Therapeutic effects of hypertonic saline on peritonitis-induced septic shock with multiple organ dysfunction syndrome in rats

Efficiency of Hypertonic Saline in the Management of Decompensated Heart Failure: A Systematic Review and Meta-Analysis of Clinical Studies

INTRODUCTION

Acute decompensated heart failure (ADHF), with an incidence of 1-2%, is a clinical syndrome with significant morbidity and mortality despite therapeutic advancements and ongoing clinical trials. A recent therapeutic approach to patients with ADHF includes combination therapy with hypertonic saline solution (HSS) and furosemide, based on the hypothesis that resistance to loop diuretics occurs because of achievement of plateau in water and sodium excretion in patients receiving long-term loop diuretic therapy.

OBJECTIVE

Our aim was to conduct a meta-analysis to evaluate the efficiency of combination HSS plus furosemide therapy in patients with ADHF in terms of mortality, readmissions, length of hospital stay, kidney function, urine output, body weight, and B-type natriuretic peptide (BNP).

METHODS

A total of 14 studies-four observational and ten randomized studies (total 3398 patients)-were included in the meta-analysis.

RESULTS

Our results demonstrate the superiority of combination HSS plus furosemide therapy over furosemide alone in terms of kidney function preservation (mean creatinine difference - 0.33 mg/dL; P < 0.00001), improved diuresis (mean difference [MD] 581.94 mL/24 h; P < 0.00001) and natriuresis (MD 57.19; P < 0.00001), weight loss (MD 0.99 kg; P < 0.00001), duration of hospital stay (MD - 2.72 days; P < 0.00001), readmissions (relative risk 0.63; P = 0.01), and mortality (relative risk 0.55; P < 0.00001). However, no difference in BNP levels was detected (MD 19.88 pg/mL; P = 0.50).

CONCLUSION

Despite the heterogeneity and possible risk of bias among the studies, results appear promising on multiple aspects. A clear need exists for future randomized controlled trials investigating the role of combination HSS plus furosemide therapy to clarify these effects and their possible mechanisms.

Hypertonic Saline in Human Sepsis: A Systematic Review of Randomized Controlled Trials

The role of hypertonic saline in sepsis remains unclear because clinical data are limited and the balance between beneficial and adverse effects is not well defined. In this systematic literature review, we searched PubMed and Embase to identify all randomized controlled trials up until January 31, 2018 in which hypertonic saline solutions of any concentration were used in patients of all ages with sepsis and compared to a cohort of patients receiving an isotonic fluid. We identified 8 randomized controlled trials with 381 patients who had received hypertonic saline. Lower volumes of hypertonic saline than of isotonic solutions were needed to achieve the desired hemodynamic goals (standardized mean difference, -0.702; 95% CI, -1.066 to -0.337; P < .001; moderate-quality evidence). Hypertonic saline administration was associated with a transient increase in sodium and chloride concentrations without adverse effects on renal function (moderate-quality evidence). Some data suggested a beneficial effect of hypertonic saline solutions on some hemodynamic parameters and the immunomodulatory profile (very low-quality evidence). Mortality rates were not significantly different with hypertonic saline than with other fluids (odds ratio, 0.946; 95% CI, 0.688-1.301; P = .733; low-quality evidence). In conclusion, in our meta-analysis of studies in patients with sepsis, hypertonic saline reduced the volume of fluid needed to achieve the same hemodynamic targets but did not affect survival.

The Harmful Effects of Hypertonic Sodium Lactate Administration in Hyperdynamic Septic Shock

Hypertonic sodium lactate (HTL) expands intravascular volume and may provide an alternative substrate for cellular metabolism in sepsis. We compared the effects of HTL, hypertonic saline (HTS), 0.9% ("normal") saline (NS) and Ringer's lactate (RL) on hemodynamics, sublingual and renal microcirculation, renal, mesenteric and brain perfusion, renal and cerebral metabolism, and survival in anesthetized, mechanically ventilated, adult female sheep. Animals (7 in each group) were randomized to receive a bolus (over 15-min) of 3 mL/kg 0.5 M HTL, 3 mL/kg 3% HTS, 10.8 mL/kg NS, or 10.8 mL/kg RL at 2, 6, and 10 h after induction of fecal peritonitis, followed by 2-h infusions of 1 mL/kg/h (HTL/HTS groups) or 3.6 mL/kg/h (NS/RL groups). Animals also received RL and hydroxyethyl starch (ratio 1:1) titrated to maintain pulmonary artery occlusion pressure at baseline levels throughout the experiment. Animals were observed until their spontaneous death. Fluid balance was lower in the HTL and HTS groups than in the other groups from 4 h. Hemodynamic variables were similar among groups during the first 12 h, but thereafter the HTL group had more pronounced decreases in blood pressure and cardiac function. Sublingual and renal microcirculatory abnormalities occurred earlier in the HTL group. Kidney and brain perfusion decreased more rapidly in the HTL group. Median survival times were significantly shorter in the HTL (17 h) and NS (16 h) groups than in the HTS (22 h) or RL (20 h) groups (P = 0.0029). In conclusion, in an ovine model of septic shock, administration of HTL was associated with earlier onset impaired tissue perfusion and shorter survival time. These observations raise concerns about use of HTL in septic shock.

