Anticlastogens in Mammalian and Human Cells

1 Introduction.- 2 Principles of Clastogenic Action and Its Estimation.- 2.1 Molecular Mechanisms of Clastogenic Action.- 2.2 Induction of Chromosome Aberrations.- 2.2.1 Chemical Structure as a Basis for Mechanisms of Action.- 2.2.2 Dose-Effect Relations.- 2.2.3 The Distribution of Chromosome Breaks on Cells.- 2.2.4 Cell-Cycle Specific Action of Clastogens.- 2.2.5 Cell Proliferation and Clastogenic Action.- 2.3 Induction of Sister Chromatid Exchange (SCE).- 2.4 Induction of Micronuclei.- 2.5 Practical Aspects of Clastogenicity and Its Estimation.- 3 Anticlastogens: Data and Problems.- 3.1 Definition and Classification of Anticlastogens.- 3.1.1 Definition and Delineation of Anticlastogenesis.- 3.1.2 Classification of Anticlastogens According to the Way They Act.- 3.1.3 Classification of Anticlastogens (Antimutagens) According to Their Chemical Reactions.- 3.2 Anticlastogenic Action on in Vitro Systems.- 3.2.1 Qualitative Data.- 3.2.1.1 Mammalian Cell Systems.- 3.2.1.2 Human Cell Systems.- 3.2.1.2.1 Action on (Induced) Clastogenicity.- 3.2.1.2.2 Action on Spontaneous Fragility.- 3.2.2 Specific Approaches.- 3.2.2.1 Time-Effect Relations.- 3.2.2.2 Concentration-Effect Relations.- 3.2.2.3 Influence of Metabolic Activation.- 3.2.2.4 Interphase Studies Using the PCC Technique.- 3.3 Anticlastogenic Action in Vivo.- 3.3.1 Studies on Mammals.- 3.3.2 Studies on Humans.- 3.4 Action of Anticlastogens on Sister Chromatid Exchange (SCE).- 3.5 A Mainly Historical Side-Glance at Anticlastogens and Ionizing Radiation.- 4 Practical Consequences.- 4.1 Practical Consequences in the Field of Anticlastogen Research.- 4.2 Practical Consequences for Humans.- 5 Concluding Remarks.- References.

Anticlastogens are antimutagens, i.e. they protect chromosomes from the damaging action of chemical and physical mutagens. The presented data obtained from in vitro as well as in vivo studies are discussed as aspects of importance in mutagen-exposed humans.