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Biomedical subjects

I Trautschold

Publications and source records attributed to I Trautschold.

At least 37 records · Page 2Linked to original sources
PubMed1982

Enzymatic composition of canine leg lymph.

In an experimental study employing anaesthetised dogs, lymph from the deep lymphatic system in a hind leg was sampled at 15-min intervals. Lymph and corresponding plasma samples were analysed for ten different enzymes and for protein. In a control group a preliminary period of 15-min lymph collections was followed by 1 h of 'rest' (no passive movement of leg) and restoration of the lymph flow for another 2 h. In a hypoxic group during the 1 h of 'rest' the blood supply of a hind limb was interrupted to cause an increase of enzyme release. Neither lymphatic enzyme activity nor lymphatic transport of enzymes was increased by hypoxia. Enzyme activities in plasma did not show any elevation either. From lymph plasma quotients of enzymes and protein it is deduced that cellular enzymes have to be transported into the intravascular space by lymph flow and scarcely via a direct entry across capillaries.

Adenylate Kinase↗
PubMed1982

Insulin binding to erythrocytes after acute 16-methyleneprednisolone ingestion.

The binding of [125I]insulin to erythrocytes, glucose and insulin were determined before and 1, 7 and 35 days after ingestion of 2 X 60-methyleneprednisolone. None of two groups of volunteers (7 males, 4 females showed clear alterations of the insulin binding parameters (Ka and R0), or of the fasting cortisol, glucose and insulin concentrations. These results exclude the possibility that the diabetogenic effect of glucocorticoides is accompanied by an alteration of the insulin receptor characteristics of erythrocytes.

Blood Glucose↗
PubMed1982

Effect of transient hypoxia in skeletal muscle on enzyme activities in lymph and plasma.

The effect of hypoxia lasting one hour on the hind leg muscle of anaesthetised dogs was investigated. Ten enzyme activities in plasma and leg lymph, and the lymphatic transport of these enzymes were investigated. Enzymes with high activity in muscle, like creatine kinase, lactate dehydrogenase, malate dehydrogenase and adenylate kinase only show an increase in the plasma, if lymph--propulsed by passive motion of the hind leg--can reach the intravascular space. This effect is independent of transient hypoxia. Depending on the level of enzyme activity in the muscle, the activity in leg lymph is up to 6-fold higher than in plasma. Enzymes from muscle have to be transported into the blood by lymph flow and not via a direct interstitial-venous entry. The results are discussed especially with respect to enzyme activity changes in plasma during physical exercise.

Adenylate Kinase↗
PubMed1982

Insulin binding to erythrocytes from pregnant, postpartum, follicular and luteal states.

Specific binding of [125I] insulin to isolate erythrocytes from four groups of women was investigated: (A) pregnant subjects between weeks 38 and 40 of pregnancy (n = 18), (B) postpartum subjects within 6 days after delivery (n = 20), (C) normal women during the follicular phase of the menstrual cycle (n = 12) and (D) normal women during the luteal phase of the menstrual cycle (N = 11). Specific [125I] insulin binding (fraction), fasting plasma glucose concentrations (mmol/l) and the corresponding insulin concentrations (mU/l) were 0.074 +/- 0.012 / 4.00 +/- 0.58 / 29.4 +/- 21.4 for group A, 0.065 +/- 0.016 / 4.40 +/- 0.75 / 41.5 +/- 26.2 for group B, 0.052 +/- 0.008 / 4.58 +/- 0.62 / 6.7 +/- 4.0 for group C and 0.054 +/- 0.011 / 4.49 +/- 0.63 / 8.3 +/- 5.9 for group D. By using a modified Scatchard analysis, statistically significant differences were observed between the receptor affinities of the groups A and D, B and D, A and C. The receptor affinities and concentrations were not significantly different between the follicular and the luteal phases. From the data, no inverse correlation between the plasma insulin concentration and receptor binding was seen, i.e. the phenomenon of downregulation of insulin receptor concentration with hyperinsulinaemia seemed not to apply to erythrocytes.

Adult↗
PubMed1982

[Effects of haemolysis, urea and bilirubin on the precision of digoxin and insulin radioimmunoassays (author's transl)].

