Teratogenic Evaluation of 2,4,5-T

Abstract

The herbicide 2,4,5-trichlorophenoxyacetic acid is teratogenic and fetocidal in two strains of mice when administered either subcutaneously or orally and in one strain of rats when administered orally. The incidences of both cystic kidney and cleft palate were increased in the C57BL/6 mice as well as the incidence of cleft palate in the AKR mice. The incidence of cystic kidney was also increased in the rats. In addition, an increase in the ratio of liver weight to body weight in the mouse fetus and the occurrence of hemorrhagic gastrointestinal tract in the rat fetus suggest that this compound also has fetotoxic properties.

A survey of the embryotoxic effects of TCDD in mammalian species.

“…The possibility that TCDD might have certain types of embryotoxic effects was realized for the first time when Courtney et al (1) reported their data on the teratogenic effect of 2,4,5-T. Substances like TCDD have been known for some time (2-4) to be contaminants of chlorinated phenols and derivatives of such compounds and they were thought to be responsible for an intoxication called chloracne (5).…”

Determination of chlorinated dibenzo-p-dioxins and dibenzofurans in various materials.

“…When this method was applied to a 1-g sample of material used by Bionetics Research Laboratory in a teratology study (14), the results shown in Figure 1 were obtained. The use of gas-liquid chromatography in combination with mass spectrometry (GC-MS) offers significant potential for selective determination of particular components in complex mixtures (15,16).…”

Bioassay of 2, 4, 5-trichlorophenoxyacetic acid for carcinogenicity in mice

“…One by Courtney et al (1970) showed that 2,4,5-T is teratogenic in mice. The other, by Vietnamese doctors, invoked 2,4,5-T as the causal agent of spontaneous abortions and congenital malformations in the inhabitants of regions of large-scale application of 2,4,5-T-based defoliants.…”

“…Many studies on its toxicity (Grigsby and Farwell, 1950;Drill and Hiratzka, 1953;Rowe and Hymas, 1954) and metabolism (Piper et al, 1973;Gehring et al, 1973) have been performed. Courtney et al (1970) showed that it was teratogenic for mice, but such an action was not confirmed in rats and rabbits (Emerson et al, 1971;Sparschu et al, 1971). Innes et al (1969) reported in a preliminary communication of an extensive study on tumorigenicity of pesticides that it had no significant carcinogenic activity.…”