with preconditioning human apolipoprotein A-I molecule mimetic (4F); (4) 8-week vibration group with post conditioning 4F peptide; (5) 8-week vibration group with pre and post conditioning 4F peptide; (6) 12-week control group; and (7) 12-week vibration group (exposed to the same vibration, 5 days/week for 12 weeks). At the end point, all rats were evaluated by brain histo-pathological studies. The pathology demonstrated capillary constriction with surrounding edema as well as thickened, uneven and damaged capillary walls. Capillary constriction reduces the oxygen supply to cerebral neurons, leading to neuronal damage. In the 12-week vibration group, each effect was more pronounced as compared to the 8-week vibration group. There was no prominent cerebral capillary damage in the 4F-peptide conditioning groups. This study showed cumulative cerebral injury from motor vehicle-induced whole body vibration and demonstrated the preventative effect of 4F-peptide conditioning.