High-performance liquid chromatography (HPLC) analysis of eu- and pheomelanin in melanogenesis control.
High-performance liquid chromatography (HPLC) analysis of eu- and pheomelanin in melanogenesis control.
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DOI：
10.1038/jid.1993.71
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发表时间：
1993-02
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影响因子：
--
通讯作者：
Shosuke Ito
中科院分区：
文献类型：
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作者：
Shosuke Ito
在一定的生理或病理条件下，两种类型的黑素生成，真黑素生成和嗜铬黑素生成，可以从一种类型转换到另一种类型。为了研究黑素生成的调控机制，我们建立了一种高效液相色谱法，无需任何分离步骤即可定量分析组织样品中的铕和褐黑素的含量。其基本原理是，高锰酸盐氧化的真黑素产生吡咯-2，3，5-三羧酸，这可能是一个定量的显着指标的真黑素，而异硫氰酸水解的褐黑素产生aminohydroxyphenylala-nine作为一个特定的指标褐黑素。该方法已成功地应用于欧盟和褐黑素的分析，不仅在合成黑色素，黑素体，头发，羽毛和黑色素瘤，而且在人类表皮和培养的黑素细胞。这些研究表明，存在着一个反关系之间的铕-和褐黑素的含量。我们提出，这两种类型的黑素生成之间的切换主要是由酪氨酸酶活性的水平控制：较高的活性导致eumelanogenesis和较低的活性导致pheomelanogenesis。当酪氨酸酶活性低时，多巴醌（黑素生成中的反应性中间体）定量转化为谷胱甘肽多巴，其仅产生褐黑素。当酪氨酸酶活性高时，产生过量的多巴醌，这导致谷胱甘肽还原酶和γ-谷氨酰转肽酶（对褐黑素生成必需的酶）失活。这些生化事件最终导致真黑素生成。
Two types of melanogenesis, eumelanogenesis and pheome-lanogenesis, can be switched from one type to another under certain physiologic or pathologic conditions. To study the regulation of melanogenesis, we developed a high-performance liquid chromatography method to analyze quantitatively the contents of eu- and pheomelanin in tissue samples without any isolation procedures. The rationale is that permanganate oxidation of eumelanin yields pyrrole-2,3,5-tri-carboxylic acid, which may serve as a quantitatively significant indicator of eumelanin, whereas hydriodic acid hydrolysis of pheomelanin yields aminohydroxyphenylala-nine as a specific indicator of pheomelanin. The method has been successfully applied to the analysis of eu- and pheomelanin not only in synthetic melanins, melanosomes, hair, feathers, and melanomas, but also in human epidermis and cultured melanocytes. These studies indicate that there exists an inverse relationship between the contents of eu- and pheomelanin. We propose that the switching between the two types of melanogenesis is mainly controlled by the level of tyrosinase activity: higher activity leads to eumelanogenesis and lower activity leads to pheomelanogenesis. When tyrosinase activity is low, dopaquinone, a reactive intermediate in melanogenesis, is quantitatively converted to glu-tathionyldopa, which gives rise exclusively to pheomelanin. When tyrosinase activity is high, an excess of dopaquinone is produced, which results in the inactivation of glutathione reductase andγ-glutamyl transpeptidase, enzymes essential for pheomelanogenesis. These biochemical events eventually leads to eumelanogenesis.