Cyclic nucleotide action is mediated through adenosine receptors in damselfish motile iridophores.

Effects of cyclic nucleotides on motile iridophores were examined in the blue damselfish, Chrysiptera cyanea. All of the cyclic nucleotides tested, i.e. cAMP, 2',3'-cAMP and cGMP, accelerated the clearing response of the cells even at concentrations of 10(-5) or 10(-4) M. The action of these nucleotides was effectively antagonized by methylxanthines. These results suggest that the effect of cyclic nucleotides on damselfish iridophores is mediated by adenosine receptors in a similar fashion to the action of adenosine.