Electron microscopical demonstration of thiols and disulphides in the porcine epidermis

Abstract

This study describes the electron microscopical distribution of free thiols and disulphides in the epidermis of the domestic pig and the wild boar, as compared to light microscopical histochemistry. With the silver methenamine method, silver labelling of thiols was clearly achieved on the keratohyalin and cytofilament accumulations in the cells of the living epidermis and the plasma membrane of granular cells. To a certain extent, the envelope and cytoplasm of young corneocytes reacted equally intensively. Disulphides were very abundant in the filaments, keratohyalin granules, and cell envelope of granular cells, and, particularly, in the envelope (marginal band) of corneal cells; the latter structure being distinctly delineated from the background. As a specific feature, the viable epidermis of the wild boar stained strongly for disulphides. The results obtained are discussed in view of actual concepts of epidermal keratinization and corneal cell function.

Sulphur, thiols, and disulphides in the fish epidermis, with remarks on keratinization

“…The second interesting aspect of this study is the fact that the findings clearly corroborate the view that there is an inverse correlation between keratinization and mucous secretion in normal fish epidermis. This feature is demonstrated by the rather homogeneous distribution of low amounts of thiols throughout the epidermal layers of the three species investigated, which is in contrast to observations in mammals (Broekaert et al , 1982; Meyer & Schlesinger, 1991). A decrease of disulphide concentrations from the stratum basale towards the stratum superficiale, as observed in the brown trout in the present study, emphasizes such a view.…”

“…Disulphide function in the mammalian epidermis, however, is more related to a general mechanical stabilization of the epidermal cells during the typical keratinization process from the stratum basale towards the stratum corneum (Meyer et al , 2005). In this connection, such a feature is more due to the fact that a distinct cornified cell envelope (CCE) is needed, which does not develop before the final stage of keratinocyte maturation from the stratum granulosum to the stratum corneum conjunctum, with ‐S‐S‐ groups found abundantly not only in the filaments and keratohyalin granules but especially in the CCE (Jessen & Behnke, 1986; Tezuka & Takahashi, 1987; Eckert, 1989; Meyer & Schlesinger, 1991; Leapman et al , 1997; Katou et al , 2003).…”

“…d . extinction were evaluated, whereby the results obtained were also tested for significance (α < 0·05) (Meyer & Schlesinger, 1991).…”

“…Thus, in order to learn more about the specific nature of normal epidermal cells and their secretions, including certain keratinization properties. With regard to the latter, the histochemical methods used have already produced excellent results in mammals (Sippel, 1978 a , b ; Broekaert et al , 1982; Meyer & Schlesinger, 1991; Meyer et al , 2005). In mammals, keratinization, i.e.…”

Changes in the Epithelium of the Vaginal Complex during the Estrous Cycle of the Marsupial <i>Monodelphis domestica</i>

“…6a). Keratohyalin contains filaggrin and loricrin; it is usually rich in disulfides, cysteines and histidine and among other things plays a role in the formation of the network of keratin filaments to keratin in the stratum corneum Meyer and Schlesinger, 1991]. The Gomori silver methenamine method by Swift [1968] allows a distinct blackening of the keratohyalin on the ultrastructural base.…”