Alternate day calorie restriction improves systemic inflammation in a mouse model of sepsis induced by cecal ligation and puncture.

BACKGROUND: Calorie restriction (CR) exerts cytoprotective effects by up-regulating survival factors, such as mammalian target of rapamycin (mTOR), sirtuin, and peroxisome proliferator-activated receptor-γ co-activator 1α (PGC-1α). These survival factors have well-established roles in attenuating the inflammatory response. However, it is unclear whether CR affects sepsis-related inflammation. The purpose of this study was to determine whether CR affects sepsis-induced inflammation in a cecal ligation and puncture (CLP)-induced mouse model of sepsis. METHODS: Male C57BL/6N mice underwent alternate day calorie restriction or normal feeding for 8 d before CLP-induced sepsis. After induction of sepsis, liver and lung histopathology and serum levels of cytokines and survival factors were assessed. RESULTS: Serum cytokine and high mobility group box protein 1 (HMGB1) levels were lower in animals that underwent alternate day calorie restriction compared with normally-fed mice after CLP. Alternate day calorie restriction also increased levels of sirtuin, PGC-1α, and mTOR. While 80% of mice in the CLP group died within 48 h after undergoing CLP, 50% of mice died in the ACR + CLP group (P < 0.05). CONCLUSION: Alternate day calorie restriction decreased mortality in a mouse model of sepsis. In addition to attenuated organ injury, a significant reduction in cytokine and HMGB1 levels was observed. These findings suggest that alternative day calorie restriction may reduce excessive inflammation.

The vitamin E derivative, EPC-K1, suppresses inflammation during hepatic ischemia-reperfusion injury and exerts hepatoprotective effects in rats.

BACKGROUND: An important component of postoperative management includes alleviation of hepatic ischemia-reperfusion (I/R) injury, which commonly results from liver surgery. EPC-K1 is a hydroxyl radical scavenger reported to have mitigating effects on I/R injury in many organs. This study evaluates the effects of EPC-K1 on hepatic I/R injury. MATERIALS AND METHODS: Rats were injected subcutaneously with either EPC-K1 (100 mg/kg) or saline. The hepatic artery and left branch of the portal vein were clamped for 45 min under general anesthesia. Indicators of liver function, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH), and of liver tissue damage were evaluated after 6h and 24h of reperfusion. Serum levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and high-mobility group box 1 (HMGB1) protein were measured, and apoptosis was quantified via caspase 3/7 activity and TUNEL assay. RESULTS: AST, ALT, and LDH levels increased significantly as a result of hepatic I/R injury, but were attenuated by EPC-K1 administration. Histologic findings revealed that normal structure of the hepatic parenchyma was maintained in rats pretreated with EPC-K1. TNF-α, IL-6, and HMGB1 levels rose significantly after reperfusion, together with activation of the inflammatory response. However, EPC-K1 administration suppressed levels of inflammatory markers and attenuated the inflammatory response. Moreover, EPC-K1 administration prevented apoptosis as determined by inhibition of caspase 3/7 activity and a decrease in apoptotic cells. CONCLUSIONS: Results demonstrate that EPC-K1 inhibits the inflammatory response and suppresses apoptosis during hepatic I/R injury. This suggests that EPC-K1 has hepatoprotective effects, and may be a valuable and novel therapeutic agent in the clinical setting.

[Reappraisal of current practice of preoperative fasting in Japan].

BACKGROUND: The American Society of Anesthesiologists (ASA) published a clinical practice guideline of preoperative fasting in 1999. A nationwide survey conducted in Japan in 2003 reveals that many hospitals have a much longer fasting period. We conducted a similar survey in three limited areas in Japan to assess the changes in fasting practice. METHODS: A written questionnaire for preoperative fasting was sent to 50 hospital in 3 prefectures. RESULTS: The duration of fasting for liquids tends to be shorter than those in the 2003 survey. The rates of application of the ASA guideline, however, are still low specifically in adults (4.2%), which is significantly lower than those in children (17.7%), or in infants (39.0%). The reasons for noncompliance are mainly due to organizational problems associated with scheduling of operation. Most hospitals aspire to have Japanese guideline about preoperative fasting periods. CONCLUSIONS: Longer preoperative fasting periods are still common practice in Japanese hospitals.

