[Effect of exhaustive weightlifting exercise on EMG, biochemical markers of muscle damage and performance capacity in young male subjects].

The aim of this study was to examine the effect of exhaustive weightlifting exercise on electrical and biochemical variables and performance capacity in young male subjects. The onset of exercise (80-50% 1RM) was associated with a decrease in the amount of work performed, which was followed by a steady performance capacity at 40-10% 1RM. There were no significant changes of m. rectus femoris EMG maximal amplitude though it tended to be increased during the first half of exercise. A significant blood lactate concentration increase indicated that an anaerobic metabolism was a predominant mechanism of muscle contraction energy-supply. CK level in blood plasma did not change but plasma myoglobin concentration doubled immediately post-exercise. The data presented here suggest that decrease in performance capacity was likely due to progressive "refusal of work" of the fast motor units and work prolongation of weaker, intermediate and slow motor units. Unchangeable CK activity and relatively small increase in myoglobin concentration in plasma suggest that used weightlifting exercise did not induced substantial damage in myocytes' membranes in our subjects.

Efficacy of green tea extract in two exercise models.

Oral administration of green tea extract in a dose of 6 mg/kg twice a day (before and after exercise) over 2 weeks significantly increased swimming times on week 1 and 2 in comparison with control animals receiving water. The 7-day and final exhaustive running in rats was accompanied by a significant decrease in spleen weight and iron serum levels associated with developed reticulocytosis. Administration of green tea extract in a dose of 12 mg/kg once a day (before exercise) for 2 weeks did not affect the duration of the running, but prevented the decrease in serum iron and spleen weight, that, along with a significantly increased concentration of reduced glutathione in erythrocytes, can indicate a normalizing effect of green tea extract on hemopoiesis and stimulating effect on the antioxidant system of erythrocytes.

Hematological parameters and redox balance of rat blood in the dynamics of immobilization.

Hematological and biochemical parameters were studied in rat blood in the dynamics of immobilization (0.5, 1, and 3 h). Immobilization was followed by a release of old erythrocytes in the circulation and the development of reticulocytosis. The neutrophil count significantly increased by the third hour of immobilization. Restraint stress induced changes in activities of antioxidant enzymes (SOD and catalase) in erythrocytes and plasma level of MDA. The correlation between each enzyme (SOD, glutathione peroxidase, and catalase) and MDA concentration was the highest 1 h after the beginning of immobilization. These data can reflect the tension of antioxidant systems in red blood cells. The biochemical parameters returned to the basal level by the third hour of immobilization. Correlation coefficients between the activities of antioxidant enzymes and MDA amount decreased after 3 h of stress and the correlation between glutathione peroxidase and reduced glutathione significantly increased. The redox status of the blood returned to the initial values after 3 h.

Sphingosine-1-phosphate: distribution, metabolism and role in the regulation of cellular functions.

The role of sphingosine-1-phosphate (S1P) in regulation of cellular functions and cell protection is reviewed. S1P, along with other sphingolipid metabolites, is believed to act as an intracellular second messenger and as an extracellular mediator molecule. S1P chemistry, production and metabolism are described. Cellular receptors for S1P and their tissue specificity are described. Platelets and erythrocytes have a crucial significance in blood transport of S1P. Hypoxic conditions induce an increase in S1P, which initiates a set of cytoprotective events via its cellular receptors. S1P involvement in regulation of cell migration, myogenesis, control of skeletal muscle function is described. It is shown that S1P balance disturbances may mediate pathological state. S1P system implication in regulation of the most important cellular functions allows considering it as a prospective remedial target.

[The effect of antioxidants on erythrocytes in rats during an exhaustive run].

The run of trained rats until exhaustion affected changes of red-ox balance in red blood cells (RBC) and deteriorated the acid stability of RBC. The oral administration of quercetin, 20 mg/kg, caused expansion of oxidative stress in RBC and a significant decrease in RBC acid stability. Pro-oxidant activity of quercetin could contribute accelerated intravascular hemolysis. It was accompanied by a significant reticulocytosis compared with a control group of rats no fed on antioxidant but exposed to run. Green tea extract (GTE) oral administration, 12 mg/kg, resulted in preventing oxidative stress in RBC, increasing in acid stability of RBC and reducing reticulocytosis. Thus, prooxidant activity of quercetin and the high antioxidant efficacy of GTE are indicative of the advantages of the complex preparations containing several antioxidant compounds. Such complex preparations may counteract an oxidative stress and save mechanical stability of erythrocytes under exhausted run.

