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Biomedical subjects

E Hultman

Publications and source records attributed to E Hultman.

At least 181 records · Page 10Linked to original sources
PubMed1977

Hypomagnesaemia and muscle electrolytes and metabolites.

Ten patients, aged 39-61 years, with hypomagnesaemia due to chronic alcoholism (7 cases) or malabsorption (3 cases), have been investigated by assessing the maximum isometric voluntary contraction force (MVC) of the quadriceps femoris muscle (7 cases), laboratory screening (9 cases) and estimating the electrolyte and metabolite content of biopsy specimens from the quadriceps femoris muscle. The MVC ranged from 0.5 to 34 kp and was significantly lower than in 12 apparently healthy normomagnesaemic controls (p is less than 0.001). The results of the laboratory screening, apart from a significant lowering of the serum magnesium concentration (p is less than 0.01), were mainly within the range of normal values, apart from signs of liver damage, such as an elevated activity of S-OCT (3 cases), alkaline phosphatease(3 cases), S-ALAT (1 case) and an elevation of bilirubin and blood ammonia (2 cases). Low serum iron-binding capacity occurred in 4 cases, a finding reported in protein-calorie malnutrition. Muscle magnesium content was significantly lower than in healthy controls (p is less than 0.001). Muslce sodium and chloride contents were significantly increased (p is less than 0.05). Total H2O content and the extracellular H2O content were both significantly increased (p is less than 0.05). Pyruvate and lactate values were within the normal range. The apparent equilibrium constant for creatine kinase differed significantly ( is less than 0.01). ATP values were within the normal range, but there were slight decreases for ADP (p is less than 0.05) and creatine phosphate ( is less than 0.01), whcih is of interest in view of the lowering of the MVC and the diminished capacity for sustained muscular effort in hypomagnesaemic patients reported earlier.

Adenosine Diphosphate↗
PubMed1977

Phosphagen and lactate contents of m. quadriceps femoris of man after exercise.

Muscle biopsies were taken from the m. quadriceps femoris of man immediately after termination of dynamic and isometric exercise. These were analyzed for adenosine triphosphate (ATP), adenosine 5'-diphosphate (ADP), adenosine 5'-phosphate (AMP), phosphorylcreatine (PC), creatine, pyruvate and lactate. Regardless of type, intensity, and duration of the preceding exercise, a general pattern of the relation between high-energy phosphates and lactate content could be observed. PG showed a nonlinear relationship to the muscle lactate content. The ratio of ATP to ADP appeared to decrease linearly when lactate content increased. The relationships are believed to be the consequence of a steady-state condition where muscle pH is one of the major determining factors.

Adenine Nucleotides↗
PubMed1976

The time course of phosphorylcreatine resynthesis during recovery of the quadriceps muscle in man.

The time course of phosphorylcreatine (PC) resynthesis in the human m. quadriceps femoris was studied during recovery from exhaustive dynamic exercise and from isometric contraction sustained to fatigue. The immediate postexercise muscle PC content after either form of exercise was 15-16% of the resting muscle content. The time course of PC resynthesis during recovery was biphasic exhibiting a fast and slow recovery component. The half-time for the fast component was 21-22s but this accounted for a smaller fraction of the total PC restored during recovery from the isometric contraction than after the dynamic exercise. The half-time for the slow component was in each case more than 170 s. After 2 and 4 min recovery the total amount of PC resynthesized after the isometric exercise were significantly lower than from the dynamic exercise. Occlusion of the circulation of the quadriceps completely abolished the resynthesis of PC. Restoration of resynthesis occurred only after release of occlusion.

Adenosine Triphosphate↗
PubMed1976

Lactate content and pH in muscle obtained after dynamic exercise.

Analyzes were made on muscle samples taken from the lateral part of the m. quadriceps femoris of man (lactate, pyruvate, and pH) on venous blood (lactate, pyruvate) and on capillary blood (pH). Samples were taken at rest, immediately after termination of dynamic exercise and during 20 min recovery from exhaustive dynamic exercise. Muscle pH decreases from 7.08 atrest to 6.60 at exhaustion. Decrease in muscle pH was linearly related to muscle content of lactate + pyruvate. The relationship was slightly different from what has been obtained after isometric exercise and this difference was ascribed to acid-base exchange with the blood during dynamic exercise. Lactate content was highly elevated in muscle after exercise and the concentration was 2-3 times higher than in blood. Pyruvate content was, however, only slightly higher than that at rest. During recovery, lactate content of muscle decreased exponentially with respect to time, whereas pyruvate content increased. The half-time of lactate decrease was 9.5 min. From the lactate dehydrogenase equilibrium relative values on NADH/NAD ratio could be calculated. It was found that NADH/NAD was highly increased after exercise and that it had not returned to the basal value after 20 min recovery.

