Ukrains'kyi biokhimichnyi zhurnal最新文献

Dynamics of the activity and correlation of isoenzyme spectra of lactate dehydrogenase in extracts of the liver, hip muscle and blood serum of the 30-60- and 108-day pig embryos was studied by polyacrilamide gel diskelectrophoresis. A high specificity of isoenzymes sets in all the tissues under study is established.

The content of the adenylic system components (ATP, ADP, AMP+IMP), creatine phosphate and inorganic phosphorus (Pin) was determined in the frog gastrochemius muscles in vivo and in vitro at different time after one-second and four-second tetanic contractions. After a one-second contraction the content of ATP in the muscles both in vivo and in vitro increases with respect to the initial level and simultaneously the contents of creative phosphate and Pin decrease. 15 seconds after a four-second contraction the content of ATP in the both cases is below the initial level; in the isolated muscles it restores the initial level during the second minute of rest and subsequently does not change significantly. In vivo the content of ATP continues to increase, accounting for 114% of the initial level during the eighth minute of rest. This rise is accompanied by an essential utilization of Pm, the content of which during the eighth minute of rest is 79.4% relative to control. The content of ADP, AMP+IMP after a one-or four-second contraction does not change significantly.

Under conditions of experimental myocardium infarction caused in dogs by ligation of the anterior descending branch of the left coronary artery, the activity of alpha-ketoglutarate dehydrogenase and succinate dehydrogenase in mitochondria of the cortex, cerebellum and medulla ablongata lowers most intensively on the first and fifth day after the appearance of acute myocardium infarction. Activation of the most important enzymes of the pentose-phosphate cycle (glucose-6-phosphate dehydrogenase and transketolase) which is clearly pronounced on the fifth day is observed in the mentioned sections. In the authors' opinions the above changes in the activity of the enzymes are due to the brain hypoxia which may be the main reason of disturbance in the function of the central nervous system under this disease.

Reconstruction of P. vitale glucose oxidase from apeonzyme and coenzyme (FAD) was studied as affected by iodine acetate as well as mercury and calcium ions. Mercury ions, iodine acetate as well as the labilizing fraction (flavin adenine-containing component) are established to inhibit the reconstruction affecting the sulphydryl groups of the apoenzyme which take part in addition of FAD to it. Calcium ions prevent the effect of the "labilizing" fraction, iodine acetate and mercury ions on the glucose oxidase apoenzyme as well as the effect of mercury ions on the glucose oxidase coenzyme. The effect of Ca2+ consists in "labilizing" fraction-calcium complexing.

A ten-fold sequential action of supersound on rats results in disturbances in synthesis of protoporphyrine IX and its excretion respectively; the level of protoporphyrine in erythrocytes and feces is reduced. Redistribution of porphyrines in erythrocytes is detected; the control level of coproporphyrines being retained; a higher initial content of protoporphyrine IX drops due to an increase in a relatively low level of porphyrines.

Affinity of an acid anion for proteins has a decisive effect on conditions for detecting using an acid medium immunoglobulin G peculiar to the malignant growth in blood serum of patients with cancer. Depending on the protein affinity of the anion of the acid used for the reaction immunoglobulin G appearing in blood of patients with cancer under equal conditions may be in a soluble state or change to a sediment. The presence of salts in the reaction mixture has no effect on conditions of the reaction performance. Exposition of blood sera to the acid medium before titration favours a more distinct detection of the studied protein in blood of patients with cancer.

It is established that Ca2+ binding with rabbit skeletal muscles plasmatic membrane depends on this cation concentration in the incubating medium. pH, temperature, incubation period and presence of Mg ions in the medium affect the Ca2+-binding ability of sarcolemma. The entropic changes observed in sarcolemma Ca2+ binding are due to conformation reconstructions of the membrane components.

It is established that in embryos incubated until the early blastula stage in the solution of insulin with addition of cycloheximide or puromycin, there is neither a decrease in the hexokinase and glucose-61 phosphate dehydrogenase activities nor an increase in the phosphofructokinase activity, as it is shown under the influence of insulin only. Puromycin removes an inhibitory effect of insulin on the glucose-6-phosphatase activity, and actinomycin D removes this influence with respect to glucose-6-phosphate dehydrogenase and glucose-6-phosphatase activities. The addition of antibiotics removes inhibition of the hexokinase, glucose-6-phosphate dehydrogenase and glucose-6-phosphatase activities by the hormone in the unfertilized eggs as well. Actinomycin D alone inhibits the hexokinase and activates the phosphofructokinase activities in the embryos and eggs, puromycin decreases their hexokinase activity and cycloheximide has the same effect on the glucose-6-phosphatase activity in the embryos only.

Distribution of lactate dehydrogenase (LDH) isoenzymes and content of lactic and pyruvic acids were studied in the heart, kidneys and skeletal muscle of rats at the age of 1, 3, 12 and 24 months at normal state and after thyroxine administration. With age the activity of aerobic isoenzymes of LDH increases and that of hybrid anaerobic isoenzymes of LDH decreases in the heart and kidneys; in the skeletal muscle the activity of LDH5 increases and that of LDH3 and LDH4 decreases, the content of the studied acids in the heart, kidneys and skeletal muscle changes irregularly. Under the effect of thyroxine the activity of aerobic isoenzymes of LDH increases in the heart of one-month animals and in the kidneys of one- and three-month animals, as well as in the skeletal muscle of 24-month rats; the activity of LDH5 rises in the skeletal muscle of one- and three-month animals. Thyroxine causes an increase in the content of pyruvic acid in the tissues of all the studied rats.

A peptide fraction with a specific property of interaction with D fragment was found in the fibrinogen tryptic hydrolyzate. This fraction is called a protector. In the protector presence the time of the monomer fibrin polymerization prolonged with D fragment is greatly lowered. The protector was found in the first minutes of fibrinogen degradation. It was shown for low concentration of trypsin (enzyme-substrate ratio being 1:7500). The gel filtration of a tryptic fibrinogen hydrolyzate on Sephadexes G-10, G-15, G-25 showed that the protector has a low molecular weight. It was found that a preincubation of the protector with D fragment should take place before interaction of their mixture with a fibrin monomer. The interaction of the protector with D fragment is reversible.