Polycyclic aromatic hydrocarbons as inducers of cytochrome P4501A enzyme activity in the rainbow trout liver cell line, RTL‐W1, and in primary cultures of rainbow trout hepatocytes

Abstract

In order to investigate cell-specific differences in the response of in vitro models to environmental toxicants, we compared the capacity of nine polycyclic aromatic hydrocarbons (PAHs) to induce cytochrome P4501A (CYPIA) in primary rainbow trout (Oncorhynchus mykiss) hepatocytes and a rainbow trout liver cell line, RTL-W1. Induction of CYPIA was estimated from the catalytic activity of 7-ethoxyresorufin-O-deethylase (EROD) and compared by median effective concentration (EC50) values, induction spans, and benzo[a]pyrene induction equivalency factors for inducing PAHs. The influence of culture conditions was investigated with respect to the presence or absence of serum and varying exposure times. Both in vitro systems lead to an identical classification of the PAHs in noninducing (anthracene, fluoranthene, phenanthrene, and pyrene) and inducing compounds with a similar ranking of inducing PAHs. Mean EC50 values in RTL-W1 cells were, respectively, 343 and 266 nM for benzo[a]anthracene, 57 and 92 nM for BaP, 134 and 283 nM for benzo[b]fluoranthene, 455 and 270 nM for chrysene, and 98 and 116 nM for 3-methylcholanthrene. Compared to primary hepatocytes, the RTL-W1 cell line was more sensitive in its EROD response to the presence or absence of serum and to the increase in exposure time, which led to higher EC50 values.

Modulation of ethoxyresorufin O-deethylase and glutathione S-transferase activities in Nile tilapia (Oreochromis niloticus) by polycyclic aromatic hydrocarbons containing two to four rings: implications in biomonitoring aquatic pollution

“…Hence these organic compounds are called as AhR agonists (Whyte et al 2000;Timme-Laragy et al 2007). In vitro studies with mammalian and piscine cell cultures and a few in vivo studies with some fish species have compared the EROD induction potency of different PAHs (Till et al 1999;Fent and Batscher 2000;Whyte et al 2000;Basu et al 2001;Behrens et al 2001;Willett et al 2001;Bosveld et al 2002;Billard et al 2004;Lu et al 2009). In general PAHs with five-or more rings are good CYP1A inducers but inconsistent information is available on EROD induction potential of PAHs containing two to four fused rings.…”

“…Behrens et al (2001) compared the capacity of nine PAHs to induce CYP1A in primary rainbow trout hepatocytes and liver cell line RTLW1 and found anthracene, phenanthrene, fluoranthene and pyrene are non-inducing PAHs. However, a recent in vivo study demonstrated significant induction of EROD activity in golden grey mullet (Liza aurata) following phenanthrene exposure (Oliveira et al 2007).…”

“…Induction of CYP1A activity has been used to infer effects such as cancer related liver lesions and reproductive impairments in fish (Whyte et al 2000). Numerous in vitro studies with mammalian and piscine cell cultures and a few in vivo studies with some fish species indicate that inducibility of EROD varies with the type of PAH (Till et al 1999;Whyte et al 2000;Basu et al 2001;Behrens et al 2001;Willett et al 2001;Bosveld et al 2002;Billard et al 2004;Lu et al 2009). Most of these studies have focused on high molecular weight PAHs with five-or more fused rings.…”

Developmental effects of aerosols and coal burning particles in zebrafish embryos

“…Bivariate correlations were tested by the non-parametric Spearman's correlation attending to the small number (6) Toxicity equivalents (TEQs) were calculated from the content of different samples in the parental PAHs (Querol et al, 2011;van Drooge et al, 2010), using previously reported toxicity equivalence factors for fish cells (Behrens et al, 2001;Fent and Batscher, 2000;Villeneuve et al, 2002) or YCM-RYA (Misaki et al, 2007). An additive action model was assumed, multiplying each PAH congener concentration by the respective TEQ factor and summing the resulting products.…”

The potential of mechanism-based bioanalytical tools in ecotoxicological exposure and effect assessment

“…[47,48,49]). For instance, to measure the dioxin-like activity, recombinant yeast cells, continuous teleostean and rodent cell lines and primary cell cultures from fish, birds and mammals have been used [50,51,52,53,54,55,56]. Differences of the gene induction response among cell systems derived from various species have been reported [53,54,57,58], which may relate to species-dependent ligandbinding affinity, in the expression level and structure of the receptors and their associated proteins, and in the ac-392 Fig.…”