Gumucio D L, Gumucio J J, Wilson J A, Cutter C, Krauss M, Caldwell R, Chen E
Am J Physiol. 1984 Jan;246(1 Pt 1):G86-95. doi: 10.1152/ajpgi.1984.246.1.G86.
To determine whether profiles of decreasing concentration were generated among hepatocytes of the liver acinus during the transport of sulfobromophthalein sodium (BSP), rat livers were perfused with various concentrations of this dye (10 microM to 1 mM) in the presence and absence of albumin. After steady-state conditions for the biliary secretion of BSP had been attained, pieces of liver were rapidly frozen. Following the alkalinization of cryostat-cut sections, the relative concentration of BSP in hepatocytes of each zone and the effect of albumin on this localization were quantitated by microspectrophotometry. The results showed that BSP, perfused in the absence of albumin, was efficiently extracted by the liver (95% on a single pass), generating distinct profiles of decreasing cellular concentration from zone 1 to zone 3 at every concentration of BSP. However, the addition of albumin to the perfusate greatly reduced the extraction of BSP from the sinusoidal compartment and resulted in the abolition of the differences in BSP content between hepatocytes of zone 1 and zone 3. These results represent a direct demonstration that, as predicted by mathematical modeling, binding of BSP to albumin indeed results in a more homogeneous distribution of BSP within the liver acinus. A simple and direct microspectrophotometric method is therefore available to follow the changes in the relative concentration of BSP among the hepatocytes of the various acinar zones.
为了确定在磺溴酞钠（BSP）转运过程中肝腺泡肝细胞内是否会产生浓度递减的分布情况，在有白蛋白和无白蛋白的情况下，用不同浓度（10微摩尔至1毫摩尔）的这种染料灌注大鼠肝脏。在达到BSP胆汁分泌的稳态条件后，迅速将肝脏组织冷冻。在对低温恒温切片进行碱化处理后，通过显微分光光度法对每个区域肝细胞中BSP的相对浓度以及白蛋白对这种定位的影响进行定量分析。结果表明，在无白蛋白灌注时，肝脏能有效提取BSP（单次通过提取率为95%），在每个BSP浓度下，从1区到3区都会产生明显的细胞浓度递减分布。然而，向灌注液中添加白蛋白会大大减少从窦状隙隔室中提取BSP，并导致1区和3区肝细胞之间BSP含量差异消失。这些结果直接证明，正如数学模型所预测的那样，BSP与白蛋白的结合确实会导致BSP在肝腺泡内分布更加均匀。因此，有一种简单直接的显微分光光度法可用于跟踪不同腺泡区肝细胞中BSP相对浓度的变化。
