Glycosaminoglycans of hair follicles of dog skin

Glycosaminoglycan synthesis by cultured human hair follicle dermal papilla cells: comparison with non-follicular dermal fibroblasts

The extracellular matrix of the hair follicle dermal papilla is rich in glycosaminoglycans, the expression of which varies during the hair growth cycle being maximal in anagen and becoming undetectable as the follicle enters telogen. These observations, together with other experimental and clinical evidence, suggest that glycosaminoglycans may be involved in regulating hair growth. To investigate the metabolism of glycosaminoglycans by the dermal papilla we have measured the incorporation of radiolabelled precursors into glycosaminoglycans released into extracellular matrix and culture medium by cultured human dermal papilla cells. We also studied glycosaminoglycan synthesis by cells cultured from the lower follicular connective tissue sheath and by non-follicular dermal fibroblasts. Compared with dermal fibroblasts, dermal papilla cells showed a three to fourfold higher level of incorporation of 35S-sulphate and 3H-glucosamine into extracellular matrix glycosaminoglycans. Dermal papilla cells also released more 3H-glucosamine-labelled glycosaminoglycan into culture medium than dermal fibroblasts but there was no difference in 35S-sulphate labelling. These findings indicate that dermal papilla cells maintain a high level of glycosaminoglycan synthesis in vitro. Specific enzyme/chemical degradation showed that dermal papilla cells and dermal fibroblasts synthesized the same glycosaminoglycan types. However, the results suggested that dermal papilla glycosaminoglycans are less sulphated than those synthesized by dermal fibroblasts and that a higher proportion of sulphated glycosaminoglycans is retained in an extracellular matrix. The synthesis of glycosaminoglycans by connective tissue sheath cells was similar to that of dermal papilla cells, supporting the view that the dermal papilla and connective tissue sheath share certain properties.

Histochemical analysis of urea-unmasked glycosaminoglycans in the skin of the rat and mouse

Histochemical analysis of urea-unmasked glycosaminoglycans has been performed in connective tissues of the rat and mouse skin by means of combined staining and enzyme digestion procedures. The staining procedures used were Alcian Blue pH 1.0, Alcian Blue pH 2.5, Aldehyde Fuchsin, periodic acid-Schiff (PAS), Alcian Blue pH 2.5-PAS, high iron diamine and low iron diamine methods. The digestive enzymes employed were Streptomyces and testicular hyaluronidases, chondroitinases ABC and AC and keratanase. The results obtained indicated that the major components of the glycosaminoglycans in the connective tissues of the skin were hyaluronic acid, dermatan sulphate and chondroitin sulphate A and/or C, whereas the tissues were devoid of keratan sulphate.

Histochemistry of complex carbohydrates in the hairy skin of the domestic pig

The hairy skin from eleven body areas of the domestic pig has been studied by means of a series of selected methods for the detection of complex carbohydrates, including peroxidase-labelled lectin-diaminobenzidine procedures. The results obtained were most distinctive in the areas where the skin accessories were involved. The complex carbohydrates in the epidermis appear to be acidic and neutral glycoproteins containing a small amount of sialic acid residues. The dermal connective tissue fibres revealed positive reactions for neutral and acidic glycoproteins with notable amounts of sialic acid residues, and for proteoglycans. In different parts of the hair follicle, neutral and acidic glycoproteins were also present, most being restricted to the connective tissue sheath and the dermal papilla. In the lower regions of the outer epithelial root sheath the epithelium contained a large amount of glycogen. The sebaceous glands reacted very weakly for neutral and acidic glycoproteins. The apocrine glands exhibited mostly neutral but also acidic glycoproteins in the secretory cells and the lumenal secretion, with substantial amounts of various saccharide residues.