Table 7.

Developmental EDC Effects on Steroidogenesis in the Brain

EDC	Animal	Sex	Exposure Period	Dosage, Route	Age at Analysis and Brain Region	Effect	Endpoint(s)	Ref.
BPA	Rat (S-D)	M/F	E7 to P21	0.01, 0.5, 5, 50, 200 mg/kg/d by gavage to dams	P4, P7, P14, P21, P56; Hippocampus	Aromatase protein was increased in a dose-dependent manner by BPA at ages prior to P56	Aromatase protein	475
PCBs: reconstituted mixture of PCBs 126, 138, 153, 180	Rat (S-D)	M/F	E15–E19 to dam, then 2 × weekly to dam until pups were P21	10 mg/kg/d given to dams sc	E20, P12, P21, P60; Hypothalamus	5α-reductase 1 mRNA was decreased in females at P21 and in both sexes at P60. 5α-reductase 2 mRNA was increased in females at P60. Aromatase mRNA was increased in males at P21	mRNA of 5α-reductase1, 5α-reductase 2, aromatase	566
PCBs: Aroclor 1254	Rat (S-D)	M/F	E15–E19 to dam; neuronal cultures also performed	25 mg/kg/d given to dams by gavage for in vivo work. In neuronal cultures, 10, 100, 500 μg/mL	E20 hypothalamus (in vivo) or hypothalamic neuronal cultures	In vivo, there were no effects of A1254 on aromatase activity or mRNA, or on 5α-reductase 1 mRNA. 5α-reductase 2 mRNA was increased in females, and AR mRNA was decreased by A1254. In vitro, the two higher doses of A1254 decreased aromatase activity	mRNA of 5α-reductase 1, 5α-reductase 2; aromatase activity	1132
PCB, PCDD, PCDF reconstituted mixture	Rat (S-D)	M/F	P1, P5, P10, P15, and P20	Gavaged at 1×, 10×, 100×, 100 × concentrations estimated based on human infant exposures from breast milk	P21; hypothalamus, hippocampus, cortex	The 1000 × mixture had significant effects on Comt (reduced in hypothalamus, hippocampus, cortex of males), Cyp1A1 (elevated in males, all regions), Esr1 (decreased in males in hypothalamus and hippocampus) and Dnmt1 (decreased in hypothalamus of males). 100 × mixture increased Comt in cortex of females. Other data were not shown	mRNA of Cyp1A1, Cyp1B1, Cyp2B1, Comt, Esr1, Dnmt1	1133

Abbreviations: M, male; F, female; sc, subcutaneous; S-D, Sprague-Dawley.