[Is there a swimmer's hypertension?].
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Adult↗
Biomedical subjects
H Weicker
Publications and source records attributed to H Weicker.
Electrochemical detection of catecholamines in urine and plasma after separation with HPLC.
The catecholamines in plasma and urine were determined by electrochemical detection after separation on a HPLC column RCM 100 C 18. Linear calibration plots of epinephrine, norepinephrine and dopamine have been obtained in the range expected to appear in urine or plasma. Coefficients of variation (0.5 to 10%), recovery rates (60 to 80%) and the standard deviation were satisfactory, whereas plasma dopamine showed a greater variation (10-15%). The values ascertained by this technique were compared with those determined by the radioenzymatic assay of Da Prada et al. They showed a good correlation for norepinephrine r = 0.92, p less than 0.001 and epinephrine r = 0.80, p less than 0.01, but less for dopamine r = 0.1. Experimental details of isolation from plasma with Al2O3 adsorption and desorption with HClO4, and from urine with ion exchange chromatography on Bio-Rex 70 and elution with boric acid are described. Technical modifications which improve the method are reported. The optimized assay could reliably be employed in investigations of more than 3000 urine and plasma samples obtained from patients and athletes before and after exercise.
Chromatography, High Pressure Liquid↗
Trial of sulfonylurea in combination with insulin in the therapy of diabetes type I and II. Evidence against a primary extrapancreatic receptor effect.
Recently in vitro evidence has been presented that sulfonylurea derivatives exert their chronic extrapancreatic effect by increasing the number of cellular insulin receptors. To ascertain if this receptor effect holds in vivo, we performed a randomized double-blind study on 21 type I (0.3 ng/ml residual C-peptide secretory capacity after glucose/glibenclamide stimulation), and on 19 insulin treated type II (2.0 ng/ml C-peptide) diabetics. The patients received for six weeks 10 mg/d of glibenclamide in addition to insulin. Insulin binding was initially lower in type II (4.7 +/- 0.75% per 10(7) monocytes and 6.39 +/- 1.08% per 4.5 X 10(9) erythrocytes) than in type I diabetic patients (5.1 +/- 0.48% and 7.95 +/- 0.88% respectively) and in 12 normal subjects (5.25 +/- 0.48 and 8.1 +/- 0.94% respectively). Glibenclamide normalized the number of monocyte receptors (from 4.14 to 5.49 X 10(4) sites/cell) in type II patients, but was without effect in type I diabetics. Blood glucose was significantly reduced (240 to 182 mg/dl; p = 0.02) in the type II group with a concomitant decrease in glycosylated hemoglobin from 12.4 to 10.5% (p = 0.01). Most of the effect occurred during the first week of treatment. Glibenclamide was the more effective the worse the initial metabolic state (r = -0.93; p = 0.001). Erythrocyte insulin receptors decreased markedly in both groups, perhaps due to a sulfonyl urea-induced change in erythrocyte plasma survival time. It is concluded that sulfonylurea treatment is a valuable adjunct in reducing the insulin resistance in insulin treated type II diabetics. The effect depends on the availability of endogenous insulin, thus exhibiting only partly extrapancreatic character.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Effects of treadmill running on the properties of guinea-pig myosin.
The effects of running training on the structure and function of ventricular myosin of guinea-pigs were studied. No differences in body or heart weights could be detected but the heart-to-body weight relation increased significantly (P less than 0.05) in the trained group. Ca2+ activated and K+ activated ventricular myosin ATPase activities as well as the electrophoretic appearances (SDS-PAGE, pyrophosphate-PAGE) did not change after training. Guinea-pig ventricular myosin in nondissociating conditions showed one band migrating close to rat-V3 isomyosin. The myosins of the trained and untrained animals also showed no immunological difference as determined by the competitive ELISA-test: they both shared antigenic determinants common to rat-V1 isomyosin.
Adenosine Triphosphatases↗
Determination of alanine, lactate, pyruvate, beta-hydroxybutyrate, and acetoacetate by flow injection analysis (FIA).
