Metabolism of Insecticides, Metabolism and Excretion of Phosphorus-32-Labeled Diazinon in a Cow

Abstract

Phosphorus-32-labeled Diazinon, administered orally to a cow at 20 mg. per kg., is rapidly metabolized and excreted. Only low levels of unchanged toxicant were found in blood and milk samples. About 74y0 of the dose, excreted as polar degradation products, was accounted for in the urine 36 hours after treatment. IAZISOS,the organic phosphorus D compound, 0,O-diethyl 0-(2-isop r o p y 1-6m e t h y l-4-pyrimidyl) phosphorothioate, has been evaluated against a wide variety of insects affecting plants and domestic animals (5). It is an effective toxicant in baits (4) and, by residual application, in the control of houseflies in dairy barns (7).McGregor and coworkers (77) have demonstrated that Diazinon is a promising chemotherapeutic agent when administered orally or subcutaneously to cattle parasitized Iby cattle grubs, Hjpoderma lineatum (De 'Vill.). It is also effective when applied externally to cattle as a back treatment 1:76).More recently the distribution and excretion of Diazinon in guinea pigs ( 9 ) and its penetration and excretion by the American cockroach (7) have been studied with the aid of phosphorus-32labeled Diazinon and paper chromatographic analysis.To gain a better understanding of its action as a mammalian systemic insecticidc and to investigate the nature of its metabolic breakdciwn products in the bovine body, phosphorus-32 Diazinon was administered orally to a Hereford COLV and, at intervals thereafter, samples of blood, milk, urine. and feces were assayed radiometrically and 'or chromatographically. Materials and MethodsExperimental Animal. The animal employed in this study was a lactating Hereford cow. At the time of administration of the labeled compound the cow weighed 267.6 kg.Radioact:ve Compound. The phosphorus-32-labeled Diazinon was synthesized by Louloudes and associates (70). The radioactive compound was diluted with nonradioactive Diazinon (99.2% pure, from Geigy Agricultural Chemists Research Laboratory, Bayonne, N. J.) and, a t the time of administration, the diluted material had an observable specific activity of 5.18 X 108 counts per minute per gram (mean of three determinations). T h e radiochemical purity of the phosphorus-32 Diazinon was found to be greater than 99% when assessed by several paper chromatographic methods of analyses.Administration of Radioactive Compound. The labeled Diazinon was administered orally in a S o . 1 1 gelatin capsule (0.5 ounce) by use of a balling gun. The dosage was 20 mg. per kg. (5.232 grams for the 267.6-kg. animal).Sample Collection. The animal was held in a metal chute modified for tracer studies. Food and water were supplied throughout the experimental period.Urine and feces were collected manually, with considerable care to prevent cross contamination. Near-quantitative collections were made for the 36-hour post-treatment interval. Subsequent to this period. samples were taken only at the various times indicated in the figures and text.Blood samples, 10 ml.. were taken from the jugular vein at each sampling; sodium citrate was used as th...

Animal Metabolism of Insecticides, Bovine Metabolism of Organophosphorus Insecticides. Metabolic Fate of O,O-Dimethyl O-(2,4,5-trichlorophenyl) Phosphorothioate in Rats and a Cow

“…Several organophosphate insecticides are effective chemotherapeutic agents for cattle grubs following oral, subcutaneous, or epidermal administration (77, 18). Robbins, Hopkins, and Eddy have published on the distribution and metabolic fate of two of these, Diazinon and Dipterex, in lactating cows (24,25) and have presented a preliminary report on the fate of a third, , -dimethyl 0- (2,4,5-trichlorophenyl) phosphorothioate (Trolene), in a calf (23)' Trolene administered orally at 100 mg. per kg. not only kills larvae present in the backs of cattle, but also completely prevents the encystment of new larvae (77.…”

Detection and distribution of32P labelled diazinon

“…All faecal samples were very fluid, yellowish in· colour and extremely radioactive, the later samples containing traces of blood. After 5 hours the animal urinated for the first time since the commencement of the experiment, the urine being radio- Robbins et al (1957). …”

Insecticide Evaluation, Dermal and Oral Treatments of Cattle with Phosphorus-32-Labeled Co-Ral

“…The low levels in the blood and urine and the high levels of activity on the hair, however, were characteristic for all the dermally treated animals. Co-Ral v'as less efficiently absorbed from the bovine digestive tract than several other organophosphorus compounds (5,6), as evidenced by the relative per cent recovered in the urine and feces. The unidentified metabolites excreted in the urine following oral administration may represent a dealkylated metabolite (4).…”