The functional changes in the basilar artery due to overpressure blast injury (685.1)

Abstract

Overpressure blast‐wave induced brain injury (OBI) leads to progressive pathophysiological changes resulting in a reduction in brain blood flow, blood brain barrier breakdown, edema and ischemia. The aim was to evaluate cerebral vascular function after single and repeated OBI. Male Sprague Dawley rats (250‐300 g) were divided into 3 groups: Control (Naive), single OBI [30 psi peak pressure, 1‐2 msec duration], and repeated (every three days) OBI (r‐OBI). Rats were sacrificed 24 h post injury (8th day) and the basilar artery was cannulised in the pressurized system (90cm H2O). Vascular responses to KCl (30‐50‐100 mM) endothelin (10‐11‐10‐7 M), acetylcholine (ACh) (10‐9‐10‐4 M) and diethylamine (DEA)‐NONO‐ate (10‐9‐10‐4 M) were evaluated.OBI resulted in an increase in the contractile responses to endothelin and a decrease in the relaxant responses to ACh in both single and repeated injury groups. However, impaired DEA‐induced dilation and increased wall thickness to lumen ratio were observed only in the r‐OBI group.These findings indicate that single OBI causes endothelium‐dependent and ‐independent alterations in cerebral vascular function and repeated injury results in increased arterial wall thickness.Grant Funding Source: This work was supported by the Medical Research Service of the Department of Veterans Affairs, McKni