TY - JOUR
T1 - Endocrine biomarkers of early fetal loss in cynomolgus macaques (Macaca fascicularis) following exposure to dioxin
AU - Guo, Yumei
AU - Hendrickx, Andrew G
AU - Overstreet, James W.
AU - Dieter, Jacquelyn
AU - Stewart, Dennis
AU - Tarantal, Alice F
AU - Laughlin, Lisa
AU - Lasley, Bill L.
PY - 1999
Y1 - 1999
N2 - This study examines the endocrine alterations associated with early fetal loss (EFL) induced by an environmental toxin, TCDD (2,3,7,8- tetrachlorodibenzo-p-dioxin), in the cynomolgus macaque, a well-documented reproductive/developmental model for humans. Females were administered single doses of 1, 2, and 4 μg/kg TCDD (n = 4 per dose group) on gestational day (GD) 12. Urinary estrogen metabolites (estrone conjugates) were monitored to establish the day of ovulation, and serum hormones (estradiol, progesterone, chorionic gonadotropin, relaxin) were measured to assess ovarian and placental endocrine status before and after treatment. EFL occurred between GDs 22 and 32 in 10 of the 12 animals treated with TCDD. The primary endocrine alterations associated with TCDD treatment were significant decreases in serum estradiol and bioactive chorionic gonadotropin concentrations (p < 0.02). Less pronounced decreases in serum progesterone (p = 0.10) and relaxin (p < 0.08) also followed TCDD treatment. In contrast, immunoreactive chorionic gonadotropin concentrations were not reduced by TCDD exposure at any level, indicating that TCDD targets specific components of the chorionic gonadotropin synthesis machinery within the trophoblast to alter the functional capacity of the hormone. These data demonstrate the value of endocrine biomarkers in identifying a toxic exposure to primate pregnancy many days before direct signs of reproductive toxicity were apparent. The increased EFL that occurred after exposure to TCDD might reflect a toxic response initially mediated via endocrine imbalance, leading to placental insufficiency, compromised embryonic circulation, and subsequent EFL.
AB - This study examines the endocrine alterations associated with early fetal loss (EFL) induced by an environmental toxin, TCDD (2,3,7,8- tetrachlorodibenzo-p-dioxin), in the cynomolgus macaque, a well-documented reproductive/developmental model for humans. Females were administered single doses of 1, 2, and 4 μg/kg TCDD (n = 4 per dose group) on gestational day (GD) 12. Urinary estrogen metabolites (estrone conjugates) were monitored to establish the day of ovulation, and serum hormones (estradiol, progesterone, chorionic gonadotropin, relaxin) were measured to assess ovarian and placental endocrine status before and after treatment. EFL occurred between GDs 22 and 32 in 10 of the 12 animals treated with TCDD. The primary endocrine alterations associated with TCDD treatment were significant decreases in serum estradiol and bioactive chorionic gonadotropin concentrations (p < 0.02). Less pronounced decreases in serum progesterone (p = 0.10) and relaxin (p < 0.08) also followed TCDD treatment. In contrast, immunoreactive chorionic gonadotropin concentrations were not reduced by TCDD exposure at any level, indicating that TCDD targets specific components of the chorionic gonadotropin synthesis machinery within the trophoblast to alter the functional capacity of the hormone. These data demonstrate the value of endocrine biomarkers in identifying a toxic exposure to primate pregnancy many days before direct signs of reproductive toxicity were apparent. The increased EFL that occurred after exposure to TCDD might reflect a toxic response initially mediated via endocrine imbalance, leading to placental insufficiency, compromised embryonic circulation, and subsequent EFL.
UR - http://www.scopus.com/inward/record.url?scp=0033037773&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033037773&partnerID=8YFLogxK
M3 - Article
C2 - 10026120
AN - SCOPUS:0033037773
VL - 60
SP - 707
EP - 713
JO - Biology of Reproduction
JF - Biology of Reproduction
SN - 0006-3363
IS - 3
ER -