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MATERNAL ATRAZINE (ATR) ALTERS HYPOTHALAMIC DOPAMINE (HYP-DA) AND SERUM PROLACTIN (SPRL) IN MALE PUPS
Citation:
Langdale, C., T E. Stoker, AND R L. Cooper. MATERNAL ATRAZINE (ATR) ALTERS HYPOTHALAMIC DOPAMINE (HYP-DA) AND SERUM PROLACTIN (SPRL) IN MALE PUPS. Presented at Society for Toxicology, March 21-25, 2004, Baltimore, MD.
Description:
Maternal Atrazine (ATR) alters hypothalamic dopamine (HYP-DA) and serum prolactin (sPRL) in male pups. 1Christopher Langdale, 2Tammy Stoker and 2Ralph Cooper. 1 Dept. of Cell Biology, North Carolina State University College of Veterinary Medicine, Raleigh, NC. 2 Endocrinology Branch, RTD NHEERL, ORD, U.S. EPA, RTP, NC. Sponsor: R. Kavlock
In rat and mouse, milk-borne PRL (MB-PRL) is important for normal development of the offspring's tuberoinfundibular (TIDA) neurons. The absence of MB PRL on postnatal days (PND) 1-5 leads to impaired TIDA activity and prepubertal hyperprolactinemia in the pups. We previously showed that ATR will block suckling-induced PRL release. Here, we characterized the effect of ATR on sPRL and HYP-DA and DOPAC in the male pups of Wistar rat dams by dosing the dam from PND 1-9 with ATR (0, 12.5, 25 or 50 mg/kg, twice daily). PRL was measured from PND 2-35 and HYPO DA and DOPAC determined on PND 20, 25, 30 and 35. On PND 12-30, PRL was significantly higher in the 12.5 mg/kg group (AUC 22.5 ng/ml control and 32.67 ng/ml for ATR), but not the 25 and 50 mg/kg groups. Posterior HYP, DA was significantly decreased on PND 30, while DOPAC was significantly decreased from PND 20-30 in the 12.5 mg/kg dose but the same as controls in the high dose. In contrast, anterior HYP DA was increased on PND 20 and 30 in the 12.5 mg/kg group and DOPAC was significantly increased in the 12.5 and 25 mg/kg dose on PND 20 and 30. DOPAC was significantly decreased in all three dose groups on PND 35. Thus atrazine produced a non-linear dose response for PRL, HYP DA and DOPAC. These results suggest that ATR either induced alterations in the developmental progression of HYP-DA and PRL regulation or compensatory changes in this system in response to increasing doses. This abstract does not necessarily reflect EPA policy; Supported by NHEERL EPA policy. This project was done in partial fulfillment of a graduate study as part of a NCSU/EPA Coop Agreement)