Buhl A E, Kawabe T T, MacCallum D K, Waldon D J, Knight K A, Johnson G A
Dermatology Research, Upjohn Company, Kalamazoo, Mich 49007.
Skin Pharmacol. 1992;5(2):114-23. doi: 10.1159/000211028.
To identify minoxidil target cells in hair follicles we followed the uptake of radiolabeled drug in mouse vibrissae follicles both in vitro and in vivo. Autoradiography showed that both 3H-minoxidil and 3H-minoxidil sulfate accumulated in the differentiating epithelial matrix cells superior to the dermal papilla, a distribution similar to that of pigment. Minoxidil localized in melanocytes, melanocyte processes, and areas of greater melanin concentrations within the epithelial cells. Although uptake of minoxidil was significantly less in unpigmented follicles, the drug stimulated proliferation and differentiation of both pigmented and unpigmented follicles. Labeled minoxidil bound to Sepia melanin and was displaced with unlabeled minoxidil and other electron donor drugs. This interaction with melanin acts as a targeting mechanism of minoxidil to pigmented hair follicles but has no apparent functional significance in hair growth. This work illustrates how measurement of drugs in hair may be biased by pigmentation.
为了确定毛囊中米诺地尔的靶细胞，我们在体外和体内追踪了放射性标记药物在小鼠触须毛囊中的摄取情况。放射自显影显示，3H-米诺地尔和3H-硫酸米诺地尔都积聚在真皮乳头上方正在分化的上皮基质细胞中，这种分布与色素的分布相似。米诺地尔定位于黑素细胞、黑素细胞突起以及上皮细胞内黑色素浓度较高的区域。尽管在无色素毛囊中米诺地尔的摄取明显较少，但该药物刺激了有色素和无色素毛囊的增殖和分化。标记的米诺地尔与乌贼墨黑色素结合，并被未标记的米诺地尔和其他电子供体药物取代。这种与黑色素的相互作用是米诺地尔靶向有色素毛囊的一种机制，但在毛发生长中没有明显的功能意义。这项工作说明了毛发中药物的测量如何可能受到色素沉着的影响。
