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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Although sepsis causes significant morbidity and mortality, its basic pathology is still not well understood. We investigated the inflammatory and physiologic alterations of non-lethal sepsis using cecal ligation and puncture (CLP), a model that induces peritonitis due to mixed intestinal flora, reproducing the complex immunology of sepsis. Groups of mice were subjected to CLP (25G needle) or sham surgery, had minimitters implanted to continuously monitor temperature and activity, and were sacrificed daily for 6 days. ⋯ Cytokines were not detected in the pulmonary airspace of the CLP-treated mice and PMNs were not recruited to this site. Our data shows altered immunopathology in non-lethal sepsis with significant blood and cytokine alterations. Since there was 100% survival, the inflammatory response was appropriate and probably even protective.
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Endotoxin given intravenously is known to cause plasma leakage and subsequent loss of circulating plasma volume. Hypertonic saline resuscitation has been successfully applied in hemorrhagic and traumatic shock, but its application for the treatment or prevention of septic or endotoxin shock is less well studied. Our aim was to investigate the effects of endotoxin on plasma leakage in hamsters when administered in two different ways: applied locally to the hamster cheek pouch microcirculation or systemically by i.v. injection. ⋯ In the second part of the study endotoxin was given i.v. 0.3 mg/kg to anesthetized hamsters (n = 41) and arterial blood samples were collected at 0, 60, 120, and 180 min after endotoxin injection for measurement of hematocrit and plasma FITC-dextran concentration. Hamsters were divided into seven groups: untreated control group (n = 6); HSC control group given only an i.v. injection of hypertonic saline (n = 6); LPS group given endotoxin 0.3 mg/kg during 1 min (n = 9); HSp group given hypertonic saline (NaCl 7.5%) 10 min prior to i.v. endotoxin (n = 6); HSa group given hypertonic saline 10 min after i.v. endotoxin (n = 6); HSD group given hypertonic saline with dextran 40, 10 min prior to i.v. endotoxin (n = 6); HSD control group given only i.v. hypertonic saline + dextran and no endotoxin (n = 2). Injection of endotoxin caused a significant increase in hematocrit, which was counteracted by hypertonic saline treatment, with or without dextran, probably due to reduced extravasation of plasma in postcapillary venules.
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The role of N(omega)-nitro-L-arginine (L-NOARG), a nitric oxide (NO) synthase inhibitor, in the control of blood flow and vasomotion in rat diaphragm microcirculation during hemorrhagic hypotension was investigated by means of laser Doppler flowmetry (LDF). Fifty-six Sprague-Dawley rats were divided into seven groups. Ten minutes after one-stage hemorrhage to 40-60% of initial blood pressure, the rats received 15 min topical superfusion of saline (group 1, time control), 0.1 mM L-NOARG (group 2), 10 mM L-arginine (group 3), or vehicle (0.1% DMSO and 0.9 mN NaOH, group 4). ⋯ The results showed no significant differences in blood flow, fundamental frequency, or relative amplitude of the rat diaphragm microcirculation before or after administration of the test agents among the first four groups during hemorrhagic hypotension or in groups 5 and 6 during sham operation without hypoperfusion. Hemorrhagic hypotension significantly decreased the vasodilator response to ACH (p = 0.003), but not to SNP. We conclude that NO did not play an important role in the regulation of blood flow or vasomotion in rat diaphragm microcirculation during acute hemorrhagic hypotension.
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Comparative Study
Hepatic gene expression and cytokine responses to sterile inflammation: comparison with cecal ligation and puncture sepsis in the rat.
Inflammatory stimulation of hepatic acute phase protein expression is, in part, modulated by tumor necrosis factor-alpha (TNFalpha), interleukin-1beta (IL-beta), and IL-6. These cytokines also may mediate some aspects of the persistent inflammation and metabolic dysregulation of sepsis. Cecal ligation and puncture (CLP) sepsis in male Sprague-Dawley rats inappropriately decreases hepatocellular transcription of phosphoenolpyruvate carboxykinase (PEPCK), glucose-6-phosphatase (G6Pase), carnitine palmitoyltransferase II (CPTII), acetyl CoA acyltransferase (ACA), and ornithine transcarbamylase (OTC). ⋯ Turpentine injection increased the activity of the TNFalpha/IL-1beta-linked transcription factor NF-kappaB and the intrahepatic abundance of TNFalpha in a manner similar to that observed after CLP but only slightly altered the activity of the IL-6-linked transcription factor Stat-3 and intrahepatic IL-6 abundance. This differed significantly from observations after CLP. We conclude that CLP-induced alterations in hepatic gene expression may reflect differences in IL-6 activity.
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The hypothesis that induction of chronic peritoneal sepsis would produce depression of serum testosterone due to a decrease in Leydig cell steroidogenic acute regulatory (StAR) protein or P450c17 steroidogenic enzyme was tested. Male Sprague-Dawley rats (350-400 g) were randomized to septic and nonseptic groups. Sepsis was induced with a cecal slurry (200 mg/kg in 5 mL of 5% dextrose in water (D5W); intraperitoneal) while nonseptic rats received only sterile D5W. ⋯ Sepsis produced a significant decrease in the serum concentration of testosterone, a down-regulation of StAR protein, and an increase in serum estradiol 24 h after induction of sepsis (as compared with the nonseptic group). Protein levels of P450c17 in Leydig cells and serum concentrations of progesterone and corticosterone 24 h after induction of sham sepsis or sepsis were not different. It is concluded that the decreases in serum testosterone after 24 h of chronic peritoneal sepsis correlated with reductions in StAR protein.