Time-Dependent Production of Endothelium-Related Biomarkers is Affected Differently in Hemorrhagic and Septic Shocks

Shock is associated with inflammation-induced endothelial dysfunction. The aim of this study was to determine time-dependent alteration of blood biomarkers related to endothelial function in hemorrhagic and septic shocks. Hemorrhagic shock was induced by bleeding the animals. A cecal ligation and incision model was used to induce septicemia. Resuscitation was carried out by infusion of lactated Ringer's solution. Resuscitation extended survival time in both shock groups. Blood pressure increased by resuscitation in the hemorrhagic shock but not in the septic shock. While hemorrhage caused a decrease in plasma levels of nitric oxide (NO) and hydrogen sulfide (H₂S), asymmetric dimethylarginine (ADMA) and total antioxidant capacity (TAC) levels were increased. Only NO and TAC levels at the late phase were reversed by resuscitation. On the other hand, plasma levels of NO, ADMA, and TAC were increased by septicemia and resuscitation did not alter the septicemia-induced increase. These results indicate that blood biomarkers related to endothelial function were differentially affected by hemorrhage and septicemia. The time scale of biomarker production should be taken into consideration for the diagnostic and therapeutic approaches to these life-threatening diseases.

200mM hypertonic saline resuscitation attenuates intestinal injury and inhibits p38 signaling in rats after severe burn trauma

BACKGROUND

An overabundant discharge of inflammatory mediators plays a significant role in intestinal injury throughout the early stages of critical burns. The present study aims to explore the outcome of 200mM hypertonic saline (HS) resuscitation on the intestinal injury of critically burned rats.

MATERIALS AND METHODS

Fifty-six Sprague-Dawley rats were randomized into three groups: sham group (group A), burn plus lactated Ringer's group (group B), and burn plus 200mM HS group (group C). Samples from the intestine were isolated and assayed for wet-weight-to-dry-weight (W/D) ratio, histopathology analyses, and p38 mitogen-activated protein kinase (MAPK) activity. Serum interleukin 1β (IL-1β) and high mobility group protein box 1 (HMGB1) concentrations were also examined.

RESULTS

Initial resuscitation with 200mM Na⁺ HS significantly decreased the intestinal W/D ratio and improved intestinal histopathology caused by severe burn. HS resuscitation also inhibited the increase of serum IL-1β and HMGB1 concentrations, and p38 MAPK activity in the intestine of critically burned rats.

CONCLUSIONS

The overall findings of this study suggest that preliminary resuscitation with 200mM HS after severe thermal injury reduces intestinal edema, inhibits systemic inflammatory response, and attenuates intestinal p38 MAPK activation, thus reduces burns-induced intestinal injury.

Hypertonic saline in critical illness - A systematic review

INTRODUCTION

The optimal approach to fluid management in critically ill patients is highly debated. Fluid resuscitation using hypertonic saline was used in the past for more than thirty years, but has recently disappeared from clinical practice. Here we provide an overview on the currently available literature on effects of hypertonic saline infusion for fluid resuscitation in the critically ill.

METHODS

Systematic analysis of reports of clinical trials comparing effects of hypertonic saline as resuscitation fluid to other available crystalloid solutions. A literature search of MEDLINE and the Cochrane Controlled Clinical trials register (CENTRAL) was conducted to identify suitable studies.

RESULTS

The applied search strategy produced 2284 potential publications. After eliminating doubles, 855 titles and abstracts were screened and 40 references retrieved for full text analysis. At total of 25 scientific studies meet the prespecified inclusion criteria for this study.

CONCLUSION

Fluid resuscitation using hypertonic saline results in volume expansion and less total infusion volume. This may be of interest in oedematous patients with intravascular volume depletion. When such strategies are employed, renal effects may differ markedly according to prior intravascular volume status. Hypertonic saline induced changes in serum osmolality and electrolytes return to baseline within a limited period in time. Sparse evidence indicates that resuscitation with hypertonic saline results in less perioperative complications, ICU days and mortality in selected patients. In conclusion, the use of hypertonic saline may have beneficial features in selected critically ill patients when carefully chosen. Further clinical studies assessing relevant clinical outcomes are warranted.

