Ukrains'kyi biokhimichnyi zhurnal最新文献

A rise in the level of carbonic acid in animal blood at practically unchanged pH causes an increase in the value of free [NAD+]/[NADH] and [NADP+]/[NADPH] ratios in the liver cells cytoplasm. The increase in the oxidizing power of the liver cells cytoplasm is observed against a background of a rise in both the total level of keto-acids in blood and concentration of pyruvate oxaloacetate and alpha-ketoglutarate in the liver and kidneys of animals. The level of lactate, glutamate and citrate in these tissues also grows. The level of ketonic bodies in blood of the animals with a higher concentration of carbonic acid is somewhat lower than that in the animals with a lower concentration of HCO3 and CO2 in blood.

Fish and bovine opsins were found generally in monomeric forms with slight content of dimers at electrophoresis in 1% sodium dodecyl sulphate--0.005 M sodium phosphate buffer (system I). Opsins have a high tendency to oligomerization and formation of trimers and higher oligomers in 1+5 M urea (system II). The molecular weight of nonomers and dimers of opsins in system I calculated according to the standard proteins, increased with a rise of acrylamide concentration. The authors believe that in both systems the hydrophobic interactions that not the reactions of intermolecular S-S bonds formation are supposed to be on the basis of opsins oligomerization.

Some indexes of catecholamines and serotonin metabolism were studied when animals were effected by dichlorodiphenyl trichlorethan and polychlorocamphene. It is shown that the mentioned pesticides cause in the animal organism intensification of serotonin metabolism and increase the sympatho-adrenalic system activity. Under the effect of polychlorocamphene the shifts in the catecholamines metabolism are more pronounced.

The ability of human blood serum for inactivating tissue thromboplastin is established to be due to the presence of two inhibitors: thermolabile inhibitor characterized by a progressive effect and thermostable one having an instant effect. Thromboplastin inhibition by the thermolabile inhibitor is partial, whereas inhibition by the thermostable one is completely reversible. In the latter case inhibition is intermediate character, between the competitive and incompetitive one. The inhibitory activity is found in Cohn's fraction V, is removed during DEAE-cellulos chromatography and gel chromatography with the first portions of eluating liquid.

Administration of thyroxine toxic doses to rats results in a considerable increase in the alanine aminotransferase and aspartate aminotransferase activity in nuclear, mitochondrial and supernatant fractions of the rat heart. The hormone action is more pronounced in the mitochondrial fraction. A simultaneous administration of thyroxine and actinomycin D decreases the hormone effect in case of nuclear and supernatant enzymes. The enzymes of mitochondrial fractions do not change after actinomycin D injection. It is possible to suggest that in mitochondria there occurs a synthesis of some enzymes.

Hydrolysis of the cattle bone insoluble collagen was studied as affected by Streptomyces griseus protease. The enzymic hydrolysis was performed before and after protein decalcination. The amino acidic composition of collagens in young and old animals is the same. Calcium-containing collagen of a young animal is hydrolyzed by Str. griseus protease more intensely than that of an adult one. However protein decalcination not only increases, on the whole, the degree of its splitting by Str. griseus protease but also changes the picture completely: hydrolyzeis of adult animal collagen is much more rapid and deep. Perhaps, collagen protein of bone is more labile with the age, and its strength and resistance increase due to the presence of calcium

Oxidation of glutamate by the brain mitrochondrial fraction was studied in the in vitro experiments in the presence of 2,4-DNP in concentrations of 5.10(-6) and 1.10(-3) M. 5.10(-6) M DNP is shown to stimulate ammonia and aspartate formation when glutamate in a concentration of 10 mM was used. Under these conditions an increase in O2 consumption occurred. When 1.10(-3) DNP was used, O2 consumption was inhbited. In this case ammonia formation was more intensive and simultaneously aspartate production was decreased. An increase in the glutamate concentration up to 20 mM diminished 2,4-DNP effects on ammonia and aspartate production.

The activity Na+, K+-ATPase of the guinea pig brain synaptosome fraction as well as the effect on this enzyme of the blood serum obtained in guinea pigs in different periods after sensibilization of the animals with the basic encephalitogenic protein were studied in dynamics of experimental allergic encephalomyelitis development. The Na+,K+-ATPase activity in the guinea pig brain synaptosome fraction is more than 50% lower from the seventh day of sensibilization up to development of characteristic symptoms of the disease in animals. The guinea pigs blood serum obtained on the seventh and tenth days of sensibilization has an inhibitory effect of the same order on the studied activity of the normal guinea pig brain synaptosome fraction. At the later stages of the disease development and with the presence of characteristic symptoms of experimental allergic encephalomyelitis in the animals the blood serum has no similar effect.

Concentration of potassium and sodium ions as well as chlorides in rabbit blood serum was determined by applying the direct potentiometric method using the ion-selective electrodes. The techniques on calibration of the applied ion-selective electrodes are described and comparative data are presented of determining the concentration of potassium and sodium by the potentiometric method and that of flame photometry and of chlorides by the potentiometric and chemical methods. By high-specific ion-selective electrodes (glass for Na+, membrane one for Cl- and valinemycinic for R+) the character of ionic disturbances is established in the blood serum of rabbits irradiated with a dose of 2000 R. The concentration of potassium ions decreases 15-18 degrees min after irradiation. The concentration of sodium ions and chlorides is not changed noticeably. The concentration of calcium determined by the method of flame photometry decreases after irradiation within a range of 30 min-72h. The found changes may be explained by the damaging effect of radiation on the structure and function of the cell membranes.

Phosphoenolpyruvate (PEP) is a potent inhibitor of muscle creatine kinase. The inhibition of ATP formation is more pronounced at pH 7.0. The substrates, creatine and creatine phosphate, partially prevent the inhibition of the enzyme activity by PEP, creatine being as an effector.