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  • 1995-1999  (4)
  • Intravital microscopy  (3)
  • Key words Haemorrhage  (1)
  • 1
    ISSN: 1432-055X
    Keywords: Schlüsselwörter Schock ; Hämorrhagie ; Streßproteine ; Hitzeschockreaktion ; Hämoxygenase ; Key words Haemorrhage ; Shock ; Stress proteins ; Heat shock response ; Haeme oxygenase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Abstract Objective: Recent evidence suggests a possible role for Haeme oxygenase (HO)-derived carbon monoxide (CO) in the regulation of vascular tone through elevation of cyclic 3′–5′ guanosine monophosphate (cGMP). Previous work from our laboratory has shown that blockade of the HO pathway by tin-protoporphyrin-IX (SnPP) after resuscitation from haemorrhage leads to a specific and profound increase in portal resistance while neither systemic nor hepatic arterial resistance are affected. We therefore investigated the organ-specific expression pattern of the stress-inducible protein haeme oxygenase-1/heat shock protein 32 after haemorrhage and resuscitation. Materials and methods: After approval of the protocol by the local review board, male Sprague-Dawley rats (n=6/group) were anaesthetised with pentobarbitone, instrumented for assessment of central haemodynamics, and subjected to haemorrhagic hypotension (40 mm Hg for 1 h) followed by resuscitation with 60% shed blood and Ringer’s solution or a time-matched sham protocol. Samples of liver, spleen, kidney, intestine, aorta, and lungs were harvested 5 h after the onset of resuscitation and subjected to Western-blot analysis using a specific anti-rat HO-1/hsp 32 antibody (StressGen, Sidney, Canada). Results: Resuscitation with shed blood/Ringer’s solution restored central haemodynamics and acid-base status while significant haemodilution was observed. Haemorrhage and resuscitation led to strong induction of HO-1 in the liver and slight induction in aortic tissue, while no increase in steady-state protein levels was observed in the other organs studied. Conclusion:These results suggest a specific contribution of the HO/CO pathway to maintenance of low hepatic portal resistance in vivo in a clinically relevant model of haemorrhagic shock and adequate resuscitation.
    Notes: Zusammenfassung Kohlenmonoxid (CO) entsteht als Intermediärstoffwechselprodukt im Hämabbau und kann nach neuesten Erkenntnissen ähnlich wie Stickstoffmonoxid über Aktivierung der Guanylatzyklase vasodilatorische Wirkungen entfalten. Für die endogene Bildung von CO ist ausschließlich die mikrosomale Hämoxygenase (HO) verantwortlich, die als konstitutives Enzym (HO-2) sowie in einer streßinduzierbaren Isoform (HO-1 oder Hitzeschockprotein 32) vorliegt. Hemmung des Hämstoffwechsels nach Schock und Volumentherapie führt nach eigenen Untersuchungen zu einer spezifischen Zunahme des Pfortaderwiderstands, ohne vasokonstriktorische Wirkungen in der systemischen Zirkulation hervorzurufen. In der vorliegenden Arbeit wurde daher das organspezifische Expressionsmuster der streßinduzierbaren Isoform des Enzyms nach hämorrhagischem Schock und Volumentherapie untersucht. Methoden und Ergebnisse: In einem kliniknah therapierten Schockmodell an der Ratte führte das Schockereignis zu einer geringfügigen Expression von HO-1 in Aortengewebe sowie zu einer ausgeprägten Expression in der Leber, während eine Induktion in anderen Organen wie Lunge, Darm oder Niere nach Hämorrhagie nicht nachweisbar war. Schlußfolgerung: Diese Ergebnisse legen nahe, daß HO-1/Hitzeschockprotein 32 in der Leber ein streßinduzierbares Vasodilatatorsystem, das zur Aufrechterhaltung der Leberperfusion nach hämorrhagischem Schock beiträgt, darstellt.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-055X
    Keywords: Schlüsselwörter Hämorrhagischer Schock ; Leukozytenadhäsion ; Lebermikrozirkulation ; Intravitalmikroskopie ; Key words Haemorrhagic shock ; Leukocyte adhesion ; Hepatic microcirculation ; Intravital microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Abstract Deferoxamine is known to reduce the iron-dependent generation of toxic oxygen- derived radicals during reperfusion of ischaemic tissue. The present study investigates the antioxidative properties of a deferoxamin-conjugated hydroxyethyl starch solution and its effects on the hepatic microcirculation in a haemorrhagic-shock rat model. Methods: Anaesthetized Sprague-Dawley rats were tracheotomized, prepared for invasive haemodynamic monitoring, and subject to haemorrhagic shock (MAP=40 mmHg during 60 min). The animals were resuscitated blood-free with lactated Ringer’s (RILA, n=10), gelatine (GELA, n=10), hydroxyethyl starch (HES, n=10), or deferoxamine-conjugated HES (DFO, n=8) solution (MAP≥70 mmHg). After 1 h of resuscitation the hepatic microcirculation was investigated by intravital microsscopy, the glutathione concentration was measured in liver homogenate, and the thiobarbituric acid reactive substances (TBARS) were determined as markers of lipid peroxidation. Results: Resuscitation resulted in restoration of MAP to ≥70 mmHg within a short time. The volume required to stabilise the arterial pressure during 1 h of resuscitation was significantly less in the DFO group compared with HES, GELA, and RILA. Significantly higher glutathione levels in liver homogenate as well as decreased TBARS levels were observed in the DFO group. The shock-induced increase of leukocyte adhesion in liver sinusoids was significantly attenuated by DFO. Conclusion: DFO significantly attenuates shock-induced oxidative stress, thereby reducing the early inflammatory reaction and improving the hepatic microcirculation.
