PYRUVIC ACID (synonym alpha ketopropionic acid, atsetilmuravyiny acid, piruvinovy acid, pyruvate) — the elementary ketonic acid, takes the central place in transformations of carbohydrates, the major metabolic product at animals, including and at the person participates in exchange of amino acids. Change of maintenance of P. to. in biol, liquids and tissues of the person occurs at some fiziol, and patol, states, however in clinic for diagnosis these data are not used yet. The item to. use by production of medicine phenoquin (see).
The item to. it is opened in 1835 by I. Bertselius. Anion P. to. CH 3 COCOO - (pyruvate) is present practically at all tissues of animals and plants, and also at microorganisms.
Blood of healthy people contains 0,5 — 1 mg / 100 P.'s ml to., and it is found preferential in uniform elements of blood. Normal contains in urine apprx. 2 mg / 100 P.'s ml to.; at healthy people with urine it is allocated from 10 to 25 dg P. to. in days.
There is P. to. in two tautomeric forms: enol, more reactive (I) and ketonic, steadier at fiziol, pH values (II):
The item to. — a colorless liquid with a pungent smell, a pier. weight (weight) 88,06, t ° pl 13,6 °, t ° kip 165 ° (at 760 mm of mercury., with partial decomposition); mixes up with water, spirtokhm and ether. The item to. has chemical properties of ketones and alpha and ketocarboxylic to - t.
In biochemical, researches use well water soluble sodium and potassium salts P. to. Receive P. to. dry distillation wine or grape to - t in the presence of potassium sulfate (KHS04); by other methods of receiving P. to. are alkaline hydrolysis α,α' - dichloropropionic to - you, ketonic splitting of ethyl oxalacetate, acid hydrolysis of an acetonitrile, oxidation milk to - you.
The item to. it is formed in an organism in process glycolysis (see) from high-energy fosfodnolpirovinogradny to - you under the influence of a pyruvatekinase (KF 2. 7. 1. 40). Further P. to. can be under action lactate dehydrogenases (see) it is recovered in milk to - that (such transformation of P. to. occurs at glycolysis in muscles and at bacterial lactic fermentation), by decarboxylation and P.'s recovery to. at spirit fermentation (see) turns into ethanol. In aerobic conditions there is oxidizing decarboxylation (see) P. to. with the participation of a piruvatdegidrogenazny multifermental complex (KF 1. 2. 2. 2) and KOA with education atsetil-KOA. This process is a necessary stage of fabric exchange of substance as a result of which carbohydrates, «burning down» in a cycle Tricarboxylic to - t (see. Tricarboxylic acids cycle ), act as power substrate. Thanks to turning into atsetil-KOA P. to. joins also in metabolism of lipids and other physiologically important connections, napr, acetylcholine.
An enzymatic carboxylation of P. to., occurring in mitochondrions of a liver and kidneys, leads to education oxalacetic to - you (oxaloacetate) — mother compound at biosynthesis of glucose (gluconeogenesis) in an organism of animals and the person. In a cardiac muscle and in other muscles as a result of P.'s carboxylation to., combined with action malate dehydrogenases (see), it is formed apple to - that (malate).
The item to. plays an important role in exchange of amino acids. Under the influence of alaninaminotranspherase (KF 2. 6.1.2) transfer and - ami-nogroup various amino acids to and - carbon to atom P. is carried out to. with formation of alanine and corresponding ketonic acid (see. Transaminirovaniye ). P.'s regeneration to. occurs in reaction of transamination of alanine and and - keto-glutaric to - you. The item to. it is formed also at not oxidizing deamination of serine, a desulfgidrirovaniya of cysteine, splitting of tryptophane and tyrosine by enzymes of microorganisms.