Which factors have a great impact on coagulopathy and hemostatic impairment after cardiopulmonary bypass in cardiovascular surgery? An analysis based on rotational thromboelastometry.

OBJECTIVES: This study aimed to investigate which factors have a great impact on coagulopathy after cardiopulmonary bypass (CPB) using rotational thromboelastometry (ROTEM). METHODS: Ninety-eight patients undergoing cardiovascular surgery using CPB were enrolled. Data of amplitude 10 min after clotting time (A10) of ROTEM measured routinely before and after CPB were retrospectively collected. ROTEM has some assays by which we can evaluate the capacity of extrinsic coagulation (EXTEM), intrinsic coagulation (INTEM), fibrin polymerization (FIBTEM), and the effect of heparin (HEPTEM). The platelet component, defined as PLTEM, can be calculated by subtracting FIBTEM from EXTEM. Age, sex, total plasma volume, pre-CPB A10, lowest body temperature, in-out balance during CPB, intraoperative bleeding amount, and type of pumps were considered as possible factors. Univariate and multivariate analyses were performed for the rate of change of A10. RESULTS: The change rate of each A10 had a significant negative correlation with bleeding amount (p < 0.01 for EXTEM, p < 0.01 for INTEM, p = 0.02 for FIBTEM, p < 0.01 for PLTEM). Female sex was a significant contributive predictor for the greater decline of EXTEM (p < 0.01) and INTEM (p < 0.01), positive balance for EXTEM (p < 0.01), FIBTEM (p = 0.01), and PLTEM (p < 0.01), long CPB time for INTEM (p = 0.01), centrifugal pump for FIBTEM (p < 0.01), and large pre-CPB A10 for PLTEM (p < 0.01). CONCLUSION: In perioperative hemostatic management using ROTEM, attention should be given to the effects of these multiple factors.

Relationship between HMGB1 and tissue protective effects of HSP72 in a LPS-induced systemic inflammation model.

BACKGROUND: Heat shock protein 72 (HSP72(a)) exhibits cell- and organ-protective effects in response to inflammation. Moreover, high mobility group box 1 (HMGB1) protein is a lethal mediator of acute inflammation. We examined associations between HMGB1 expression and protective effects observed when whole-body hyperthermia (WH) induces HSP72 in a lipopolysaccharide (LPS(b))-induced inflammation model. MATERIALS AND METHODS: Serum cytokine and HMGB1 levels, as well as HSP72 and HMGB1 expression in lung tissue were analyzed after WH treatment. Furthermore, effects of prior induction of HSP72 and silencing of HSP72 on HMGB1 secretion were examined in cultured RAW264.7 cells. RESULTS: Survival improved significantly from 33% in the LPS group to 78% in the WH+LPS group. Interleukin-6, tumor necrosis factor-α, and HMGB1 concentrations were significantly lower in WH-treated rats. Furthermore, inflammation was reduced in lungs of WH-treated rats. Prior induction of HSP72 resulted in significantly decreased HMGB1 secretion by RAW264.7 cells in vitro, while silencing of HSP72 prevented this decrease. CONCLUSIONS: Our results suggest that HSP72 induction by thermal pretreatment reduced inflammation and improved survival in the LPS-induced systemic inflammation model. These effects, which were associated with inhibition of HMGB1 expression, potentially involve HSP-mediated inhibition of HMGB1 secretion.

Gabexate mesilate inhibits the expression of HMGB1 in lipopolysaccharide-induced acute lung injury.

