Atrazine disrupts the hypothalamic control of pituitary-ovarian function.

The chloro-S-triazine herbicides (i.e., atrazine, simazine, cyanazine) constitute the largest group of herbicides sold in the United States.

Estrous cycle patterns of Sprague-Dawley rats during acute and chronic atrazine administration.

An increased incidence or earlier onset of mammary tumors (MT) has been associated with lifetime feeding of atrazine, an agricultural herbicide, to Sprague-Dawley (SD) female rats. Because MT occur spontaneously in this strain, along with episodes of persistent estrus and acyclic estrogen secretion, it was proposed that atrazine may act to promote this process. SD female rats, 7 to 8 wks old, were administered atrazine while vaginal cytology was monitored.

Placental villous glucose metabolism and hormone release respond to varying oxygen tensions.

Objective: The effects of varying oxygen tensions on tissue metabolic behavior are not well understood, yet many intracellular pathways are influenced by them. In the placenta, optimal in vivo oxygen tension at the villous level is unknown. The purpose of this study was to determine effects of varying oxygen tensions on glucose metabolism and hormone release from perifused placental villous explants.

Effect of atrazine on ovarian function in the rat.

The effect of the chlorotriazine herbicide, atrazine, on ovarian function was studied in Long-Evans hooded (LE-hooded) and Sprague-Dawley (SD) rats. Atrazine was administered by gavage for 21 d to females displaying regular 4-d estrous cycles. In both strains, 75 mg/kg/d disrupted the 4-d ovarian cycle; however, no distinct alteration (i.

Human chorionic gonadotropin: properties and assay methods.

Modern HCG assay methodology provides a level of sensitivity such that "HCG" immunoactivity in normal individuals or other unexplained low-level "HCG" measurements may be problematic. Two-site assays improve specificity for authentic HCG by selectively measuring intact hormone, and such measures correlate well with biological activity. In some cases, 125I has been replaced with nonradioisotopic labels without sacrificing sensitivity.