Developmental toxicity of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). II. Multireplicated dose-response studies with technical and analytical grades of 2,4,5-T in four-way outcross mice

• Published in: Fundamental and applied toxicology Vol. 19; no. 2; p. 298
• Main Authors: Nelson, C J, Holson, J F, Gaines, T B, LaBorde, J B, McCallum, W F, Wolff, G L, Sheehan, D M, Young, J F
• Format: Journal Article
• Language: English
• Published: United States 01-08-1992
• Subjects: 2,4,5-Trichlorophenoxyacetic Acid - toxicity; Animals; Body Weight - drug effects; Dose-Response Relationship, Drug; Female; Hysterectomy; Mice; Pregnancy; Species Specificity; Teratogens - toxicity
• ISSN: 0272-0590
• DOI: 10.1016/0272-0590(92)90164-D

A series of multireplicated developmental toxicity studies were conducted in four-way outcross mice and CD-1 outbred mice administered either analytical or technical grades of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) by gavage on Gestational Days 6 through 14. The formulations of 2,4,5-T differed by a factor of 10-fold in 2,3,7,8-tetrachlorodibenzo-p-dioxin levels. Reduced fetal weight and increased incidences of cleft palate and embryolethality were the most significant prenatal effects of both formulations of 2,4,5-T observed in all strains/stocks of mice. Both the outcross and outbred mice exhibited a dose-response relationship with each of the above endpoints and the dose-response curves were parallel. There were no embryotoxic or fetotoxic differences between the technical and analytical grades of 2,4,5-T with regard to extent of fetal weight reduction, resorption rate, or cleft palate incidence. There was little difference in the results between the four-way outcross mouse and the CD-1 outbred mouse.