Insulin action: 1948-80.
Insulin is an old hormone from the standpoint of evolution. It is found in primitive vertebrates, insects, and crustacea and has effects on growth and glucose uptake in animals low on the evolutionary ladder, yes even unicellular organisms. The fascinating problem to consider is the relative emergence of the hormone and of its receptor. Csaba has reviewed recently the work with more primitive species. He argues convincingly that receptor molecules precede the hormones and adapt themselves to become the specific recognition sites they now are in the mammalian organism. This is a fascinating basis area for further research. The history of insulin research is rich and vivid, and has served to open up very important aspects of biochemistry and physiology. It was the first of the protein or peptide group of hormones; the protein whose amino acid sequence studies served to initiate this fruitful area of polymer biochemistry; and it began the important era of specific immunoassays, a technique that has revolutionized the study of the behavior and action of potent natural materials that are highly active in minute concentrations. Last but certainly not the least of its virtues is its medical use to maintain the life and health of countless victims of severe diabetes. The continuing study of the details of insulin action will undoubtedly have further profound influences on the basic and applied aspects of medicine and biology.