Violation of lipid metabolism
lipids - fats and lipids - a large group of substances, including a large number of different substances, such as triglycerides, cholesterol, cholesterol esters, free fatty acids, phospholipids, sphingolipids.General physico-chemical property of most lipids are poorly soluble in water.In connection with this movement of the body is only possible in the form of complexes with proteins or in the presence of bile acids.Lipids are the major component of all body cells and are part of cell membranes.Considerable quantities of lipids are concentrated in the marrow, subcutaneous fat layer, perirenal adipose tissue.They have a low thermal conductivity, function as an insulator, which protects the body from cooling.The presence of lipid is necessary for the delivery of the body of fat-soluble vitamins - A, D, E and K. Fatty acids are an important source of energy, at the expense of which may be provided up to 50% of the daily energy needs.
Splitting and lipid absorption mainly occurs in the small intestine.Dig
most intensive absorption of fat incoming food, is carried out in the initial small intestine, whereas in the more remote sections along with the suction occurs and sebum.In this connection, while limiting the fat in the diet it stands slightly more than is contained in the food.Great value for the absorption of fat is the size of the fat particles.With the shortage of pancreatic enzymes of fat absorption from the small size of the molecules may be intact, while the larger particles are hardly absorbed.Fat transition to a state in which it can be absorbed in the intestine (fat emulsification - into a state of emulsion), promote bile acids.These acids form complex with fats, soluble in water, and ensures that their absorption.Malabsorption occurs when excess fat in the diet of calcium and magnesium salts.Some antibiotics inhibit cleavage of lipids and thereby increase its excretion in the feces (steatorrhea).Absorption of fat is broken as in inflammatory processes in the gut, intoxication, with a deficiency of vitamins A and set B, in diseases of the adrenal glands.
a lot of attention paid to studying the role of fatty acids in the body in recent years - linoleic, linolenic, arachidonic.These acids except arachidonic, received only the diet.In case of shortage of these substances are developing all kinds of dysfunction of many organs and systems.In animal experiments it was found that the use of food that does not contain unsaturated fatty acids, delayed the growth of young animals.In addition, there is peeling of the skin, hair loss, bruising, increased fluid intake and oxygen, reduces the formation of urine, urine protein appeared and erythrocytes (red blood cells).Similar health disorders with a deficit of the same fatty acids have been observed in children.In the latter case the fatty acid deficiency syndrome manifested stunting, reduced body resistance towards various infections of the skin changes.All deficit symptoms disappear if not less than 2% of the caloric requirements of the child provided by linoleic acid.All the above facts are allowed to merge into one fatty acid group - vitamins F. Substantial amounts of these acids contained in vegetable oils, which explains the need to include these products in the diet of children as a breast or older.It has been established that arachidonic acid is ingested with food, but only it is synthesized, and it is also formed from a fatty acid - linolenic.Significant impact on the exchange of fatty acids having vitamin B6 (pyridoxine).
Compounds such as triglycerides, operate in humans mainly functions backup connections, of which, if necessary fatty acids are formed.Since the latter is the material from which the body as a result of numerous chemical transformations receives energy, they are formed of triglycerides and only by increasing the energy needs of the body material.In fact, they perform the same function that is performed by the glycogen, being a reserve carbohydrate compound.
value lipid such as cholesterol, is, on the one hand, that he is a member of a number of organs and tissues to provide their normal chemical structure, and on the other, is a precursor to many of the steroid series compounds.By steroid compounds include adrenocortical hormones (corticosteroids), and sex hormones, and vitamin D, and bile acids.The greatest amount of cholesterol in a healthy person is contained in the adrenal glands, brain and nervous tissue.In smaller amounts it is found in liver, bone marrow, fat tissue and blood.Part of cholesterol in the body is in a free state, the other - in the form of compounds with the fatty acids (esters).The ratio of free and bound cholesterol in blood plasma is relatively constant at 1: 3, respectively.When the proportion of liver injury associated cholesterol greatly reduced.Cholesterol not only enters the human body through food, but also it can be formed from other compounds.Cholesterol Decay occurs mainly in the liver.As a result, formed the bile acids that are excreted in the bile.The bile enters the intestine, and with it there gets large amount of cholesterol, which is inversely absorption in the duodenum and initial small intestine.Thus cholesterol may be output from the colon in some amounts.
Phospholipids - substances presenting a fat, which contains a certain amount of phosphorus.Such compounds are soluble in organic solvents and in water.Phospholipids are a part of cell membranes, play a significant role in the process of blood clotting.They are divided into several groups, one of which are sphingolipids, play a big role in the formation of membrane processes, covering the nerve fibers in the body of a healthy person (the myelin sheath).Since the construction of such a shell is involved and such amino acid such as tyrosine, its disadvantage with phenylketonuria may also lead to considerable disturbances in the nervous system.
Up to 6 months of life myelin content in the brain even slightly, but it increases rapidly after this period, and a three-year life of the chemical structure of the brain tissue corresponds to that in adults.
The human brain consists of gray and white matter.The cerebral cortex consists of gray matter, and the rest of the fabric - white.When this white matter contains three times more cholesterol and other lipids than the cortex.The water content in the brain in the formation is 90%, and is reduced in the process of maturation, reaching 75% in the mature brain.Fetal brain absorbs a small amount of oxygen, but it increased sharply at 2-6 months of age.This explains the relative newborn brain resistance to oxygen deficiency (hypoxia).
To identify different lipid metabolism disorders become important modern biochemical research methods, with which it is possible to determine the content of total lipids in the body, cholesterol, phospholipids.
Currently decided to allocate 3 basic types of inherited disorders of fat metabolism:
1) with a primary disease increased levels of blood lipids, plasma or lipoidozy;
2) of the disease, which is characterized by the accumulation of lipids within a cell - intracellular lipoidozy;
3) disease lipoprotein metabolism (lipid complexes with proteins).