Silveira S R, Hadler W A
Acta Histochem. 1985;77(1):11-8. doi: 10.1016/S0065-1281(85)80006-4.
The vitamin D transepidermis absorption was studied by means of a histochemical technique suitable to detect this vitamin and to discriminate it from cholesterol and its esters. Such technique shows vitamin D inside the mast cell granules. As the mast cell granules contain metachromatic substances its own histochemical reactivity must be previously blocked by methylation. After this treatment the mast cell granules do not stain by toluidine blue and do not react to the peracetic acid-toluidine blue reaction. However, the granules remains reactive to alkaline permanganate-toluidine blue and to alkaline permanganate-Schiff reactions. These results show that the mast cell granules do not contain cholesterol but they contain vitamin D. The lack of cholesterol suggests that vitamin D is not synthesized inside the granules. As the mast cells may appears within the epidermis or in close relationship with the epidermis, although it is placed into the superficial dermis, it was admitted that the mast cells uptake vitamin D contained inside the epidermis intercellular compartment. In such instances, the vitamin D synthesized by the keratinocytes enter the intercellular compartment, where its synthesis accomplishes, and migrate towards the basement membrane. At the basal epidermis layer or after passing through the basement membrane the vitamin D is taken up by mast cells, where it is stored inside its granules.
采用一种适合检测维生素D并将其与胆固醇及其酯类区分开来的组织化学技术，对维生素D经表皮吸收进行了研究。该技术显示肥大细胞颗粒内有维生素D。由于肥大细胞颗粒含有异染性物质，其自身的组织化学反应性必须事先通过甲基化进行阻断。经过这种处理后，肥大细胞颗粒不会被甲苯胺蓝染色，也不会与过氧乙酸-甲苯胺蓝反应发生反应。然而，这些颗粒对碱性高锰酸钾-甲苯胺蓝反应和碱性高锰酸钾-席夫反应仍有反应。这些结果表明，肥大细胞颗粒不含胆固醇，但含有维生素D。缺乏胆固醇表明维生素D不是在颗粒内合成的。尽管肥大细胞位于浅表真皮层，但它们可能出现在表皮内或与表皮密切相关，因此可以认为肥大细胞摄取了表皮细胞间隔内所含的维生素D。在这种情况下，角质形成细胞合成的维生素D进入细胞间隔（其合成在此完成），并向基底膜迁移。在基底表皮层或穿过基底膜后，维生素D被肥大细胞摄取，并储存在其颗粒内。
