Effect of azynphos methyl on polyamine levels during Bufo arenarum embryonic development

CECILIALASCANO; A.CCOCHÓN; NOEMÍ VERRENGIA GUERRERO; ANA FERRARI; ANDRÉS VENTURINO

Rosario, Santa Fé, Argentina

Congreso; XLII Reunión Anual de la Sociedad Argentina de Investigaciones Bioquímicas y Biología Molecular (SAIB); 2006

SAIB

The polyamines (PA) putrescine (Pu), spermidine (Sd) and spermine (Sm) are ubiquitous polycations involved in cell growth and differentiation. On the other hand, azynphos methyl (AM) is an organophosphate insecticide widely applied in the Alto Valle region. Our objective is to determine the effects of AM on PA levels during the embryogenesis of the common toad Bufo arenarum). Embryos were exposed to 9 mg/l of AM since fertilization and until complete development (11 days), with medium replacement every 48 h. PA levels were determined by HPLC at different days of development. The three PA showed a continuous increase during development until complete operculum, being Pu the most relevant followed by Sd. Sm was detectable only in the last stages. AM induced a significant increase on Pu levels (131%) on late developmental stages, while caused a significant drop in Sd (30%) and Sm (below detection limit) levels. AM might block Sd and Sm synthesis, increase their oxidation by polyamine oxidase, or both thus increasing Pu levels and disturbing normal embryonic development. Pu might also increase as a secondary response to stress. Oxidation hypothesis is in agreement with the oxidative stress due to AM exposure duringB. arenarum embryonic development suggested by the responses of superoxide dismutase, catalase, glutathione reductase and glutathione transferase activities.