缺氧缺血时新生鼠脑内t-PA活性的变化

目的：探讨缺氧缺血时新生鼠脑不同源性组织型纤溶酶原激活物（t-PA）活性的变化及其临床意义。方法：一日龄新生SD大鼠分为空白对照组、假手术组和3个缺氧和复氧时间不同的实验组（n=4)；体外培养鼠脑 微血管内皮细胞和星形胶质细胞，并分为空白对照组和缺氧组；取鼠脑组织和培养液测t-PA活性。结果：在动物组中以缺氧缺血组的t-PA活性最高，随着复氧时间的增加而下降（P＜0．01）；缺氧时鼠脑微内皮细胞t－PA活性增高，而星形胶质细胞t-PA活性无变化。结论：缺氧导致新生鼠脑内t-PA活性增高；随着缺氧改善，t-PA活性在一定程度上可以下降；缺氧时新生鼠脑内可能主要是微血管内皮细胞产生的t-PA活性增高，降解微血管基膜，破坏微血管的完整性，最终导致脑出血。

Activity of Tissue-type Plasminogen Activator in Rat Brain on Hypoxia

Objective\ To investigate variation in activity of the tissue\|type plasminogen activator(t\|PA) in rat brain on hypoxia and its clinical significance.\ Methods\ Neonatal SD rats were divided \{into\}: (1)control group, (2)false operation group, (3)hypoxic\|ischemia group, (4)surviving for 24 hours after hypoxic\|ischemia group, (5)surviving for 48 hours after hypoxic\|ischemia group,n=4.\ Brain microvascular endothelial cells and astrocytes were cultured in vitro in control and hypoxia group.\ Cerebral tissues and cultural fluids were measured for activity of t\|PA.\ Results\ The activity of t\|PA in hypoxic\|ischemic group was the highest in hypoxic\|ischemic group, and came down in the surviving.\ However, \{t\|PA\} activity of endothelial cells was enhanced, and astrocytes did not changed in hypoxia group in vitro.\ Conclusion\ Hypoxia can stimulate to raise the activity of t\|PA in the brain of neonatal rat, and t\|PA activity comes down as surviving.\ The t\|PA activity of microvascular endothelial cells rises in brain on hypoxia condition.\ It damages the basement membrane of cerebral microvessels and cerebral hemorrhage may occur finally.