Efectos "in vivo" de Pb2+, Cd2+ y Cu2+ Sobre la actividad específica de la ALA-D y PBG-D de embriones de pollo

PAUZA NL; GIL CARDEZA ML; BELLO GAY E; COPPINI C; CASTRO F; GUTIÉRREZ ML; FERRAMOLA DE SANCOVICH AM; SANCOVICH HA

Bariloche, Río Negro, Argentina

Simposio; Protein Symposium SAIB; 2003

SAIB

The chick embryo has been used as a novel system in screening for the toxicological and teratogenic effects of many chemical substances. Heavy metals like Pb, Cd and Cu are environmental pollutants and have shown to cause teratogenic defects in fetuses. On day 12 of incubation, the eggs were injected in the yolk with 100 and 200 Pb2+ mM. The eggs were opened 12 and 60 hours later, yolk sac membrane and liver removed and ALA-D and PBG-D activities assayed administration induced much lower mortality rate than Cd2+ injection. The higher doses causes higher mortality rates, except in the case of copper administration. The acute loading of cadmium induced teratogenic effects in the chicken embryo more marked than for lead and copper, but has no effects on ALA-D and PBG-D activities. Lead administration caused an important decrease on yolk sac membrane ALA-D activity, much more marked than in liver enzyme activity, and reduced poorly PBG-D activity. Copper injection showed an inhibitory effect only on yolk sac membrane ALA-D enzyme at the higher dose.The different effects observed in vivo on these enzyme activities for these metals, could be explained due to its different capacity to cross vitelline membrane. The more markedly effect observed on yolk sac membrane enzyme activity could be due to this tissue ability for mobilization, uptake and short-term storage for these trace minerals.