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  • 1
    Electronic Resource
    Electronic Resource
    Dietary modulation of fatty acid composition of mast cell phospholipids does not affect histamine release induced by compound 48/80 (1997)
    Springer
    Inflammation research 46 (1997), S. 185-190 
    Details
    ISSN: 1420-908X
    Keywords: Key words: Mast cell — Histamine — Fatty acids — Rat — Diet
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Objective and Design: In the present study we determined the extent to which the degranulation process in mast cells was related to the fatty acid composition of membrane phospholipids.¶Material: Peritoneal mast cells were isolated from Wistar rats (3 groups of 18 animals each), fed for 6 weeks diets which differed in their fatty acid compositions: (i) genuine salmon oil, abundant in (n-3) fatty acids, (ii) sunflowerseed oil, rich in (n-6) fatty acids, particularly linoleic acid, and (iii) hydrogenated coconut oil, rich in saturated fatty acids.¶Methods: Mast cells (106/ml) were stimulated with various concentrations of the mast cell-degranulating agent, compound 48/80 (0.1–10 〈mu〉g/ml). The extent of mast cell degranulation was quantified by determination of histamine in the supernatants using HPLC techniques.¶Results: No differences in compound 48/80-induced histamine release between the three dietary groups for any of the concentrations of compound 48/80 tested were found. Analysis of variance followed by Tukey's method for multiple comparisons was used to evaluate the effect of changes in the dietary fat type.¶Conclusion: These findings strongly suggest that in contrast to the formation of eicosanoids, the process of mast cell degranulation by a receptor-independent pathway is not controlled by the fatty acid composition of membrane phospholipids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000110050170
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  • 2
    Electronic Resource
    Electronic Resource
    Antigen-evoked mast cell degranulation in the isolated rat heart: No effect on subsequent ischemia-reperfusion induced damage (1997)
    Springer
    Inflammation research 46 (1997), S. 40-45 
    Details
    ISSN: 1420-908X
    Keywords: Key words: Rat — Mast cell degranulation — Heart — Ischemia — Reperfusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. In the present study, the possible role of mast cells in ischemia/reperfusion-induced myocardial injury was evaluated in the isolated 'mast cell depleted' rat heart. Hearts isolated from sensitized and non-sensitized rats were perfused according to Langendorff. After 30 min of normoxic perfusion, hearts were challenged with antigen, a procedure which is known to result in a massive mast cell degranulation in sensitized hearts. After another 20 min, both 'mast cell depleted' and control hearts were subjected to 30 min of ischemia followed by 30 min of reperfusion. The release of lactate dehydrogenase (LDH) was determined to quantitate the extent of irreversible injury of cardiomyocytes. Histamine release was measured to establish mast cell degranulation. Coronary flow (CF) and left ventricular developed pressure (LVDP) were monitored to study the consequences of the procedures on hemodynamic recovery. It was found that both CF and LVDP sign ificantly increased during the first min after antigen challenge. These changes were accompanied by an almost complete degranulation of cardiac mast cells. The increase in CF and LVDP values were rapidly followed by a decrease, reaching minimal values of 159 ± 4% and 85 ± 4% of those before administration of antigen, respectively, at 2–3 min after antigen challenge. No effect of antigen challenge on LDH release were found indicating that mast cell degranulation did not compromise myocyte integrity. During reperfusion following 30 min of ischemia both the increase in CF and LVDP in 'mast cell-depleted' hearts were not significantly different from those in control (non-sensitized) hearts. Similarly, at the end of the reperfusion-phase, CF and LVDP values in sensitized hearts were comparable to those in control hearts. Reperfusion results in increased LDH release, which at no point in time was significantly different between sensitized and non-sensitized hearts. In non-sensitized hearts histamine release during the reperfusion phase was not detectable. Therefore, the results indicate that in the isolated rat heart, mast cells are most likely not involved in acute ischemia/reperfusion-induced myocardial injury.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000110050051
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  • 3
