Avaliação dos efeitos toxicológicos após exposição subaguda ao herbicida gramoxone® em ratos

Abstract

Gramoxone is a commercial herbicide widely used because of its effectiveness, has as active ingredient the Paraquat (PQ), substance which belongs to the chemical group of bipyridylium, highly toxic to the lung. Despite its wide use, a little is known regarding its toxicological aspects, thereby, in the present study, it was evaluated the systemic toxicological effects to the subacute exposure of the PQ herbicide in Wistar rats. The animals were exposed, orally (gavage) to 0; 0,1; 0,5 and 1,0 mg/kg/PQ, during 28 days. No clinical signs of toxicity were observed in animals of the experimental groups during the treatment with PQ. It was noticed a growth in absolute and relative weight of the lung in the animals that received the 0,5 mg/kg/PQ/day dose, and also in the weight of other organs of the treated animals in comparison to the control group. It was also noticed an increase in serum aspartate aminotransferase levels (AST) in the group that received 0,5 mg/kg/PQ/day, and a decrease in urea levels of 1,0 mg/kg/PQ/day, however, with no significant changes in the evaluated alanine aminotransferase levels (ALT), creatinine and in the hematologic parameters. As there was an increase in the AST levels and in the lung weight, we suggest that the PQ, in this experimental model, was toxic to the lung.