Major chondroitin sulfate proteoglycans identified in L6J1 myoblast culture.

The major proteoglycans from L6J1 rat myoblast culture were identified. The proteoglycans were isolated from different constituents of cell culture: culture medium, extracellular matrix (ECM), and myoblasts. To identify their core proteins, the proteoglycans were treated with enzymes specifically digesting chondroitin/dermatan sulfates or chondroitin sulfates. Subsequent electrophoresis and mass spectrometry revealed versican, collagen XII, and inter-α-trypsin inhibitor classified as chondroitin sulfate proteoglycans and biglycan known to be chondroitin/dermatan sulfate proteoglycan. Versican was identified in ECM and the other proteoglycans in the culture medium. Such difference in localization is likely to be a consequence of different biological functions. Versican, collagen XII, and biglycan are synthesized by myoblasts and inter-α-trypsin inhibitor originates from fetal bovine serum (a culture medium component).

[Acute and remote biochemical and physiological effects of exhaustive weightlifting exercise].

The goal of the work was a study of exhaustive weightlifting exercise effect on prolonged changes in physiological and biochemical variables characterized functional status of skeletal muscles. An exercise gave rise to significant blood lactate concentration increase that was indicative of an anaerobic metabolism to be a predominant mechanism of muscle contraction energy supply. A reduction of m. rectus femoris EMG activity (amplitude and frequency), tonus of tension and an increase in tonus of relaxation were found immediately after exercise. Both EMG amplitude and frequency were increased 1 day post-exercise. However, after 3 days of recovery, EMG amplitude and frequency were decreased again and, in parallel, blood serum creatine kinase (CK) activity was significantly increased. After 9 recovery days, all measured variables with the exception of CK were normalized. A significant reverse correlation was found between blood serum lactate concentration and m. rectus femoris EMG activity at the same time points. Blood serum CK activity and m. rectus femoris EMG and tonus variables were observed to be significantly reversely correlated on the 3rd post-exercise day. Presented data demonstrate that exhaustive exercise-induced muscle injury resulted in phase alterations in electrical activity and tonus which correlated with lactate concentration and CK activity in blood serum.

Glucural (amigluracyl) improves survival of isolated rat hepatocytes in suspension.

Nonsteroid anti-inflammatory drug glucural (water-soluble N-methyl-D-glucosamine complex with 6-methyluracyl) improves survival of isolated rat hepatocytes stored in suspension. This effect of glucural is presumably explained by its membranotropism.

[Proteoglycans of L6J1 myoblast extracellular matrix. Characteristics and effect on myoblast adhesion].

Proteoglycans were isolated from extracellular matrix of L6J1 rat myoblasts and their influence on myoblast adhesion was studied. Proteoglycan digestion with chondroitinase AC and heparinase III degrading the polysaccharide moieties revealed that chondroitin sulfate proteoglycans are the main class of myoblast extracellular matrix proteoglycans. Electrophoresis of enzymatically processed proteoglycans was used to examine their core proteins. Myoblast adhesion was suppressed by proteoglycans or the mixture of proteoglycans and fibronectin/extracellular matrix. When being processed with chondroitinase AC the combined substrate of fibronectin and proteoglycans lost the capability of myoblast adhesion suppression. Thus, as a result of presented work the proteoglycans of L6J1 rat myoblast extracellular matrix were isolated and purified. The main class of proteoglycans was chondroitin sulphate proteoglycans. Isolated proteoglycans suppressed myoblast adhesion and this effect was mediated by polysaccharide moieties of proteoglycans.

Isolation and characterization of proteoglycans synthesized by rat myoblasts L6J1 in culture.

Proteoglycans synthesized by rat myoblasts L6J1 in culture were isolated using sorbent Q-Sepharose from culture medium, extracellular matrix (ECM), and cells. Elution of the sorbed material in a NaCl gradient separated proteoglycans from the bulk of proteins eluted at low concentration of the salt. Four fractions (fractions I-IV) were obtained for each component of the cell culture, including two proteoglycan fractions for the ECM and culture medium and one fraction for the myoblasts. Proteoglycans of the culture medium were virtually completely represented by proteoglycans of fetal calf serum. With enzymes chondroitinase ABC and heparinase III chondroitin/dermatan sulfate proteoglycans were shown to prevail in all components of the myoblast culture. The core proteins of proteoglycans were characterized by electrophoresis.

[Hepatocyte mitochondrion respiratory chain in rats with experimental toxic hepatitis].