The flow infection analysis (FIA) described by Ruzicka and Hansen was adjusted for lactic acid determination by Rydevik et al. We were able to elaborate some other NAD or NADH-dependent enzyme reactions with the FIA system. The reliability of the alanine assay corresponds to that of the lactate FIA method. The coefficient of variation was on an average 2.8%; th sample rate was 60/h with consistent duplicates. The beta-OHB assay had almost the same validity. Pyruvate, however, was less reliable with higher coefficients of variation. ACAC FIA assay, which was suitable for the determination in acid solution after neutralization, could not yet be employed for the determination in serum. In comparison to the manual enzyme methods, the FIA assays described here indicated a higher sampling rate, a lower reagent consumption, a lower coefficient of variation, a better reproducibility, and a greater consistency of duplicates.
3-Hydroxybutyric Acid↗
Bidirectional alteration of insulin receptor affinity by different forms of physical exercise.
Insulin binding of monocytes and erythrocytes was studied in untrained male volunteers after 15 min of exhaustive bicycle exercise (EE) and several days later after moderate exercise (ME) for 90 min. Insulin receptor affinity decreased after EE in monocytes (26.4% decrease; P less than 0.01) and in erythrocytes (10.4%; P less than 0.05) with no change in receptor number. After ME, however, binding to monocytes was enhanced by 15.2% (P less than 0.05) due to increased receptor affinity. The number of circulating monocytes was markedly increased after both forms of exercise, averaging 105% after EE and 57% after ME. The bidirectional effect on monocyte insulin binding could be reproduced in vitro by incubation of preexercise cells with post-exercise serum: 12.4% (P less than 0.05) decrease with EE serum and 6.1% (P less than 0.05) increase with ME serum. The effect was prevented by overnight dialysis. These results suggest that physical exercise not only entails adjustment of serum insulin but also of cellular hormone sensitivity, presumably through the mediation of low-molecular-weight serum components.
Adult↗
Ultrastructural and morphometric investigations on the effects of training and administration of anabolic steroids on the myocardium of guinea pigs.
The effects on the myocardium of guinea pigs of a training program, of the administration of anabolic steroids (Dianabol), and of both combined were investigated at the ultrastructural level. Quantitative electron microscopy showed an enlargement of the sarcoplasmic space in all experimental groups and a disbalance of the mitochondrial/myofibrillar ratio in favor of the mitochondria, which was most pronounced after administration of anabolic steroids. The augmentation of the mitochondrial volume was assumed to occur by fusion, hypertrophy, and development of new mitochondria. When the administration of anabolic steroids and training were combined, some myocardial cells were pathologically altered; destructed mitochondria and aberrant myofibrils were found. Focally dehiscent intercalated discs and necrotic cells were also observed. It is suggested from these findings that the administration of anabolic steroids in competitive sports may lead to pathological alterations in the myocardium.
Animals↗
Bioluminescent and fluorometric techniques for determinations of 19 metabolites of ADP/ATP-dependent transformations in energy metabolism in 200 (or 400) mg muscle.
A procedure is described for the determination of the following 19 metabolites in 200 mg gastrocnemius muscle from guinea pig: glucose 1-phosphate and 6-phosphate, fructose 6-phosphate, fructose 1,6-bisphosphate, glyceraldehyde 3-phosphate, dihydroxyacetone phosphate, 3-phospho- and 2-phosphoglyceric acid, phosphoenolpyruvate, pyruvate, glycerol, glycerol 3-phosphate, AMP, ADP, ATP, inorganic phosphate, creatine, creatine phosphate. Bioluminometric and fluorometric techniques for mono- and dinucleotide determinations were used. In the case of fluorometric measurement for NADH, 400 mg tissue were necessary. The coefficient of variation for assays on the same sample was 0.04 for bioluminometric techniques and 0.10 for fluorometric techniques.
Adenosine Diphosphate↗
ATP-ADP-dependent phosphorylations of glycolysis metabolites, creatine and glycerol: their compartition and thermodynamic relationship in gastrocnemius muscle cell of exercised guinea pigs.
