A Chronic-Low-Dose Exposing of DEHP with OECD TG 443 Altered the Histological Characteristics and Steroidogeic Gene Expression of Adrenal Gland in Female Mice

Phthalates and their metabolites are well-known endocrine disrupting chemicals. Di-(2-ethylhexyl) phthalate (DEHP) has been widely used in industry and the exposing possibility to adult is high. In this study, DEHP was treated (133 μg/L and 1,330 μg/L in drinking water) according to the OECD test guideline 443 to mature female mice and their adrenal gland were examined for histological characteristics and steroidogenic gene expression. The wet weight of the adrenal gland was increased in all administrated groups compared to control. The diameter of zona fasciculata (ZF) was increased by DEHP in both outer ZF and inner ZF but there was no difference in morphology of the cells and arrangements into zona between groups. In addition, the arrangement of extracellular matrix was not different between control and DEHP groups. CYP11B1 was mainly localized at ZF and the intensity was not different between groups. DAX1 was localized in zona glomerulosa (ZG) and ZF, and its expression levels were decreased by DEHP administration. Its level was lower in DEHP133 group than DEHP1330 group. On the other hand, CYP17A1 was localized in ZG of DEHP1330 group. These results suggest that chronic low-dose DEHP exposing may modify the microstructure and function of the adrenal cortical cortex.