Abstract
This study was aimed at assessing steroidogenesis stimulated by low-dose exposure to DBP in prepubertal female rats. Animals were gavaged with DBP from postnatal day 21 to 33 at 0, 1, 10 and 500 mg kg(-1) day(-1). 500 mg kg(-1) day(-1) was selected since it was used in numerous studies and the inhibitory effect could be observed at this dosage. After treatment, hormone levels in serum were detected by enzyme-linked immunosorbent assay. mRNA and protein expressions of vimentin, nuclear factor-κB (NF-κB) p65 and phosphorylation of NF-κB p65 (p-p65) were assayed by quantitative real-time polymerase chain reaction (qRT-PCR) assay, western blotting, and immunohistochemistry, respectively. Uterus weights, progesterone levels in serum, and protein expression of vimentin and p-p65 in ovaries increased significantly after the animals were exposed to DBP at 1 mg kg(-1) day(-1). Additionally, steroidogenesis and vimentin expression stimulated by DBP were blocked when the activity of NF-κB p65 was inhibited by the NF-κB inhibitor, pyrrolidine dithiocarbamic acid (PDTC). These results strongly suggested that DBP may activate uterus development by up-regulated steroidogenesis through the NF-κB-vimentin signaling pathway.