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
-
Comparative Study
Relationships of circulating nitrite/nitrate levels to severity and multiple organ dysfunction syndrome in systemic inflammatory response syndrome.
Excessive nitric oxide (NO) production has been implicated to be responsible for the development of septic shock. To determine whether plasma nitrite/nitrate (NOx) levels are related to the severity of systemic inflammatory response syndrome (SIRS) and the degree of multiple organ dysfunction, we studied plasma NOx levels in 70 patients with SIRS consisting of noninfectious SIRS (n = 32), sepsis (n = 23), and septic shock (n = 15). Infection is a microbial phenomenon characterized by an inflammatory response to the presence of microorganism. ⋯ Plasma NOx levels were positively correlated with Acute Physiology, Age, and Chronic Health Evaluation (APACHE) III score (r = 0.414, P < 0.01) and sequential organ failure assessment (SOFA) score (r = 0.433, P < 0.01). Plasma NOx levels in patients with sepsis (51.0 +/- 38.5 microM/L) and septic shock (94.5 +/- 53.7 microM/L) were significantly (P < 0.01) higher than those in patients with noninfectious SIRS (25.8 +/- 16.9 microM/L) and healthy subjects (29.6 +/- 8.9 microM/L). Our study shows that plasma NOx levels are increased in patients with infectious, but not noninfectious SIRS, which increase as the severity of SIRS and the development of multiple organ dysfunction syndrome, suggesting its possible pathogenic role in SIRS.
-
Hemorrhagic shock and resuscitation cause hepatocellular damage by mechanisms involving oxidative stress. However, the sources of free radicals mediating hepatocellular injury remain controversial. Thus, this study tested the hypothesis that NADPH oxidase plays a role in producing hepatocellular injury after hemorrhagic shock and resuscitation. ⋯ Immunohistochemical staining for 3-nitrotyrosine, indicative of reactive nitrogen species formation, was also blunted in the livers of knockout mice (11.6% +/- 2.8% vs. 37.4% +/- 3.4, P < 0.05). In conclusion, hemorrhagic shock and resuscitation cause hepatocellular damage via NADPH oxidase-mediated oxidative stress. The absence of NADPH oxidase substantially attenuates hepatocellular injury after hemorrhagic shock and resuscitation, blunts neutrophil infiltration, and decreases formation of reactive oxygen and reactive nitrogen species.
-
We tested the hypothesis in a rat model that body cooling suppresses circulatory shock and cerebral ischemia in heatstroke. Animals under urethane anesthesia were exposed to water blanket temperature (Tblanket) of 42 degrees C until mean arterial pressure (MAP) and local cerebral blood flow (CBF) in the hippocampus began to decrease from their peak levels, which was arbitrarily defined as the onset of heatstroke. Control rats were exposed to 26 degrees C. ⋯ Cooling immediately after the onset of heatstroke reduced the heatstroke-induced circulatory shock, cerebral ischemia, neuronal damage, and surge of tissue ischemia and damage markers in the hippocampus, and resulted in prolongation of survival time. Delaying the onset of cooling reduced the therapeutic efficiency. The results suggest that body cooling attenuates circulatory shock and cerebral ischemia insults in heatstroke.
-
Severe burn induces the hepatic acute phase response. We previously showed that recombinant human growth hormone (GH) treatment after burn down-regulated acute phase protein (APP) production and gene expression in vivo. In this study, we hypothesized that the inhibitory effect of GH on the hepatic acute phase response was due to increased suppressor of cytokine signaling (SOCS) gene expression. ⋯ APP gene expression was significantly decreased in cells transfected with plasmid over expressing SOCS-3 after IL-6 and IL-1beta treatment. GH attenuates IL-1beta or IL-6 induced APP gene expression, which is associated with increased expression of SOCS-3. This study suggests that SOCS-3 plays an important role in the suppression of cytokine signaling by GH in down-regulating the acute phase response after injury.
-
To monitor the ischemic and/or reperfusion injury after porta hepatis occlusion (Pringle maneuver) in livers subjected to hypotension, serum alanine amino transferase (ALT), liver malondialdehyde (MDA), and liver glutathione (GSH) levels were measured. MDA is a by-product of oxidant-induced lipid peroxidation, and GSH is an endogenous antioxidant. The effects of lactated Ringer's (LR) and hypertonic saline (7.5%)/Dextran (6%; HSD) resuscitation on liver injury, if any, was investigated. ⋯ Liver tissue MDA was 353 +/- 22 nmol/g/tissue in the HI group and LR decreased it to 261 +/- 17 nmol/g/tissue, whereas HSD decreased it to 273 +/- 20 nmol/g/tissue. The decrease in ALT and the increase in liver GSH were more pronounced with HSD resuscitation (P < 0.05). HSD seems to be more effective than LR in decreasing the liver tissue damage produced by total hepatic inflow occlusion under hypovolemic conditions.