Early biochemical changes produced by malathion on toad embryos

The exposure of newly fertilized amphibian embryos to malathion (44 mg/L) produces 67% mortality on the fifth day of exposure. Clinical signs of intoxication are evident on the fourth day. A variety of biochemical parameters, such as enzyme activity, lipid and protein content, was examined in control and malathion-treated embryos. The activity of acetyl, butyrylcholinesterase and aliesterase are quickly inhibited. An interference with cellular protein synthesis and redistribution is possible. A slight increase in total phospholipids is evident after 24 hr of exposure.