Yoshizato K, Nishikawa A, Taira T
Department of Biology, Faculty of Science, Tokyo Metropolitan University, Japan.
J Cell Sci. 1988 Dec;91 ( Pt 4):491-9. doi: 10.1242/jcs.91.4.491.
Rat epidermal cells were cultured on a transparent collagen film, which was permeable to low Mr substances. Then the cells were bathed in both media (apical and basal), which were separated by the collagen membrane. The cells formed a multi-layered epidermal sheet with well-developed structures of desmosomes. This sheet on a permeable support was found to be an effective permeability barrier for glucose and amino acids. The epidermal layer showed functional polarity for the uptake and excretion of nutrients, metabolites and newly synthesized proteins: glucose and amino acids were taken up exclusively from the basal medium and lactate was secreted selectively into the same medium, whereas ammonia was secreted into the apical medium. The apical media became more acidic than the basal ones, presumably due to the preferential distribution of H+ transport systems on the apical side of the epidermal layer. The epidermal cells that expressed functional polarities in vitro as described above were able to proliferate and differentiate, and remained healthy for as long as at least 40 days even using a conventional culture medium with foetal calf serum, but without any special growth factors and feeder cells.
大鼠表皮细胞培养在对低分子量物质具有通透性的透明胶原膜上。然后将细胞置于由胶原膜分隔的两种培养基（顶端和基底）中培养。细胞形成了具有发育良好的桥粒结构的多层表皮片。发现这种置于可渗透支持物上的表皮片对葡萄糖和氨基酸是一种有效的渗透屏障。表皮层在营养物质、代谢产物和新合成蛋白质的摄取和排泄方面表现出功能极性：葡萄糖和氨基酸仅从基底培养基中摄取，乳酸选择性地分泌到同一培养基中，而氨则分泌到顶端培养基中。顶端培养基比基底培养基酸性更强，这可能是由于H⁺转运系统在表皮层顶端侧的优先分布所致。上述在体外表现出功能极性的表皮细胞能够增殖和分化，即使使用含有胎牛血清的传统培养基，在没有任何特殊生长因子和饲养细胞的情况下，也能至少健康存活40天。
