In utero and lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin in rats disrupts brain sexual differentiation

Developmental programming and endocrine disruptor effects on reproductive neuroendocrine systems

“…Ikeda et al [80] showed that prenatal dioxin exposure decreased SDN-POA volume of male rats but did not influence this parameter in female rats, suggesting a demasculinizing effect. The estrogenic pharmaceutical diethylstilbestrol (DES) also organizes the developing hypothalamus: the SDN-POA region was increased in size in the female rat but was not affected in male littermates, indicating a masculinizing effect [169].…”

Sexual differentiation of the rodent hypothalamus: Hormonal and environmental influences

“…Moreover, newborns can be further exposed to pollutants during all the lactation period. PCBs may therefore affect the whole developmental period (both gestational and post-natal phases) inducing neurotoxicity and interfering with brain development, particularly with the mechanisms of sexual differentiation [41]. The detrimental impact of PCBs on the neuro-endocrine system development is due to their ability to interact with the mechanism of action of many hormones, including sex steroids.…”

Suppression of fetal testicular cytochrome P450 17 by maternal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin: A mechanism involving an initial effect on gonadotropin synthesis in the pituitary

“…However, TCDDproduced disorders affecting development and reproduction would be much more serious, because those injuries appear at much low doses of TCDD than are required for acute toxicity (Peterson et al, 1993). In animal experiments, in utero and lactational exposure to TCDD causes a number of disorders in pups including retardation of growth, damage to psychological functions and defects in gender-specific phenotypes such as sexual behavior in males and saccharin preference in females (Peterson et al, 1993;Mably et al, 1992;Gray et al, 1995;Seo et al, 1999;Amin et al, 2000;Hamm et al, 2000;Ikeda et al, 2005;Hojo et al, 2006).…”