    Electronic Resource
    Electronic Resource
    Effects of pyruvate on post-ischemic myocardial recovery at various workloads (1988)
    Springer
    Pflügers Archiv 413 (1988), S. 167-173 
    Details
    ISSN: 1432-2013
    Keywords: Pyruvate ; Transient ischemia ; Adenine nucleotides ; Enzyme release ; Workload ; Working rat heart
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In the present study the hemodynamic and metabolic effects of pyruvate (5 mM), added as cosubstrate to glucose (11 mM) perfused, transiently ischemic, isolated working rat hearts, were evaluated. During 2 h of normoxic perfusion pyruvate improved functional stability, prevented depletion of glycogen and triacylglycerol stores, and increased non-esterified fatty acid (NEFA) levels, even at relatively high workloads. The elevated NEFA levels are in line with the notion that pyruvate competes with endogenously produced fatty acids for oxidative energy production. After 45 min of global ischemia pyruvate was found (a) to affect markedly the relative contribution of ATP, ADP and AMP to the total adenine nucleotide content and (b) to stimulate the degradation of glycogen and to enhance the accumulation of lactate, suggesting enhanced anaerobic ATP rroduction. After restoration of flow pyruvate reduced the incidence of fibrillation and markedly improved recovery of cardiac output at both normal and high workload. Pyruvate did neither attenuate the release of lactate dehydrogenase, a marker for cell death, nor improve the conservation of the total adenine nucleotide and ATP content of hearts reperfused for 30 min. The latter findings indicate that hemodynamic recovery during reperfusion in the presence of pyruvate is neither related to the absolute tissue content of ATP nor to a reduction of irreversible cell damage, and suggest that pyruvate exerts its advantageous hemodynamic effects rather by improving the condition of reversibly damaged cells during reperfusion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00582527
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  • 4
    Electronic Resource
    Electronic Resource
    High energy phosphates and related compounds, glycogen levels and histology in the rat tibialis anterior muscle after forced lengthening and isometric exercise (1992)
    Springer
    Pflügers Archiv 420 (1992), S. 354-358 
    Details
    ISSN: 1432-2013
    Keywords: Eccentric exercise ; Energy-rich phosphates ; Glycogen ; Inosine monophosphate ; Histology ; Muscle damage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Eccentric exercise may elicit damage to the contractile elements. This primary damage is followed by secondary changes, consisting of histological changes and changes in glycogen and energy metabolism. The mechanism underlying changes in glycogen homeostasis and energy metabolism is not well established. The aim of this study was to investigate the possible relationship between changes in adenine and guanine nucleotides, inosine monophosphate (IMP), creatine phosphate, glycogen content and histology in the rat tibialis anterior (TA) muscle after forced lengthening or isometric exercise. The right muscles were either forcibly lenghtened or isometrically exercised, while the contralateral muscles served as non-exercised controls. The exercised muscles were dissected 0, 6 and 24 h post-exercise and the contents of adenine and guanine nucleotides, IMP, creatine phosphate, and glycogen determined. In addition, histological changes were assessed. Immediately after both types of exercise increases in tissue IMP levels were found. Irrespective of the type of exercise, glycogen content was decreased immediately post-exercise, but restored 6 h postexercise. Twenty-four hours later a second decline in glycogen content was found after both types of exercise. In forcibly lengthened muscles ATP content was decreased 24 h post-exercise. In isometrically exercised muscles ATP was not decreased at any time. Gross structural changes were found in all forcibly lengthened muscles (9–12% of TA muscle volume). In isometrically exercised muscles structural changes were minor (up to 0.1 % of muscle volume), were found only immediately post-exercise and in only 4 out of 18 muscles. It is concluded that forced lengthening results in decreased ATP levels. Changes in glycogen homeostasis were found after both isometric exercise and forced lengthening, demonstrating that these changes are not strictly related to degenerative changes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00374470
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  • 5
    Electronic Resource
    Electronic Resource
    Retrograde oxygen persufflation in combination with UW solution enhances adenine nucleotide contents in ischemically damaged rat kidney during cold storage (1996)
    Springer
    Transplant international 9 (1996), S. 396-402 
    Details
    ISSN: 1432-2277
    Keywords: Kidney, preservation, retrograde oxygen ; Preservation, kidney, retrograde oxygen ; Retrograde oxygen, preservation, kidney ; Adenosine, kidney, preservation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Retrograde oxygen persufflation (ROP) has been reported to be beneficial to kidney preservation. The purpose of this study was to investigate whether use of ROP during cold storage (CS) with Universita of Wisconsin (UW) solution could ameliorate energy metabolism and functional recovery of ischemically injured rat kidneys and, moreover, to study the particular role of adenosine (ADO) in CS with ROP. Kidneys subjected to 30 min of warm ischemia (WI) were preserved for 24 h in 4°C UW solution with or without ROP and with or without ADO. Measurements of tissue highenergy phosphate levels showed that reduced total adenine nucleotides (TAN) after 30 min of WI further declined during the subsequent CS. In ROP kidneys, however, TAN were less reduced, suggesting that even during CS, TAN can still be regenerated in the injured kidneys when ROP is combined with UW solution. When UW did not contain ADO, regeneration of TAN by ROP was slightly less than in the case of UW with ADO. This indicates that the supply of molecular oxygen is a significant factor in TAN resynthesis during CS. There was no statistically significant difference in survival rate between the ROP and CS group, indicating that an improved energy status is not the sole determinant of functional recovery. We conclude that the gaseous oxygen supply provided by ROP during CS in UW solution ameliorates the energy state of ischemically injured rat kidneys and that exogenous ADO from the UW solution contributes to the improvement of energy metabolism to a limited extent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00335702
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  • 6
    Electronic Resource
    Electronic Resource
    An improved isolated, left ventricular ejecting, murine heart model (1999)
    Springer
    Pflügers Archiv 437 (1999), S. 182-190 
    Details
    ISSN: 1432-2013
    Keywords: Key words Isolated murine heart ; Antegrade perfusion ; Functional stability ; High-energy phosphates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  An improved, isolated, left ventricular-ejecting, murine heart model is described and evaluated. Special attention was paid to the design and impedance characteristics of the artificial aortic outflow tract and perfusate composition, which contained glucose (10 mM plus insulin) and pyruvate (1.5 mM) as substrates. Temperature of the isolated perfused hearts was maintained at 38.5 °C. During antegrade perfusion (preload 10 mm Hg, afterload 50 mm Hg, 2.5 mM Ca2+) proper design of the aortic outflow tract provided baseline values for cardiac output (CO), left ventricular developed pressure (LVDP) and the maximum first derivative of left ventricular pressure (LV dP/dt max) of 11.1±1.7 ml min–1, 83±5 mm Hg and 6283±552 mm Hg s–1, respectively, resembling findings in the intact mouse. During 100 min normoxic antegrade perfusion CO declined non-significantly by less than 10%. Varying pre- and afterloads resulted in typical Frank-Starling relationships with maximal CO values of 18.6±1.8 ml min–1 at pre- and afterload pressures of 25 and 50 mm Hg, respectively. Left ventricular function curves were constructed at free [Ca2+] of 1.5 and 2.5 mM in the perfusion medium. Significantly higher values for CO, LVDP and LV dP/dt max and LV dP/dt min were obtained at 2.5 mM Ca2+ at all loading conditions investigated. Phosphocreatine and creatine levels remained stable throughout the perfusion period. Despite a small but significant decline in tissue ATP content, the sum of adenine nucleotides did not change during the normoxic perfusion period. The tissue content of glycogen increased significantly.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004240050767
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  • 7
    Electronic Resource
    Electronic Resource
    Incorporation of radioiodinated fatty acids into cardiac phospholipids of normoxic canine myocardium (1992)
    Springer
    Molecular and cellular biochemistry 116 (1992), S. 79-87 
    Details
    ISSN: 1573-4919
    Keywords: normal canine myocardium ; radioiodinated fatty acids ; phospholipid distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The aim of this study was to assess the phospholipid distribution of radioiodinated 17-iodoheptadecanoic acid (IHDA), 15-(p-iodophenyl)pentadecanoic acid (p-IPPA) and 15-(p-iodophenyl)-3,3-dimethylpentadecanoic acid (DMIPPA) under normoxic conditions and to compare these data with the fatty acid composition of the phospholipid classes. After simultaneous i.v. injection of the radioiodinated fatty acids (1-123-IHDA; 1-131-p-IPPA; 1-125 DMIPPA) in open-chest dogs seven myocardial biopsies were taken over 40 min (n = 26). After lipid extraction of the biopsies the organic phase was analyzed for both neutral and polar lipids by two different TLC systems. The following polar lipid fractions were analyzed: lysophopshatidylcholine (LPC), sphingomyelin (SPH), phosphatidy1choline (PC; lecithin), phosphatidylinositol (PI), phosphatidylserine (PS), phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG; cardiolipin) and neutral lipids. Fractions were counted in a gamma well counter and corrected for cross-over and recovery. Results of the polar phospholipids analysis showed that IHDA has the highest incorporation into the phospholipids. The IHDA was mainly incorporated into PI (45.6%) followed by PC (30.9%), PE (14.0%) and PS (5.6%). The p-IPPA was predominantly incorporated incorporated into PC (37.2%), followed by PS (20.1%) and PE (13.7%). In contrast to IHDA, incorporation of p-IPPA into PI was small (6.4%). The DMIPPA analogue was incorporated into phopsholipids to only a very small degree, compared to IHDA and p-IPPA. PS (27.4%) was the only considerable phospholipid fraction into which DMIPPA was incorporated. The results clearly demonstrated that these radioiodinated fatty acid analogues have entirely different patterns of phospholipid incorporation. Major resemblances have been found between the incorporation into phospholipids of IHDA and the phospholipid distribution of the natural counterpart: stearic acid. The p—IPPA phospholipid incorporation only partly resembles the phospholipid distribution of palmitic acid. DMIPPA is because of its modified structure, incorporated into phospholipids to a low extent, mainly into PS. (Mol Cell Biochem116: 79–87, 1992)
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01270573
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  • 8
    Electronic Resource
    Electronic Resource
    Biochemistry of radioiodinated free fatty acids (1989)
    Springer
    Molecular and cellular biochemistry 88 (1989), S. 185-190 
    Details
    ISSN: 1573-4919
    Keywords: Iodinated fatty acids ; dog heart metabolism ; myocardial distribution of fatty acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Summary Radioiodinated free fatty acids have been developed to study myocardial metabolism non-invasively in man. In the present study the distribution of radiolabeled lipids in the myocardium and in arterial and coronary sinus blood was evaluated following injection of three commonly used iodinated fatty acids in fasted (n = 5) and lactate loaded (n = 3) dogs. Five minutes after simultaneous i.v. injection of radioiodinated 17-I-heptadecanoic acid (IHDA),15-(p-I-phenyl) pentadecanoic acid (IPPA) and 15-(p-I-phenyl)-3,3-dimethylpentadecanoic acid (DMIPPA) a biopsy specimen and samples of arterial and coronary sinus blood were taken. After extraction and TLC the relative distribution of radioactivity in the aqueous phase (containing the oxidation products), pellet and organic phase was calculated. The organic phase was further divided into phospholipids, diglycerides, free fatty acids, triglycerides and cholesterolesters. Seventy two percent of IHDA was oxidized, 36% of IPPA and 7% of DMIPPA. The organic phase consisted primarily of triglycerides and phospholipids. The ratios of triglycerides to phospholipids were about the same for IHDA, IPPA and DMIPPA (0.58, 0.65 and 0.50, respectively). Free IHDA in tissue samples was low (4%) and elevated for IPPA and DMIPPA, (17% and 37%). During lactate loading triglycerides were higher for all three fatty acids. For IHDA and IPPA this increase was paralleled by a decrease in the aqueous phase, in case of DMIPPA the aqueous phase remained the same. Five minutes after injection most of the organic phase of both arterial and coronary sinus blood consisted of the injected fatty acids, the aqueous phase contained oxidation products. There were only minor differences during lactate loading. During the evaluation of scintigraphic patterns of the radioiodinated fatty acids under normal conditions (eg at rest) and during elevated lactate levels (eg during exercise) the differences in distribution must therefore be considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223442
