title: Mediation of cyclic adenosine 3',5'-monophosphate in 1-methyladenine production by starfish ovarian follicle cells.
abstract: Resumption of meiosis in starfish oocytes is induced by 1-methyladenine (1-MeAde) produced by ovarian follicle cells under the influence of a gonad-stimulating substance (GSS). It has also been reported that concanavalin A (Con A) and two serine proteolytic enzymes (trypsin and Pronase) can stimulate 1-MeAde production. This study was undertaken to determine if 1-MeAde production induced by these compounds is mediated through elevation of cAMP in starfish (Asterina pectinifera) follicle cells. GSS at a concentration of 0.1 mg/ml significantly stimulated 1-MeAde accumulation in extracellular medium after 1-2 hr of follicle cell incubations. GSS also caused a four- to fivefold increase in intracellular levels of cAMP. The continuous presence of GSS was required for the maintenance of elevated levels of cAMP and 1-MeAde. Basal levels of intracellular cGMP were only about 20% of those of cAMP and were not influenced by treatment with GSS. At 1 mM, 3-isobutyl-1-methylxanthine (IBMX), a potent phosphodiesterase inhibitor, stimulated both 1-MeAde and cAMP production in a concentration-dependent manner. Con A and two serine proteases also raised both cAMP and 1-MeAde production. Con A-induced (1.0 mg/ml) increases in cAMP and 1-MeAde were greater than the response to GSS (0.1 mg/ml) and were completely suppressed by treatment with alpha-methyl-D-mannoside (10 mM), a competitive inhibitor of Con A. These results strongly suggest that cAMP is a second messenger in the production of 1-MeAde by starfish ovarian follicle cells.
authors.affiliation: Department of Biochemistry, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Mita
authors.forename: N
authors.initials: N
authors.lastname: Ueta
authors.forename: Y
authors.initials: Y
authors.lastname: Nagahama
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000378:metabolism; D000818:Animals; D003208:Concanavalin A / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology / Q000502:physiology*; D006152:Cyclic GMP / Q000378:metabolism; D005260:Female; D010053:Ovary / Q000166:cytology; D010447:Peptide Hydrolases / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D013215:Starfish / Q000378:metabolism*
chemical_list: D010455:Peptides; D010726:Phosphodiesterase Inhibitors; D003208:Concanavalin A; C008407:1-methyladenine; D000242:Cyclic AMP; D010447:Peptide Hydrolases; D006152:Cyclic GMP; D000225:Adenine