title: Localization of beta-glucosidase activity within keratinizing epithelia.
abstract: 1. Serial frozen sections (10 microns thick) were cut parallel to the plane of the epithelium from skin, hard palate and gingiva of the pig (Sus scrofa), and beta-glucosidase activity was measured in each section. 2. In each of these tissues, there was a low constitutive level of beta-glucosidase activity in the inner portion of the epithelium, and a several-fold increase in activity was observed in the region of the stratum granulosum-stratum corneum interface. 3. The maximum specific activity of beta-glucosidase was significantly lower in gingiva (8 nmol substrate/hr/slice) than in epidermis and palate (15-18 nmol/hr/slice). 4. The increase in expression of beta-glucosidase activity near the stratum granulosum-stratum corneum boundary appears to be intimately involved in the conversion of glucosylceramides to ceramides in the final stages of differentiation. This conversion may be a major determinant of the barrier properties of the stratum corneum.
authors.affiliation: Dows Institute for Dental Research, University of Iowa, Iowa City 52242.
authors.forename: F
authors.initials: F
authors.lastname: Chang
authors.forename: P W
authors.initials: PW
authors.lastname: Wertz
authors.forename: C A
authors.initials: CA
authors.lastname: Squier
mesh_terms: D000818:Animals; D004817:Epidermis / Q000201:enzymology*; D004848:Epithelium / Q000201:enzymology; D005881:Gingiva / Q000201:enzymology*; D007633:Keratins / Q000096:biosynthesis*; D010159:Palate / Q000201:enzymology*; D013552:Swine; D001617:beta-Glucosidase / Q000032:analysis*
chemical_list: D007633:Keratins; D001617:beta-Glucosidase