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Gestational exposure to atrazine has little effect on female reproductive parameters in Sprague-Dawley (SD) rats
Citation:
Davis, L. K., A. S. Muss, T. E. STOKER, M. G. NAROTSKY, J. M. Goldman, AND R. L. COOPER. Gestational exposure to atrazine has little effect on female reproductive parameters in Sprague-Dawley (SD) rats. Presented at Society of Toxicology (SOT) Annual Meeting, Washington, DC, March 06 - 10, 2011.
Impact/Purpose:
In brief, these data indicate that gestational exposure to ATR at doses as high as 100 mg/kg in the dam, had few adverse effects on these standard measures of reproductive development.
Description:
Atrazine (ATR), a commonly used herbicide, has been shown to exert reproductive effects in animals; however, most ofthese studies have focused on adult exposure. In contrast, there is limited information available on the reproductive and developmental effects of gestational exposure to this herbicide. Here, we examined the effects of 0, 1,5,20 and 100 mg/kg ATR administered to SD dams on gestational days 14-21, a key developmental window, on female reproductive end points. Dosing occurred once daily or was divided into two doses per day; the lower doses were chosen based on existing female LOELs, while 100 mg/kg served as a positive control. lOa mg/kg decreased both maternal and offspring body weights, and postnatal mortality was higher in this group shortly after birth. By postnatal day (PND) 21 no differences in offspring body weights were present. Age of vaginal opening, used as a pubertal index, was significantly delayed only in the 100 mg/kg group. No differences in body weights were seen at this time. Based on recently established guidelines, mammary gland whole mounts were prepared on PND 45 and analyzed by individuals blind to experimental treatment. There were no apparent treatment effects on mammary gland development, including the number of terminal end buds and branch points. To determine the effects of gestational ATR exposure on estrous cycles in the adult offspring, vaginal smears were examined until the control animals reached reproductive senescence (approximately 9 months). These tracking data indicated that animals in the highest treatment group continued to cycle over this time, while growing numbers of females in the lower dose groups showed an emerging acyclicity. In brief, these data indicate that gestational exposure to ATR at doses as high as 100 mg/kg in the dam, had few adverse effects on these standard measures of reproductive development. This is an abstract of a proposed presentation and does not necessarily reflect EPA policy.