The influence of haemolysis, uraemia and hyperbilirubinaemia on the radioimmunoassay for both digoxin and insulin has been investigated for five separation techniques (dextran/charcoal; coated tube; polyethyleneglycol 4000; sodium sulphite; double antibody). Recoveries, and intra- and interassay precision were calculated. It was demonstrated that even in serum samples with a rather high degree of haemolysis (haemoglobin up to 50 g/l)digoxin can be measured by using each of the five separation techniques without any significant interference. Visible haemolysis (haemoglobin above 200 mg/l) leads either to disturbance or to a complete failure of insulin radioimmunoassays with all separation techniques. This effect can be largely neutralized, and precision improved, by using N-ethylmaleimide. With the exception of the coated tube separation technique the intraassay precision has a CV of less than 10%, and the interassay CV is between 10 and 20%. Elevated urea concentrations interfered in the digoxin radioimmunoassay only when the coated tube technique was used. The insulin radioimmunoassay, however was affected by high urea when either the double antibody or the coated tube technique was used. Here the intraassay precision also has a coefficient of variation less than 10%, the interassay CV lying between 10 and 20%. Bilirubin influenced the digoxin test when the sodium sulphite separation was used, and it affected the insulin determinations with polyethyleneglycol 4000 and sodium sulphite. The intra- and interassay precision were however also around 10% and between 10 and 20% respectively. Compared with the interassay precision of 15% CV for digoxin and 13% for insulin for a pool-serum from blood donors, the decrease of interassay precision caused by haemolysis, uraemia and hyperbilirubinaemia was insignificant.

Animals↗
PubMed1981

Hepatotoxic effects of sera from patients with fulminant hepatitis B on isolated rat hepatocytes in culture.

The hepatotoxicity of sera from patients with terminal fulminant hepatic failure has been investigated by cell culture techniques. It could be shown that both untreated and heat-treated sera are cytotoxic in nature. Compared with the action of sera from healthy individuals on liver cells in primary monolayer culture, the pathological sera exhibited significantly different behaviour with respect to morphological and biochemical parameters such as cell adhesion, growth and proliferation, and enzyme release.

Alanine Transaminase↗
PubMed1980

Gas chromatographic method for the quantitative assay of alkane thiol S-methyltransferase.

A method is described for the quantitative assay of the methylation of alkane-thiols from the methyl-donor S-adenosylmethionine, catalysed by the microsomal enzyme S-adenosyl-L-methionine:thiol S-methyltransferase (E.C. 2.1.1.9). The reaction is carried out in sealed vials, one fifth of whose volume is taken up by an aqueous phase containing the enzyme and reactants. The volatile substrates and products of the reaction, thiols and thioethers, respectively, are present in equilibrium both in the liquid and gas phases in the reaction vessels. Aliquots of the gas phase are removed at intervals in gas-tight syringes, and analysis is performed directly on a gas chromatograph fitted with a flame-ionization detector. The amounts of thiol and thioether detected are then related to the total amounts of substance in the reaction vessels from calibration measurements, so that the kinetics of the enzymatic process can be evaluated. This technique offers distinct advantages over previously reported methods, in that no radioactively labelled compounds are required. Furthermore, decreases in substrate and increases in product can be assayed simultaneously, and the methylation of a mixture of thiols can be monitored in a single set of analyses.

Chromatography, Gas↗
PubMed1979

Lymphatic transport of cellular enzymes from muscle into the intravascular compartment.

In an experimental study, employing anaesthetized dogs, it was investigated whether cellular enzymes from peripheral skeletal muscle get into the circulating blood by diffusion across capillary membranes or by lymphatic transport. In the experimental group 1, the animals were anaesthetized only. The plasma activities of the four enzymes measured--lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, creatine kinase--did not show any mentionable change during a time period of 6 h. In group 2 one hind limb of each animal was moved passively for 1 h. Alanine aminotransferase remained unchanged in plasma, the activities of the three other enzymes increased significantly. In group 3 one hind limb was made hypoxic by clamping the femoral blood vessels for 1 h. No activity changes were observed. When the period of hypoxia was followed by a 1-hour period of passive movement in group 4, the alterations in plasma activities were almost identical to those observed in group 2. In group 5 the experimental procedure was as in group 4, in addition the lymph from the thoracic duct was quantitatively withdrawn. The enzyme activities in plasma revealed a tendency to decrease rather than increase. Lymph flow increased significantly as well as the lymphatic activities of those enzymes which have high intracellular activities in muscle. The results prove, that enzymes from muscle are transported from the interstitial into the intravascular compartment mainly by lymphatic transport. Indications were found that the interruption of blood flow in one hind limb did not result in an enzyme release from muscle cells. It is discussed how changes in lymph flow, occurring during physical exercise for example, affect enzyme activities in plasma.