Procainamide Inhibits DNA Methylation and Alleviates Multiple Organ Dysfunction in Rats with Endotoxic Shock

Excessive inflammatory and oxidative stress lead to circulatory failure, multiple organ dysfunction, and high mortality in patients with sepsis. Microbial infection-induced DNA hypermethylation is associated with the augmentation of inflammation and oxidative stress. In our previous study, the antiarrhythmic drug procainamide inhibits the expression of DNA methyltransferase 1 (DNMT1) and diminishes IL-6 levels in rats with rhabdomyolysis. Thus, we further evaluated the effects of procainamide on the development of circulatory failure and multiple organ dysfunction in rats with endotoxic shock. Male Wistar rats were intravenously infused with saline or lipopolysaccharide (LPS) followed by procainamide administration. The changes of hemodynamics, blood glucose, biochemical variables, and plasma nitric oxide (NO) levels were analyzed during the experimental period. At the end of experiments, animal organs were also obtained for examining superoxide production, neutrophil infiltration, and DNA methylation status. Our results showed that LPS induced circulatory failure, multiple organ dysfunction, and high mortality rate in endotoxemic rats. Overt neutrophil infiltration and superoxide production, accompanied by the elevations of DNMT1 and 5-methylcytosine levels in the lung of endotoxemic rats were also observed. Treatment of endotoxemic animals with procainamide not only inhibited the increased levels of DNMT1 and 5-methylcytosine but also ameliorated neutrophil infiltration and superoxide production in the lung. In addition, the anti-inflammatory gene, IL27RA, was down-regulated in the LPS group and up-regulated in the LPS + Procainamide group. Procainamide also diminished IL27RA methylation in the lung of endotoxemic rat. Moreover, both DNMT inhibitors procainamide and hydralazine improved hypotension, hypoglycemia, and multiple organ dysfunction of LPS-treated rats. Thus, we suggest that the beneficial effects of procainamide could be attributed to the suppression of DNA methylation, neutrophil infiltration, superoxide production, and NO formation. It seems that this old drug may have new potential uses in infectious diseases, in particular, associated with endotoxemia.

Celastrol prevents circulatory failure via induction of heme oxygenase-1 and heat shock protein 70 in endotoxemic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Celastrol, a quinone methide extracted from the root of Tripterygium wilfordii Hook, possesses anti-oxidant and anti-inflammatory effects. Tripterygium wilfordii Hook is officially listed in the Chinese Pharmacopoeia and is used traditionally against rheumatoid arthritis, ankylosing spondylitis, and cancer. Furthermore, the circulatory protective effect of celastrol on an in vivo animal model of sepsis was investigated.

AIM OF THE STUDY

Sepsis is a systemic inflammatory disorder that increases tissue oxidative stress and leads to multiple organ injury. We evaluated the beneficial effects of celastrol on multiple organ failure induced by lipopolysaccharide (LPS) in rats.

MATERIALS AND METHODS

Celastrol (0.5 and 1.0 mg/kg, i.v.) was administered to anaesthetized rats 2 h before and 30 min after LPS challenge (10 mg/kg, i.v.). Eight hours later, cardiac and aortic protein expressions related to inflammatory responses, superoxide anion production, and reduced glutathione (GSH) level were measured.

RESULTS

Treatment with celastrol prevented circulatory failure (bradycardia and hypotension) 8h after LPS challenge. The plasma levels of ALT, LDH, TNF-α, and nitric oxide metabolites increased markedly during sepsis, which significantly reduced after celastrol treatments. Celastrol attenuated iNOS, TNF-α, NF-κB phospho-p65 expression, superoxide anion production, and caspase 3 activity in the cardiovascular system, all of which were markedly elevated after LPS challenge. Furthermore, celastrol induced HO-1 and HSP70 expressions increase in nuclear levels of Nrf2 and HSF-1, respectively, and increase cardiac GSH level 8h after LPS challenge.

CONCLUSION

Anti-inflammatory and anti-oxidant effects of celastrol contribute to prevent circulatory failure in sepsis. Induction of HO-1 and HSP70 by celastrol participates in these beneficial effects.

Levosimendan attenuates multiple organ injury and improves survival in peritonitis-induced septic shock: studies in a rat model

INTRODUCTION

The aim of this study was to investigate the effects of levosimendan on rodent septic shock induced by cecal ligation and puncture (CLP).

METHODS

Three hours after peritonitis-induced sepsis, male Wistar rats were randomly assigned to receive an intravenous infusion of levosimendan (1.2 μg/kg/min for 10 min and then 0.3 μg/kg/min for 6 h) or an equivalent volume of saline and vehicle (5% dextrose) solution.

RESULTS

The levosimendan-treated CLP animals had significantly higher arterial pressure and lower biochemical indices of liver and kidney dysfunction compared to the CLP animals (P < 0.05). Plasma interleukin-1β, nitric oxide and organ superoxide levels in the levosimendan-treated CLP group were less than those in CLP rats treated with vehicle (P < 0.05). In addition, the inducible nitric oxide synthase (iNOS) in lung and caspase-3 expressions in spleen were significantly lower in the levosimendan-treated CLP group (P < 0.05). The administration of CLP rats with levosimendan was associated with significantly higher survival (61.9% vs. 40% at 18 h after CLP, P < 0.05). At postmortem examination, the histological changes and neutrophil filtration index in liver and lung were significantly attenuated in the levosimendan-treated CLP group (vs. CLP group, P < 0.05).