Adult↗
PubMed1976

Enzyme activities in hepatic venous blood under strenuous physical exercise.

In order to study the influence of physical exercise on liver function, experiments were performed in healthy volunteers subjected to controlled major physical effort. Blood samples obtained by catheterization of hepatic vein during exercise were analyzed for activities of LD (thermostabile and thermolabile isoenzymes), AlAT, SDH, ICD, AP and CPK, and these activities were compared with corresponding values in arterial blood samples taken simultaneously. Hepatic blood flow and oxygen saturation of hepatic venous blood were measured. Physical exercise resulted both in diminished hepatic blood flow and a fall in hepatic venous oxygen saturation. These changes were accompanied by release of liver specific enzymes, indicating that exhausting exercise may induce an "increased hepatocyte membrane permeability" in man.

Adult↗
PubMed1976

Influence of severe potassium depletion and subsequent repletion with potassium on muscle electrolytes, metabolites and amino acids in man.

1. Two women with severe hypokalaemic alkalosis were investigated by means of muscle biopsy before and at the end of 2 and 3 weeks respectively of intense therapy with potassium chloride. 2. The muscle biopsy material was analysed for water, electrolytes, adenine nucleotides, phosphocreatine, free creatine, pyruvate, lactate, glycogen and free amino acids. The extra- and intra-cellular distribution of water, electrolytes and amino acids was calculated by the chloride method. 3. Both patients showed a marked loss of intracellular potassium and an increase in intracellular sodium concentration. The muscle magnesium content was also slightly decreased. After repletion with potassium chloride, muscle sodium and potassium became normal. 4. The contents of creatine phosphate, ATP, ADP, AMP, lactate and pyruvate were within normal limits, but the phosphocreatine/total creatine ratio was reduced. After repletion, a small change in the apparent creatine-phosphokinase equilibrium had occurred, suggesting a minor increase in intracellular pH. 5. The concentrations of the basic amino acids, lysine, arginine and ornithine were increased far above normal. The intracellular accumulation of arginine was much higher than the increase in lysine concentration and histidine concentration was normal. This differs from findings in potassium-depleted rats, where the intracellular lysine concentration is much higher than arginine concentration and histidine is high as well. After potassium repletion the intracellular concentration of ornithine, lysine and arginine became normal in one case and decreased considerable in the other. An increased intracellular concentration of glutamate and glutamine was also observed after potassium repletion.

Acidosis↗
PubMed1976

Glycogen phosphorylase activity in biopsy samples and single muscle fibres of musculus quadriceps femoris of man at rest.

Glycogen phosphorylase activity in biopsy samples of the quadriceps muscle of man taken at rest was measured in the direction of glycogen breakdown. The conditions of assay used were pH 6.8 and 35 degrees C. Mean phosphorylase activity per kg fresh muscle in 8 male volunteers was: phosphorylase a - 259 U, and total phosphorylase - 627 U, where 1 U is the production of 1 mumol glucose-1-phosphate/s under the conditions of assay. The mean value of total activity, transposed to the in vivo condition, is sufficient to support a maximum rate of glycogen degradation calculated as glucosyl units utilized per kg fresh muscle, of 627 mumol/s. This is approximately the rate at which glycolysis occurs during a maximum voluntary isometric contraction. The mean ratio of phosphorylase a activity to total activity at rest was 0.40. Estimates of the mean total phosphorylase activity in type I ('slow') muscle fibres isolated from the quadriceps of 9 volunteers ranged from 210-385 U/kg fresh muscle, and in type II ('fast') muscle fibres from 493-934 U/kg fresh muscle. The average ratio of activity in type II fibres compared with that in type I fibres was 2.5.

Adolescent↗
PubMed1976

Serum lipids in alcoholics.

Fasting serum lipid values (cholesterol, triglycerides and phospholipids) have been analysed in a group of 85 male and 10 female alcoholics of various ages in connection with an acute drinking bout and compared to the values of twice as many control subjects. The most prominent finding was an increase in the mean concentration of triglycerides and phospholipids, most marked in the younger age groups. The elevations, however, were moderate and most alcoholics had the same serum lipid values as the controls. Serum triglyceride values above 2 and 3 mmol/1, respectively, occurred in 23% and 4% in controls and in 28% and 13% in alcoholics. It is suggested that excessive intake of alcohol induces hypertriglyceridaemia only when other factors are present. One such factor may be a reduced i.v. fat tolerance.

Adult↗
PubMed1976

Lactate production during fructose infusion with or without amino acids.

