Cytochemical and Biochemical Localization of Lipase and Sphingomyelinase Activity in Mammalian Epidermis

摘要: Abstract Despite a wealth of new information on epidermal lipids and their role in permeability barrier function desquamation, little is known about the location enzymes that regulate catabolism. In this study we have localized lipase (triacylglycerol hydrolase) sphingomyelinase outer epidermis simultaneously by cytochemical cell fractionation techniques. Aldehyde-fixed tissues (100- μm slices) incubated either Tween 85 or triolein plus taurocholate/calcium chloride-containing buffer, pH 7.2 4.5, were then exposed to lead form insoluble soaps, processed for electron microscopy. Simultaneously, homogenates isolated lamellar body fractions with methylumbilliferyl oleate under similar conditions, released, free methylumbelliferone serving as an index activity. On microscopy fractionation, both primarily intercellular domains stratum corneum. granulosum lipases found, ultrastructurally biochemically, bodies perinuclear cistern mitochondria. summary, these studies: (1) demonstrating lipid-catabolic corneum, lend further support 2-compartment model corneum; (2) provide differentiating epidermis; (3) insights how are during formation desquamation.