CONCLUSIONS

In this clinically relevant model of septic shock induced by fecal peritonitis, the administration of levosimendan had beneficial effects on haemodynamic variables, liver and kidney dysfunction, and metabolic acidosis. (1) Lower levels of interleukin-1β, nitric oxide and superoxide, (2) attenuation of iNOS and caspase-3 expressions, and (3) decreases of neutrophil infiltration by levosimendan in peritonitis-induced sepsis animals suggest that anti-inflammation and anti-apoptosis effects of levosimendan contribute to prolonged survival.

Early resuscitation of dengue shock syndrome in children with hyperosmolar sodium-lactate: a randomized single-blind clinical trial of efficacy and safety

INTRODUCTION

Dengue shock syndrome (DSS) fluid resuscitation by following the World Health Organization (WHO) guideline usually required large volumes of Ringer lactate (RL) that might induce secondary fluid overload. Our objective was to compare the effectiveness of the recommended volume of RL versus a smaller volume of a hypertonic sodium lactate solution (HSL) in children with DSS. The primary end point was to evaluate the effect of HSL on endothelial cell inflammation, assessed by soluble vascular cell adhesion molecule-1 (sVCAM-1) measurements. Secondarily, we considered the effectiveness of HSL in restoring hemodynamic fluid balance, acid-base status, and sodium and chloride balances, as well as in-hospital survival.

METHODS

A prospective randomized single-blind clinical trial including 50 DSS children was conducted in the Pediatrics Department of Hasan Sadikin Hospital, Bandung, Indonesia. Only pediatric patients (2 to 14 years old) fulfilling the WHO criteria for DSS and new to resuscitation treatments were eligible. Patients were resuscitated with either HSL (5 ml/kg/BW in 15 minutes followed by 1 ml/kg/BW/h for 12 hours), or RL (20 ml/kg/BW in 15 minutes followed by decreasing doses of 10, 7, 5, and 3 ml/kg BW/h for 12 hours).

RESULTS

In total, 50 patients were randomized and included in outcome and adverse-event analysis; 46 patients (8.2 ± 0.5 years; 24.9 ± 1.9 kg; mean ± SEM) completed the protocol and were fully analyzed (24 and 22 subjects in the HSL and RL groups, respectively). Baseline (prebolus) data were similar in both groups. Hemodynamic recovery, plasma expansion, clinical outcome, and survival rate were not significantly different in the two groups, whereas fluid accumulation was one third lower in the HSL than in the RL group. Moreover, HSL was responsible for a partial recovery from endothelial dysfunction, as indicated by the significant decrease in sVCAM-1.

CONCLUSION

Similar hemodynamic shock recovery and plasma expansion were achieved in both groups despite much lower fluid intake and fluid accumulation in the HSL group.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00966628. Registered 26 August 2009.

Hypertonic saline solution reduces mesenteric microcirculatory dysfunctions and bacterial translocation in a rat model of strangulated small bowel obstruction

We examined the effects of hypertonic saline (HS) on inflammatory, metabolic variables, and bacterial translocation (BT) in rats submitted to intestinal obstruction and ischemia (IO). Male Wistar rats were submitted to IO and treated, 2 h thereafter, with lactated Ringer's (LR) (4 mL/kg per 5 min, i.v.) or HS (7.5% NaCl, 4 mL/kg per 5 min, i.v.). Twenty-four hours after IO, rats were also submitted to enterectomy/enteroanastomosis to resection of necrotized small bowel. Leukocyte-endothelial interactions were investigated by intravital microscopy and the expression of P-selectin and intercellular adhesion molecule 1 by immunohistochemistry. Bacterial cultures of mesenteric lymph nodes, liver, spleen, and blood were used to evaluate BT. Levels of chemokines (cytokine-induced neutrophil chemoattractants 1 and 2), insulin, and corticosterone were determined by enzyme-linked immunosorbent assay. Intestinal histology, serum urea and creatinine levels, and hepatic enzymes activities were performed to evaluate local and remote damage. Relative to IO and LR-treated rats, which exhibited increases in the number of rolling (1.5-fold), adhered (3.5-fold) and migrated (9.0-fold) leukocytes, and increased expression of P-selectin (3-fold) and intercellular adhesion molecule 1 (3-fold) on mesenteric microcirculation, treatment with HS followed by enterectomy reduced leukocyte-endothelial interactions and expression of both adhesion molecules to values attained in sham rats. Serum chemokines were normalized after treatment with both solutions followed by enterectomy. Hypertonic saline-treated rats demonstrated a significant reduction in BT to 50% in liver and spleen samples and bacteremia (14%), compared with 82% of BT in liver and spleen samples of IO and LR-treated rats and bacteremia (57%). Local intestinal damage was attenuated, and renal and hepatic function preserved by treatment with HS followed by enterectomy. Survival rate increased to 86% up to 15 days. Data presented suggest that HS solution followed by enterectomy reduces mesenteric microcirculatory dysfunctions and BT, attenuating local and remote damage in a model of strangulated small bowel obstruction.

