Metoprolol treatment decreases tissue myeloperoxidase activity after spinal cord injury in rats
ABSTRACT Neutrophil infiltration has been reported to play an important role in spinal cord injury (SCI). In addition to their cardioprotective effects, beta-blockers have been found to have neuroprotective effects on the central nervous system, but their effect on SCI has not yet been studied. In the current study, we investigated the effect of metoprolol on myeloperoxidase (MPO) activity, a marker of neutrophil activation, in the spinal cord after experimental SCI in rats. Rats were divided into six groups: controls received only laminectomy and spinal cord samples were taken immediately; the sham operated group received laminectomy, and spinal cord samples were taken 4h after laminectomy; the trauma only group underwent a 50g/cm contusion injury but received no medication; and three other groups underwent trauma as for the trauma group, and received 30mg/kg methylprednisolone, 1mg/kg metoprolol, or 1mL saline, respectively. All the medications were given intraperitoneally as single doses, immediately after trauma. Spinal cord samples were taken 4h after trauma and studied for MPO activity. The results showed that tissue MPO activity increased after injury. Both metoprolol and methylprednisolone treatments decreased MPO activity, indicating a reduction in neutrophil infiltration in damaged tissue. The effect of metoprolol on MPO activity was found to be similar to methylprednisolone. In view of these data, we conclude that metoprolol may be effective in protecting rat spinal cord from secondary injury.
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ABSTRACT: After acute spinal cord injury (SCI), a large number of axons are lost by a cascade of pathophysiological events known as a secondary injury. The main aim of the current study was to investigate the potential neuroprotective effects of curcumin on lipid peroxidation (LPO), neurological function, and ultrastructural findings after SCI. Forty adult Wistar albino rats were randomized into five groups: control, SCI alone (50 g/cm weight drop), methylprednisolone sodium succinate (MPSS) (30 mg/kg), curcumin + dimethyl sulfoxide (DMSO) (300 mg/kg), and DMSO alone (0.1 mg/kg). Administration of curcumin significantly decreased LPO in first 24 hours. However, there were no differences in the neurological scores of injured rats between the medication groups and the control group. Curcumin was more effective than DMSO and MPSS in reducing LPO, whereas DMSO was more effective than curcumin and MPSS in minimizing ultrastuctural changes. The results of this study indicate that curcumin exerts a beneficial effect by decreasing LPO and may reduce tissue damage. Since ultrastructural and neurological findings does not support biochemical finding, our findings do not exclude the possibility that curcumin has a protective effect on the spinal cord ultrastructure and neurological recovery after SCI. A combination of curcumin with other vehicle may also have a considerable synergy in protecting spinal cord.Turkish neurosurgery 03/2012; 22(2):189-95. DOI:10.5137/1019-5149.JTN.5193-11.1 · 0.53 Impact Factor
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ABSTRACT: Throughout the body, the extracellular matrix (ECM) provides structure and organization to tissues and also helps regulate cell migration and intercellular communication. In the injured spinal cord (or brain), changes in the composition and structure of the ECM undoubtedly contribute to regeneration failure. Less appreciated is how the native and injured ECM influences intraspinal inflammation and, conversely, how neuroinflammation affects the synthesis and deposition of ECM after CNS injury. In all tissues, inflammation can be initiated and propagated by ECM disruption. Molecules of ECM newly liberated by injury or inflammation include hyaluronan fragments, tenascins, and sulfated proteoglycans. These act as “damage-associated molecular patterns” or “alarmins”, i.e., endogenous proteins that trigger and subsequently amplify inflammation. Activated inflammatory cells, in turn, further damage the ECM by releasing degradative enzymes including matrix metalloproteinases (MMPs). After spinal cord injury (SCI), destabilization or alteration of the structural and chemical compositions of the ECM affects migration, communication, and survival of all cells – neural and non-neural – that are critical for spinal cord repair. By stabilizing ECM structure or modifying their ability to trigger the degradative effects of inflammation, it may be possible to create an environment that is more conducive to tissue repair and axon plasticity after SCI.Experimental Neurology 08/2014; 258. DOI:10.1016/j.expneurol.2013.11.020 · 4.62 Impact Factor
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ABSTRACT: The structural secuelae of acute myocardial infarction (AMI) is mostly dictated by left ventricular (LV) remodelling, leading to heart failure. Monocyte chemoattractant protein-1 (MCP-1), matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) play a critical role in LV remodelling. β-blockers are first line therapy for AMI and heart failure; however, the mechanisms responsible for their benefits remain poorly understood. Different β-blocker agents have been shown to exert beneficial activities both in AMI and heart failure, however, their role in early remodelling after ischemia/reperfusion is to be fully elucidated. We sought to compare the effect of 2 of the most prescribed β-blocker agents in early markers of LV remodelling after AMI. A reperfused AMI was induced in Yorshire pigs, being randomized to early intravenous carvedilol, metoprolol or placebo. Twenty-four hours after reperfusion markers of early remodelling were addressed in the LV. The early administration of both β-blockers is able to significantly reduce macrophage infiltration as well as the expression and activity of MCP-1 and MMP-2 compared to placebo. The effects of carvedilol were much stronger than those of metoprolol. Conversely, carvedilol upregulated the expression TIMP-2 to a greater extent than metoprolol. In an AMI model closely mimicking human pathophysiology, the early administration of carvedilol reduced the expression of markers associated with early LV remodelling to greater extent than metoprolol. These findings may explain the superior clinical benefits exerted by carvedilol in heart failure.International journal of cardiology 12/2011; 153(3):256-61. DOI:10.1016/j.ijcard.2010.08.018 · 6.18 Impact Factor