2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) exerts its toxic action via the aryl hydrocarbon (Ah) receptor, which induces a battery of xenobiotic-metabolizing enzymes, including the cytochrome P450 isozyme, CYP1A1. TCDD-induced 7-ethoxycoumarin-O-deethylase activity was reduced 75% in cultured human endometrial ECC-1 cells exposed to various concentrations of 17beta-estradiol for up to 72 h, wit...

Hepcidin is known to be expressed in fish with bacterial challenge and iron overload. Here we first report the hepcidin expression induced in the developmental stages from embryo to fry of red sea bream (Pagarus major) and in juvenile black porgy (Acanthopagrus schlegelii B.) upon continuous waterborne exposure to BaP. The gene expression of CYP1A1 and IgL (immunoglobulin light chain) were both...

The putative cardioprotective and chemopreventive properties of the red wine phenolic resveratrol (RES) have made it the subject of a growing body of clinical and basic research. We have begun investigations focusing on the effects of RES on the activity of the aryl hydrocarbon receptor (AHR) complex. Our evidence suggests that RES is a potent repressor of 2,3,7,8-tetrachlorodibenzo-p-dioxin (T...

Background and Aims: The cytochrome P450 1A1 (CYP1A1) plays a curial role in phase I metabolism of polycyclic aromatic hydrocarbons to their ultimate biologically active intermediates that have potential reproductive toxicity in men. Reproductive functions in men may be impaired by many environmental, physiologic, and genetic factors. The majority of the environmental factors are xenobiotics. M...

AIMS We investigated the mechanisms of shear stress (SS)-induced activation of cytochrome P450 (CYP) 1A1 and cell cycle arrest with regard to the role of the aryl hydrocarbon receptor (AhR), since AhR mediates the expression of CYP1A1 induced by polycyclic aromatic hydrocarbons (PAHs) and is thought to be involved in the regulation of cell growth and differentiation. METHODS AND RESULTS Human...

Gene polymorphisms of phase I (CYP1A1 and CYP2E of cytochrome P,) and phase II (GSTM1, GSTT1 and GSTP1 of glutathione-S-transferase,) enzymes and the TP53 tumor suppressor gene were studied as markers in a sample of 262 Brazilians of European descent, the sample consisting of 97 patients with non-small-cell lung cancer (NSCLC), 75 patients with chronic obstructive pulmonary disease (COPD) and 9...

Selective inhibitory crosstalk has been known to occur within the signaling pathways of the dioxin (AhR) and estrogen (ERα) receptors. More specifically, ERα represses a cytochrome P450-encoding gene (CYP1A1) that converts cellular estradiol into a metabolite that inhibits the cell cycle, while it has no effect on a P450-encoding gene (CYP1B1) that converts estrodiol into a genotoxic product. H...