The cardioprotective effect of hypertonic saline is associated with inhibitory effect on macrophage migration inhibitory factor in sepsis

Sepsis can cause myocardial dysfunction, which contributes to the high mortality of sepsis. Hypertonic saline (HS) has been reported to increase myocardial contractility in sepsis. In the present study, mechanisms of action of HS resuscitation (4 mL of 7.5% NaCl per kilogram) on cardiac function have been evaluated in septic rats. HS was administered 1 h after LPS (10 mg/kg, i.v.) challenge. The mean arterial blood pressure significantly decreased 4 h after LPS challenge, and septic shock was observed at the end of experiment (6 h). Posttreatment with HS prevented hypotension caused by LPS and significantly improved cardiac function, evidenced by increases in left ventricular developed pressure, mean +dP/dt and -dP/dt. The amplitude of electrical-stimulated intracellular Ca(2+) transient in isolated single cardiomyocytes was significantly reduced after 6 h LPS insult, which was recovered by HS. In addition, LPS resulted in significant increases in neutrophil myeloperoxidase activity, macrophage migration inhibitory factor (MIF), and NF-κB phospho-p65 protein levels in myocardium at 6 h, which were significantly attenuated by HS. In conclusion, HS improved myocardial contractility and prevented circulatory failure induced by endotoxemia, which may attribute to improvement of intracellular calcium handling process and inhibitory effects on neutrophil infiltration and MIF production in hearts.

Effect of peritoneal cavity lavage with 0.9% and 3.0% saline solution in the lung and spleen of gerbils with induced peritonitis

BACKGROUND

Peritoneal cavity lavage is used widely in the treatment of peritonitis. Nonetheless, some studies question its rationale and prove it to be deleterious to the mesothelium. The present study aims to determine whether 0.9% and 3.0% saline lavage of the peritoneal cavity have an effect on the early systemic inflammatory response, namely, in the lung injury and splenic cellularity of gerbils with induced peritonitis.

METHODS

Thirty-four male gerbils were divided into four groups: Control (n=9), submitted to laparotomy at time zero, re-laparotomy after 2 h, and sacrificed after a total of 6 h from start; untreated (n=8), submitted to peritonitis induction through cecal ligation and puncture (CLP) at time zero, re-laparotomy intended for drying of abdominal cavity and resection of the ischemic cecum after 2 h, and sacrifice after a total of 6 h from start; saline (n=8), submitted to peritonitis induction through CLP at time zero, re-laparotomy intended for warm 0.9% saline lavage of the abdominal cavity and resection of the ischemic cecum after 2 h, and sacrificed after a total of 6 h from start; and hypertonic (n=9), submitted to peritonitis induction through CLP at time zero, re-laparotomy intended for warm hypertonic saline (3.0%) lavage of the abdominal cavity and resection of the ischemic cecum after 2 h, and sacrificed after a total of 6 h from start. After sacrifice, we collected the left lung and the spleen for morphometric analysis.

RESULTS

In the both the saline and hypertonic groups, there was significant decrease in the mean nuclei count in the lungs, compared with the untreated group (p<0.01). There was no difference in terms of nuclei count in the spleen among groups (p>0.05).

CONCLUSIONS

The present study demonstrated that the peritoneal lavage with large volumes of warm 0.9% and 3.0% saline has a beneficial effect on the early systemic inflammatory response in infected animals, modulating and reducing the lung injury but having no effect on splenic cell count.

Early fluid resuscitation with hypertonic solution in a rat crush injury model

AIM OF THE STUDY

The aim of the study was to evaluate the effects of bolus infusion of hypertonic hydroxyethyl starches (HHESs) and continuous infusion of hypertonic saline (HTS) in the early resuscitation in crush syndrome.

METHODS

A rat model of crush injury was established. Rats were randomly divided into five groups: (1) HHES group, (2) HTS group, (3) volume resuscitation group, (4) normal resuscitation (NR) group, and (5) sham group. Blood samples were collected 6 h after the crush period for biochemical evaluation. Blood pressure was monitored throughout this experiment. Muscles and kidneys were evaluated morphologically 24 h after reperfusion. Twenty rats in each group were taken for survival observation for 72 h.

RESULTS

Compared with the NR and HTS groups, the HHES group had significantly increased the survival rate 72 h after release (P < 0.05). In the first 2 h after release, mean arterial blood pressure in the HHES group was significantly higher than in HTS, volume resuscitation, and NR groups (respectively, P < 0.05). Animals that received HHES infusion showed a better acid-base balance and renal function. However, there was no significant difference in survival rate between the HTS and NR groups. Furthermore, animals in the HTS group showed a bad acid-base balance and a higher serum sodium level.

CONCLUSIONS

Bolus infusion of HHES combined with normal saline could be an effective therapy for crush syndrome in the early resuscitation period. However, continuous HTS injection was not seemed to be a suitable choice particularly in the absence of monitoring equipment for serum irons or blood gases (institutional protocol no. ZN5R20110016).

