Transitory metabolic disruption and cytotoxicity elicited by benzo<&lsqb;>a<&rsqb;>pyrene in two cell lines from rainbow trout liver

Abstract

Two cell lines, RTL‐W1 and R1, from rainbow trout liver were used to investigate the effects of benzo[A]pyrene (BaP). BaP induced a catalytic measure of CYP1A, 7‐ethoxyresorufin‐O‐deethylase (EROD) activity, in the rainbow trout liver cell line RTL‐W1 but not in R1. Geldanamycin inhibited EROD induction by BaP. Potential BaP metabolites, BaP‐7,8‐dihydrodiol (BDP) and 6,12‐BaP quinone (BQ) also induced EROD activity in RTL‐W1. Very low BaP concentrations slightly stimulated cell proliferation in both cell lines. Higher BaP concentrations caused cytotoxicity in RTL‐W1 but not in R1. Cytotoxicity was detected in a cell viability assay with 5‐carboxyfluorescein diacetate acetoxymethyl ester, and as a decline in cell number. In both cell lines, BaP exposure impaired the reduction of the redox dye, alamar Blue (AB). After BaP removal, AB reduction recovered. Similar results were observed with BQ. As AB monitors metabolic activity, this novel phenomenon was termed transitory metabolic disruption. This decline in AB readings that was caused by BaP was ameliorated in RTL‐W1 by α‐naphthoflavone and geldanamycin, which suggests a role for CYP1A, and in R1 by indomethacin, which suggests involvement of prostaglandin‐H‐synthase. The significance of the response to BaP that is detected with AB and whether other PAHs cause it will be interesting future questions. © 2000 John Wiley & Sons, Inc. J Biochem Toxicol 14:262–276, 2000

Alteration of cellular lipids and lipid metabolism markers in RTL-W1 cells exposed to model endocrine disrupters

“…RTL-W1 cells have been mostly used in toxicological studies, including induction of CYP1A (EROD activity) and evaluation of DNA damage (Segner et al, 2000;Schirmer et al, 2000;Schnell et al, 2009;Boettcher et al, 2010). The metabolism of lauric acid and the glucuronidation of 1-naphthol and testosterone by RTL-W1 cells have also been described (Thibaut et al, 2009).…”

Proposal to improve vertebrate cell cultures to establish them as substitutes for the regulatory testing of chemicals and effluents using fish

“…A number of these cell lines have been described to possess specific functions of their origin. For example, the liver cell line RTL-W1 is capable of biotransformation (Lee et al, 1993;Schirmer et al, 2000), and the gill cell line RTgill-W1 (Bols et al, 1994) shows mitochondria rich chloride-like cells and secretes mucus that allows growth of the causative agent for amoebic gill disease (Lee et al, 2006). As well, the macrophage cell line, RTS-11, has been shown to express cytokines, such as tumor necrosis factor ␣ (TNF␣), transforming growth factor ␤ (TGF␤) and interleukins 1␤, 8, 11, 18 (Brubacher et al, 2000;Wang et al, 2005;Zou et al, 2004).…”

Molecular mechanisms of cold-induced CYP1A activation in rat liver microsomes

“…According to literature, when classic AhR ligands are used, herbimycin A and geldanamycin inhibit in vitro CYP1A1 activity [25,45] and reduce the CYP1A1 mRNA [22,56] and protein levels [25,50]. Studies of the effects of genistein on CYP1A1 have produced conflicting results.…”