Lactate production from the liver during fructose infusion was decreased when an amino acid infusion was given simultaneously. The most pronounced decrease was observed when the amino acid infusion was started before the simultaneous administration of fructose and amino acids. The explanation of the phenomenon is thought to be a stimulation of gluconeogenesis by amino acids.

Amino Acids↗
PubMed1975

Effect of noradrenaline on triglyceride and glycogen concentrations in liver and muscle from man.

Fifteen male subjects aged 21-29 were given noradrenaline infusions for 4 hr. The noradrenaline infusions started at a rate of 0.1 mug/kg/min and were increased stepwise at hourly intervals. Blood was sampled before and at hourly intervals during and after the noradrenaline infusions. Needle biopsies were taken from the femoral muscle in 10 subjects and frim the liver in 8 subjects before and after the noradrenaline infusion. The concentrations of FFA in lasma and of beta-hydroxybutyric acid in blood were markedly elevated during noradrenaline infusion. The concentrations of plasma TG and blood glucose were slightly elevated. In liver the TG concentration increased from 23.1 to 32.7 mmole/kh (p smaller than 0.001). It was estimated that the de novo synthesis of TG in the liver could have required about 30% of the plasma FFA entering the slanchnic region. In muscle the TG concentration was 3.6 mmole/kh lower after the noradrenaline infusion (p smaller than 0.001). No change was found in the concentrations of cholesterol and phospholipids in muscle or of cholesterol in liver. The glycogen concentration in muscle did not change during noradrenaline infusion. The decrease in liver glycogen concentration was of the same order of magnitude as previously observed in fasting man. The results suggest that noradrenaline was without major net effects on the metabolism of glycogen in liver and muscle.

Adult↗
PubMed1975

Creatine kinase equilibrium and lactate content compared with muscle pH in tissue samples obtained after isometric exercise.

Muscle biopsies taken from the musculus quadriceps femoris of man were analysed for pH, ATP, ADP, AMP, creatine phosphate, creatine, lactate and pyruvate. Biopsies were taken at rest, after circulatory occlusion and after isometric contraction. Muscle pH decreased from 7.09 at rest to 6.56 after isometric exercise to fatigue. Decrease in muscle pH was linearly related to accumulation of lactate plus pyruvate. An increase of 22mumol of lactate plus pyruvate per g of muscle resulted in a fall of 0.5pH unit. The apparent equilibrium constant of the creatine kinase reaction (apparent K(CK)) increased after isometric contraction and a linear relationship between log(apparent K(CK)) and muscle pH was obtained. The low content of creatine phosphate in muscle after contraction as analysed from needle-biopsy samples is believed to be a consequence of an altered equilibrium state of the creatine kinase reaction. This in turn is attributed mainly to a change in intracellular pH.

Adenosine Diphosphate↗
PubMed1975

Adenine nucleotide content of human liver. Normal values and fructose-induced depletion.

A method is described for the determination of metabolites in liver biopsy samples. Normal values of lactate, pyruvate, and adenine nucleotide content of human liver are presented. Infusion of D-fructose, 5.9 mmol9kg-minus l.h-minus l, for 70 min resulted in a 22.5 per cent decrease of the adenine nucleotide pool (mainly by ATP depletion), increased content of fructose 1-phosphate, lactate, and pyruvate. The extent of adenine nucleotide depletion varied greatly between subjects and appeared related to the degree of increase in plasma urate. Infusion of glucose at the same rate did not affect the hepatic content of adenine nucleotides.

Adenine Nucleotides↗
PubMed1975

The effect of circulatory occlusion on isometric exercise capacity and energy metabolism of the quadriceps muscle in man.

Occlusion of the circulation to the quadriceps muscle for 20 min resulted in decreases in the muscle ATP and phosphorylcreatine (PC) contents of 1 and 32 per cent, respectively, and increases in ADP and AMP of 7 and 37 per cent. Decrease in PC was statistically significant after 4 min of occlusion, suggesting that the local intramuscular oxygen store was sufficiently depleted at this time as to be limiting to normal mitochondrial function. Pyruvate and lactate concentrations in muscle and the lactate to pyruvate ratio were significantly increased after 15 min of occlusion but not before. The calculated local oxygen store in the muscle was 2.0 mmol O2 - (kg dry muscle)-1. Local oxygen store depletion after 4 and 10 min of occlusion was estimated to be 40-50 and 90-100 per cent complete. Increasing time of pre-exercise occlusion resulted in decreased isometric endurance capacity. The observed decreases in endurance, however, were far greater than could be accounted for by any parallel decrease in the local muscle energy stores.

Adenosine Diphosphate↗