This study tested whether maternal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) may disrupt
the development of neuroendocrine system of their offspring during the perinatal period. TCDD (0.2 or
0.4 lg/kg body weight) was orally administered to pregnant rats from gestation day (GD) 1 to lactation
day (LD) 30. Potential effects on neuroendocrine function were evaluated by measuring serum thyroid
hormone levels in pregnant rats and their offspring and measuring some biochemical parameters in cerebellum
of these offspring on GD 16 and 19, and LD 10, 20, and 30. In both treated groups, a decrease in
serum thyroxine (T4), triiodothyronine (T3) and increase in thyrotropin (TSH) levels were noticed during
the tested days in dams and offspring, as well as GH levels were decreased in offspring with respect to
control group. In cerebellum of control offspring, the levels of monoamines, c-aminobutyric acid (GABA)
and acetylcholinesterase (AchE) were found to be increased from GD 16 to LD 30. The hypothyroid conditions
due to both maternal administrations of TCDD produced inhibitory effects on monoamines and
AchE, and stimulatory actions on GABA in cerebellum of offspring. These alterations were dose and age
dependent. Overall, these results suggest that TCDD may act as neuroendocrine disruptor.
Ahmed R. G. | Ahmed R. G. | 2259