The purpose of this study was to examine hepatocyte mitochondrion respiratory chain in rats subjected to ethanol and CCl4 administration within 4 weeks to induce an experimental hepatitis. Oxygen consumption was determined as a measure of mitochondrion respiration chain function. The development of liver pathology was accompanied by fat accumulation, fibrosis, triglycerides and lipid peroxidation increase. Respiratory chain characteristics damage was found. Endogenous oxygen consumption by hepatocytes isolated from pathological liver was found 34% higher compared to control. Exogenous malate and pyruvate substrates delivery didn't stimulate cell respiration. Rotenone (the inhibitor of the I complex) decreased 27% oxygen consumption by pathological hepatocytes while dinitrophenol produced 37% cell respiration increase. States 3 (V3) and 4 (V4) mitochondrial respiration with malate + glutamate as substrates were found to be 70 and 56% higher accordingly compared to control level. V3 and Vd (dinitrophenol respiration) for mitochondria from pathological liver didn't differ from control when being tested with malate + glutamate or succinate as substrates. Cytochrome c oxidase activity increased (+ 80%) as compared to control. Administration of hypolipidemic agent simvastatin simultaneously with ethanol and CC14 resulted in decrease liver fat accumulation, fibrosis and peroxidation products. Simvastatin administration caused hepatocyte endogenous respiration decrease while malate + pyruvate, dinitrophenol or rotenone delivery produced oxygen consumption alterations similar to control. However, when isolated mitochondria from liver of simvastatin treated animals being tested the decrease of oxidative phosphorylation coupling for substrates malate + glutamate was found. While simvastatin did not cause changes in cytochrome c oxidase activity. We propose the hypothesis that the NCCR complex in rat mitochondria with experimental toxic hepatitis works extensively on superoxydanion production. Alterations of SCCR, Coenzyme Q-cytochrome c-reductase, cytochrome c oxidase and ATP-synthase activities have an adaptive nature to compensate for impaired NCCR function.

[Morphological and biochemical aspects of skeletal muscle injury and regeneration subjected to physical load and hypodynamia].

This paper reviews the literature data on morphological and biochemical aspects of skeletal muscle injury by exercises, hypodynamia and microgravity. Muscle injury depends on the duration and intensity of action. In spite of differences of muscle injury mechanisms by exercises and hypodynamia, this injury restricts muscle function and capacity to continue muscle work. Possible approaches to minimization of the muscular tissue injury and accelerating its regeneration are discussed.

Neutrophil antiserum response to decrease in proteolytic activity in loaded rat muscle.

The leukocytes that are found in skeletal muscles after intense muscular activity have been shown to infiltrate areas of injury in skeletal muscle tissue. We believe that leukocyte enzymes, which appear in the tissue after the degranulation or destruction of leukocytes, could play a role in tissue enzyme activities. Neutrophil proteinases were investigated. Histological data provided evidence of rat muscular tissue infiltration by leukocytes after intense physical loading. To reduce the influx of leukocytes in rat muscles, a rabbit antiserum against rat peritoneal leukocytes was injected into rats after muscle loading. This resulted in a reduction in muscle cytosol proteolytic activity as compared to control animals (who received saline injections). The levels of proteolytic activities of media conditioned by the soleus muscle isolated from antiserum-treated rats were also reduced. These data provide evidence that the increase in proteolytic activity observed in rat skeletal muscles after physical loading is partially induced by neutrophil proteinases.

Isolation and characterization of myeloperoxidase from leukocytes of rat peritoneal fluid.

Myeloperoxidase (MPO) was isolated from rat peritoneal leukocytes with a yield of 51% and A430/A280 = 0.75 - 0.80, and its physicochemical properties were studied. The molecular weight of the MPO is about 150 kD. The MPO was assayed for amino acid content. We used substrate mixture containing phenol, 4-aminoantipyrine, and H2O2 to detect 10(-10) M of the enzyme. The MPO was localized in rat blood neutrophils using polyclonal anti-MPO antibodies and secondary fluorescein isothiocyanate-labeled antibodies. Immunofluorimetric assay (IFMA) was developed for quantitative measurement of the MPO. The MPO and leukocytes can iodinate BSA using NaI or thyroxine as the source of iodine.

[The effect of the carbohydrate ration and physical loading on superoxide dismutase activity and on the diene conjugate concentration of the blood and skeletal muscle cytosol in rats]. / Vliianie uglevodnogo ratsiona i fizicheskoi nagruzki na aktivnost' superoksiddismutazy i kontsentratsiiu dienovykh kon''iugatov v krovi i tsitozole skeletnoi myshtsy krys.

