Assessing the consequences of the pesticide methoxychlor: neuroendocrine and behavioral measures as indicators of biological impact of an estrogenic environmental chemical.
Japanese quail provide an advantageous avian model for assessing long-term biological consequences of endocrine disrupting chemicals (EDCs). These studies examined route of exposure and vulnerability to biological impact of EDCs over the life cycle in a precocial avian model, the Japanese quail. Embryonic exposure occurs with maternal deposition and methoxychlor (MXC) accumulated with maternal exposure. Egg injections of MXC or estradiol at selected stages of development impacted hypothalamic neuroendocrine systems in hatchlings and affected sexual maturation, with evidence for long-term effects on neurotransmitters and male behavior. Two-generation dietary studies were conducted to examine transgenerational effects of EDCs. Adult quail (P1) were exposed to dietary MXC (0, 0.5 and 5 ppm), with continued exposure in their offspring (F1), and control diet for all F2 chicks. Toxicological end points, including fertility, hatching success, and 14-day viability were unaffected. F1 and F2 male offspring from MXC-treated pairs MXC had impaired mating behavior and altered plasma hormones. These studies confirm neuroendocrine and behavioral measures as reliable indices of exposure to an estrogenic EDC. Moreover, maternal deposition remains a primary route of EDC exposure, with potential deleterious consequences for field birds, especially precocial species that appear to be particularly sensitive to embryonic EDC exposure.
Ottinger
Mary Ann
MA
Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20742, USA. maotting@umd.edu
Wu
Julie M
JM
Hazelton
Julie L
JL
Abdelnabi
Mahmoud A
MA
Thompson
Nichola
N
Quinn
Michael L
ML
Donoghue
Dan
D
Schenck
Frank
F
Ruscio
Michael
M
Beavers
Joanne
J
Jaber
Mark
M
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D015306:Biogenic Monoamines / Q000378:metabolism; D001923:Brain Chemistry / Q000187:drug effects; D003370:Coturnix; D004305:Dose-Response Relationship, Drug; D004625:Embryo, Nonmammalian; D004703:Endocrine System / Q000187:drug effects* / Q000502:physiology; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D005526:Food, Formulated; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D007306:Insecticides / Q000633:toxicity*; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects; D008731:Methoxychlor / Q000633:toxicity*; D023421:Models, Animal; D011784:Quail; D011930:Reaction Time / Q000187:drug effects; D012726:Sexual Behavior, Animal / Q000187:drug effects; D013997:Time Factors
D015306:Biogenic Monoamines; D004785:Environmental Pollutants; D007306:Insecticides; D008731:Methoxychlor