Biomaterial Database

Ultrastructural cytochemical visualization of chromium in the skin of sensitized guinea pigs. 1988

J Saloga, and J Knop, and G Kolde

Department of Dermatology, University of Münster, Federal Republic of Germany.

Using a modified sulfide silver method for electron microscopy, the intraepidermal and intracellular localization of epicutaneously applied potassium dichromate was investigated at varying times in sensitized and nonsensitized guinea pigs. The hapten penetrated rapidly into the epidermis. There was a homogeneous extra- and intracellular staining of the keratinocytes in the upper epidermis. The basal and suprabasal cells, by contrast, exhibited a predominant extracellular and plasma membrane localization of the silver grains. This membrane staining pattern was also observed in the Langerhans cells showing cellular and endocytotic activation in the sensitized animals. No specific cellular uptake of the hapten by the Langerhans cells was found. These results demonstrate that the epicutaneous application of chromate resulted in a characteristic intraepidermal distribution which may be related to the epidermal conversion of the hexavalent chromate to the immunogenic trivalent form. Moreover, the absent intracellular localization of the hapten in the activated Langerhans cells supports the notion that contact allergens can be presented to T cells without prior intracellular processing.

UI	MeSH Term	Description	Entries
D007801	Langerhans Cells	Recirculating, dendritic, antigen-presenting cells containing characteristic racket-shaped granules (Birbeck granules). They are found principally in the stratum spinosum of the EPIDERMIS and are rich in Class II MAJOR HISTOCOMPATIBILITY COMPLEX molecules. Langerhans cells were the first dendritic cell to be described and have been a model of study for other dendritic cells (DCs), especially other migrating DCs such as dermal DCs and INTERSTITIAL DENDRITIC CELLS.	Langerhans Cell,Dendritic Cells, Dermal,Dendritic Cells, Epidermal,Dendritic Cells, Skin,Dermal Dendritic Cells,Epidermal Dendritic Cells,Skin Dendritic Cells,Cell, Dermal Dendritic,Cell, Epidermal Dendritic,Cell, Langerhans,Cell, Skin Dendritic,Cells, Dermal Dendritic,Cells, Epidermal Dendritic,Cells, Langerhans,Cells, Skin Dendritic,Dendritic Cell, Dermal,Dendritic Cell, Epidermal,Dendritic Cell, Skin,Dermal Dendritic Cell,Epidermal Dendritic Cell,Skin Dendritic Cell
D008297	Male		Males
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D002857	Chromium	A trace element that plays a role in glucose metabolism. It has the atomic symbol Cr, atomic number 24, and atomic weight 52. According to the Fourth Annual Report on Carcinogens (NTP85-002,1985), chromium and some of its compounds have been listed as known carcinogens.
D003877	Dermatitis, Contact	A type of acute or chronic skin reaction in which sensitivity is manifested by reactivity to materials or substances coming in contact with the skin. It may involve allergic or non-allergic mechanisms.	Contact Dermatitis,Dermatitis Venenata,Eczema, Contact,Hypersensitivity, Contact,Sensitivity, Contact,Contact Dermatitides,Contact Eczema,Contact Hypersensitivities,Contact Hypersensitivity,Contact Sensitivities,Contact Sensitivity,Dermatitides, Contact,Hypersensitivities, Contact,Sensitivities, Contact
D004705	Endocytosis	Cellular uptake of extracellular materials within membrane-limited vacuoles or microvesicles. ENDOSOMES play a central role in endocytosis.	Endocytoses
D005260	Female		Females
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D006651	Histocytochemistry	Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.	Cytochemistry
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia