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Biomedical subjects

B Rüstow

Publications and source records attributed to B Rüstow.

At least 73 records · Page 4Linked to original sources
PubMed1984

Diacylglycerol species in microsomes and mitochondria of normal and dystrophic human muscle.

The concentration of 1.2-diacylglycerol in mitochondria and microsomes of normal human muscle was estimated to be 1.7 +/- 0.6 and 9.2 +/- 1.9 nmol X mg protein-1, respectively. The molecular species profile of 1.2-diacylglycerol was obtained using high pressure liquid chromatography which yielded 14 fractions. Corresponding studies were carried out for normal and dystrophic muscle. No significant difference could be seen between the 1.2-diacylglycerol patterns in normal muscle mitochondria and in microsomes. There was a radical shift in the 1.2-diacylglycerol pattern in both dystrophic organelles, mainly with a decrease in 16:0/16:0 species. In dystrophic mitochondria the total level of 1.2-diacylglycerol was higher.

Diglycerides↗
PubMed1984

Glycerophosphate acylation by microsomes and mitochondria of normal and dystrophic human muscle.

The incorporation of [14C]glycerophosphate into phosphatidic acid, diacylglycerol, triacylglycerol and phosphatidylcholine by microsomes and mitochondria prepared from normal and dystrophic human muscle incubated in vitro in the presence of 0.3 mmol/l CDP-choline was measured. In mitochondria only phosphatidic acid and diacylglycerol are labelled; the rate of incorporation into these two compounds showed no difference between dystrophic and normal mitochondria. In dystrophic microsomes the incorporation into phosphatidic acid was delayed and decreased. No incorporation of glycerol into diacylglycerol, phosphatidylcholine and triacylglycerol could be measured. Thus in dystrophic muscle microsomes only PA was labelled during an incubation of up to 45 min. In both types of microsomes the concentration of endogenous free fatty acids and diacylglycerol was nearly identical. The level of phosphatidylcholine was 186 and 79 nmol/mg microsomal protein in normal and dystrophic muscle microsomes, respectively. Whether the results could be explained as secondary changes was discussed. Despite some unsolved problems the conclusion was drawn that a better explanation of the results is to assume a primary defect involving microsomal-bound phosphatidic acid phosphohydrolase and possibly glycerol-P-acyltransferases.

Acylation↗
PubMed1984

Synthesis of phosphatidylcholine and phosphatidylethanolamine in relation to the concentration of membrane-bound diacylglycerols of rat lung microsomes.

Different concentrations of membrane-bound diacylglycerol were generated in vitro in rat lung microsomes by treatment with CMP. Diacylglycerol concentrations of between 16 (endogenous content) and 48 nmol/mg of microsomal protein were obtained. The relative proportion of the disaturated species of diacylglycerol remained constant at all diacylglycerol concentrations. Choline- and ethanolaminephosphotransferase activity was determined in relation to the diacylglycerol concentrations of microsomes. The activity of both phosphotransferases increased. The relative proportion of disaturated phosphatidylcholine synthesized at each diacylglycerol concentration was nearly the same and corresponded to the relative proportion of the disaturated species in the diacylglycerol. Disaturated phosphatidylethanolamine was not formed. The affinities of the choline- and ethanolaminephosphotransferases for the diacylglycerol substrate were different. We conclude that the cholinephosphotransferase is generally non-selective for the diacylglycerol substrate. The available diacylglycerol pattern seems to govern the species pattern of phosphatidylcholine and phosphatidylethanolamine. The kinetics of the phosphotransferases regulate the mass proportion of these phospholipids.

Animals↗
PubMed1983

Phospholipase A activation following extracorporeal circulation and its blockade by procaine.

The phospholipase A activity of human plasma was investigated in the course of operations with the aid of extracorporeal circulation. After an initial increase following heparin application, there is a continuous rise up to the end of perfusion and a decrease to normal values 30 minutes after the end of perfusion and the application of protamine. Procaine is suitable for the inhibition of the increased phospholipase A activity. In accordance with in vitro determinations of an effective dose of 1 mmol/ml, corresponding concentrations were attained with an infusion rate of 1.5-2 mg/kg/min. In a second series of investigations, a significantly smaller phospholipase A activation in the course of perfusion was detectable through the addition of procaine.