The concentrations of following metabolites were determined in freeze-clamped gastrocnemius muscle samples: glucose 1-phosphate, glucose 6-phosphate, glucose, fructose 1,6-diphosphate, fructose 6-phosphate, D-glyceraldehyde 3-phosphate. dihydroxyacetone phosphate, phosphoenolpyruvate, pyruvate, glycerol 3-phosphate, glycerol, creatine phosphate, creatine, glycerate 3-phosphate, glycerate 2-phosphate, adenosine monophosphate, adenosine diphosphate, adenosine triphosphate, inorganic phosphate. The results showed that within the limits of experimental error, concentration homeostasis for this metabolites is founded at least in some cases on equilibria between enzymic transformations. Discrepancies between constant mass ratios measured in this study and equilibrium constants allow the free energy variation delta G to keep creatine phosphate at high concentration to be calculated. For the phosphoglycerate mutase system, the equilibrium constant in controls and trained animals is unchanged and corresponds to that in vitro. Training hindered glycolysis and favoured phosphorylation of creatine by glycerol 3-phosphate. Metabolites of the pyruvate kinase and hexokinase system cannot be homogeneously distributed in one space. The creatine kinase system is also separated from the hexokinase und pyruvate kinase system. A compartition of glycolytic process in gastrocnemius muscle seems to be inferred from these results.
Adenosine Diphosphate↗
Determination of enantiomer-labeled amino acids in small volumes of blood by gas chromatography.
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Amino Acids↗
Comparative studies on fast muscle myosin light chains after different training programs.
Fast muscle myosin of guinea pigs exposed to different training programs was examined by means of SDS gel electrophoresis. The percentile distribution of the light chains was calculated. Training at 0.7 m/s and 5 degrees slope 20 min per day for 30 days caused a significant decrease in the DTNB light chains and a significant increase in the A2 light chains compared to the control group. In contrast, training at 0.4 m/s and 45 degrees slope caused a significant increase in the DTNB light chains and a significant decrease in the A2 light chains. These changes can be interpreted as a combination of muscle transformation and a shift of myosin isoenzymes.
Animals↗
Influence of training and anabolic steroids on the LDH isozyme pattern of skeletal and heart muscle fibers of guinea pigs.
The influence of training and anabolic steroids (methandrostenolone) on the enzyme activity of the LDH system was investigated in 72 male guinea pigs. Sedentary animals and animals subjected to two different training regimens with and without anabolic steroids were compared in six groups each consisting of 12 guinea pigs. The training was performed on a rodent treadmill for 1 month, 30 min/day at an inclination of 45 degrees or 5 degrees, and at a speed of 30 m/min. Total LDH, its isozymes, and the composition of M and H subunits were determined enzymatically and by electrophoretical separation on cellulose acetate membrane in the following muscle fiber types; m. vastus lateralis white (FG) and red portion (FOG), m. soleus (SO), m. psoas major white (FG) and red portion (FOG), and in the left ventricle of the heart. The administration of anabolic steroids did not change the activity of total LDH or the composition of M and H subunits in sedentary animals. Exercise at 5 degrees inclination significantly reduced the total LDH and the concentration of H subunits in FOG, SO, and heart muscle fibers but not in FG muscle fibers. The additional application of anabolic steroids intensified these changes and also reduced the total LDH and the H subunit in FG as well as the M subunit in FOG, SO, and heart muscle fibers. After exercise at 45 degrees inclination with and without the application of anabolic steroids, the activity of LDH and its isozymes was identical to the values obtained in untrained animals but significantly higher than after the training at 5 degrees inclination. The typing of FG, FOG, and SO muscle fibers by the LDH isozyme pattern was not satisfactory, especially for the discrimination between FOG and SO fibers but also between FG and FOG fibers of muscle with different anatomic functions both in sedentary and trained animals.
Anabolic Agents↗
Bioluminescent assay for determination of picomole amounts of AMP, ADP, and ATP in adipose and muscle tissue biopsies.
A method is described for quantitative determinations of AMP, ADP, and ATP in tissue samples weighing a few milligrams by utilizing constant bioluminescent light intensity after reagent mixing. The smallest measurable quantity of adenosine nucleotide amounts to 0.2 pmol (coefficient of variation = 0.05) in the bioluminescent assay.
Adenine Nucleotides↗
A new gas chromatographic method for determination of amino acid levels in human serum.
Amino acid levels of biological fluids are usually determined by the classical ion exchange procedure. Although the gas chromatographic method offers the advantage of higher sensitivity and speed of analysis, apparent difficulties in achieving accuracy and precision similar to the ion exchange procedure prevented its acceptance as a routine method. The main problems associated with gas chromatographic amino acid analysis were overcome by application of a novel approach called enantiomer-labelling: the optical antipode to each L-amino acid is added to the sample prior to the clean-up and serves as an internal standard having identical chemical properties. The enantiomers of all amino acids are separated by gas chromatography on capillaries coated with a thermally stable, chiral stationary phase. The shortcomings previously inherent in the gas chromatographic method are thus eliminated. Accuracy and precision of the new procedure are equal or better than of the classical ion exchange method.
