Extractive substances

Extractive substances are organic nonprotein nitrogen and nitrogen-free compounds extracted water from animal and plant tissues. Extractive substances have strong physiological effect. Extractive substances from meat and vegetables increases the secretion of gastric juice. Among animal tissue is particularly rich in extractive substances muscle tissue. Part of extractive substances in relatively large amounts are adenosinetriphosphoric acid, creatine, glutamine and glutamic acid. Other amino acids are found in very small amounts. The exception is the tissue of the lower animals and fish. In muscles of fish contains a large number of free amino acids. In small quantities contain urea, uric acid, available purines, by, Danilova (see Danilova acid) and insanova acid, choline and acetylcholine. Specific parts of the skeletal muscles are imidazolidinone dipeptides - carnosine (see), anserin (see)and carnitine - methylated derivative ' -amino-beta-hydroxybutyric acid. The content of carnosine and anserina in the muscles of various animals varies widely. Muscle man's relatively poor dipeptides, it contains only carnosine. The physiological function of carnitine linked to education atsiprasome fatty acids, transport them in mitochondria and oxidative their transformation. Creatine is mainly in the form of creatine phosphate connection with phosphoric acid. The ratio between free creatine and phosphocreatine is dependent on the functional state of the fabric. In the muscles of most invertebrate animals instead of creatine contains arginine, a large part of which is in connection with phosphoric acid - arginineif. The physiological function of arginine in invertebrates is the same as creatine in vertebrates. Among nitrogen-free extractive substances are glycogen, glucose, intermediate products of carbohydrate metabolism - phosphorus derivative of glucose and fructose, lactic and pyruvic acid. The content of glycogen in the muscles depends on their physiological state. The content of glycogen is falling at denervation and dystrophy of muscles. The composition of the extractive substances of plant tissues are various organic acids (citric, malic, oxalic acid).