Dietary protein and pesticide toxicity in male weanling rats.

The studies reviewed in this paper were undertaken at the request of the World Health Organization to obtain information on pesticides that would be least toxic for use in countries where the diet is deficient in protein. To investigate the problem, the acute oral LD(50) and the associated clinicopathological syndrome of toxicity were measured in weanling male albino rats fed for 28 days from the time of weaning on diets containing different amounts and different types of proteins. Initial results suggested that the type of dietary protein was of minor importance provided it was present in adequate amounts. Using casein as a source of dietary protein, it was found that the toxicity of 5 pesticides was not appreciably increased when the amount of dietary casein was reduced to one-third of normal requirements. When dietary casein was reduced to 13% of the requirements for normal growth, the toxicity of all 13 pesticides under study was increased. The greatest increases were associated with carbaryl, parathion and, particularly, captan. When dietary casein was increased to 3 times the normal amount, the toxicity of some pesticides such as DDT was augmented while that of others such as carbaryl was unaltered.