Adult↗
Transport and utilization of amino acids and glucose in human monocytes: activation of glucose metabolism by insulin.
The influence of insulin on transport and utilization of amino acids and glucose in purified human peripheral blood monocytes has been studied. Insulin had an immediate stimulating effect on the uptake of 3-O-methylglucose and 2-deoxyglucose; the maximal effects were 55% and 47% increases, respectively, during the first 2 min, in which energy-dependent hexose uptake dominates. Later, with advancing free diffusion, values declined to 16% and 25%. After a lag of 30 min, the rise in glucose uptake was followed by a small rise in glucose oxidation, documented by an 18% increase of 14CO2 production from [1-14C]glucose in the presence of hormone. No effect of insulin on sodium dependent alpha-aminoisobutyric acid or sodium-independent leucine uptake in monocytes could be found. The incorporation of amino acids into monocyte protein remained unchanged as well. Our results prove that the well documented binding of insulin to human monocytes initiates specific cellular reactions. The increased hexose monophosphate shunt activity may result in increased immune reactivity of the monocyte.
Adult↗
Metabolic adaptation to prolonged exercise.
A study was undertaken to evaluate and to examine the role of substrate supply in 50 healthy subjects after long distance events, such as 10 km, 25 km, and marathon races. The metabolic, variables of carbohydrate metabolism were greatest in 10-km runners, with the highest increase in glucose, lactate, and pyruvate, while in marathon runners only moderate changes were observed. Marathon competitors gave the greatest decrease in insulin concentration whereas glucagon and cortisol showed a contrary tendency. As for lipid concentrations, the most remarkable point was that after the marathon competition the best runners had the highest increase in free fatty acids; the longer the race, the higher were the beta-hydroxybutyrate and acetoacetate levels after the competition. It is important to emphasize that the limiting factor up to 90 min duration is the competitor's ability to deplete the stores of glycogen. Beyond 90 min (or 25 km) the decrease in insulin, the rise in cortisol and the higher concentration of ketnne bodies found indicate a change in metabnlic response.
Adaptation, Physiological↗
Metabolic response to heavy physical exercise before and after a 3-month training period.
Twenty healthy athletes performed a heavy physical exercise before and after a controlled training period of 3 months. As a result of physical training there was a reduction in lactate concentration during and after exercise. Plasma free fatty acids and triglyceride levels were lower at rest as well as during and after exercise. Insulin concentrations decreased during exercise before the training period whereas they remained constant afterwards. The composition of individual free fatty acids changed in the same way during exercise before and after training: fatty acids with shorter hydrocarbon chains increased, those with longer chains decreased. Comparing the pattern of individual free fatty acids before and after training a higher percentage of saturated and a lower percentage of mono-unsaturated fatty acids was observed. It is concluded that changes in the plasma free fatty acid profile during heavy exercise reflect a preferential uptake and oxidation of certain individual free fatty acids. The significance of training-induced changes in the plasma free fatty acid pattern is discussed.
Adult↗
Inhibition of K+-sensitive p-nitrophenylphosphatase activity on Rhesus-positive red cells after incubation with IgG-anti-Rhesus-D.
The incubation of ghosts derived from human Rhesus-positive red cells with IgG-anti-Rhesus-D inhibited the K+-sensitive p-nitrophenylphosphatase activity. This enzyme has a partial function in the (Na+ + K+)-ATPase system related to the phosphorylation step, which is important for active potassium transport through the red cell membrane. The specificity of the impairment by the antigen-antibody reaction in the Rhesus-D system was proved by the following controls. Ghosts obtained from Rhesus-negative red cells incubated by IgG-anti-Rhesus-D and those of Rhesus-positive red cells treated with non-immune serum did not show any reduction of the K+-p-nitrophenylphosphatase activity. The ghost preparation with lanthanum carried out after hypotonic hemolysis of the washed red cells in 2 mM LaCl3 at pH 6 was the most suitable procedure to explore this topic in comparison to other techniques for preparing ghosts of red cells.
4-Nitrophenylphosphatase↗