新生鼠缺氧缺血性脑损伤脑组织Na^+、K^+-ATPase活性变化

The observation of Na^+、K^+-ATPase activity in brain tissues of neonatal rat with HIBD

目的了解新生大鼠缺氧缺血性脑损伤(HIBD)脑组织Na+、K+-ATPase的活性变化,探讨在脑损伤脑水肿发生中的可能作用。方法健康7d龄SD大鼠随机分为对照组和HIBD模型组。HIBD组经右侧颈总动脉结扎后,吸入8%O21h,建立HIBD模型。对照组仅行假手术,不予颈总动脉结扎和缺氧。两组均于HIBD模型制成后6、24、48h和72h分别处死动物(各时间点动物24只),进行脑含水量观察。用定磷法测定脑组织匀浆Na+、K+-ATPase的活性。结果①HIBD新生鼠脑组织6、24、48h和72h Na+、K+-ATPase的活性呈进行性下降的趋势,较相应各对照组明显降低(P均<0.05),HIBD各时间段之间脑组织Na+、K+-ATPase的活性差异均有统计学意义(P均<0.05);②HIBD组6、24、48h和72h脑组织含水量均较对照组增加,差异有统计学意义(P均<0.05)。结论缺氧缺血损伤新生鼠脑组织Na+、K+-ATPase的活性降低,其变化趋势与损伤脑组织含水量及病理学改变趋势一致,提示,它可能在脑损伤时脑水肿的发生机制中具有作用。

Objective To detect the changes of Na^＋、K^＋-ATPase activity in the bran tissues of neonatal rat with HIBD and observe the relationship of Na^＋、K^＋-ATPase activity and the brain edema. Methods The HIBD model and grouping of rats were conducted as the reference 1.The 7day old SD rats were subjected to the ligation of right carotid artery（ischemia）, then they were put into a box full with 8% oxygen and 92% nitrogen for an hour （hypoxia）. The SD rats with HIBD model were divided into 4 groups, including 6,24,48h and 72h after setup of HIBD. The normal control groups were also divided into 4 groups same as HIBD groups. The changes of Na^＋、K^＋-ATPase activity were measured by detecting phosphor in all groups of the control and the HIBD. The brain water contents of both HIBD and the contrel groups were measured. Results①The activity of Na^＋、K^＋-ATPase in brain tissues was decreased significantly in HIBD group after 6h of HIBD compared with that in the control group and continued to fall in 24,48h and 72h groups of HIBD with time compared with those in the related control groups （P〈0.05）;②The brain water content was increased markedly after 6h of HIBD and increased further in 24,48h and 72h groups of HIBD with time compared with those in the control groups （P〈0.05）. Conclusion The decrease of Na^＋、K^＋-ATPase activity in rat brain tissues of HIBD was correlated with the brain water contents and the brain pathological changes of HIBD. The studies suggest that Na^＋、K^＋-ATPase possibly participated the mechanism of formation of brain edema during hypoxic-isehemic brain damage of rat.