PMID- 14962502
OWN - NLM
STAT- MEDLINE
DCOM- 20040322
LR  - 20220321
IS  - 0041-008X (Print)
IS  - 0041-008X (Linking)
VI  - 195
IP  - 1
DP  - 2004 Feb 15
TI  - Exposure parameters necessary for delayed puberty and mammary gland development 
      in Long-Evans rats exposed in utero to atrazine.
PG  - 23-34
AB  - Our studies suggested that prenatal exposure to the herbicide atrazine (ATR) 
      could delay vaginal opening (VO) and mammary development in the offspring of 
      Long-Evans (LE) rats. To evaluate ATR exposure parameters required for pubertal 
      delays, including mammary gland development, we used cross-fostering to determine 
      if effects were strictly dam-mediated (via milk) or a direct effect 
      (transplacental) on the pups. Timed-pregnant LE rats (N = 20/treatment group) 
      were gavaged on gestational days (GD) 15-19 with 100 mg ATR/kg body weight (BW) 
      or vehicle (controls, C). On PND1, half of all litters were cross-fostered, 
      creating four treatment groups: C-C, ATR-C, C-ATR, and ATR-ATR (dam-milk source, 
      respectively). A significant delay in VO and increase in VO BW was seen only in 
      the litters receiving milk from ATR-exposed dams. However, mammary glands of 
      female offspring (two per dam) in all groups exposed to ATR (ATR-C, C-ATR, and 
      ATR-ATR) displayed significant delays in epithelial development. These changes 
      were detected as early as PND4 and stunted development was evident through PND40. 
      Further, at all developmental stages examined, offspring in the ATR-ATR group 
      exhibited the least developed glands. These delays in pubertal endpoints do not 
      appear to be related to body weight or endocrine hormone concentrations. Our data 
      suggest that the delay in VO of ATR-exposed offspring (C-ATR lactationally, 
      ATR-ATR lactationally and in utero) is mediated via the dam [milk], whereas brief 
      direct exposure to ATR in utero can cause delays in mammary gland development. 
      Our data suggest that milk-derived factors (growth factors or hormones), in 
      addition to transplacental exposure during mammary bud outgrowth, may be involved 
      in ATR mode of action on delayed mammary gland development.
FAU - Rayner, Jennifer L
AU  - Rayner JL
AD  - Reproductive Toxicology Division, Office of Research and Development, National 
      Health and Environmental Effects Research Laboratory, US Environmental Protection 
      Agency, Research Triangle Park, NC 27711, USA.
FAU - Wood, Carmen
AU  - Wood C
FAU - Fenton, Suzanne E
AU  - Fenton SE
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - United States
TA  - Toxicol Appl Pharmacol
JT  - Toxicology and applied pharmacology
JID - 0416575
RN  - 0 (Herbicides)
RN  - 9002-62-4 (Prolactin)
RN  - 9002-67-9 (Luteinizing Hormone)
RN  - 9002-71-5 (Thyrotropin)
RN  - EC 1.14.14.1 (Aromatase)
RN  - EC 2.7.10.1 (ErbB Receptors)
RN  - QJA9M5H4IM (Atrazine)
SB  - IM
MH  - Administration, Oral
MH  - Animals
MH  - Aromatase/genetics
MH  - Atrazine/*toxicity
MH  - Body Weight/drug effects
MH  - ErbB Receptors/genetics
MH  - Estrous Cycle/*drug effects
MH  - Female
MH  - Gene Expression/drug effects
MH  - Herbicides/*toxicity
MH  - Luteinizing Hormone/blood
MH  - Mammary Glands, Animal/drug effects/*growth & development/metabolism
MH  - Polymerase Chain Reaction
MH  - Pregnancy
MH  - *Prenatal Exposure Delayed Effects
MH  - Prolactin/blood
MH  - Rats
MH  - Rats, Long-Evans
MH  - Thyrotropin/blood
MH  - Vagina/drug effects/growth & development
EDAT- 2004/02/14 05:00
MHDA- 2004/03/23 05:00
CRDT- 2004/02/14 05:00
PHST- 2003/09/15 00:00 [received]
PHST- 2003/11/08 00:00 [accepted]
PHST- 2004/02/14 05:00 [pubmed]
PHST- 2004/03/23 05:00 [medline]
PHST- 2004/02/14 05:00 [entrez]
AID - S0041008X03005386 [pii]
AID - 10.1016/j.taap.2003.11.005 [doi]
PST - ppublish
SO  - Toxicol Appl Pharmacol. 2004 Feb 15;195(1):23-34. doi: 
      10.1016/j.taap.2003.11.005.