The relevance of growth control (chalones) to the aging process

A large amount of data suggests that a wide variety of cells and tissues contain cell-specific endogenous inhibitors of mitosis which are non species-specific. Increasingly, it appears that these chalone inhibitors are actually relatively small polypeptides capable of complexing with large molecular weight anionic molecules. The purification and chamical characterization of these inhibitors has been rendered extraordinarily difficult and the results have been very slow in forthcoming because of this ability to form complexes with anionic polyelectrolytes. Our recent understanding of this behavior should markedly accelerate our understanding and knowledge of chalone biochemistry in the future. If, in fact, chalones are ubiquitously important to the control of cell proliferation, then they will be important to our understanding of the development of post-mitotic cells and to our concepts of programmed senescence; both in turn might be important to our knowledge of the aging process.