Insulin
Insulin (/\ˈɪn.sjʊ.lɪn/, from Latin insula, 'island') is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the insulin gene. It is essential for regulating carbohydrate and fat metabolism in the body.
Production and Function
The pancreas, an organ located behind the stomach, is the primary site for insulin production. Within the pancreas, clusters of cells known as the islets of Langerhans contain beta cells that synthesize and release insulin. The release of insulin is triggered by rising blood glucose levels, which typically occur after eating.
Insulin facilitates the uptake of glucose into cells by binding to the insulin receptor on the cell membrane. This binding triggers a cascade of events inside the cell, promoting the absorption of glucose from the bloodstream into the liver, muscle, and fat tissues, where it is either used for energy or stored for future use.
Types of Diabetes
Type 1 Diabetes
Type 1 diabetes, formerly known as juvenile diabetes, is an autoimmune disease where the body’s immune system attacks and destroys the insulin-producing beta cells in the pancreas. This leads to a severe deficiency of insulin, necessitating lifelong insulin therapy for individuals affected by this condition.
Type 2 Diabetes
Type 2 diabetes is characterized by insulin resistance and a relative lack of insulin. In this condition, cells in the body become less responsive to insulin, requiring higher levels of insulin to achieve the same effect. Over time, the pancreas is unable to produce enough insulin to maintain normal blood glucose levels. This type of diabetes is often associated with obesity, poor diet, and lack of physical activity.
Insulin Resistance
Insulin resistance is a pathological condition in which cells fail to respond normally to insulin. This can occur due to downregulation of insulin receptors or defects in the signaling pathways inside the cells. Insulin resistance is a key feature of metabolic syndrome and type 2 diabetes.
Medical Use of Insulin
As a medication, insulin is any pharmaceutical preparation of the insulin protein that is used to treat high blood glucose levels. This is essential for managing type 1 diabetes and is also used in advanced cases of type 2 diabetes. Various forms of insulin, including rapid-acting, long-acting, and intermediate-acting insulins, are available to meet the differing needs of patients.