pancreatic function.Endocrine pancreas function due to the specialized cells of the islets of Langerhans - α-, β-, D- and F-type.Cells of each of these types secrete certain hormones: β-cells of the islets of Langerhans insulin synthesized, α-cells - glucagon, D-cells - somatostatin, secretin and pankreogastrin, F-cells synthesize hormone-like substances (lipokain and vagotonin).Therefore, an important organ which participates in the regulation of metabolic processes, a pancreas.Hormones synthesized this gland affect all types of exchanges in the body.Insulin is opened LVSobolєv in 1902. In the mid-19th century and established the structure of the hormone produced by its synthesis.
Hormones of the pancreas: insulin.Targets of free insulin are liver cells, muscle and connective tissue.Insulin affects all types of exchanges: protein, carbohydrate, lipid, but the best studied its effect on the metabolism of carbohydrates.First Insulin increases the permeability of cell membranes to glucose and that it provides a transition from blood to tissue.This enzyme activates hormone fosfoglyukotransferazu (geksozokinazu) and thus provides the conversion of glucose to glucose 6-phosphate.The net result of the influence of insulin on carbohydrate metabolism is the reduction of blood glucose concentrations (hypoglycemia) and the accumulation of glycogen in muscle, liver and other organs.Due to the lack of insulin cells lose their ability to use glucose.Its number in the blood gradually increases (hyperglycemia), and she begins to stand out in the urine (glycosuria).
addition of glucose insulin promotes a more active transport of amino acids from the blood, lymph in the cytoplasm of cells, activates the transcription and translation, resulting in increased protein synthesis.
Effect of insulin on lipid metabolism caused by the fact that it provides for the use of carbohydrate synthesis of higher carboxylic acids, are already formed triacylglycerols and other lipids.On the other hand, insulin inhibits tissue lipase, including by inhibition of cAMP formation.Lack of insulin in the body formation is accompanied by increased degradation of the amino acids, which ultimately leads to the accumulation of ammonia and urea in the blood.It activates lipolysis that leads to accumulation in the blood free fatty acids, ketone bodies and cholesterol.
Hormones of the pancreas: glucagon.Glucagon target cells are liver, muscle and adipose tissue, but the main one is the liver, which is activated under the influence glucagon phosphorylase, which in turn activates glycogen hydrolysis.Therefore, the amount of glycogen in the liver decreases and increases in blood glucose.Moreover, glucagon increases gluconeogenesis and activates lipolysis of adipose tissues and thus prevents the development of obesity.This is accompanied by formation of large amounts of acetyl-CoA and ketone bodies.Glucagon secretion decreases with hyperglycemia and increases with stress and hard work.
pancreatic hormones: somatostatin.This igibiruet incretia hormone insulin and glucagon release of gastrin and gastrinstimuliruyuschuyu secretion of hydrochloric acid.Violations of incretion of insulin, glucagon, and somatostatin underlie the development of diabetes.This disease is characterized by general weakness, hyperglycemia, glucosuria, polyuria (daily amount of urine is increased by 3-5 times), there is a diabetic cataract, corneal opacities are recorded.
Hormones of the pancreas: lipokain and vagotonin.Lipokain - hormone-like substance that prevents fatty liver, it stimulates the oxidation of fats, fatty acids and their outlet from the liver to the tissues, promotes the biosynthesis of phospholipids.Vagotonin stimulates the activity of the parasympathetic nervous system, especially the vagus, activates the process of hematopoiesis.
