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Oxford University Press: Oxford and New
York, 1997. xv + 368 pp. ISBN 0-19-509340-2. $56.00.
This well-written book presents concepts of
toxicology from a chemical, biochemical, and molecular
biological perspective and serves as a welcome companion to
other books on toxicology, which tend to have as a basis the
characterization and quantification of toxic responses.
This mechanistic approach should be particularly appealing
to scientists with a strong chemical background. The book is
an outgrowth of a course in molecular toxicology taught at
the University of Guelph by the author, and it fills a
much-needed niche as a textbook for a course focusing on
biochemical mechanisms of toxicology. The clientele for such a course
is advanced undergraduates or graduate students with a
strong background in biochemistry, bioorganic chemistry,
toxicology, or pharmacology.
The book covers reactive intermediates and their
interactions with nucleic acids, proteins, and lipids, the
toxicology of molecular oxygen and oxidative stress being a
particular highlight. In addition, the toxicology of aromatic
amines, nitrosamines, polycyclic aromatic hydrocarbons, and
chlorinated organic compounds is specifically addressed.
After two introductory chapters that review some of
the more important concepts in biochemistry and
molecular biology, the next five chapters consider in detail
biological oxidation and the toxicology of molecular oxygen. The
oxygen-metabolite-detoxifying enzymes superoxide dismutase
(SOD), catalase, and the peroxidases are discussed in separate
chapters, as are the oxidative processes involving the respiratory
burst, lipid peroxidation (written by Manfred Brauer and
Phillipe Couture from the University of Guelph), and erythrocyte
oxidative stress. These chapters are all written from the
perspective of biochemical or chemical mechanism, with side bars on
a variety of topics that add breadth to the presentation. As
an example of this breadth, the chapter Superoxide and
Superoxide Dismustases has sections on (i) the chemical and
biological sources of superoxide, (ii) the forms, distribution,
and assays of SOD (iii) genetic aspects of SOD, and (iv)
mechanisms of superoxide toxicity and superoxide reactivity.
Side bars in this chapter include discussions of the radiolysis
of water, kinetics of SOD-catalyzed reactions, EPR spin
trapping, and gene fusion. The chapters on catalase and the
peroxidases, the respiratory burst, lipid peroxidation, and
erythrocyte oxidative stress are less detailed, but they provide a
framework for discussion of these topics that could easily be
enhanced in a course setting.
Chapter 9 is an introduction to xenobiotic
metabolism and is a concise description of the important processes
involved in modification of xenobiotics. These processes
are considered in detail in Chapters 10 (Glucuronide
Formation), 11 (Glutathione and Detoxification, written by
Bengt Mannervik from the University of Uppsala), 12
(Arylamine N-Acyltransferase, written by Denis Grant from the
Hospital for Sick Children, Toronto), 13 (Sulfotransferase), 14 (Cytochrome P-450, written by Paul Ortiz de
Montellano from the UCSF), and 15 (The AH Receptor [that
mediates the toxic response of p-dioxin], written by Patricia
Harper from the Hospital for Sick Children, Toronto). These
chapters are all excellent reviews of important topics, the
cytochrome P-450 chapter being particularly detailed and
informative.
The last five chapters of the book focus on DNA
modification and carcinogenesis. These sections detail the
formation of modified DNA, how DNA adducts cause mutation in
the genetic sequence, and how such mutagenesis may
ultimately lead to carcinogenesis. Chapter 16 focuses on common
DNA adduct formation and methods for the isolation and
chemical characterization of small quantities of modified DNA
isolated from cellular milieu. Identification of DNA
adducts provides evidence for reactive intermediates and allows
for elucidation of the mechanism of adduct formation.
Chapter 17 reviews the basic types of mutations caused by DNA
modifications such as chemical lesions and strand breaks, with
a thorough consideration of enzymatic repair mechanisms
for DNA damage, both before and after replication.
Common mutagenicity assays, such as the
lacI system and Ames assays, are discussed. Chapter 18 (written by Jean Jordan from
the University of Ottawa) considers both oncogene activation
and tumor suppressor gene inactivation as a consequence of
mutation in these genes important in the initiation of
carcinogenesis. The final two chapters offer a more detailed
analysis of two classes of potent mutagens/carcinogens,
Polycyclic Aromatic Hydrocarbons (Chapter 19) and Aromatic
Amines (Chapter 20). These segments provide insight into the role
of in vivo activation of these xenobiotics to ultimate
carcinogens and their mode of action to produce DNA adducts
and mutations, with Chapter 19 being a particularly
thorough review of PAH chemistry.
The book is well organized. The text is liberally
augmented with chemical structures, reaction sequences,
and graphical representations of protein structures and the
like. At the end of each chapter is a list of notes providing
entry to the primary literature. Referencing tends to be a bit
uneven from chapter to chapter, probably because of the
different authorships. In general, however, the notes do
provide critical leading references or reviews for the reader
seeking more depth in a topic. Of references, most are
post-1980 some are very recent; others give reference to classic
publications going back several decades. The book, then, will be
of interest to a wide range of scientists, is an absolute
necessity for every chemistry, biochemistry, or biosciences or
medical center library, and will serve as a valuable supplement for
both undergraduate and graduate courses in toxicology or as a
text for a course designed around a mechanisms of toxicology
format. Biochemists, toxicologists, and chemists will also
want to have it at the ready on their bookshelves.
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