Coronary Artery Bypass↗
PubMed1982

Some examples of the clinical importance of the basic and heparin-induced phospholipase A in human plasma.

Phospholipase A activity was determined in human plasma with biological 32P-labelled phosphatidylethanolamine from rat liver following cardiac operations with the aid of the heart-lung-machine. The basic activity before heparin and the initiation of bypass was 72 nmol . ml-1 . h-1 plasma; thereby large differences in the basic activity were detected between cyanotic and acyanotic heart diseases. A sharp increase of phospholipase activity was observed after heparin (a smaller one in intensive care patients with low-dose heparin), and a further increase up to the end of perfusion. Normal values are reached after giving protamine at the end of the operation. An important role for plasma phospholipase in the regulation of physiological and pathophysiological processes may be supposed from these results.

Child, Preschool↗
PubMed1982

[Endogenous lipid pattern, organ distribution and effect of diet on a fatty acid binding protein fraction of rat liver cytosol].

The endogenous lipid pattern of a fatty acid binding protein (FABP; synonym: "Z"-protein) in the cytosolic fraction of rat liver involves besides "free" fatty acids also phospholipids and mono-, di- and triacylglycerols. The relation between "free" fatty acids and the sum of all other lipids is nearly 1. In consequence of this result a correction of the idea is necessary that the FABP specifically binds only fatty acids. With immunological techniques it has been shown that the FABP has no organ-specificity and no immunological relation to the lipoproteins of the serum. A high content of fat in the diet (25% fat) compared with a low fat content of the diet (1% fat) led to an increase of the concentration of FABP in the cytosols of different rat organs (liver, intestinal mucosa, fat tissue and heart). Therefore a physiological function in the intracellular translocation of the fatty acids in different rat organs was inferred.

Animals↗
PubMed1981

[Effect of portasystemic anastomoses in childhood on propranolol pharmacokinetics].

Kinetics of propranolol after oral administration were investigated in 9 children aged 5--11 years with intact liver function who had undergone porto-systemic anastomosis surgery for pylethrombosis and in a 16-year-old boy with a Warren shunt. Bioavailability of the drug had increased by twice the values measured in physiologic liver blood flow; elimination half-life had doubled. These alterations must be taken into consideration in medication, e.g. extreme care must be exercised in the oral administration of "first pass" drugs in porto-systemic shunt patients and it is recommended that the initial dose should be at the level of intravenous administration. The reduced rate of elimination should be taken into account in the case of drugs whose elimination depends on liver blood flow.

Administration, Oral↗
PubMed1981

Incorporation of 14C-linoleic acid in cerebrosides of psoriatic and normal human skin.

Psoriasis is marked by loss of glycoalyx. Glycocalyx is composed of glycoproteins and glycolipids such as cerebrosides. It was shown that the incorporation of 14C-linoleic acid in cerebrosides of normal and psoriatic human skin is different. In psoriatic epidermis and corium the turnover of this fatty acid is significantly elevated. It is suggested that in psoriasis the epidermal cell is not able to build up a regular carbohydrate sequences of lipids because the false carbohydrate chain activates the degradation of glycolipids and in compensating for the increased degradation raises the synthesis rate of glycolipids.

Carbon Radioisotopes↗
PubMed1980

Studies of selected enzymes of phospholipid metabolism in the dystrophic human muscle.

Proceeding from deviations of the phospholipid pattern in the muscle in progressive muscular dystrophy, the activities of a number of enzymes of phospholipid metabolism in the normal and dystrophic human muscle were measured. Twelve cases of the Duchenne type and four of the Becker-Kiener type were studied. The activities of CDP-choline:diglyceride-P-cholinetransferase, of CDP-choline:ceramide-P-cholinetransferase and of phosphatidylcholine degradation were determined in normal and dystrophic human muscle. A significant difference in enzyme activities between normal and dystrophic muscle could not be established. The activities of a phosphatidylethanolaminemethyltransferase and a transfer of P-choline directly from phosphatidylcholine to sphingomyelin could be excluded for normal human muscle. The significance of these results for the integration of phospholipid findings in ideas about pathogenesis of progressive muscular dystrophy is discussed.

