新生小猪脑含氧量和O-酪氨酸在双侧颈动脉结扎和失血中的变化

采用小猪双侧颈动脉结扎伴失血模型检测双侧颈动脉的结扎伴失血对脑氧分压和O-酪氨酸变化的影响,结果发现小猪脑氧分压为(51±4)托.颈动脉结扎和失血后60min降为(10±1.5)托(P<0.001),当颈动脉恢复通畅和失血再灌注后,脑氧分压增至(40±6)托,此值与预试验时的脑氧分压无明显差异.对照组中脑纹状体中的O-酪氨酸的含量为(0.57±0.19)nmoles/g组织.缺血试验后1h其含量明显升为(29±0.5)nmoles/g组织(P<0.005),显示缺血后再灌注导致脑纹状体O-酪氨酸显著上升.提示组织中羟基产生增加,可能与新生小猪脑缺血和再灌注损伤有一定作用.

Brain Oxygen and O-Tyroxine Changes in Bilateral Carotid Ligation and Hemorrhage in Newborn Piglets

The goal of the present study was to determine the effect of bilateral carotid ligation and of bilateral carotid ligation with hemorrhange on the cortical oxygen pressure and changes in level of O-tyrosine,a marker of oxygen radical production.In sham operated animals the PcO2 was (51±4) Torr.During a 60minute period of ligation and bleeding thd PcO2 decreased to (10±1.5) Torr (P<0.001).At the end of the hour,release of ligation and reinfusion of the removed blood resulted in the PcO2 increasing to (40±6) torr,a value not significantly different from control.The level of O-tyrosine in the striatum of sham operated animals was (0.57±0.19)nmoles/g tissue.This increased significantly to (2.9±0.5)nmoles/g tissue (P<0.005) at one hour after release of the ligation.Our data show that reperfusion after ischemia produced by bilateral carotid ligation plus hemorrhage causes a statisticlly significant increase in the striatal level of O-tyrosine,indicating increased generation of hydroxyl radicals in the tissue.This increase in hydroxyl radicals can be at leat partly responsible for ischemia/reperfusion injury to newborn brain.