Hansen T W
Department of Pediatrics, Pediatric Research, Rikshospitalet, University of Oslo, Norway.
Biol Neonate. 1995;67(3):203-7. doi: 10.1159/000244164.
In kernicterus bilirubin appears at higher concentrations in the basal ganglia, the cerebellum, and the medulla. The mechanism for this distribution is unknown, but might involve differences in bilirubin entry among brain regions. We infused [3H]bilirubin (30 mg/kg over 5 min) intravenously into young Sprague-Dawley rats (n = 21, weight 144 +/- 10 g, mean +/- SD). Blood was sampled from the tail, and groups of rats were killed at 15, 30, 45, 60, and 75 min by intravenous pentobarbital. After in situ flushing of the brain vasculature, the brain was dissected into seven regions, each of which was weighed, dissolved in Soluene-350, and subsequently scintillation counted. Blood samples were analyzed for bilirubin (including specific activity), albumin, and blood gases. Brain bilirubin concentrations in each of the regions were calculated by comparing the radioactivity in that region with the specific activity of bilirubin. Using a curve-fitting program (EXPOFIT), the concentrations of bilirubin in each brain region at 5 min (i.e. the end of bilirubin infusion) could be estimated, and were as follows (nmol/g +/- SD): cortex 6.4 +/- 4.4; hippocampus 6.2 +/- 3.3; striatum 6.3 +/- 4.5; midbrain 7.3 +/- 4.4; hypothalamus 6.3 +/- 4.6; cerebellum 6.7 +/- 4.1, and medulla 7.0 +/- 4.0. There were no significant differences in the bilirubin concentrations between brain regions (F6,140 0.205). The mechanism for preferential localization of bilirubin to the basal ganglia probably does not involve the acute entry of bilirubin into brain.
在核黄疸中，基底神经节、小脑和延髓中的胆红素浓度较高。这种分布的机制尚不清楚，但可能涉及不同脑区胆红素进入的差异。我们将[3H]胆红素（5分钟内30毫克/千克）静脉注射到幼年斯普拉格-道利大鼠（n = 21，体重144±10克，平均值±标准差）体内。从尾部采集血液，在15、30、45、60和75分钟时通过静脉注射戊巴比妥处死大鼠组。在对脑血管系统进行原位冲洗后，将大脑解剖成七个区域，每个区域称重，溶解在Soluene-350中，随后进行闪烁计数。分析血液样本中的胆红素（包括比活）、白蛋白和血气。通过将该区域的放射性与胆红素的比活进行比较，计算每个区域的脑胆红素浓度。使用曲线拟合程序（EXPOFIT），可以估计在5分钟（即胆红素输注结束时）每个脑区的胆红素浓度，结果如下（纳摩尔/克±标准差）：皮质6.4±4.4；海马体6.2±3.3；纹状体6.3±4.5；中脑7.3±4.4；下丘脑6.3±4.6；小脑6.7±4.1，延髓7.0±4.0。脑区之间的胆红素浓度没有显著差异（F6,140 0.205）。胆红素优先定位于基底神经节的机制可能不涉及胆红素急性进入脑内。
