Alteration of polyamine metabolism in the effect of azinphos-methyl on Rhinella arenarum developmen

LASCANO C; FERRARI A; MAIALE S; RUIZ O; VENTURINO A

Congreso; XLVII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecula; 2011

SAIB

The objective of this study was to evaluate the impact of the pesticide azinphos-methyl (AM) on polyamine (PA) metabolism along embryonic development of the toad Rhinella arenarum. HPLC analysis of extracts from exposed embryos showed an increase in putrescine (Put) and a decrease in spermidine (Spd) and spermine (Spm) levels at late embryonic development. Ornithine decarboxylase (ODC) and diamine oxidase (DAO) activities measured by 14CO2 release and spectrophotometry respectively were increased at intermediate and late embryonic stages by AM exposure. The transcription factor c-Fos, which participates in the transcriptional control of Odc gene, showed an increase in its translocation to the nucleus in response to AM exposure at intermediate stage (Western Blot analysis). At the end of embryonic development, a significant decrease in GSH levels and a significant increase in the percentage of malformations were also observed in AM-exposed embryos. We conclude that AM affects PA metabolism decreasing Spd and Spm levels, which alter embryo development and may also trigger ODC induction and Put synthesis. Both a decreased synthesis and an increased degradation of Spd/Spm may contribute to Put accumulation leading to an increased degradation through DAO. PA increased degradation generates oxyradicals which could contribute to oxidative stress and altered development.