Receptor-mediated gonadotropin action in the ovary. Inhibitory actions of concanavalin A and wheat-germ agglutinin on gonadotropin-stimulated cyclic AMP and progesterone responses in ovarian cells.
Pretreatment of ovarian cells with concanavalin A and wheat-germ agglutinin blocked the gonadotropin-induced cyclic AMP and progesterone responses and this effect was time- and concentration-dependent. Basal production of either cyclic AMP or progesterone, however, was not affected by treatment of cells with lectin. The effect of concanavalin A on gonadotropin-mediated cyclic AMP and progesterone responses was blocked by alpha-methyl D-mannoside and alpha-methyl d-glucoside. Similarly the inhibitory effect of wheat-germ agglutinin was reversed by N-acetyl-D-glucosamine. Pretreatment of ovarian cells with concanavalin A or wheat-germ agglutinin had no effect on protein synthesis in the ovary as monitored by [3H]proline incorporation studies. Concanavalin A and wheat-germ agglutinin did not affect steroid production in response to dibutyryl cyclic AMP and 8-bromo cyclic AMP, indicating that the inhibitory action of lectin was occurring at a step before cyclic AMP formation. Lectins specific for L-fucose, D-galactose and N-acetyl-D-galactosamine, gorse seed agglutinin, peanut agglutinin and Dolichos biflorus agglutinin respectively, did not interfere with gonadotropin-induced cyclic AMP and progesterone responses. The present studies suggest that gonadotropin receptors may be glycoprotein in nature or closely associated with glycoprotein structures with the carbohydrate chain containing N-acetyl-D-glucosamine, mannose and possibly N-acetylneuraminic acid.
D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D003208:Concanavalin A / Q000494:pharmacology*; D000242:Cyclic AMP / Q000096:biosynthesis*; D005260:Female; D066298:In Vitro Techniques; D037102:Lectins / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000494:pharmacology; D010053:Ovary / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D011374:Progesterone / Q000096:biosynthesis*; D014176:Protein Biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface / Q000378:metabolism*; D014909:Wheat Germ Agglutinins
D006063:Chorionic Gonadotropin; D037102:Lectins; D011956:Receptors, Cell Surface; D014909:Wheat Germ Agglutinins; D003208:Concanavalin A; D011374:Progesterone; D007986:Luteinizing Hormone; D000242:Cyclic AMP