猫颅脑火器性伤早期软脑膜血管管径及血流量变化

Early-stage changes of caliber and blood flow of cat pial microvessels following craniocerebral missile wound

目的研究猫在低速弹所致火器性颅脑损伤(CMW)后软脑膜微循环的改变.方法用气枪制作猫CMW模型,观察损伤前后软脑膜微血管的管径(D)、血流速度(V)、血流量(Q)及脑组织的病理学变化.结果(1)软脑膜细动脉Da、Va和Qa在伤后5～20 min期间明显降低,45 min后逐渐恢复,并且Qa和Da超过伤前水平.(2)伤后软脑膜细静脉Dv即超过伤前水平,而Vv伤后一直偏低,Qv在45min后升高超过伤前呈淤血状态.结论(1)CMW后出现微循环障碍,导致脑缺血缺氧,引起神经功能障碍;(2)CMW45 min后挫伤区、震荡区脑微循环出现代偿性微血管血流量增加,进一步导致缺血后再灌流损伤.

Objective To investigate the early-stage changes of cerebral microcirculation after craniocerebral missile wound (CMW) in cats. Methods Twelve mongrel cats of either sex were used for measuring the caliber (D), velocity (V) and blood flow (Q) of the pial microvessels and observing the vital signs 10 min before CMW and from 5 min to 5 h after CMW. The pathological changes of the brain tissue were also examined. Results After CMW, the D, V and Q of the pial arteriole decreased within the initial 5 to 20 min, followed by elevation of Da and Qa at 90 min. No significant changes were noted in the Dv of the pial venule but its Vv and Qv remained at low levels. Conclusion After CMW, the Q of microvessels may increase progressively in the areas of concussion, contusion and laceration injuries to induce reperfusion injury following ischemia and hypoxia of the brain tissue resulting from microcirculation disorder caused by the wound.