Effect of two isomeric tetrachlorobiphenyls on rats and their hepatic enzymes

Metabolism and biochemical toxicity of PCBs and PBBs

“…The synthetic and isomerically pure PCBs have been investigated for enzyme induction, Chen et al (12) found that both 2,3,4,5-and 3,5,3',5'-tetrachlorobiphenyls induced enzyme systems in male rats, but no significant differences were found June 1978 ; between the two isomers. Johnstone et al (17) and Ecobichon et al (19,20) compared the effects of position of chlorine atoms on the ring.…”

“…In rats the maximum activity of demethylase was observed with the 54% chlorine PCBs; maximum activity for nitroreductase was obtained with the 60% chlorine PCBs. Chen et al (12) reported that 54% chlorinated PCBs gave maximum response of demethylase in rats. Similar results were reported by intraperitoneal injection of various PCBs in rats (/3).…”

Sublethal effects of structurally related tetrachloro-, pentachloro-, and hexachlorobiphenyl on juvenile coho salmon

“…Aside from the above species differences, different routes of metabolism could be involved in fish depending on the mode of entry of the compounds into the organisms. PCB's induce microsomal enzymes in higher animals, notably in rats (24)(25)(26). The practical implication of such induced enzymatic activities is that the animals may be expected to metabolize many foreign compounds at elevated rates.…”

Liver aryl 4‐monooxygenase activity in the progeny of hens receiving dietary polychlorinated biphenyls

“…In the last decade, work has been directed toward elucidating the detailed mechanism of action of these mixtures of compounds on liver structure and enzyme activity (Norback and Allen, 1970;Vos et al, 1971). Whereas in mammals the inducing properties of PCB on hepatic monooxygenase are well documented (Chen et al, 1973;Litterst and Van Loon, 1974;Orberg and Lundberg, 1974), little is known about such effects in birds (Bailey and Bunyan, 1972;Turner and Green, 1976).…”