Alanine Transaminase↗
PubMed1979

On the mechanism of lactate dehydrogenase release from skeletal muscle in relation to the control of cell volume.

The mechanism of enzyme release from isolated skeletal muscle was illustrated by the study of the release of lactate dehydrogenase (LDH). In hypotonic media of different composition but of same tonicity the increase of LDH permeability was triggered at the same range of relative osmolality R (0.45 less than R less than 0.55), although the swelling in the respective media showed appreciable differences. The kinetics of muscle swelling showed that a deviation from the theoretically computed swelling curve to lower values of swelling was connected with an increased LDH permeability. The reduction of swelling was ATP- and Ca2+ and/or Mg2-dependent. It is concluded that swelling of cells generally precedes the leakage of soluble enzymes, and the cross-linking of filaments at the sarcoplasmic side of the sarcolemma under appropriate conditions can counteract swelling, thereby blebbing off the cell membrane from the filament meshwork. In the course of this process, sufficiently large membrane lesions are produced through which macromolecules may escape into the extracellular space.

Adenosine Triphosphate↗
PubMed1976

[The feigned release of cell enzymes. Distribution and transport of cell enzymes within the extracellular space. I (author's transl)].

A sudden increase of enzyme activities in plasma is not necessarily due to a release of enzymes from damaged cells. Three experimental models were used to demonstrate that acute alterations of enzyme activities, as much as +/- 15%, can be caused by fluid-shifts between the intra- and extravascular compartments. Venous occlusion of the forearm by tourniquet produces an increase of the intravascular hydrostatic pressure and subsequently results in a decrease of the plasma volume distal to the tourniquet. Because enzyme molecules are not freely diffusible across the capillary membrane the enzymatic activity increases proportionally to the decrease of plasma volume. Changes in the body posture are accompanied by changes in plasma volume and similarly by alterations in the concentration of plasma-proteins and by alterations in intravascular enzyme activities. Increased enzyme activities in plasma during strenuous physical effort are due chiefly to a concentration of macromolecules within the intravascular space because of a decrease in plasma volume and not to a release of enzymes from hypoxic muscle cells. During recovery after termination of the exercise there is a second and longer lasting increase in enzyme activities in plasma which could be related to a release of enzymes from injured cells. It is suggested that some of these changes could be due to an increase in lymph flow and thereby an increasing transport of enzymes from the interstitial to the intravascular compartment.

Biological Transport↗
PubMed1976

[Cell enzymes in lymph. Distribution and transport of cell enzymes within the extracellular space. II (author's transl)].

Enzyme patterns were measured in the lymph of the thoracic duct of the dog and in the intestinal lymph of the rat. Those patterns were compared to the corresponding activities in blood plasma. From the results it is concluded that under physiological conditions cell enzymes are released into the interstitial space and from there are transported via the lymph into the intravascular space. Only enzymes with a low molecular weight such as myokinase are able to penetrate the capillary membrane, thereby reaching the plasma without being transported exclusively by the lymph. There is a close relationship between the molecular weight of enzymes and their plasma/lymph ratios. In the rat the enzyme patterns in mesenteric lymph nodes and in intestinal mucosa and muscularis (duodenum as well as ileum) were also determined. No direct correlation between those intracellular patterns and the enzyme patterns in the intestinal lymph could be established. The significance of lymph and lymph flow for clinical enzymology is discussed with respect to physiological and pathological conditions. High sensitivity of diagnosis by means of enzyme measurements in plasma can be achieved only if the capillary permeability in the injured organ is high and/or the lymph flow from the organ is not restricted by the injury.

Animals↗
PubMed1976

[Distribution of intravenously injected enzymes of heterologous, homologous and autologous origin. Distribution and transport of cell enzymes within the extracellular space. III (author's transl)].

