Kastl I, Anton-Lamprecht I
Institut für Ultrastruckturforschung der Haut, Hautklinik der Ruprecht-Karls-Universität Heidelberg, Federal Republic of Germany.
Arch Dermatol Res. 1990;282(2):71-5. doi: 10.1007/BF00493461.
Up to now, bicomponent keratohyalin has only been described for rat epithelium and human intraepidermal sweat ducts and fetal nail organ cells. In normal human interductal epidermis, the keratohyalin appears homogeneous, osmiophilic and stellate in shape. Under pathological conditions, bicomponent keratohyalin has been observed in different palmoplantar keratoses and has therefore been thought to be associated with abnormal keratosis. We studied the keratinization process in normal human plantar epidermis, in which keratohyalin was found to exhibit several morphological differences as compared to that seen in non-ridged skin. The most striking feature was seen in upper granular cells, where the keratohyalin granules consisted of two components of differing electron density. The electron-dense component formed the main part of the composite granule and was found in the cytoplasm of lower and upper granular cells. The less-electron-dense component was attached to the main component and appeared in the cytoplasm of upper granular cells, forming the convex contact zone. No intranuclear osmiophilic inclusions were present. The respective electron densities of the two keratohyalin components of ridged skin were obviously different to that of the bicomponent keratohyalin granules seen in the epidermal sweat-duct cells of the same specimen. These findings indicate the presence of at least two different types of keratohyalin proteins in normal human ridged skin. They can be distinguished at the electron-microscope level and differ from the keratohyalin of human non-ridged skin as well as from bicomponent keratohyalin granules derived from human epidermal sweat-duct cells or from rat epithelium.
到目前为止，双组分透明角质颗粒仅在大鼠上皮、人表皮内汗腺导管及胎儿甲器官细胞中被描述过。在正常人类导管间表皮中，透明角质颗粒呈现均匀、嗜锇且呈星状的形态。在病理条件下，已在不同的掌跖角化病中观察到双组分透明角质颗粒，因此被认为与异常角化病有关。我们研究了正常人类足底表皮的角质化过程，发现其中的透明角质颗粒与非嵴状皮肤中的相比呈现出几种形态学差异。最显著的特征见于上层颗粒细胞，其中透明角质颗粒由两种电子密度不同的成分组成。电子密度高的成分构成复合颗粒的主要部分，见于下层和上层颗粒细胞的细胞质中。电子密度较低的成分附着于主要成分上，出现在上层颗粒细胞的细胞质中，形成凸状接触区。不存在核内嗜锇性包涵体。嵴状皮肤的两种透明角质颗粒成分各自的电子密度明显不同于同一标本表皮汗腺导管细胞中所见的双组分透明角质颗粒。这些发现表明正常人类嵴状皮肤中存在至少两种不同类型的透明角质蛋白。它们在电子显微镜水平上可被区分，且不同于人类非嵴状皮肤的透明角质颗粒以及源自人类表皮汗腺导管细胞或大鼠上皮的双组分透明角质颗粒。
