RESUMO
Two doses of butyphos (1/10 and 1/50 LD50) were administered into rats within 6 months. Content of DNA was distinctly decreased in liver and kidney tissues within the first 2 weeks of the pesticide administration. Then DNA synthesis was increased 2-fold in liver tissue and remained high during all the 6 months of intoxication. Protein synthesis was increased in liver tissue within 3 months of the administration and remained elevated up to the end of experiment. High rate of protein synthesis, found in kidney and spleen tissues at the initial steps, was markedly decreased within 6 months. Content of DNA and RNA was decreased in the tissues studied within 1 month of the intoxication and restored within 3 months, while it remained at considerably lower level in liver and spleen tissues as compared with control values. Cholinesterase activity was lowered by 90% in blood within 11 weeks with the subsequent increase; but in the experimental group intoxicated with butyphos at 1/10 LD50 the enzymatic activity constituted only 60% of control values within 6 months. Histological study showed development of necrodystrophy in liver tissue and of fibroplastic glomerulonephritis in kidney. The deteriorating effect of butyphos on cellular genome functions appears to relate not only to its cytotoxicity but also to the cancerogenic and mutagenic properties of the pesticide.