Effects of small-volume hypertonic saline on acid-base and electrolytes balance in rats with peritonitis-induced sepsis

Our previous study has demonstrated that hypertonic saline (HS) given at 3 h after cecal ligation and puncture (CLP) surgery alleviates circulatory failure, multiple organ dysfunction syndrome, and mortality rate in rats. However, only few data exist on the application of HS in acid-base and electrolyte imbalance of sepsis. In addition, early one-dose HS administration seems to have only modest improvement on mortality rate. Thus, we evaluated the effects of HS on acid-base equilibrium and electrolyte balance in CLP-induced sepsis model and further compared with the effects of two- and one-dose HS administration. Male Wistar rats received CLP or sham operation followed by the administration of saline or HS (7.5% NaCl, 4 mL/kg, intravenously at 3 and 9 h after laparotomy or CLP). The changes in hemodynamics, biochemical variables, blood gas, electrolytes, organ histology, and plasma levels of nitric oxide (NO) and interleukin 1β (IL-1β) were examined during the 18-h observation. Hypertonic saline given either at 3 h (one-dose administration) or at 3 and 9 h (two-dose administration) after CLP attenuated circulatory failure, multiple organ dysfunction syndrome, metabolic acidosis, hyperkalemia, neutrophil infiltration, and 18-h mortality. Moreover, both one- and two-dose HS administrations significantly diminished plasma NO and IL-1β levels in CLP rats. However, only the two-dose HS administration significantly improved hyponatremia and hypocalcemia in septic rats. Beneficial effects of HS in septic rats may be attributed to not only reducing plasma levels of NO and IL-1β, but also improving metabolic acidosis and electrolyte imbalance. In addition, two-dose HS administration could reverse electrolyte imbalance caused by CLP.

RhoA/Rho-kinase and nitric oxide in vascular reactivity in rats with endotoxaemia

RhoA/Rho-kinase (RhoA/ROK) pathway promotes vasoconstriction by calcium sensitivity mechanism. LPS causes nitric oxide (NO) overproduction to induce vascular hyporeactivity. Thus, we tried to examine the role of RhoA/ROK and NO in the regulation of vascular reactivity in different time-point of endotoxaemia. Male Wistar rats were intravenously infused for 10 min with saline or E. coli endotoxin (lipopolysaccharide, LPS, 10 mg/kg) and divided to five groups (n = 8 in each group): (i) Control, sacrificed at 6 h after saline infusion; (ii) LPS1h, sacrificed at 1 h after LPS infusion; (iii) LPS2h, sacrificed at 2 h after LPS infusion; (iv) LPS4h, sacrificed at 4 h after LPS infusion; and (v) LPS6h, sacrificed at 6 h after LPS infusion. LPS1h and LPS2h were regarded as early endotoxaemia, whereas LPS4h and LPS6h were regarded as late endotoxaemia. Indeed, our results showed that LPS reproduced a biphasic hypotension and sustained vascular hyporeactivity to noradrenaline (NA) in vivo. Interestingly, this hyporeactivity did not occur in ex vivo during early endotoxaemia. This could be due to increases of aortic RhoA activity (n = 5, P<0.05) and myosin phosphatase targeting subunit 1 phosphorylation (n = 3, P<0.05). In addition, pressor response to NA and vascular reactivity in early endotoxaemia were inhibited by ROK inhibitor, Y27632. Furthermore, plasma bradykinin was increased at 10 min (24.6±13.7 ng/mL, n = 5, P<0.05) and aortic endothelial NO synthase expression was increased at 1 h (+200%. n = 3, P<0.05) after LPS. In late endotoxaemia, the vascular hyporeactivity was associated with aortic inducible NO synthase expression (n = 3, P<0.05) and an increased serum NO level (n = 8, P<0.05). Thus, an increased RhoA activity could compensate vascular hyporeactivity in early endotoxaemia, and the large NO production inhibiting RhoA activity would lead to vascular hyporeactivity eventually.

Modulation of the number and functions of endothelial progenitor cells by interleukin 1β in the peripheral blood of pigs: involvement of p38 mitogen-activated protein kinase signaling in vitro

BACKGROUND

Endothelial progenitor cells (EPCs) have therapeutic potential for the treatment of organ ischemia following trauma or sepsis, frequently associated with inflammatory conditions. We aimed to investigate the effects of interleukin 1β (IL-1β) on the properties of EPCs and explore its possible relationship with p38 mitogen-activated protein kinase (MAPK).

METHODS

EPCs were isolated from peripheral blood of a porcine model and were characterized. Effects of IL-1β on cell number, proliferation, migration, adhesion, and angiogenic function of EPCs were evaluated in a time- and dose-dependent manner. The activity of p38 MAPK in EPCs was measured by Western blot. Moreover, the effects of SB203580, a specific p38 MAPK inhibitor, on levels of p38 MAPK phosphorylation and the number and functions of EPCs under IL-1β conditions were examined.