Carbohydrate diet (CD) increased the superoxide dismutase (SOD) activity in the blood and skeletal muscles of rats, while decreasing the diene levels in the blood serum and cytosols. Physical training normalised these alterations to a considerable extent. The CD seems to activate the lipid peroxidation.

[Effectiveness of the glutathione s-transferase assay in diagnosing lung cancer]. / Otsenka éffektivnosti opredeleniia glutation s-transferazy pi kak diagnosticheskogo markera raka lëgkogo.

The paper deals with a description of a procedure of immunoradiometric assay of glutathione S-transferase pi in blood serum. A significantly increased level of said enzyme of more than 9.85 ng/ml in 75% of patients with different cancers of the lung has been established, as compared with non-tumor pathologies. These findings point to the feasibility of application of this enzyme in lung cancer diagnose.

[Activity of neutrophil proteinase in rat skeletal muscles after muscle activity]. / Aktivnost' proteinaz neitrofilov v skeletnykh myshtsakh krys posle myshechnoi deiatel'nosti.

Neutrophil proteinases have been studied for their activity in the rat skeletal muscles after muscular activity using antiserum to neutrophils. The increase of proteolytic activity after physical load partially determined by neutrophil proteinases in the skeletal muscles is shown.

[The mechanisms of the neutrophil suppression of creatine kinase and aspartate aminotransferase activities in rat skeletal muscles]. / Mekhanizmy podavleniia neitrofilami aktivnosti kreatinkinazy i aspartataminotransferazy skeletnykh myshts krys.

Abdominal neutrophils effect on rat skeletal muscle m. soleus was investigated in vitro. The incubation was carried out in Hanks balanced solution within 24 hrs. It was a release of proteins from m. soleus 1 hr later. Creatine kinase (CK) and aspartate aminotransferase (AAT) activities increase was detected in incubation medium. The neutrophils released their proteins quicker than muscles. A dramatic inhibition of CK and AAT activities took place during coincubation of m. soleus and neutrophils. Zymosan-activated cells had a higher inhibition potency in comparison to nonactivated neutrophils. Analysis of proteinase and myeloperoxidase activities in incubation medium has given evidence that CK and AAT inhibition by non-activated neutrophils mainly depends on cell-secreted proteinases. Zymosan-activated neutrophil inhibition of CK and AAT consists of proteinases and myeloperoxidase effects. AAT appeared to be more resistant than CK to the damage by neutrophils. The used approach failed to demonstrate the direct damage effect of neutrophils on m. soleus, but the described enzyme inhibition mechanism can take place in vivo during leukocyte infiltration of skeletal muscles after intensive muscular activity.

[The late examination results in children with pylorospasm and dyskinesia of the proximal sections of the small intestine]. / Otdalennye rezul'taty obsledovaniia detei s pilorospazmom i diskeneziiami proksimal'nykh otdelov tonkoi kishki.

The article analyses the late-term results of examination of 46 children with neurogenous dyskinesias of the gastrointestinal tract which were recognised in infancy for the first time. The author believes that the functional, motor-evacuation, and sphincter disorders of the proximal parts of the digestive tube lead to the development of organic noninfectious diseases of the gastroduodenal system.

[Determination of esterase activity of human and animal serine proteinases using fluorogenic esters of amino acids as substrates]. / Opredelenie ésteraznoi aktivnosti serinovykh proteinaz cheloveka i zhivotnykh s ispol'zovaniem v kachestve substratov fliuorogennykh éfirov aminokislot.

Two fluorogenic derivatives of amino acids are proposed as substrates for the purpose of enzymatic assay: N-benzyloxycarbonyl-phenylalanine-4-methyl umbelliferyl ester (substrate-1) and tert-butyloxycarbonyl-alanine-4-methyl-umbelliferyl ester (substrate-II). Chymotrypsin-like (hydrolysis of substrate-1), elastase-like (hydrolysis of substrate-II) esterase activity of bovine pancreatic chymotrypsin, activities of cathepsin G and elastase from human, porcine and rat neutrophils and esterase activity of human, porcine and rat serum were assayed. Differences in the level of chymotrypsin-like and elastase-like activities of human, porcine and rat serum were established. Activities of purified elastase and cathepsin G from human and animal neutrophils were shown to have no significant distinctions.