The disappearance rates of intravenously injected enzymes of heterologous, homologous and autologous origin were determined in rats. Within four hours after administration, the activities show an exponential decline, that is either mono- or biphasic. The constant of the exponential function is a measure of the capillary permeability. In the case of biphasic disappearance this holds true only for the first slope, whereas the second one represents the elimination of active enzyme molecules from the extracellular space. If the decline in enzyme activity is monophasic the elimination of those enzymes from the interstitial space is limited by the permeability of the capillary membrane. Enzymes of homologous and autologous origin (extracts of liver or muscle) show a close correlation between their molecular weights and their rates of distribution within the extracellular compartment. For heterologous enzymes (crystallized) such a correlation could not be found. Possible causes for these differences in distribution are discussed. Heterologous and/or crystallized enzymes seem not to be suited for studies on the distribution of cell enzymes within the extracellular space. After enzymes are released from injured cells they undergo the processes of distribution, transport and elimination which are superimposed. The effects of the distribution and transport of enzymes on the results of clinical studies on enzyme elimination are discussed. It seems questionable at this point to assume that from the elimination rate of enzymes and their actual plasma activity one can account for the amount of enzymes originally released from injured cells.

Animals↗
PubMed1976

[Plasmapheresis as an experimental model for studies on the extracellular distribution of enzymes. Distribution and transport of cell enzymes within the extracellular space. IV (author's transl)].

The rate of distribution of cell enzymes between the intravascular and extravascular space was studied, following a sudden decrease of enzyme activities in plasma. This rapid decrease of enzyme activities was achieved in rats by a rapid exchange of the blood with a twofold volume of a suspension of homologous erythrocytes in isoosmolar bovine serum albumin solution. After this plasmapheresis, the activities of seven cell enzymes in the plasma were decreased to 14 to 22% of their original values. The subsequent increase in activities showed different kinetics, depending on the enzyme. After 120 min, creatine kinase had reached the starting activity; malate dehydrogenase and aldolase reached their original activities after 180 min. Aspartate aminotransferase, glutamate dehydrogenase, alanine aminotransferase and pyruvate kinase increased more slowly and they had still not reached their starting values after 240 min. Repetition of the plasmapheresis after 90 min had no obvious effect on the kinetics of the subsequent activity increase. During the first minutes after plasmapheresis the adjustment of the activity equilibrium between the interstitial and the intravascular compartments depends mainly on the capillary permeability. It is therefore possible to determine half-life constants for the distribution of enzymes within the extracellular space. The constants for malate dehydrogenase and aldolase are almost identical with those determined by intravenous injection, whereas there are discrepancies in the constants for the remaining enzymes. The constants for pyruvate kinase and glutamate dehydrogenase are significantly lower, while those for aspartate aminotransferase, alanine aminotransferase and creatine kinase are significantly higher, than those determined after intravenous injection. Possible reasons for these differences are disucssed.

Animals↗
PubMed1975

[Effects of blood sampling on enzyme activities in the serum of small laboratory animals (author's transl)].

Because of the difficulties in drawing blood for clinical chemistry in small laboratory animals there exist many methods for sampling blood and the preparation of serum, none of which is generally accepted or well standardised. It was the aim of this study to investigate the effects of sampling techniques on normal values of enzyme activities in the serum of rat and mouse. The activities of the following enzymes were determined: sorbitol dehydrogenase, lactate dehydrogenase, malate dehydrogenase, glutamate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, pyruvate kinase, creatine kinase, myokinase, alkaline phosphatase and leucine aminopeptidase. In addition plasmaproteins, urea and inorganic phosphorus were measured. In rats blood was obtained from the following sites: retroorbital venous plexus, jugular vein, heart and ventral aorta. In mice blood was sampled from the jugular vein and the ventral aorta. Shifts of water from the interstitial to the intravascular space due to hypovolemia occurring during the experimental procedure were followed up by measuring the hematocrit and the distribution of radioiodide labelled albumin. In rats the activities of lactate dehydrogenase, malate dehydrogenase, aspartate aminotransferase, pyruvate kinase, creatine kinase and myokinase found in blood serum obtained from the retroorbital venous plexus and the ventral aorta were too high compared to the other sampling sites. Activities of alkaline phosphatase and alanine aminotransferase were slightly elevated when blood was sampled from the punctured retroorbital venous plexus. Small differences in plasmaproteins and hematocrit values were found to be due to acute shifts of water within the extracellular space. In mice the activities of lactate dehydrogenase, malate dehydrogenase, aspartate aminotransferase and myokinase were found to be too high in blood serum obtained from the ventral aorta. Efflux of enzymes from damaged cells and the interstitial space ive caused erroneous results too, but only to a minor extent. The most reliable method for blood sampling in rat and mouse is the cannulation of the jugular vein. The heart puncture can be recommended too. Attention should be paid, however, to the possibility of aspirating disrupted muscle cells through the inserted needle.

Adenylate Kinase↗