Involvement of cyclic nucleotides and IP(3) in the regulation of luminescence in the brittlestar Amphipholis squamata (Echinodermata).
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.
De Bremaeker
N
N
Laboratory of Animal Physiology, Université Catholique de Louvain, Place Croix du Sud, 5, B-1348 Louvain-la-Neuve, Belgium. debremaeker@bani.ucl.ac.be
Dewael
Y
Y
Baguet
F
F
Mallefet
J
J
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
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