Acetone body

Acetone body (ketone bodies) - a group of compounds with similar chemical composition, and associated in the body of mutual transition:
β-hydroxybutyric acid >< acetoacetic acid > acetone.
Acetoacetic and beta-hydroxybutyric acid is a normal intermediate products of oxidative metabolism of fatty acids. In pathological conditions (e.g. diabetes, fasting, the lack of carbohydrates in the diet), they accumulate in the body and is found in high levels in the tissues, organs, blood, urine, causing acetonemia and acetonuria. The accumulation of acetone bodies in the blood leading to acidosis (see Acid-base balance).

Acetone body (ketone bodies) - a group of organic compounds that includes β-hydroxybutyric acid, acetoacetic acid and acetone, between which there is a close relationship: the oxidation β-hydroxybutyric acid her secondary alcohol group enters ketone and formed acetoacetic (arethousa) acid; this reaction is reversible. In the process carboxylation acetoacetic acid dissolves in acetone and CO2. Hydroxybutyric and acetoacetic acid as intermediate products of fat metabolism are formed mainly in the liver in the oxidation of higher fatty acids with an even number of carbon atoms. A significant number acetoacetic acid, not only formed in the oxidation β-hydroxybutyric acid, but also by the condensation of two molecules of acetic acid, otdalyayutsya in-oxidation of higher fatty acids or formed from pyruvic acid. Acetoacetic acid is formed in the process of intermediate metabolism of amino acids phenylalanine, tyrosine, leucine, hydroxyproline and partly isoleucine. Acetone bodies are oxidized to CO2 and H2O not in the liver, and other organs and tissues (lungs, kidneys, muscles and other). Oxidation acetoacetic acid to CO2 and H2O is performed in the tricarboxylic acid cycle (see biological Oxidation). From β-hydroxybutyric and acetoacetic acid can also resentatives higher fatty acids due to the energy produced during the oxidation of carbohydrates.
Education acetone bodies is hampered by the introduction of carbohydrates. Insulin enables the resynthesis A. T. in higher fatty acids. Improving education A.T. in the liver usually observed in the decrease in the content of glycogen is associated with excess flow in the liver from fatty fat depot and its subsequent oxidation. Insufficient oxidation A.T. depends on violations of the tricarboxylic acid cycle. Contents A. T. in the blood normally do not exceed 2-4 mg% (expressed as acetone) or 8 mg% (expressed as β-hydroxybutyric acid).
In some pathological processes (diabetes, a sharp reduction in the content of carbohydrates in the diet, fever, starvation and other) number of A.T. in the blood and urine increases (see acetone anaemia, Acetonuria). When excessive content of acetone in the blood, it is highlighted not only by the kidneys, and lungs. The accumulation in the body A.T. as a result of increased their education, lack of oxidation and resynthesis in fatty acids leads to the development of acidosis (see Acid-base balance) and to poisoning, as manifested by a sharp oppression CNS (see Coma). Quantitative research A.T. in blood and urine is held by transformation β-hydroxybutyric and acetoacetic acid in acetone and its subsequent determination.