Pötsch L, Skopp G, Rippin G
Institut für Rechtsmedizin, Johannes Gutenberg Universität, Mainz, Germany.
Int J Legal Med. 1997;110(2):55-62. doi: 10.1007/s004140050031.
The in vitro experiments on the interaction of 3H-cocaine and melanin from Sepia officinalis confirmed the existence of drug binding sites on melanin granules. The results suggested that the binding of 3H-cocaine to melanin could be analyzed by assuming that the binding to the surface of pigment granules is analogous to the adsorption of a drug on a solid and follows Langmuir adsorption isotherm type I. Scatchard analysis indicated heterogeneity of binding sites. Structural and chemical alterations caused by isolation of the melanoproteins, which are heterogeneous in nature and show different physico-chemical properties, are considered to be most crucial. The studies on hair samples confirmed that melanin-drug interaction occur on the surface of melanin granules. These seem to be of minor importance compared to the drug-melanoprotein loading during melanogenesis for the observed influence of pigmentation on the drug content of hair fibers. From the results it was concluded that in vitro studies on melanin provide limited information and even drug-soaked hair must be regarded as inappropriate for the study of melanin-drug-binding in hair.
对3H-可卡因与乌贼墨黑色素相互作用的体外实验证实了黑色素颗粒上存在药物结合位点。结果表明，3H-可卡因与黑色素的结合可以通过假设其与色素颗粒表面的结合类似于药物在固体上的吸附，并遵循朗缪尔吸附等温线I型来进行分析。斯卡查德分析表明结合位点具有异质性。黑色素蛋白在性质上是异质的，表现出不同的物理化学性质，其分离所引起的结构和化学变化被认为是最为关键的。对毛发样本的研究证实，黑色素与药物的相互作用发生在黑色素颗粒表面。与黑素生成过程中药物与黑色素蛋白的结合相比，这些作用对于观察到的色素沉着对毛发纤维药物含量的影响似乎不太重要。从结果得出的结论是，对黑色素的体外研究提供的信息有限，甚至浸泡过药物的毛发也必须被视为不适用于研究毛发中黑色素与药物的结合。
