Introduction. Regulation of Glucose Homeostasis. Clinical Aspects of Diabetes Mellitus. Mechanisms of Insulin Action. Therapeutic Use of Insulin. The Secretory Machinery of Insulin Release. Compounds Acting on Insulin Secretion: Sulphonylureas. Compounds Acting on Glucose Uptake: Biguanides. Compounds Acting on Glucose Absorption. Aldose Reductase Inhibitors as New Antidiabetic Drugs. Conclusions. References. Cumulative Index of Authors. Cumulative Index of Titles.