Date of Award


Degree Type


Degree Name



Biological Sciences

First Advisor

Dufresne, M. J.


Chemistry, Biochemistry.




To assess the relevance of H4IIE for human populations, we examined levels of aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin O-deethylase (EROD) activities H4IIE rat liver, HepG2 human liver and MCF-7 human breast cells after exposure to a variety of HAHs. These included TCDD, and three coplanar non-ortho substituted polychlorinated biphenyl (PCB) congeners: 3,3$\sp\prime$,4,4$\sp\prime$-tetrachlorobiphenyl (PCB 77), 3,3$\sp\prime$,4,4$\sp\prime$5-pentachlorobiphenyl (PCB 126), and 3,3$\sp\prime$,4,4$\sp\prime$,5,5$\sp\prime$-hexachlorobiphenyl (PCB 169), either alone or in combination. AHH and EROD activities were also examined after treatment with muscle tissue extracts of Lake Ontario rainbow trout (Oncorhynchus mykiss). H4IIE was generally more sensitive to all HAH treatments. AHH and EROD activities were induced in all cells treated with TCDD and PCB 126, alone or combined with each other. In contrast, neither activity is induced in human cells treated with PCB 77 or PCB 169. The induction response all cell lines treated with 5 nM TCDD-PCB mixtures was generally nonadditive; only the response in H4IIE treated with 10$\sp{-3}$ nM TCDD-PCB mixtures was generally additive. With tissue-extracts, induction was restricted to H4IIE cells. A tissue-extract fraction containing primarily TCDD, PCBs and organochlorides, and a fraction containing primarily organochloride pesticides were both able to induce dose related increases in AHH and EROD activities, in H4IIE. These dose related activities were observed in murine H4IIE but not in human HepG2 or MCF-7. A comparison of AHH activity in murine cells by TCDD, PCB 77, PCB 126 and PCB 169 in AHH responsive and four AHH non-responsive Hepa genetic variants, demonstrated that these HAHs induce AHH and EROD activities via the same mechanism. (Abstract shortened by UMI.)Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1995 .V35. Source: Masters Abstracts International, Volume: 34-06, page: 2375. Adviser: M. J. Dufresne. Thesis (M.Sc.)--University of Windsor (Canada), 1995.