For quantitative definition of P. to. a number of the colorimetric methods based on P.'s reactions to is developed. with Sodium nitroprussidum, and - or (3 naphthol, phenylhydrazine, 2,4-dinitrofe-nilgidrazinom, salicylic aldehyde. The most widespread is P.'s definition to. on reaction about 2,4-dinite-rofenilgidrazinom on which P.'s detection is based to.; in blood — Umbrayt's method and Liu's method, in urine — Fridemann's method — Haugen. 2,4-dinitro-phenythydrazone P. to., P. which is formed at interaction to. with acid solution 2,4 of dinitrophenylhydrazine, unlike hydrazones of other ketonic acids we will well dissolve in toluene which it is extracted from reaction mixture. After addition to toluene extract of spirit solution of alkali there is a red-brown coloring which intensity is determined by a kolorimetrirovaniye. One of modifications of a method of Umbrayt is P.'s definition to. blood on reaction about 2,4-dinite-rofenilgidrazinom in water solution without use of toluene and alcohol. In the presence in biol, material, except P. to., a large amount of other ketonic acids yields good results chromatography (cm). or paper electrophoresis (see. Electrophoresis ) dinitrophenythydrazones of ketonic acids.
Also colorimetric method of definition of P. is widespread to. on intensity of the yellow coloring arising at P.'s reaction to. with salicylic aldehyde in silnoshchelochnsy to the environment. A bisulfite method of definition of P. to. it is based on P.'s reaction to. with hydropotassium sulfite (KHSO 3 ) or sodium (NaHSO 3 ) in acid medium with the subsequent decomposition of bisulfite derivative P. to. sodium bicarbonate and titration of the released bisulphite iodine. The most sensitive and specific enzymatic method of definition of P. to. blood across Gloucester and Harris it is based on P.'s recovery to. under the influence of a lactate dehydrogenase in the presence of the recovered NAD (NAD-N) which oxidation is registered spektrofotometrichesk at 340 nanometers.
Increase in maintenance of P. to. in an organism of healthy people occurs after massive loading glucose, at hard muscular work, in the conditions of the lowered partial pressure of oxygen in inhaled air, in particular at stay at height. Change of maintenance of P. to. in biol, liquids and body tissues can confirm also disbolism. Strengthening of P. to. in blood (piruvatemiya) it is observed at many patol, processes: lack of an organism of thiamin (vitamin B 1 ), heavy heart failure, a rheumatic carditis, diseases of a liver, uraemia, some forms of nephrite, hron, tonsillitis, at a number of pulmonary diseases, meningitis of various etiology and some other acute infections, malignant new growths, a diabetes mellitus, radial illness, poisonings with arsenic, antimony, mercury etc. In cerebrospinal liquid sharp strengthening of P. is noted to. after injuries and at inflammatory processes (meningitis, abscess of a brain). P.'s accumulation to. in nervous tissue it is observed at polyneurites. P.'s maintenance to. in blood decreases at an anesthesia a little. In urine P.'s concentration to. raises at a heavy renal failure, treatment by streptomycin of tuberculosis of kidneys, lungs, a brain etc.
Contents in P.'s organism to. it is closely connected with the maintenance of a product of recovery of P. to. — milk to - you. The quantitative ratio of these to - t in blood is an indicator of a ratio of intensity of glycoclastic and oxidizing transformations of carbohydrates. The size of the relation a pyruvate/lactate is equal in blood of healthy people on average 10 (9,3—14,3), and its change indicates disturbance of normal metabolism. Determination of size of the relation a pyruvate / lactate in blood can be useful in clinic; e.g., the size of this relation which is an indicator of security of an organism with oxygen can be used as criterion for evaluation of weight of an acute heart failure.
At oligophrenias (see) in an organism derivative P. collects to. — phenyl-pyruvic to - that.
See also Ketonic acids .
Bibliography: Babaskin P. M. A method of definition of pyruvic acid in blood, Laborat, business, No. 7, page 497, 1976; Biochemical methods of a research in clinic, under the editorship of A. A. Pokrovsky, page 112, etc., M., 1969: Lenindzhera. Biochemistry, the lane with English, M., 1976; Meshkova N. P. and Severin G. E. Praktikum on biochemistry of animals, M., 1950; Me Murray \V. Page of Essential of human metabolism, relationship of biochemistry to human physiology and disease, Hagerstown, 1977; Rapo-p o r t S. M. Medizinische Biochemie, B., 1977.
H. V. Gulyaeva.