Hydroxyethyl Starch Inhibits Intestinal Production of Cytokines and Activation of Transcription Factors in Endotoxaemic Rats

Protective effects of phosphocreatine administered post-treatment combined with ischemic post-conditioning on rat hearts with myocardial ischemia/reperfusion injury

Background

The aim of the study was to investigate the effects of phosphocreatine (PCr) post-treatment combined with ischemic post-conditioning on myocardial ischemia/reperfusion (I/R) injury in a rat model.

Methods

Forty Sprague-Dawley rats that had undergone 30 minutes ischemia and 120 minutes reperfusion were randomly divided into four groups (n = 10 in each group): the I/R group, the ischemia post-conditioning (IPost) group, the PCr group, and the IPost + PCr group. The activities of serum creatine kinase (CK), myeloperoxidase (MPO), and lactate dehydrogenase (LDH) were measured after 120 minutes of reperfusion. At the end of the experiment, serum levels of nuclear factor (NF)-κB and tumor necrosis factor (TNF)-α were detected, myocardial infarct size (IS) was measured by triphenyltetrazolium chloride staining, and myocardial expression of Bcl-2 and phosphorylated Akt (p-Akt) was determined by western blot.

Results

The IPost, PCr, and PCr + IPost groups had significantly lower IS than the I/R group (P < 0.05). The reductions in CK, LDH, and MPO release were consistent with the decrease in the myocardial IS (P < 0.05). Serum concentrations of TNF-α and NF-κB in the IPost, PCr, and PCr + IPost groups were significantly lower than those in the I/R group (P < 0.05). The levels of p-Akt and Bcl-2 in the IPost, PCr, and PCr + IPost groups were greater than those in the I/R group (P < 0.05). CK, LDH, MPO, NF-κB, TNF-α, p-Akt, Bcl-2 and IS were further enhanced in the IPost + PCr group (P < 0.05).

Conclusions

Post-treatment with PCr enhanced the protective effect of IPost on rat myocardium affected by I/R injury, possibly by inhibiting the inflammatory response and activating the phosphatidylinositol 3-kinase (PI-3K)/Akt/Bcl-2 signaling pathway.

The interaction of nuclear factor-kappa B and cytokines is associated with schizophrenia

BACKGROUND

Many reports suggest that schizophrenia is associated with the inflammatory response mediated by cytokines, and nuclear factor-kappa B (NF-kappaB) regulates the expression of cytokines. However, it remains unclear whether the interaction between NF-kappaB and cytokines is implicated in schizophrenia and whether the effect of neuroleptics treatment for 4 weeks is associated with the alteration of cytokines.

METHODS

Sixty-five healthy subjects and 83 first-episode schizophrenic patients who met DSM-IV criteria and who were never treated with neuroleptics previously were included. Serum levels of cytokines such as interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) were examined by using sandwich enzyme immunoassay (EIA). Peripheral blood mononuclear cell (PBMC) mRNA expressions of cytokines (IL-1beta, TNF-alpha) and NF-kappaB were detected by using semiquantitative reverse transcription polymerase chain reaction (RT-PCR). NF-kappaB activation was examined by using transcription factor assay kits.

RESULTS

Schizophrenic patients showed significantly higher serum levels and PBMC mRNA expressions of IL-1beta and TNF-alpha compared with healthy subjects. However, treatment with the neuroleptic risperidone for 4 weeks significantly decreased serum levels and PBMC mRNA expressions of IL-1beta in schizophrenic patients. NF-kappaB activation and PBMC mRNA expression in patients were significantly higher than those in healthy subjects. Furthermore, PBMC mRNA expressions of IL-1beta and TNF-alpha were positively correlated to NF-kappaB activation in both schizophrenic patients and healthy control subjects.

CONCLUSIONS

Schizophrenic patients showed activation of the cytokine system and immune disturbance. NF-kappaB activation may play a pivotal role in schizophrenia through interaction with cytokines.

RESUSCITATION WITH HYDROXYETHYL STARCH SOLUTION PREVENTS NUCLEAR FACTOR κB ACTIVATION AND OXIDATIVE STRESS AFTER HEMORRHAGIC SHOCK AND RESUSCITATION IN RATS

Fluid resuscitation is vital for treating traumatic hemorrhagic shock (HS), but reperfusion is believed to have the adverse consequences of generating reactive oxygen species and inflammatory cytokines, both of which cause multiple organ dysfunctions. We investigated the effects of various resuscitation fluids on the changes of redox-sensitive molecules after HS and fluid resuscitation (HS/R). We induced HS by bleeding male Sprague-Dawley rats to a blood pressure of 30 to 40 mmHg for 60 minutes. Thirty minutes later, the rats were killed (HS group) or immediately resuscitated with shed blood (HS + BL group), L-isomer lactated Ringer's solution (HS + LR group), or hydroxyethyl starch (HS + HES group). After HS, we found a significant increase in nuclear factor kappaB DNA binding activity, which was effectively inhibited using HES solution or blood resuscitation. Moreover, resuscitation with blood or LR solution, but not HES solution, induced significant oxidative stress, manifested by a high ratio of oxidized glutathione to reduced glutathione in the lungs, liver, and spleen. HS alone, however, did not increase the ratio of the oxidized glutathione to reduced glutathione in all organs. Although the protein expression of anti-apoptotic Bcl-2 and pro-apoptotic Bax varied in different organs, we found that resuscitation using HES solution prevented the HS-induced reduction of the Bcl-2/Bax ratio in the heart. HES solution was an appropriate resuscitation fluid in reversing nuclear factor kappaB activation, maintaining the Bcl-2/Bax ratio, and preventing oxidative stress after acute HS.