Search results for "Reperfusion"

Isolated in-vitro perfusion of pig hearts obtained from the abattoir: an alternative to animal experiments?

1994

Isolated pig hearts (German farm pigs) were characterized after global in-vivo ischaemia as a potential alternative to in-vivo animal studies. Hearts were harvested from adult farm swine at the abattoir 10.3 +/- 2.1 min after incision of the carotid artery. They were immediately perfused and thereafter stored in ice-cold cardioplegic (St Thomas's) solution. After 38 +/- 3 min, retrograde perfusion was started with oxygenated pig blood (37 degrees C; 5000 U Heparin.l-1; pH 7.38 +/- 0.1; 11 mmol glucose.l-1) at a flow rate of 85 ml.min-1 100 g-1 wet weight (gww-1) for 30 min (n = 10). Additionally, shortly after obtaining the hearts, ATP and CP content were measured by enzymatic tests in 10 p…

The role of mitochondrial transition pore, and its modulation, in traumatic brain injury and delayed neurodegeneration after TBI

2009

Following severe traumatic brain injury (TBI), a complex interplay of pathomechanism, such as exitotoxicity, oxidative stress, inflammatory events, and mitochondrial dysfunction occurs. This leads to a cascade of neuronal and axonal pathologies, which ultimately lead to axonal failure, neuronal energy metabolic failure, and neuronal death, which in turn determine patient outcome. For mild and moderate TBI, the pathomechanism is similar but much less frequent and ischemic cell death is unusual, except with mass lesions. Involvement of mitochondria in acute post-traumatic neurodegeneration has been extensively studied during the last decade, and there are a number of investigations implicatin…

RATIONALE FOR THE USE OF ANTIOXIDANT VITAMINS IN CLINICAL ORGAN TRANSPLANTATION

1996

VEGF-B-induced vascular growth leads to metabolic reprogramming and ischemia resistance in the heart

2014

Abstract Angiogenic growth factors have recently been linked to tissue metabolism. We have used genetic gain‐ and loss‐of function models to elucidate the effects and mechanisms of action of vascular endothelial growth factor‐B (VEGF‐B) in the heart. A cardiomyocyte‐specific VEGF‐B transgene induced an expanded coronary arterial tree and reprogramming of cardiomyocyte metabolism. This was associated with protection against myocardial infarction and preservation of mitochondrial complex I function upon ischemia‐reperfusion. VEGF‐B increased VEGF signals via VEGF receptor‐2 to activate Erk1/2, which resulted in vascular growth. Akt and mTORC1 pathways were upregulated and AMPK downregulated, …

Ischämietoleranz der Rattenleber durch alpha-Liponsäure

2003

Ischemia reperfusion injury (IRI) represents a major clinical problem in liver resection and transplantation. The present work investigated the potential of α-lipoic-acid (LA), a well established drug in the therapy of diabetes, to reduce IRI of the rat liver in vivo. Two groups were chosen: one group with injection of 500 μmol α-lipoic acid 15 min before clamping of the left and median liver lobes for 90 min, the other with injection of NaCl 0,9%. Reperfusion was carried out for 1 h and 7 days. The results showed that a-lipoic acid reduced IRI. LDH, α-GST and lipid peroxidation were significantly decreased in the LA-group after 1 h reperfusion indicating less cell death during reperfusion.…

Identification and role of inflammatory oxygen free radicals in cardiac ischemia and reperfusion injury

2003

Prolonged myocardial ischemia results in a variety of severe cellular, metabolic and ultra-structural damages. It is therefore generally accepted that reperfusion is an absolute prerequisite for the survival of ischemic tissue. However, reperfusion may precipitate arrhythmias, cause myocardial stunning and accelerate necrotic process. Oxygen free radicals have been suggested as possible mediators of reperfusioninduced injury and there is circumstantial evidence that supports this hypothesis. Indirect evidence in support of this concept derives from studies in which antioxidant enzymes, enzyme inhibitors, free radical scavengers and iron chelators are able to protect against reperfusion inju…

Beeinflussung des Leberzellmetabolismus, der Freisetzung von reaktiven Sauerstoffspezies sowie Apoptoseaktivierung durch hypotherme oxygenierte Leber…

2003

Two different methods of liver preservation were compared : simple cold storage (CS) and hypothermic oxygenated perfusion extracorporal (HOPE). After 10 h of preservation (4°C) with modified UW solution reperfusion was performed by isolated liver perfusion for 90 minutes. Reperfusion injury was estimated by release of cytosolic enzymes, formation of superoxide anions, determination of lipid peroxidation, glycolytic metabolites, bileflow and by PCR analysis. The results showed that after cold storage the formation of reactive oxygen species was significant higher as compared with perfused livers. Correspondingly expressions of mediators (TNFα, NF kappa B, MIP-2, SAPK) and apoptosis (Caspase …

2013

Re-canalization of cerebral vessels in ischemic stroke is pivotal to rescue dysfunctional brain areas that are exposed to moderate hypoxia within the penumbra from irreversible cell death. Goal of the present study was to evaluate the effect of moderate hypoxia followed by reoxygenation (MHR) on the evolution of reactive oxygen species (ROS) and blood-brain barrier (BBB) integrity in brain endothelial cells (BEC). BBB integrity was assessed in BEC in vitro and in microvessels of the guinea pig whole brain in situ preparation. Probes were exposed to MHR (2 hours 67-70 mmHg O2, 3 hours reoxygenation, BEC) or towards occlusion of the arteria cerebri media (MCAO) with or without subsequent repe…

EndothelinA receptor antagonist BSF-208075 causes immune modulation and neuroprotection after stroke in gerbils.

2005

Leukocytes contribute to the ischemia-reperfusion injury. Recent studies suggested endothelins could be important mediators for leukocyte activation in stroke. We tested if the endothelinA receptor antagonist BSF-208075 (ambrisentan) could reduce an ischemic lesion by modulation of leukocyte-endothelium interactions. Twenty-four gerbils underwent either a sham operation (n=6) or 15 min of bilateral carotid artery occlusion resulting in global cerebral ischemia. Ischemic animals received normal saline (n=6), 5 mg/kg BSF-208075 (n=6) or 30 mg/kg (n=6) administered intravenously at 10 min of reperfusion. Leukocytes rolling or adhering to endothelium were counted by intravital microscopy in par…

Effect of a Diet Supplemented with alpha-Tocopherol and beta-Carotene on ATP and Antioxidant Levels after Hepatic Ischemia-Reperfusion.

2008

Ischemia-reperfusion injury associated with liver transplantation remains a serious complication in clinical practice. In the present study the effect of intake of alpha-tocopherol or beta-carotene to limit liver injury by oxidative stress in ischemia and reperfusion was explored. Wistar rats were fed with diets enriched with alpha-tocopherol (20 mg/day) or beta-carotene (3 mg/day) for 21 days. After 21 days, their livers were subjected to 15 and 30 min of ischemia and afterwards were reperfused for 60 min. The recovery of levels of ATP during reperfusion was better in the group of rats whose diets were supplemented with alpha-tocopherol or beta-carotene than in the group control. The suppl…