Meeting Abstract

P2.126  Thursday, Jan. 5  Melatonin in Cnidarians PERES, R.*; MARQUES, A.C.; CIPOLLA-NETO, J.; University of São Paulo, São Paulo - Brazil; University of São Paulo, São Paulo - Brazil; University of São Paulo, São Paulo - Brazil peresrafaperes@aol.com

Melatonin, the main secretory product of the vertebrate pineal gland is suspected to be a ubiquitous molecule principally involved in the transduction of photoperiodic information and protection against free radicals. Besides vertebrates, melatonin has been detected throughout phylogeny in numerous non-vertebrate taxa. In the present study, the occurrence of melatonin in the cnidarian Olindias sambaquiensis and its possible pathway of production was evaluated. Melatonin was evaluated by HPLC with a electrochemical detector. Presence of isoforms of the genes tryptophan hydroxylase and arylalkylamine N- acetyltransferase from the pathway of melatonin's production was evaluated by PCR. Activity of the enzyme arylalkylamine N- acetyltransferase was checked by radio assays. Our results indicate the presence of melatonin in the cnidarian Olindias sambaquiensis, with a circadian pattern of production. This pattern is sustained even in constant darkness, indicating that this melatonin's production is the manifestation of a endogenous clock. We also have find isoforms of the gene of the enzyme tryptophan hydroxylase and arylalkylamine N- acetyltransferase. Together with the results of the activity of the enzyme arylalkylamine N- acetyltransferase, in a rhythm near of the melatonin's production, these data indicate that the melatonin's pathway of production in Olindias sambaquiensis is similar to the one observed in vertebrates. Taken together, our results show, for the first time, the presence of melatonin in an cnidarian. More than that, we have demonstrated that the classical pathway of production of the hormone is probably the one used in this marine invertebrate. More research are necessary to evaluate possible functions of the melatonin in this specie.