Free Radicals in Aging [antikvár]

PREFACE Advancement in the understanding of free radical biochemistry and its multifaceted effects on biological function have led to a renewed interest in studying the role of free radicals and related reactions in the biological and pathological changes occurring in aging organisms. Scientific interest and experimental inquiry into the role of free radicals in aging formally began with Denham Harman's proposal in 1956 of The Free Radical Theory of Aging. This theory has since served as a useful underlying hypothesis for the field of gerontology and has thus guided experimental gerontologists who have continuously sought the biochemical and molecular bases underlying the complex biological and pathological problems of aging. The Free Radical Theory of Aging was neither the first nor the last to try to explain the aging process. In fact, no other discipline of science has as many theories and hypotheses as gerontology. Unfortunately, most of the theories or hypotheses of aging, proposed in the past and present, limit themselves to merely describing epiphenomena and fail to provide a means by which to be tested. Similariy, no satisfactory experimental verification of The Free Radical Theory of Aging has yet been provided, and this theory has thus been criticized on these grounds. Hopefully, our recently improved ability to better design critical experiments will now allow more direct examination of The Free Radical Theory of Aging and its implications. For example, data recently obtained from experiments in both fields have provided further insights implicating free radicals in major age-related diseases such as atherosclerosis, cancer, and diabetes. It is the purpose of this book to bring together two diverse fields in a more comprehensive manner by discussing salient subjects ranging from the basic free radical biochemistry to future directions of the study of free radicals in aging. This will include modem variations on the theme of The Free Radical Theory of Aging, such as The Free Radical-Glycation/Maillard Theory of Aging, recently proposed by myself and my colleague, Bruce Kristal. It should be emphasized that none of the existing theories are sufficient to explain all the phenomena observed in aging organisms, but free radical-related reactions appear to have the widest implication in both primary aging processes and age-related pathological processes, as we know them today. I wish to express my sincere thanks to my many colleagues who contributed their time and effort in making this book possible. I also thank Mrs. Kimberley Kennedy for her assistance in preparing and editing this book. Byung Pal Yu