Aroclor 1254 as a 2,3,7,8-tetrachlorodibenzo-p-dioxin antagonist: Effects on enzyme induction and immunotoxicity

Characterisation of transcriptional responses to dioxins and dioxin-like contaminants in roach ( Rutilus rutilus ) using whole transcriptome analysis

“…Expression of the major histocompatibility complex I UFA (mhc1ufa), a central protein in the immune system, was reduced by 70.9-and 25.5-fold following treatment with TCDD and BkF, respectively. In summary, these findings indicate a potential disruption of the innate immune system by DLCs, an effect that has previously been shown in fish and other vertebrates (Bannister et al, 1987;Ross et al, 1996;Zelikoff, 1998).…”

Inhibition of 3,3′,4,4′,5-Pentachlorobiphenyl-Induced Chicken Embryotoxicity by 2,2′,4,4′,5,5′-Hexachlorobiphenyl

“…However, the results obtained for complex and simple (binary) mixtures of PCBs indicate that there are species-and response-specific additive (Eadon et al, 1986;Van der Kolk et al, 1992;De Jongh et al, 1992, 1993aSilkworth et al, 1993) and nonadditive (primarily antagonistic) (Bannister et al, 1987;Haake et al, 1987;Biegel et al, 1989;Safe, 1989, 1990;Morrissey et al, 1992;Harper et al, 1995) interactions. For example, the induction of CYPlAl-dependent hepatic microsomal enzyme activities by commercial Aroclor mixtures in the rat were essentially additive contributions from the individual Ah receptor agonists in the mixture (Harris et al, 1993).…”

Towards the development of a multidisciplinary understanding of the effects of toxic chemical mixtures on health

“…There are a few clear examples in simple mixtures: hexachlorobenzene potentiation of 2,3,7,8-tetrachlorodibenzop-dioxin (TCDD) reduction of body and thymus weights (Li et al 1989); PCB antagonism of TCDD immunotoxicity and developmental toxicity (Banister et al 1987;Davis and Safe 1989); and synergism between PCBs and methyl mercury in disrupting regulation of brain dopamine levels that might influence neurological function and development (Birnbaum et al 1985;Haake et al 1987).…”