Bile acids.

Over the past few decades, managed to get a lot of new information about her bile acids.Therefore, it became necessary to revise and expand the ideas of their importance for the functioning of the human body.

role of bile acids.General

rapid development and improvement of research methods made it possible to examine in more detail the bile acids.For example, there is now a better understanding of the metabolism of their interaction with proteins, lipids, pigments and content in tissues and body fluids.Confirmed information indicating that bile acids are of great importance not only for the normal functioning of the gastrointestinal tract.These compounds are involved in many processes in the body.It is also important that the application of new research methods, the most able to accurately determine the behavior of bile acids in the blood, and how the impact on the respiratory system.In addition, some compounds act on the central nervous system sections.It proved their value in the outer membrane and

the intracellular processes.This is due to the fact that bile acids act as surfactants in the internal environment of an organism.

Historical facts

This type of chemical compounds Strecker scientist discovered in the middle of the XIX century.He found out that the bile of cattle has two organic acids.The first of these contains sulfur.The second also contains the substance, but has a completely different formula.In the process of digestion of these chemical compounds formed cholic acid.As a result of transformation of the above compounds formed glycerol.At the same time, another bile acid forms a completely different matter.It is called taurine.As a result, the original two compounds were assigned names, the same name produced substance.So there tauro- and glycocholic acid respectively.The discovery of the scientist gave a new impetus to the study of this class of chemical compounds.

bile acid sequestrants

These substances are a group of drugs that have lipid-lowering effect on the human body.In recent years, they were actively used for lowering blood cholesterol.It is possible to considerably reduce the risk of various cardiovascular pathologies and coronary heart disease.At the moment, modern medicine is widely used another group of more effective drugs.These lipid-lowering agents are statins.They are used more often due to fewer side effects.At the present time sequestering bile acids are used less and less.Sometimes they are used exclusively within the framework of integrated and auxiliary treatment.

details

steroid class includes monokarbainovye hydroxy acids.They are active solids that do not dissolve in water.These acids are the result of processing of liver cholesterol.In mammals, they consist of 24 carbon atoms.The composition of dominant bile compounds in different animal species is different.These types formed in the body tauholevuyu and glycolic acid.Chenodeoxycholic and cholic compounds belong to the class of the primary.How are they formed?This process has a value liver biochemistry.Primary connections result from the synthesis of cholesterol.Further, the process of conjugation with taurine or glycine.Then, these types of acids undergo secretion into the bile.Lithocholic and deoxycholic substance included in the secondary connections.They are produced from primary colonic acids under the influence of indigenous bacteria.The rate of absorption of deoxycholic compounds is considerably higher than that of lithocholic.Other secondary bile acids occur in very small volumes.For example, these include the ursodeoxycholic.If there is a chronic cholestasis, that these compounds are present in large numbers.Average ratio of these substances - 3: 1.While in cholestasis bile acid content considerably exceeded.The micelles are aggregates of the molecules.They are formed only when the concentration of these compounds in the aqueous solution exceeds the limit mark.This is due to the fact that bile acids are surfactants.

Features cholesterol

This substance is poorly soluble in water.The ratio of concentrations of lipid and the molar lecithin concentration and the solubility of acid affects the speed of cholesterol in bile.Mixed micelles occur only while retaining the normal proportion of these elements.They contain cholesterol.Draft of its crystals is subject to violations of this relationship.The functions of bile acids are not limited to the removal of cholesterol from the body.They contribute to the absorption of fats in the intestine.The micelles are also formed during this process.

movement joints

One of the main conditions for the formation of bile acids is an active movement.These compounds play an important role in the transport of electrolytes, the water in the small and large intestines.They are solid, particulate substances.Their melting temperature is sufficiently high.They have a bitter taste.Bile acids are poorly soluble in water, whereas in the alkali solution and alcohol - good.These compounds are derivatives holanovoy acid.All such acid occur exclusively in hepatocytes cholesterol.

Influence

basic meaning of all acidic compounds are salts.This is due to a number of properties of the products.For example, they are more polar than salts of free bile acids, have a small limit concentration of micelle formation and will secreted.The liver is the only organ capable of converting cholesterol into specific holanovye acid.This is due to the fact that the enzymes which participate in conjugation are in hepatocytes.Change their activity is directly dependent on the composition and rate of oscillation of the liver bile acids.The synthesis process is regulated by a negative feedback mechanism.This means that the intensity of this phenomenon is correlated with the current of the secondary bile acids in the liver.Normal synthesis in the human body is quite low - from two hundred to three hundred milligrams per day.

main tasks

Bile acids have an extensive range of destinations.In humans, they are mainly carried out the synthesis of cholesterol and affect fat absorption from the intestine.In addition, the compounds involved in the regulation of bile and biliary excretion.These substances also have a strong influence on the process of digestion and absorption of lipids.Their compound are collected in the small intestine.The process takes place under the influence of monoglycerides and free fatty acids, which are on the surface of fat.This forms a thin film that prevents the connection of small droplets of fat in more voluminous.Because of this there is a strong reduction of surface tension.This leads to the formation of micellar solutions.They, in turn, facilitate the action of pancreatic lipase.With the reaction it cleaves fatty of glycerol, which is further absorbed intestinal wall.Bile acids are connected with fatty not dissolve in water and form holeinovye.These compounds are readily cleaved and are rapidly absorbed via the top of the villi of the small intestine.Holeinovye acid converted into micelles.Further, they are absorbed into the cells, thus easily overcoming their membranes.Information was received with the most recent research in this area.They argue that the relationship between fat and bile acids in the cell splits.The first are the end result of absorption of lipids.Last - penetrate through the portal vein to the liver and blood.