6. Parkinson, A., Biotransformation of xenobiotics, in Klasssen, C.D., Ed.,
Casarett and Doull’s Toxicology, 6th ed., McGraw-Hill Medical Publishing
Division, New York, 2001, p.133.
7. Otto, D.M.E. and Moon, T.W., Phase I and II enzymes and antioxidant
responses in different tissues of brown bullheads from relatively polluted and
non-polluted systems, Arch. Environ. Contam. Toxicol., 31, 141, 1996.
8. Lawson, P. and Yu, M.H., Fluoride inhibition of superoxide dismutase (SOD)
from the earthworm Eisenia fetida, Fluoride, 36, 138, 2003.
9. Sun, G.F., Shen, H.Y. and Ding, G.Y., Effects of extraneous GSH on toxicity
and metabolism of fluoride, Proceedings of the 20th Conference of the
International Society for Fluoride Research, Beijing, China, 1994, p.156.
10. Sun, G.F. et al., Lipid peroxidation and changes in antioxidant levels in
aluminum plant workers, Environ. Sci., 5, 139, 1997.
11. Munkittrick, K.R. et al. Survey of receiving water environmental impacts
associated with discharges from pulp mills. II. Gonad size, liver size, hepatic
EROD activity and plasma sex steroid levels in white sucker, Envrion. Toxicol.
Chem., 13, 1089, 1994.
12. Burnison, B.K. et al., Isolation and tentative identification of compound in
bleached-kraft mill effluent capable of causing mixed-function oxygenase
induction in fish, Environ. Toxicol. Chem., 18, 2882, 1999.
13. Korzekwa, K.R., The cytochrome P450 enzymes and chemical carcinogenesis,
ACS Short Courses, Chemical Mechanisms in Toxicology, ACS, Washington,
D.C., 1994.
6.9 REVIEW QUESTIONS
1. What is the significance of biotransformation in the body’s response to
environmental chemicals?
2. What are the main differences between Phase I and Phase II reactions?
3. Give the three types of reactions in Phase I biotransformation.
4. List the names of the functional groups that participate in Phase I
biotransformation.
5. List the characteristics of the mixed-function oxidases (MFO).
6. What specific role does the liver play in biotransformation?
7. List the endogenous substances that are associated with Phase II reactions.
8. What are the possible problems involved in biotransformation?
9. Give an overall reaction whereby an environmental chemical, RH, is
oxidized by the cytochrome P450 system.
10. Name the four major antioxidant enzymes.
11. Give the names of cellular antioxidants that may prevent free-radicalmediated cellular damage.
12. Explain the important role that SOD plays in the cell.
13. Which environmental chemicals can inhibit microsomal enzymes?
14. List four environmental chemicals that can stimulate microsomal enzymes.
15. Briefly explain the term genetic polymorphism.
16. Explain how cytochrome P450s may be related to cancer.
17. What are the main differences between a substrate and the conjugate in
biotransformation?
Biotransformation – Metabolism of Xenobiotics
97
[16:54 26/8/04 P:/CRC PRESS/4365 MING-HO.751 (1670)/4365-006.3d]
Ref: 4365 MING-HO YU Chap-006 Page: 97 85-98
Casarett and Doull’s Toxicology, 6th ed., McGraw-Hill Medical Publishing
Division, New York, 2001, p.133.
7. Otto, D.M.E. and Moon, T.W., Phase I and II enzymes and antioxidant
responses in different tissues of brown bullheads from relatively polluted and
non-polluted systems, Arch. Environ. Contam. Toxicol., 31, 141, 1996.
8. Lawson, P. and Yu, M.H., Fluoride inhibition of superoxide dismutase (SOD)
from the earthworm Eisenia fetida, Fluoride, 36, 138, 2003.
9. Sun, G.F., Shen, H.Y. and Ding, G.Y., Effects of extraneous GSH on toxicity
and metabolism of fluoride, Proceedings of the 20th Conference of the
International Society for Fluoride Research, Beijing, China, 1994, p.156.
10. Sun, G.F. et al., Lipid peroxidation and changes in antioxidant levels in
aluminum plant workers, Environ. Sci., 5, 139, 1997.
11. Munkittrick, K.R. et al. Survey of receiving water environmental impacts
associated with discharges from pulp mills. II. Gonad size, liver size, hepatic
EROD activity and plasma sex steroid levels in white sucker, Envrion. Toxicol.
Chem., 13, 1089, 1994.
12. Burnison, B.K. et al., Isolation and tentative identification of compound in
bleached-kraft mill effluent capable of causing mixed-function oxygenase
induction in fish, Environ. Toxicol. Chem., 18, 2882, 1999.
13. Korzekwa, K.R., The cytochrome P450 enzymes and chemical carcinogenesis,
ACS Short Courses, Chemical Mechanisms in Toxicology, ACS, Washington,
D.C., 1994.
6.9 REVIEW QUESTIONS
1. What is the significance of biotransformation in the body’s response to
environmental chemicals?
2. What are the main differences between Phase I and Phase II reactions?
3. Give the three types of reactions in Phase I biotransformation.
4. List the names of the functional groups that participate in Phase I
biotransformation.
5. List the characteristics of the mixed-function oxidases (MFO).
6. What specific role does the liver play in biotransformation?
7. List the endogenous substances that are associated with Phase II reactions.
8. What are the possible problems involved in biotransformation?
9. Give an overall reaction whereby an environmental chemical, RH, is
oxidized by the cytochrome P450 system.
10. Name the four major antioxidant enzymes.
11. Give the names of cellular antioxidants that may prevent free-radicalmediated cellular damage.
12. Explain the important role that SOD plays in the cell.
13. Which environmental chemicals can inhibit microsomal enzymes?
14. List four environmental chemicals that can stimulate microsomal enzymes.
15. Briefly explain the term genetic polymorphism.
16. Explain how cytochrome P450s may be related to cancer.
17. What are the main differences between a substrate and the conjugate in
biotransformation?
Biotransformation – Metabolism of Xenobiotics
97
[16:54 26/8/04 P:/CRC PRESS/4365 MING-HO.751 (1670)/4365-006.3d]
Ref: 4365 MING-HO YU Chap-006 Page: 97 85-98