Adolescent↗
PubMed1976

[Relationship between food protein quality and adrenal cortex function. 7. Relationship between activity of selected liver and small intestine hydrolases and adrenal cortex function].

Male Wistar rats received 10% true digestible crude protein of varying quality (maize gluten (MK) = low protein quality; maize gluten + lysine, tryptophan, threonine, isoleucine (MK + AS) = high protein quality) for a period of three weeks. The trial was carried out to investigate the activity of the two enzymes leucine-arylamidase (LNA) and aminotripeptidase (TP) in the liver and the mucosa of the small intestine and that of alpha and gamma amylases and of total amylases in the mucosa of the small intestine in animals exhibiting differences in the functional state of their adrenal cortices (adrenalectomized animals (AE), normal rats (N) and animals receiving additional treatment with cortisol (KS). It was found that mucosal LNA and gamma amylase did not respond to functional changes in the adrenal cortex. Mucosal LNA had a higher activity if the dietary protein was of low quality and a lower activity if the protein quality was high. The level of liver LNA activity was significantly lower in N and KS animals than in AE animals. The highest activity of mucosal and liver TP was found in KS animals; it was lowest in N animals. Statistically significant differences brought about by changes in the quality of dietary proteins were only found to occur in the KS group. The activity of alpha amylase and total amylases was found to be lowest in N animals; it was significantly higher in animals of the AE and KS groups. Animals of the N and KS groups receiving MK + AS exhibited a significantly higher level in their alpha and total amylase activities than animals in the same group receiving MK. Here, the "permissive action" of glucocorticosteroids on metabolically active hydrolases is clearly evident. The pattern of mucosal LNA activity in the small intestine and that of gamma amylase may be regarded as further characteristic evidence for the digestive action of these enzymes. Liver LNA and liver TP as well as mucosal TP and alpha amylase acted like metabolic enzymes.

Adrenal Cortex↗
PubMed1975

[Relation between quality of dietary protein, plasma corticosteroid concentration and various enzyme activities in liver and mucosa of small intestine].

Comprehensive studies were performed in Wistar rats on the relations between the dietary protein quality and the function of the adrenocortical system. The authors determined: the increase in body mass, the urea and corticosteroid concentrations in the blood plasma, the GOT (EC 2.6.I.I.) and GPT (EC 2.6.I.2.) activities in the liver, the reactivity of the adrenocortical system in vitro, the ACTH content in the hypophyses and the content of corticosteroid-binding globulin in the blood plasma. In adrenalectomized and normal rats as well as in rats treated with corticosterone or cortisol, the authors determined the GPT, GOT, amino-acid aryl amidase (EC 3.4.I.2.) and tripeptidase (EC 3.4.I.3.) activities in the liver and the mucosa of the small intestine, and the total, alpha and beta-amylase activities in the small intestine.

Adrenal Cortex Hormones↗
PubMed1975

Effect of RNA synthesis on the binding of 3H-cortisol to nuclear ribonucleoprotein particles from rat liver carrying DNA-like RNA in vivo.

3H-cortisol was found to associate with rat liver nuclear 30S ribonucleoprotein particles carrying D-RNA in vivo. No interaction was detectable when RNA synthesis was inhibited by alpha-amanitine. The association appears to be specifically for RNP carrying RNA synthesized after the administration of cortisol to adrenalectomized rats. The DNA/protein/RNA ratio of rat liver nuclei was not effected by alpha-amanitine under our conditions. However, the drug caused a 5-10 fold decrease in nuclear uptake of cortisol. The results are discussed in relation to a supposed transfer of cortisol-receptor complexes from the chromatin template to the nascent RNA chains.

Adrenalectomy↗