title: Biphasic rate of synthesis of glycoconjugates, phospholipids and DNA in concanavalin A-stimulated mouse thymocytes. Involvement of cortisone-sensitive and -resistant subpopulations.
abstract: The time course of the rate of labeling of membrane components (phospholipids, glycolipids and glycoproteins) and DNA was followed in concanavalin A-stimulated CBA/J mouse thymocyte cultures. Two peaks of stimulated biosynthetic activity were noted, the first at the beginning of the cultivation and the second about 25 h later. Both early and late peaks of biosynthesis of membrane components were accompanied by blast transformation and were unimpeded by suppression of DNA synthesis by hydroxyurea. Cortisone-sensitive and cortisone-resistant thymocytes were prepared by selective agglutination of the cortisone-sensitive cells with peanut agglutinin (Reisner et al. Cell. Immunol. 1976. 25: 129) or cortisone treatment of the animals. Cortisone-sensitive cells responded early, while the cortisone-resistant population gave only the late response. The autoradiographic patterns from sodium dodecyl sulfate polyacrylamide gels of [3H]fucose or [3H]galactose-labeled glycoproteins from early and late labeling cells, and cortisone-resistant cells, were compared. Late-labeling and cortisone-resistant cells gave indistinguishable patterns, but differed significantly in their patterns from early-labeling cells. It is concluded that the two peaks of biosynthetic activity during the course of concanavalin A stimulation of thymocytes are caused by two different cell populations which require different times for maximal response and react independently of one another.
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000276:immunology; D003208:Concanavalin A / Q000494:pharmacology; D003348:Cortisone / Q000494:pharmacology*; D004247:DNA / Q000096:biosynthesis*; D003907:Dexamethasone / Q000378:metabolism; D006017:Glycolipids / Q000096:biosynthesis*; D006023:Glycoproteins / Q000096:biosynthesis*; D006918:Hydroxyurea / Q000494:pharmacology; D007700:Kinetics; D037102:Lectins / Q000276:immunology; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D010743:Phospholipids / Q000096:biosynthesis*; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology; D013997:Time Factors
chemical_list: D006017:Glycolipids; D006023:Glycoproteins; D037102:Lectins; D010743:Phospholipids; D003208:Concanavalin A; D003907:Dexamethasone; D004247:DNA; D003348:Cortisone; D006918:Hydroxyurea