Rahman A, Barrowman J A, Rahimtula A
Can J Physiol Pharmacol. 1986 Sep;64(9):1214-8. doi: 10.1139/y86-205.
The mechanisms governing absorption of polynuclear aromatic hydrocarbons (PAHs) are important since these carcinogenic compounds occur as solutes in dietary lipids. These highly lipophilic compounds are well absorbed in the intestine. Bile salt micellar solubilization probably facilitates their transport across the unstirred water layer to the enterocytes. To study the role of bile in the intestinal absorption of PAHs, conscious rats with bile duct and duodenal catheters were given isotopically labelled 2,6-dimethylnaphthalene (DMN), phenanthrene, anthracene, 7,12-dimethylbenzanthracene (DMBA), and benzo[alpha]pyrene (BP); the recovery of radioactivity in bile and urine was measured. The PAHs were given intraduodenally in corn oil with or without exogenous bile. Cumulative recovery of radiolabel in bile and urine over 24 h was used to assess the efficiency of absorption of the hydrocarbons with and without bile. The following values for absorption without bile (as percentage of absorption with bile) were obtained: DMN, 91.6%; phenanthrene, 96.7%; anthracene, 70.8%; DMBA, 43.4%; BP, 22.9%. The values for anthracene, DMBA, and BP were significantly less than 100% (P less than 0.05); the values for DMN and phenanthrene were not significantly different from 100%. The dependence of the tricyclic compound anthracene (a structural isomer of phenanthrene) on bile for its absorption correlates with its lower water solubility. These results are consistent with the concept that the unstirred water layer presents a significant barrier to the absorption of this group of compounds and that micellar solubilization facilitates the uptake process.
多环芳烃（PAHs）的吸收机制很重要，因为这些致癌化合物会以溶质形式存在于膳食脂质中。这些高度亲脂性的化合物在肠道中很容易被吸收。胆盐胶束增溶作用可能有助于它们穿过未搅动水层转运至肠上皮细胞。为了研究胆汁在PAHs肠道吸收中的作用，给有意识的、带有胆管和十二指肠导管的大鼠给予同位素标记的2,6 - 二甲基萘（DMN）、菲、蒽、7,12 - 二甲基苯并蒽（DMBA）和苯并[a]芘（BP）；测量胆汁和尿液中的放射性回收率。PAHs通过十二指肠内注射给予，溶媒为玉米油，其中添加或不添加外源性胆汁。通过24小时内胆汁和尿液中放射性标记物的累积回收率来评估有胆汁和无胆汁情况下烃类的吸收效率。得到以下无胆汁时的吸收值（相对于有胆汁时吸收的百分比）：DMN，91.6%；菲，96.7%；蒽，70.8%；DMBA，43.4%；BP，22.9%。蒽、DMBA和BP的值显著低于100%（P < 0.05）；DMN和菲的值与100%无显著差异。三环化合物蒽（菲的结构异构体）对胆汁吸收的依赖性与其较低的水溶性相关。这些结果与以下概念一致，即未搅动水层对这组化合物的吸收构成了显著障碍，且胶束增溶作用促进了摄取过程。
