title: Effects of colchicine and cytochalasin B on distribution of concanavalin A receptors in isolated and cultured guinea pig epidermal cells.
abstract: Regulation of the distribution of concanavalin A (Con A)/receptor complexes by the cytoskeletal contracture system was studied in guinea pig epidermal cells in suspension and culture using the fluorescence double staining method. After treatment with 100 micrograms/ml of Con A at 37 degrees C for 30 min lectin/receptor complexes were endocytosed by the less-differentiated cells in suspension and by the adherent cells in 1- and 3-day cultures that represent a growing cell fraction. The same treatment resulted in diffuse surface distribution of the complexes in the well-differentiated cells in suspension. Colchicine (10(-5) and 10(-6) M) inhibited internalization of the complexes with resultant diffuse distribution in 60% of the adherent cells in culture. Cytochalasin B (5 and 10 micrograms/ml) not only inhibited endocytosis but promoted formation of surface patchy clumps of the complexes in suspended, less-differentiated cells and cultured adherent cells. The distribution profile was not influenced by these drug treatments in the well-differentiated cells. SDS polyacrylamide gel electrophoresis and autoradiography of 125I-labelled epidermal membranes revealed several Con A-reactive polypeptides common to the cells at various differentiation steps. The progressive decrease in endocytosis and mobility of Con A/receptor complexes was suggested to occur with differentiation. In the germinative cells the distribution of lectin/receptor complexes seemed to be regulated by microfilaments and microtubules.
authors.affiliation: Department of Dermatology, Hamamatsu University School of Medicine, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Takigawa
authors.forename: K
authors.initials: K
authors.lastname: Danno
authors.forename: F
authors.initials: F
authors.lastname: Furukawa
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002469:Cell Separation; D002478:Cells, Cultured; D003078:Colchicine / Q000493:pharmacokinetics*; D003571:Cytochalasin B / Q000493:pharmacokinetics*; D004591:Electrophoresis, Polyacrylamide Gel; D004817:Epidermis / Q000187:drug effects* / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006168:Guinea Pigs; D066298:In Vitro Techniques; D010873:Pinocytosis / Q000187:drug effects; D011940:Receptor Aggregation / Q000187:drug effects; D011952:Receptors, Concanavalin A / Q000187:drug effects* / Q000378:metabolism; D013997:Time Factors
chemical_list: D011952:Receptors, Concanavalin A; D003571:Cytochalasin B; D003078:Colchicine