目的：探讨胆红素神经毒性的作用环节，研究胆红素脑病发病机理。方法：72只新生7d SD大鼠随机分为对照组(C组)和实验组(T组)，T组又根据腹腔注射胆红素剂量的依次增加分为T1，T2，T3，T4和T5组。检测各组脑组织和血清中胆红素含量，定磷法测定脑组织中Na+ K+ ATP酶(Na+ K+ ATPase)活力。结果：给药后4 h和8 h均随着腹腔注射胆红素量的增加，血清总胆红素浓度、脑组织内胆红素含量逐渐增加，脑组织Na+ K+ ATPase活力则逐渐降低，除T1组外余各组与对照组相比差异均有显著性(P<0.05 或 0.01)；各实验组血清胆红素浓度4 h，8 h之间差异无显著性(P>0.05)，但脑组织内胆红素含量、Na+ K+ ATPase活力除T1组外各组4 h，8 h之间差异有显著性(P<0.05)。血清总胆红素浓度与脑组织内胆红素含量无相关性(r=0.28，P>0.05)，脑组织内胆红素含量与Na+ K+ ATPase活力呈负相关(r=-0.86，P<0.01)。结论：脑组织内胆红素对Na+ K+ ATPase活力有抑制作用。

OBJECTIVE: To observe the action of Na + K + ATPase of the brain in neonatal rats with hyperbilirubinemia and to explore the pathogenesis of bilirubin encephalopathy. METHODS: Seventy two 7 day old SD rats were randomly assigned to the control group and the experiment group. The rats of the experiment group were subdivided into 5 groups: T 1, T 2, T 3, T 4 and T 5 groups according to the increased bilirubin injected intraperitoneally. And the hyperbilirubinemic animal model was established. The bilirubin contents in the brain and serum were measured and the action of Na + K + ATPase in the brain was assayed by measuring the inorganic phosphorous content per milligram protein of brain tissues in the rats. RESULTS: Four and 8 hours after the bilirubin injection, as the injected bilirubin was increasing, the serum total bilirubin concentration and the brain bilirubin content were increasing, and the action of Na + K + ATPase in the brain was decreasing. Except for the T 1 group, there were significant differences in all the experiment groups compared with the control group (P< 0.05 or 0.01 ). No difference was found in the serum bilirubin content between 4 and 8 hours after the bilirubin injection in all the experiment groups, while there were significant differences in the brain bilirubin content and the action of Na + K + ATPase in the brain between 4 and 8 hours after the bilirubin injection in the T 2～T 5 groups (P< 0.05 ). There was negative relation between the bilirubin content and the action of Na + K + ATPase in the brain (r= -0.86 , P< 0.01 ). No relation was noted between the serum total bilirubin concentration and brain bilirubin content. CONCLUSIONS: The bilirubin might inhibit the action of Na + K + ATPase in the brain.