The effect of atrazine administered by gavage or in diet on the lh surge and reproductive performance in intact female sprague-dawley and long evans rats

Chad D. Foradori, Prägati Sawhney Coder, Merrill Tisdel, Kun Don Yi, James W. Simpkins, Robert J. Handa, Charles B. Breckenridge

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

Atrazine (ATR) blunts the hormone-induced luteinizing hormone (LH) surge, when administered by gavage (50-100 mg/kg/day for 4 days), in ovariectomized rats. In this study, we determined if comparable doses delivered either by gavage (bolus dose) or distributed in diet would reduce the LH surge and subsequently affect fertility in the intact female rat. ATR was administered daily to intact female Sprague-Dawley (SD) or Long Evans (LE) rats by gavage (0, 0.75 1.5, 3, 6, 10, 12, 50, or 100 mg/kg/day) or diet (0, 30, 100, 160, 500, 660, or 1460 ppm) during one complete 4-day estrous cycle, starting on day of estrus. Estrous status, corpora lutea, ova, and LH plasma concentrations were evaluated. A second cohort of animals was mated on the fourth treatment day. Fertility metrics were assessed on gestational day 20. A higher portion of LE rats had asynchronous estrous cycles when compared to SD rats both during pretreatment and in response to ATR (≥50 mg/kg). In contrast, bolus doses of ATR (≥50 mg/kg) inhibited the peak and area under the curve for the preovulatory LH surge in SD but not LE animals. Likewise, only bolus-treated SD, not LE, rats displayed reduced mean number of corpora lutea and ova. There were no effects of ATR administered by gavage on mating, gravid number, or fetus number. Dietary administration had no effect on any reproductive parameter measured. These findings indicate that short duration, high-bolus doses of ATR can inhibit the LH surge and reduce the number of follicles ovulated; however, dietary administration has no effect on any endocrine or reproductive outcomes

Original languageEnglish (US)
Pages (from-to)262-275
Number of pages14
JournalBirth Defects Research Part B - Developmental and Reproductive Toxicology
Volume101
Issue number3
DOIs
StatePublished - Jun 2014

Keywords

  • Mating/fertility
  • Pesticides
  • Risk assessment

ASJC Scopus subject areas

  • Embryology
  • Toxicology
  • Developmental Biology
  • Health, Toxicology and Mutagenesis

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