The British journal of dermatology
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Laminin, type IV and type V collagen were localized in twenty-five basal cell carcinomas (BCCs) by immunofluorescence. All basal cell carcinomas were separated from the connective tissue by a continuous basement membrane (BM) which always contained the three antigenic determinants. ⋯ The linear deposits probably represent BM debris that remains undigested and the globular deposits correspond to residual cytoplasmic fragments occurring during apoptosis. These results suggest that BM components are synthesized by epithelial cells and are secreted to polymerize at the dermo-epidermal junction.
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The effects of local glucocorticosteroid treatment on collagen biosynthesis and basement membrane components were studied in suction blisters in human abdominal skin. Pretreatment with clobetasol-17-propionate, applied three times a day for 4 days, did not affect the activity of galactosylhydroxylysyl glucosyltransferase (GGT) in fresh blisters but post-blistering treatment for 3 days with the steroid markedly inhibited the increase of this enzyme activity during the initial phases of re-epithelialization. The GGT activity was over 50% lower in steroid-treated blisters compared with control values. ⋯ These results suggest that local glucocorticosteroid decreases either the synthesis of GGT or its release from the tissue into the blister fluid. The treatment did not affect the blister histology nor the early process of re-epithelialization. Immunohistochemically, type IV and V collagens and laminin of the basement membrane zone were similarly located in blisters of steroid-treated and placebo-treated skin, suggesting that local glucocorticosteroid does not affect the integrity of the basement membrane.