Shock : molecular, cellular, and systemic pathobiological aspects and therapeutic approaches : the official journal the Shock Society, the European Shock Society, the Brazilian Shock Society, the International Federation of Shock Societies
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Comparative Study
Effects of tramadol and buprenorphine on select immunologic factors in a cecal ligation and puncture model.
Sepsis research relies on animal models. The models that most closely resemble clinical disease, such as cecal ligation and puncture, require surgery. After surgery, analgesics may not be included in experimental protocols because of concern over effects on inflammatory responses. ⋯ Again,differences were observed between the treatments. The results suggest that judicious and limited use of some analgesics may not dramatically affect the outcome of similarly conducted cecal ligation and puncture studies when compared with those not using analgesics. However, when different analgesics are used, comparisons between studies may be complicated.
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Anesthetics used in burn and trauma animal models may be influencing results by modulating inflammatory and acute-phase responses. Accordingly, we determined the effects of various anesthetics, analgesia, and euthanasia techniques in a rodent burn model. Isoflurane (ISO), ketamine-xylazine (KX), or pentobarbital (PEN) with or without buprenorphine were administered before scald-burn in 72 rats that were euthanized without anesthesia by decapitation after 24 h and compared with unburned shams. ⋯ Our findings indicate that brief anesthesia with ISO immediately before euthanasia by decapitation exerted the least dampening effect on the cytokines measured. Conversely, KX with buprenorphine may offer a better balance during longer procedures to avoid significant modulation. Standardization across all experiments that are compared and awareness of these findings are essential for those investigating the pathophysiology of inflammation in animal models.
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Comparative Study
Direct cardiac effects of dobutamine, dopamine, epinephrine, and levosimendan in isolated septic rat hearts.
In septic patients, myocardial depression-the so-called septic cardiomyopathy-needing inotropic support is common. The aim of this study was to compare the dose-responsive electrophysiological and mechanical properties concerning metabolic effects of clinically available inotropic agents in an isolated septic rat heart model. After 20 h of incubation, both sham-operated and septic (cecal ligation and single puncture) hearts from male Wistar rats (n = 64) were isolated and received dobutamine, dopamine, epinephrine, or levosimendan at concentrations of 10 to 10 M. ⋯ However, cardiac efficiency was significantly improved in the epinephrine-treated septic hearts. With the drug-induced increase in cardiac performance, the myocardial oxygen supply-demand ratio decreased proportionally in the epinephrine-, dobutamine-, and dopamine-treated septic hearts. However, epinephrine showed the most favorable results with regard to cardiac efficiency, and levosimendan showed no beneficial effect in septic hearts with regard to efficiency in this study.
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Intestinal ischemia-reperfusion (I/R) injury may cause acute systemic and lung inflammation. Here, we revisited the role of TNF-alpha in an intestinal I/R model in mice, showing that this cytokine is not required for the local and remote inflammatory response upon intestinal I/R injury using neutralizing TNF-alpha antibodies and TNF ligand-deficient mice. We demonstrate increased neutrophil recruitment in the lung as assessed by myeloperoxidase activity and augmented IL-6, granulocyte colony-stimulating factor, and KC levels, whereas TNF-alpha levels in serum were not increased and only minimally elevated in intestine and lung upon intestinal I/R injury. ⋯ In fact, the inflammatory lung response is dramatically reduced in TLR2/4-deficient mice, confirming an important role of TLR receptor signaling causing the inflammatory lung response. In conclusion, endogenous TNF-alpha is not or minimally elevated and plays no role as a mediator for the inflammatory response upon ischemic tissue injury. By contrast, TLR2/4 signaling induces an orchestrated cytokine/chemokine response leading to local and remote pulmonary inflammation, and therefore disruption of TLR signaling may represent an alternative therapeutic target.
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Ischemia-reperfusion (I/R) injury of the kidney is a complex pathophysiological process and a major cause of acute renal failure. It has been shown that I/R injury is related to inflammatory responses and activation of apoptotic pathways. Inhibition of certain elements of inflammatory responses and apoptotic pathway seemed to ameliorate renal I/R injury. ⋯ NR1 attenuated I/R-induced renal dysfunction as indicated by the level of serum creatinine and histological evaluation. It prevented the I/R-induced increases in the levels of proinflammatory cytokine TNF-alpha, myeloperoxidase activity, phosphorylation of p38, and activation of nuclear factor kappaB with cell apoptosis in the kidney and enhanced expression of antiapoptosis cytokine bcl-2. Treatment with NR1 improves renal function after I/R associated with a significant reduction in cell apoptosis and inflammatory responses, which may be related to p38 and nuclear factor kappaB inhibition.