Animal Metabolism of Insecticides, Metabolism of Orally Administered Malathion by a Lactating Cow

Elimination of intravenously injected malathion in sheep

“…The major metabolite resulting from administration of malathion to sheep was MCA, followed by DCA in both urine and feces. This is in agreement with the findings of O'Brien et al (1961) who reported that MCA was the principal urinary metabolite after oral administration of malathion to a lactating cow. However, he found that dimethyl phosphate and , -dimethyl phosphorothioate were the principal degradation products in feces, which may be due to a more extensive degradation of malathion and metabolites by the microorganisms in the rumen when administered orally.…”

Para-oxon hydrolyzing enzymes in rat liver

“…All organophosphates are desalkylated to some extent in mammals, insects, and plants Lindquist, 1964, 1966; Dauterman et al, 1959;Knaak and O'Brien, 1960;Krueger et al, 1959;O'Brien et al, 1961; Casida, 1958b, 1958c), although usually desalkylation is of minor importance except for cases where a resistance factor of rice stem borer, Chilo supressalis, to parathion was involved (Iyatomi and Saito, 1965;Kojima et al, 1963b); and for some dimethyl organophosphates with low mammalian toxicity, particularly Sumithion (Hollingworth et al, 1967;Miyamoto, 1964). A desalkylating enzyme for dimethyl organophosphates was found in the soluble fraction of rat liver and other tissues, and insect tissues Shishido, 1963, 1966; Hodgson and Casida, 1962; Shishido and Fukami, 1963).…”

Absorption, Metabolism, and Excretion of Tritium-Labeled Famphur in the Sheep and Calf

“…To evaluate the possible toxicological hazards associated with the use of this material, its metabolic degradation in biological systems has been investigated. O'Brien et al (1961) studied the metabolism of famphur-H3 in several insects and in the mouse and found that the degradation rates in the various animals differed markedly, although the compound was essentially equitoxic when injected into the animals studied. Among the metabolic products identified were the oxygen analog (famoxon) and VV-demethyl famphur, the latter compound being present to a very minor extent in the mouse.…”