title: Involvement of cyclic nucleotides and IP(3) in the regulation of luminescence in the brittlestar Amphipholis squamata (Echinodermata).
abstract: We investigated the effects of cyclic nucleotides (cGMP, cAMP) and the phosphoinositide IP(3) on the luminescence of the ophiuroid Amphipholis squamata. The cGMP analogue, dibutyryl-cGMP, and the guanylate cyclase activator, sodium nitroprusside, had no effect on the luminescence. The cAMP analogue, dibutyryl-cAMP, and the adenylate cyclase activator, forskolin, triggered luminescence. Moreover, the adenylate cyclase inhibitor, MDL-12330A, significantly reduced ACh-induced luminescence. The phospholipase C inhibitor, U-73122, also significantly reduced ACh-induced luminescence. The results suggest that ACh-induced luminescence is mediated by both cAMP and IP(3) pathways but not by cGMP. The effects of calcium-free ASW confirmed this hypothesis. A hypothetical scheme of the transduction mechanisms involved in the intracellular control of luminescence is presented.
authors.affiliation: Laboratory of Animal Physiology, Université Catholique de Louvain, Place Croix du Sud, 5, B-1348 Louvain-la-Neuve, Belgium. debremaeker@bani.ucl.ac.be
authors.forename: N
authors.initials: N
authors.lastname: De Bremaeker
authors.forename: Y
authors.initials: Y
authors.lastname: Dewael
authors.forename: F
authors.initials: F
authors.lastname: Baguet
authors.forename: J
authors.initials: J
authors.lastname: Mallefet
mesh_terms: D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism*; D006152:Cyclic GMP / Q000378:metabolism*; D003995:Dibutyryl Cyclic GMP / Q000494:pharmacology; D004447:Echinodermata / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006162:Guanylate Cyclase / Q000378:metabolism; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D049449:Luminescence; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors
chemical_list: D000067956:Adenylyl Cyclase Inhibitors; D004791:Enzyme Inhibitors; D003995:Dibutyryl Cyclic GMP; D003994:Bucladesine; D015544:Inositol 1,4,5-Trisphosphate; D000242:Cyclic AMP; D010738:Type C Phospholipases; D000262:Adenylyl Cyclases; D006162:Guanylate Cyclase; D006152:Cyclic GMP; D002118:Calcium