Introduction
Insulin is the most abundant hormone secreted by the islet of Langerhans and is the most important controller of organic metabolism¡CIt's secretion and plasma concentration, are increased during the absorptive state and decreased during the postabsorptive state. For simplicity, insulin's many actions are often divided into two broad categories: (1) metabolic effects on carbohydrate, lipid, and protein synthesis; and (2) growth-promoting effects on DNA synthesis, cell division, and cell differentiation.At same time, insulin is controlled by negative-feedback of plasma glucose (Figure 5) and several other factors (Figure 6).