RESULTS

Incubation of EPCs with IL-1β (5 ng/mL) for 5 days and with IL-1β (0.05-50 ng/mL) for 48 hours induced a significant reduction in EPC numbers and proliferation, respectively (p < 0.01 vs. control cells). The capacities for migration, adhesion, and angiogenic function of EPCs were also reduced in a time- and dose-dependent manner. IL-1β induced dose- and time-dependent activation of p38 MAPK in EPCs. Moreover, inhibition of p38 MAPK by SB203580 significantly increased the total number of EPCs by twofold as compared with the IL-1β-alone group (p < 0.01) and blocked the ability of IL-1β to impair the functional response of EPCs.

CONCLUSION

These results demonstrate that there is a negative cause-effect relationship between IL-1β and EPCs. Thus, IL-1β inhibits EPC proliferation, migration, adhesion, and tube formation by a mechanism, which involves p38 MAPK signaling in regulating the number and functions of EPCs in vitro.

Ringer's malate solution protects against the multiple organ injury and dysfunction caused by hemorrhagic shock in rats

Malic acid, in the form of its anion malate, is a key intermediate in the major biochemical energy-producing cycle known as the citric acid or Krebs cycle. In this study, the authors investigated the protective effect of a novel crystalloid solution of Ringer's malate following fluid resuscitation of hemorrhagic shock using a rat model. Under general anesthesia, Sprague-Dawley male rats were subjected to 60 min of hemorrhagic shock (40 mmHg for 60 min) followed by crystalloid resuscitation. Groups were as follows: (1) sham shock, (2) normal saline, (3) Ringer's lactate, and (4) Ringer's malate. The experiment was terminated at 4 h after resuscitation. Mean arterial blood pressure (MAP) and blood biophysical parameters were monitored during the experiment. The alanine aminotransferase, aspartate aminotransferase, urea, creatinine, superoxide dismutase, and malondialdehyde levels in plasma were detected. The intestine, liver, lung, and renal histopathology were measured. It was found that Ringer's malate could increase MAP immediately and maintain MAP for a long time. Ringer's malate could reduce the level of alanine aminotransferase, aspartate aminotransferase, urea, and creatinine. At the same time, the activity of superoxide dismutase was increased, and the level of malondialdehyde was decreased. Histopathology indicated that Ringer's malate can protect against the multiple organ injury caused by hemorrhagic shock in rats. Ringer's malate prevented circulatory failure and alleviated multiple organ dysfunction syndrome in animals with hemorrhagic shock. The study suggests that Ringer's malate solution could be a potential novel therapeutic agent for fluid resuscitation.

Hyperoncotic albumin attenuates lung and intestine injuries caused by peritonitis-induced sepsis in rats

BACKGROUND

Hyperoncotic albumin may be a therapeutic option to improve tissue perfusion and organ injury in sepsis. To clarify the hypothesis and its mechanism, hyperoncotic albumin was administered to the rats in a polymicrobial sepsis-peritonitis model.

MATERIALS AND METHODS

Peritonitis was induced by a surgery of cecal ligation and puncture (CLP) in 27 male Wistar rats. For control purposes, sham operations without ligating and puncturing the cecum were performed in 20 rats. Three hours later, rats were randomized to receive intravenously 3 mL/kg of 5% albumin, 25% albumin, or normal saline. All the hemodynamic and biochemical parameters were measured during the 18-h observation.

RESULTS

In septic rats, 25% albumin attenuated hypotension, vascular hyporeactivity to norepinephrine, and the elevated serum levels of lactate dehydrogenase and blood urea nitrogen. However, these improvements were not noted in CLP rats after 5% albumin treatment. In addition, 25% albumin decreased metabolic acidosis and improved the CLP-induced hypoperfusion in the intestine and kidney. Superoxide levels in the aorta and lung and the protein expression of inducible nitric oxide synthase in the lung were also attenuated by 25% albumin in CLP rats. Microscopic findings confirmed that 25% albumin attenuated the substantial swelling and cell infiltration in the intestine and lung caused by CLP.

CONCLUSIONS

In this sepsis rat model, 25% albumin reduced macro- and microhemodynamic changes and attenuated intestine and lung injuries in peritonitis-induced sepsis.

Baicalein, an active component of Scutellaria baicalensis Georgi, improves cardiac contractile function in endotoxaemic rats via induction of heme oxygenase-1 and suppression of inflammatory responses

AIM OF THE STUDY

To evaluate the protective effect of baicalein on myocardial dysfunction caused by endotoxaemia in rats and to explore the possible mechanisms.

MATERIALS AND METHODS

Baicalein (10mg/kg, intravenous) was administered to conscious Wistar rats 30min after lipopolysaccharide (LPS; 10mg/kg, intravenous) challenge. Six hours after LPS administration, the contractile function of the isolated heart was examined using the Langendorff technique. Cardiac protein expression related to inflammatory responses, superoxide anion production and caspase-3 activity were measured.

