THREE-DIMENSIONAL STRUCTURE OF IN VIVO MELANOCYTES

为了解人体表皮黑素细胞的三维空间分布和细胞结构，应用计算机立体摄影和体视测量技术对正常皮肤标本进行了研究。标本固定后进行二羟苯丙氨酸（DOPA）-前黑素体反应。将它们用戊二醛和四氧化锇后固定，脱水，并包埋在Epon中。在超薄切片机中制作每个标本的连续切片，并用甲苯胺蓝染色。表皮黑素细胞通过DOPA-前黑素体反应被染成深棕色。从黑素细胞的连续二维图，使用计算机立体成像系统（Cosmozone 2SA，Nikon，Tokyo）重建其细胞结构的三维图像。表皮黑素细胞立体显示不均匀分布在一个波浪状的表皮基底膜上，其中一些经常聚集。黑素细胞呈球形细胞体延伸几个薄的过程，而表皮基底角质形成细胞呈椭圆形细胞体。通过立体测量，黑素细胞的细胞质明显大于基底角质形成细胞，细胞核体积较小。这些结果对进一步研究各种正常或异常黑素细胞的体视学特征具有重要意义。

To know the three-dimensional distribution and cell structure of human epidermal melanocytes in vivo, normal skin specimens were studied with newly developed stereographic and stereometric method using computer. After fixation, the specimens were received dihydroxyphenylalanine (DOPA)-premelanosome reaction. They were post- fixed with glutaraldehyde and osmium tetroxide, dehydrated, and embedded in Epon. Serial sections of each specimen were made in an ultramicrotome and stained with toluidine blue. Epidermal melanocytes were stained dark brown by the DOPA-premelanosome reaction. From the serial two-dimensional figures of the melanocytes, three-dimensional images of their cell structures were reconstructed using a computer- stereography system (Cosmozone 2SA, Nikon, Tokyo). The epidermal melanocytes stereographically showed an uneven distribution on a waving epidermal basement membrane; some of them often gathered. The melanocytes showed a spherical cell body extending several thin processes, whereas epidermal basal keratinocytes showed an ellipsoidal cell body. By stereometry, the melanocytes had significantly larger cytoplasm and a smaller nucleus in volumes than those of the basal keratinocytes. These results may be very important for further stereological studies on various kinds of normal or abnormal melanocytes.