EFFECT OF PESTICIDES ON THE ANTIOXIDANT DEFENSE SYSTEM IN VARIOUS RAT TISSUES

ASTIZ MARIANA; ALANIZ MARIA J.T. DE; MARRA CARLOS ALBERTO

Mar del Plata, buenos Aires, Argentina

Congreso; 43 Reunion Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2007

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

The effect of intoxication with dimethoate (D), glyphosate (G) or zineb (Z) administered alone or in combination (i.p 1/50 to 1/250 LD50, three times a week for 5 weeks) was studied on the antioxidant defense system of plasma, liver, kidney and brain rat homogenates. In all preparations we found that TBARS and [NOx] were augmented by D, Z o G treatment. The association of pesticides increased these effects. Concomitantly, glutathione content was incremented in all tissues except brain in which it was decreased. a-Tocopherol also decreased in a direct proportion to the degree of intoxication. As a result, total antioxidant capacity (FRAP) in plasma was diminished up to 5 times in the group in which the three drugs were combined. Catalase activity was incremented by administration of D, G o Z alone; however, association of drugs inhibited the enzyme probably due to overproduction of ROS. GSH-transferase and -reductase activities were both inhibited while superoxide-dismutase was decrease in the group treated with Z+G+D. In brain, only GSH-peroxidase was inhibited. Oxidative stress also affected proteins since carbonyls were incremented. In conclusion, we demonstrated that relatively low doses of pesticides were able to produce an oxidative stress that affects main organs such as SNC, liver and kidney. This scenario was aggravated by simultaneous administration of more than one toxic. A battery of biomarkers should be implemented for the control of populations involuntary exposed to these frequently used agrochemicals. This may be useful to prevent human illnesses, especially neurodegenerative disorders such as Parkinson disease.