RESULTS

Post-treatment with baicalein significantly attenuated the LPS-induced hypotension with accompanying tachycardia. The contractile function of isolated heart was significantly preserved 6h after LPS administration, following treatment with baicalein. Furthermore, baicalein induced the expression of heme oxygenase-1 protein and reduced superoxide anion formation in the myocardium of LPS-treated rats. Cardiac levels of inducible nitric oxide synthase, monocyte chemoattractant protein-1, phospho-IκBα and phospho-p65 protein and caspase-3 activity significantly increased 6h after LPS challenge but baicalein significantly attenuated these LPS-induced changes.

CONCLUSIONS

Baicalein improves myocardial contractility in LPS-induced sepsis, which may be related to reductions in oxidative stress, myocardial inflammatory responses and apoptosis.

Beneficial effects of hyperoncotic albumin on liver injury and survival in peritonitis-induced sepsis rats

Liver injury/dysfunction developing in patients with sepsis may lead to an increased risk of death. Small-volume resuscitation with hyperoncotic albumin (HA) has been proposed to restore physiologic hemodynamics in hemorrhagic and septic shock. We evaluated whether HA resuscitation could alleviate the development of liver injury/dysfunction in rats with polymicrobial sepsis induced by cecal ligation and puncture (CLP). The male Wistar rats received 0.9% saline or HA (25%, 3 mL/kg intravenously) at 3 h after CLP or sham operation. All hemodynamic and biochemical variables were measured during the 18-h observation. After 18 h of CLP, the septic rats developed circulatory failure (i.e., hypotension, tachycardia, and poor tissue perfusion), liver injury (examined by biochemical variables and histologic studies), and a higher mortality. Hyperoncotic albumin not only ameliorated the deterioration of hemodynamic changes but also attenuated neutrophil infiltration and cell death in the liver of septic animals. The septic rats treated with HA had a higher survival when compared with those with 0.9% saline treatment. Moreover, the increased plasma IL-1β, plasma IL-6, plasma nitrite/nitrate concentrations, liver iNOS expression, and liver superoxide levels in CLP rats were attenuated after administration of HA. Thus, HA may be regarded as a potential therapeutic agent in the early treatment of septic shock to prevent or reduce subsequent liver failure.

Osmoregulation of vasopressin secretion is altered in the postacute phase of septic shock

OBJECTIVE

To determine whether septic shock patients have an abnormal reponse to increasing osmolarity.

DESIGN

Prospective interventional study.

SETTING

Intensive care unit at Raymond Poincaré and Etampes Hospitals.

PATIENTS

Normonatremic patients at > 72 hrs from septic shock onset.

INTERVENTION

Osmotic challenge consisting of infusing 500 mL of hypertonic saline solution (with cumulative amount of sodium not exceeding 24 g) over 120 mins.

MEASUREMENTS AND MAIN RESULTS

Plasma arginine vasopressin levels were measured 15 mins before the test and then four times every 30 mins. A slope of the relation between arginine vasopressin and plasma sodium levels of < 0.5 pg/mEq defined nonresponders. Among the 33 included patients, 17 (52%) were nonresponders. During osmotic challenge, variations throughout the test in plasma sodium levels, blood pressure, and central venous pressure were comparable between the two groups. Arginine vasopressin increased from 4.8 pg/mL [3.3-6.4 pg/mL] to 14.4 pg/mL [11.2-23.3 pg/mL] in responders but only from 2.8 pg/mL [2.3-4.0 pg/mL] to 4.0 pg/mL [3.1-5.3 pg/mL] in nonresponders (p < .0001). Responders had a higher plasma arginine vasopressin levels at baseline and a more severe hematosis alteration. Nonresponders had more frequently bacteremia and liver dysfunction, been referred from the ward and undergone surgery. Critical illness severity, hemodynamic alteration, hydroelectrolytic disturbances, treatment, and outcome did not differ between the two groups.

CONCLUSION

Osmoregulation is dramatically altered in half of patients with prolonged septic shock.

Meprin A and meprin alpha generate biologically functional IL-1beta from pro-IL-1beta

The present study demonstrates that both oligomeric metalloendopeptidase meprin A purified from kidney cortex and recombinant meprin alpha are capable of generating biologically active IL-1beta from its precursor pro-IL-1beta. Amino-acid sequencing analysis reveals that meprin A and meprin alpha cleave pro-IL-1beta at the His(115)-Asp(116) bond, which is one amino acid N-terminal to the caspase-1 cleavage site and five amino acids C-terminal to the meprin beta site. The biological activity of the pro-IL-1beta cleaved product produced by meprin A, determined by proliferative response of helper T-cells, was 3-fold higher to that of the IL-1beta product produced by meprin beta or caspase-1. In a mouse model of sepsis induced by cecal ligation puncture that results in elevated levels of serum IL-1beta, meprin inhibitor actinonin significantly reduces levels of serum IL-1beta. Meprin A and meprin alpha may therefore play a critical role in the production of active IL-1beta during inflammation and tissue injury.