title: Interactions between Ca2+ and cAMP in ecdysteroid secretion from the prothoracic glands of Bombyx mori.
abstract: The interaction between Ca2+ and cAMP in the mediation of ecdysteroid secretion from prothoracic glands (PGs) of Bombyx mori was investigated in vitro. Omission of Ca2+ from the PGs' incubation medium decreased basal ecdysteroid secretion from day 3 until day 6. On day 6, the ability of forskolin or 3-isobutyl-1-methylxanthine (IBMX) to stimulate ecdysteroid secretion was affected by the omission of Ca2+ from the medium. The cAMP agonist Sp-adenosine 3',5'-cyclic monophosphothioate (Sp-cAMPS) and the cAMP analogue dibutyryl cyclic AMP (dbcAMP) stimulated ecdysteroid secretion even in the absence of Ca2+ from the medium. The Sp-cAMPS-stimulated ecdysteroid secretion was inhibited by the cAMP antagonist Rp-adenosine 3',5'-cyclic monophosphothioate (Rp-cAMPS) and the L-type Ca2+ channel blocker verapamil. Both the Ca2+ ionophore A23187 and the L-type Ca2+ channel agonist S(-) Bay K 8644 could stimulate ecdysteroid secretion. The A23187-induced ecdysteroid secretion was partially inhibited by Rp-cAMPS. The combined results indicate that Ca2+ and cAMP signaling pathways can cooperatively, as well as independently, stimulate ecdysteroid secretion from the PGs.
authors.affiliation: Department of Biological Production, Tokyo University of Agriculture and Technology, Japan.
authors.forename: S G
authors.initials: SG
authors.lastname: Dedos
authors.forename: H
authors.initials: H
authors.lastname: Fugo
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000818:Animals; D012831:Bombyx / Q000378:metabolism*; D003994:Bucladesine / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology*; D004347:Drug Interactions; D004441:Ecdysterone / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D015290:Second Messenger Systems / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D013873:Thionucleotides / Q000494:pharmacology; D014700:Verapamil / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D010726:Phosphodiesterase Inhibitors; D013873:Thionucleotides; D005576:Colforsin; C016957:adenosine-3',5'-cyclic phosphorothioate; D000001:Calcimycin; D004441:Ecdysterone; D003994:Bucladesine; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D014700:Verapamil; D000242:Cyclic AMP; D002118:Calcium; D015056:1-Methyl-3-isobutylxanthine