    Notes: Zusammenfassung Fragestellung: Die Synthese der während der Reperfusion ischämischen Gewebes aus der Haber-Weiss-Reaktion Fe-abhängig hervorgehenden toxischen Sauerstoffradikale kann durch Deferoxamin, einen potenten Fe-Chelator, verringert werden. Die vorliegende Studie untersucht eine Deferoxamin-konjugierte Hydroxyethylstärkelösung auf ihre antioxidativen Eigenschaften und Auswirkungen auf die hepatische Mikrozirkulation am hämorrhagischen Schockmodell der Ratte. Methodik: Sprague-Dawley-Ratten wurden in Pentobarbitalanästhesie tracheotomiert, für ein invasives hämodynamisches Monitoring präpariert und einem hämorrhagischen Schock unterzogen (MAP=40 mm Hg während 60 min). Die blutfreie Volumentherapie wurde entweder mit Ringerlaktat (RILA; n=10), Gelatinelösung (GELA; n=10), Hydroxyethylstärke (HES; n=10) oder mit Deferoxamin-konjugierter Hydroxyethylstärkelösung (DFO; n=8) durchgeführt (MAP≥70 mm Hg). Eine Studie nach Beginn der Volumentherapie wurde die Mikrozirkulation der Leber intravitalmikroskopisch untersucht und die Glutathionkonzentration im Leberhomogenat sowie die Thiobarbitursäure-reaktiven Substanzen als Marker der Lipidperoxidation gemessen. Ergebnisse: Mit jeder der verwendeten Volumenersatzlösungen konnte der MAP innerhalb kurzer Zeit auf ≥70 mm Hg angehoben werden. In der mit DFO behandelten Gruppe konnte eine signifikant geringere Abnahme an reduziertem Glutathion im Lebergewebe sowie eine geringere Zunahme der Lipidperoxidation als Zeichen des verminderten oxidativen Stresses beobachtet werden. Die schockinduzierte verstärkte Leukozytenadhäsion in Lebersinusoiden wurde durch DFO signifikant vermindert. Schlußfolgerung: DFO vermindert signifikant den schockinduzierten oxidativen Streß, schwächt damit die frühe Entzündungsreaktion ab und bewirkt eine Verbesserung der Lebermikrozirkulation.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 74 (1996), S. 51-58 
    ISSN: 1432-1440
    Keywords: Tumor necrosis factor ; Hemorrhagic shock ; Leukocyte adhesion ; Intravital microscopy ; Liver
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The relevance of tumor necrosis factor-α (TNF-α) inducing early inflammatory reactions in the liver after hemorrhagic shock, for example, leukocyte adhesion, has been well described. This study evaluated the anti-inflammatory effects of a monoclonal antibody against TNF-α (TN3.19.12) in terms of the time of application, namely, prior to shock induction, at the time of resuscitation, and after resuscitation. The hepatic micro-circulation was investigated by intravital fluorescence microscopy in female Sprague-Dawley rats undergoing severe hemorrhagic shock for 60 min and subsequent resuscitation. TN3.19.12 or placebo was given in a randomized and blinded manner either 60 min prior to shock induction, l min prior to resuscitation, or 15 min after the onset of resuscitation. The number of firmly adherent leukocytes in the livers of treated animals depended on the time of application of TN3.19.12. Leukocyte adhesion was significantly reduced when TN3.19.12 was given prior to shock induction or at the time of resuscitation and was less effective when administered after the onset of resuscitation. The results further confirm that TNF-α initiates very early pathological leukocyte adhesion in the liver 5 h following shock. Inhibition of leukocyte adhesion after shock, however, depends strongly on the time of TNF-α blocking. While TN3.19.12 prior to shock induction resulted in most effective attenuation, only very early treatment allowed limitation of posttraumatically increased leukocyte adhesion.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 74 (1996), S. 51-58 
    ISSN: 1432-1440
    Keywords: Key words Tumor necrosis factor ; Hemorrhagic shock ; Leukocyte adhesion ; Intravital microscopy ; Liver
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The relevance of tumor necrosis factor-α (TNF-α) inducing early inflammatory reactions in the liver after hemorrhagic shock, for example, leukocyte adhesion, has been well described. This study evaluated the anti-inflammatory effects of a monoclonal antibody against TNF-α (TN3.19.12) in terms of the time of application, namely, prior to shock induction, at the time of resuscitation, and after resuscitation. The hepatic microcirculation was investigated by intravital fluorescence microscopy in female Sprague-Dawley rats undergoing severe hemorrhagic shock for 60 min and subsequent resuscitation. TN3.19.12 or placebo was given in a randomized and blinded manner either 60 min prior to shock induction, 1 min prior to resuscitation, or 15 min after the onset of resuscitation. The number of firmly adherent leukocytes in the livers of treated animals depended on the time of application of TN3.19.12. Leukocyte adhesion was significantly reduced when TN3.19.12 was given prior to shock induction or at the time of resuscitation and was less effective when administered after the onset of resuscitation. The results further confirm that TNF-α initiates very early pathological leukocyte adhesion in the liver 5 h following shock. Inhibition of leukocyte adhesion after shock, however, depends strongly on the time of TNF-α blocking. While TN3.19.12 prior to shock induction resulted in most effective attenuation, only very early treatment allowed limitation of posttraumatically increased leukocyte adhesion.
    Type of Medium: Electronic Resource
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