Winston S H, Tishler P V
Methods Find Exp Clin Pharmacol. 1986 Apr;8(4):233-7.
The acute attacks of the acute hepatic porphyrias may be precipitated by the excessive intracellular accumulation of the porphyrin precursors delta-aminolevulinic acid (ALA) or porphobilinogen (PBG). Sorbents that bind porphyrin precursors in the gastrointestinal tract may interrupt their enterohepatic circulation, thus reducing the body burden of these materials and minimizing the frequency or severity of acute attacks. We have determined the adsorption capacities (Qm's) of several activated charcoals and the ion exchange resin cholestyramine for ALA and PBG. Qm's (mg ALA or PBG adsorbed/gm dry sorbent) were determined from Langmuir isotherms, which were derived from studies of the amount of porphyrin precursor adsorbed after the addition of a constant amount of ALA or PBG to varying amounts of sorbent. These experiments were carried out pH 8.2 in 0.1% desoxycholate, to simulate conditions of the small intestine. Extremely high Qm's were obtained for all charcoals and both porphyrin precursors; those for cholestyramine were one or several orders of magnitude lower. For ALA, the Qm of Gulf Bio-Systems Super Char charcoal (110 +/- 35 [SD]) was not significantly greater than that of Med-Corp Acta-Char charcoal (95 +/- 20), but it did exceed those of all other charcoals by a statistically significant amount. For PBG, the Qm of Super Char (68 +/- 14) was marginally greater than that of Mallinckrodt USP charcoal (42 +/- 21, t8 = 2.18, p approximately equal to 0.06), but it was significantly greater than that of Acta-Char charcoal (27 +/- 12). All sorbents adsorbed ALA or PBG at comparable rates, and the complex of sorbent and porphyrin precursor appeared to be undissociable.(ABSTRACT TRUNCATED AT 250 WORDS)
急性肝卟啉病的急性发作可能是由于卟啉前体δ-氨基-γ-酮戊酸（ALA）或胆色素原（PBG）在细胞内过度蓄积所致。能在胃肠道结合卟啉前体的吸附剂可能会中断其肠肝循环，从而减轻这些物质在体内的负担，并将急性发作的频率或严重程度降至最低。我们已经测定了几种活性炭和离子交换树脂考来烯胺对ALA和PBG的吸附容量（Qm）。Qm（每克干吸附剂吸附的ALA或PBG毫克数）由朗缪尔等温线确定，该等温线来自于在不同量的吸附剂中加入恒定剂量的ALA或PBG后对卟啉前体吸附量的研究。这些实验在pH 8.2的0.1%脱氧胆酸盐中进行，以模拟小肠环境。所有活性炭和两种卟啉前体都获得了极高的Qm；考来烯胺的Qm则低一个或几个数量级。对于ALA，海湾生物系统超级活性炭（110±35[标准差]）的Qm并不显著高于Med-Corp Acta-Char活性炭（95±20），但确实比所有其他活性炭的Qm高出具有统计学意义的量。对于PBG，超级活性炭的Qm（68±14）略高于马林克罗特USP活性炭（42±21，t8 = 2.18，p约等于0.06），但显著高于Acta-Char活性炭（27±12）。所有吸附剂以相当的速率吸附ALA或PBG，吸附剂与卟啉前体的复合物似乎是不可解离的。（摘要截短于250字）
