Insulin

related topics
{disease, patient, cell}
{acid, form, water}
{food, make, wine}
{rate, high, increase}
{service, military, aircraft}
{system, computer, user}
{company, market, business}
{work, book, publish}
{black, white, people}
{school, student, university}

Insulin is a hormone that is central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle.

Insulin stops the use of fat as an energy source by inhibiting the release of glucagon. When insulin is absent, glucose is not taken up by body cells and the body begins to use fat as an energy source or gluconeogenesis; for example, by transfer of lipids from adipose tissue to the liver for mobilization as an energy source. As its level is a central metabolic control mechanism, its status is also used as a control signal to other body systems (such as amino acid uptake by body cells). In addition, it has several other anabolic effects throughout the body.

When control of insulin levels fails, diabetes mellitus will result. As a consequence, insulin is used medically to treat some forms of diabetes mellitus. Patients with Type 1 diabetes mellitus depend on external insulin (most commonly injected subcutaneously) for their survival because the hormone is no longer produced internally. Patients with Type 2 diabetes mellitus are often insulin resistant, and because of such resistance, may suffer from a relative insulin deficiency. Some patients with Type 2 diabetes may eventually require insulin if other medications fail to control blood glucose levels adequately, though this is somewhat uncommon.

Insulin also influences other body functions, such as vascular compliance and cognition. Once insulin enters the human brain, it enhances learning and memory and in particular benefits verbal memory.[2] Enhancing brain insulin signaling by means of intranasal insulin administration also enhances the acute thermoregulatory and glucoregulatory response to food intake, suggesting that central nervous insulin contributes to the control of whole-body energy homeostasis in humans.[3]

Insulin is a peptide hormone composed of 51 amino acids and has a molecular weight of 5808 Da. It is produced in the islets of Langerhans in the pancreas. The name comes from the Latin insula for "island". Insulin's structure varies slightly between species of animal. Insulin from animal sources differs somewhat in "strength" (in carbohydrate metabolism control effects) in humans because of those variations. Porcine insulin is especially close to the human version.

Contents

Full article ▸

related documents
Rheumatoid arthritis
Inclusion body myositis
Multiple sclerosis
Ketamine
Combined oral contraceptive pill
Atherosclerosis
Homeopathy
Infectious disease
Chronic obstructive pulmonary disease
Glossary of medical terms related to communications disorders
Hormone
Reelin
Bipolar disorder
Sudden infant death syndrome
Inflammation
Breast cancer
Hypoglycemia
Sleep
Lysergic acid diethylamide
Testosterone
Mental disorder
Vitamin D
Attention-deficit hyperactivity disorder
Puberty
HIV
Epilepsy
Omega-3 fatty acid
Menopause
Drug addiction
Tocopherol