Inhibition of 3,3',4,4',5-pentachlorobiphenyl-induced fetal cleft palate and immunotoxicity in C57BL/6 mice by 2,2',4,4',5,5'-hexachlorobiphenyl.

Abstract

3,3',4,4',5-Pentachlorobiphenyl (pentaCB) caused a dose-dependent induction of fetal cleft palate in offspring from pregnant C57BL/6 mice exposed to a single dose (783 or 1044 micrograms/kg) of this compound on gestation day 10. In contrast, 2,2',4,4',5,5'-hexaCB did not cause cleft palate at a dose of 271 mg/kg and, in pregnant mice cotreated with 2,2',4,4',5,5'-hexaCB (271 mg/kg) plus 783 or 1044 micrograms/kg 3,3',4,4',5-pentaCB, fetal cleft palate formation was significantly inhibited. 3,3',4,4',5-PentaCB (6 micrograms/kg) also inhibited the splenic plaque-forming cell (PFC) response and serum IgM levels in C57BL/6 mice treated with the T cell-independent antigen trinitrophenyl-lipopolysaccharide. At doses as high as 72 mg/kg, 2,2',4,4'-5,5'-hexaCB was not immunotoxic; however, in mice cotreated with a immunotoxic dose of 3,3',4,4',5-pentaCB plus different doses of 2,2',4,4',5,5'-hexaCB (18, 36 and 72 mg/kg), there was a dose-dependent inhibition of 3,3',4,4',5-pentaCB-induced immunotoxicity. These non-additive (antagonistic) interactions of prototypical polychlorinated biphenyl (PCB) congeners may be an important consideration in development of a toxic equivalency factor approach for hazard and risk assessment of PCB mixtures.

• Authors: F Zhao, K Mayura, N Harper, S H Safe, T D Phillips
• Journal: Chemosphere (Chemosphere) 1997 Mar-Apr Vol. 34 Issue 5-7 Pg. 1605-13 ISSN: 0045-6535 [Print] England
• PMID: 9134691 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Immunotoxins
• Polychlorinated Biphenyls
• 3,4,5,3',4'-pentachlorobiphenyl
• 2,4,5,2',4',5'-hexachlorobiphenyl

Topics

• Animals
• Cleft Palate (chemically induced, embryology)
• Embryonic and Fetal Development (drug effects)
• Female
• Immunotoxins (toxicity)
• Mice
• Mice, Inbred C57BL
• Polychlorinated Biphenyls (antagonists & inhibitors, therapeutic use, toxicity)
• Pregnancy
• Toxicity Tests