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  • 9
    Electronic Resource
    Electronic Resource
    Fatty acid oxidation capacity and fatty acid-binding protein content of different cell types isolated from rat heart (1990)
    Springer
    Molecular and cellular biochemistry 98 (1990), S. 19-25 
    Details
    ISSN: 1573-4919
    Keywords: fatty acid oxidation ; fatty acid-binding protein ; ELISA ; cardiomyocytes ; endothelial cells ; fibroblast-like cells ; rat heart
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Summary Heart tissue contains appreciable amounts of fatty acid-binding protein (FABP). FABP is thought to play a crucial role in the transport of fatty acids from the cellular membrane to the intracellular site of oxidation and also, in case of endothelial cells, in the transfer of fatty acids from the vascular to the interstitial compartment through the endothelial cytoplasm. The present study was designed to delineate a possible quantitative relationship between the capacity of different cell types in the heart to oxidize fatty acids and the presence of FABP. Palmitate oxidation capacity, measured in homogenates of cells isolated from adult rat hearts, was 2 nmol/min per mg tissue protein in freshly isolated cardiomyocytes (CMC), but only 0.09 and 0.31 nmol/min per mg tissue protein in cultivated endothelial (CEC) and fibroblast-like cells (CFLC), respectively. Palmitate oxidation rates were closely related to the cytochrome C oxidase activity and, hence, to the mitochondrial density in the cells under investigation. In CMC the content of cytosolic H-FABP (H-FABPc) was about 4.51 µg/mg tissue protein. However, in CEC and CFLC the FABP content was less than 0.01 and 0.004 µg/mg tissue protein, respectively, corresponding to at maximum 0.2% of the FABP content of CMC. These findings indicate a marked difference between CMC and non-myocytal cells in the heart regarding their capacity to oxidize fatty acids, and a marked disproportion between the fatty acid oxidation capacity and immunochemically determined FABP content in both CEC and CFLC. The functional implication of these observations remains to be elucidated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231363
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  • 10
    Electronic Resource
    Electronic Resource
    Arachidonic acid incorporation in cardiomyocytes, endothelial cells and fibroblast-like cells isolated from adult rat heart (1992)
    Springer
    Molecular and cellular biochemistry 116 (1992), S. 203-209 
    Details
    ISSN: 1573-4919
    Keywords: arachidonic acid ; rat heart ; endothelial cells ; fibroblast-like cells ; cardiomyocytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The incorporation of radiolabeled arachidonic acid (3[H]-AA) in normoxic cardiomyocytes (MC), cardiac endothelial cells (EC) and fibroblast-like cells (FL) isolated from adult rat heart was studied. Deposition of3[H]-AA in the cellular lipid pool was assessed with biochemical and autoradiographic techniques. Extraction and subsequent analysis of lipids from the three different cell types revealed that MC contained significantly more triacylglycerols than EC and FL. The proportion of (unlabeled) AA was also higher in MC triacylglycerols than in EC and FL. The quantity of phospholipids did not differ among the three cell types studied. However, the content of (unlabeled) AA in the MC phospholipid pool was twice as high as in EC and FL. The amount of3[H]-AA incorporated in the cellular lipid pool of MC, EC and FL depended on the concentration of AA in the incubation medium and the incubation time. In EC and FL incorporation of3[H]-AA was highest in the cellular phospholipid pool (0.01μM AA, 30 min incubation). With increased concentration of AA and longer incubation times, the cellular triacylglycerol pool became more important as site of3[H]-AA incorporation. In MC, comparable amounts of3[H]-AA were incorporated in the cellular triacylglycerol and phospholipid pools (0.01 and 1μM AA). At higher AA concentrations (10μM) the triacylglycerol pool was the preferred site of3[H]-AA deposition. Autoradiograhic analysis at the light microscopic level revealed that the extra-nuclear space was readily stained when the three cell types were incubated with3[H]-AA. These findings indicate that all cellular lipid pools and membranes are most likely site of deposition of radiolabeled arachidonic acid. (Mol Cell Biochem116: 203–209,1992)
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01270589
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