High mobility group box 1 (HMGB1) is an important late mediator of acute lung injury. Gabexate mesilate (GM) is a synthetic protease inhibitor with some anti-inflammatory action. We aimed to evaluate the effect of GM on HMGB1 in lipopolysaccharide (LPS)-induced lung injury in rats. Prior to the injection of LPS to induce lung injury, rats were administered saline or GM. Injury to the lung and expression of HMGB1, plasminogen activator inhibitor-1 (PAI-1), and protease-activated receptor-2 (PAR-2) were examined. In an accompanying in vitro study, we performed LPS stimulation under GM administration in a mouse macrophage cell line and measured the quantity of HMGB1 and cytokines in the supernatant, and cell signal in the cells. Histologic examination revealed that interstitial edema, leukocytic infiltration, and HMGB1 protein expression were markedly reduced in the GM+LPS group compared wih the LPS group. Furthermore, LPS-induced increases in PAI-1 and PAR-2 activity and in plasma HMGB1 concentrations were lower in the rats given both GM and LPS than in the rats given LPS alone. Release of HMGB1 and cytokines from the cell after the administration of LPS were decreased by GM. Phosphorylation of IκB was inhibited by GM. GM may have inhibited PAI-1 and PAR-2, thereby indirectly inhibiting HMGB1 and reducing tissue damage in the lung. This indicates that GM can inhibit lung injury induced by LPS in rats. GM is a candidate for use in novel strategies to prevent or minimize lung injury in sepsis.

EPCK1, a vitamin C and E analogue, reduces endotoxin-induced systemic inflammation in mice.

BACKGROUND: Phosphate ester of vitamin C and vitamin E (EPCK1), a strong antioxidant, is a water- and lipid-soluble phosphate ester of vitamin C and vitamin E. In the current study, we tested whether EPCK1 inhibits oxidative stress and prevents systemic inflammation. MATERIALS AND METHODS: Mice were randomly divided into a negative control group, a lipopolysaccharide (LPS)-induced sepsis group, and a group treated with an intraperitoneal infusion of EPCK1 (10 mg/kg) prior to or following LPS administration. In addition, RAW 264.7 cells were treated with LPS in the presence or absence of EPCK1. We examined levels of high mobility group box 1 (HMGB1) protein and inducible nitric oxide synthase (iNOS) in both in vivo and in vitro experiments, and liver histopathology in the in vivo experiment. RESULTS: Liver histopathology significantly improved in the EPCK1 group compared with the LPS group. Although LPS administration increased HMGB1 and nitric oxide (NO) secretion, EPCK1 decreased the secretion of these mediators in vitro and in vivo. CONCLUSIONS: Our findings suggest that EPCK1 may inhibit inflammation and potentially function as a novel anti-inflammatory therapeutic agent.

Insulin treatment of diabetic rats reduces cardiac function in a lipopolysaccharide-induced systemic inflammation model.

BACKGROUND: Diabetes is a common comorbidity in patients with various medical conditions. Tight glucose control is known to improve systemic inflammation; however, whether it is effective in diabetic patients is unknown. The purpose of this study was to examine how strict glucose control affects systemic inflammation in diabetic patients. MATERIALS AND METHODS: Male Wistar rats. We determined the effect of insulin therapy on cardiac function in a rat model of systemic inflammation. We administered lipopolysaccharide intravenously, with or without insulin, to streptozotocin-induced diabetic rats. After induction of systemic inflammation, we determined serum cytokine (IL-6 and TNFα) and nitrate/nitrite levels and measured cardiac function. RESULTS: Cytokine levels and cardiac function were significantly reduced in diabetic rats compared to non-diabetic rats. Moreover, insulin treatment was associated with higher cytokine levels and decreased cardiac function. CONCLUSION: In systemic inflammatory conditions, diabetes increases various proinflammatory mediators and inhibits cardiac function; insulin treatment exacerbates these effects. Thus, strict glucose control may not be desirable in diabetic patients with systemic inflammatory conditions.

The effect of experimental diabetes on high mobility group box 1 protein expression in endotoxin-induced acute lung injury.

The incidence and prevalence of diabetes have recently increased. Hyperglycemia, which is commonly seen in intensive care medicine, is associated with increased morbidity and mortality. For instance, diabetes is associated with altered immune and hemostatic responses. High mobility group box 1 (HMGB1) protein plays a key role in various inflammatory diseases. This study investigated the increase in lung damage due to diabetes and the rise in HMGB1 levels in a lipopolysaccharide (LPS)-induced systemic inflammation rat model. Diabetes was induced by streptozotocin infusion 4 wk prior to LPS administration, followed by measurements of blood glucose and serum cytokine levels. Separate cohorts were sacrificed 12h post-LPS administration and analyzed for lung damage. Diabetic animals had significantly higher blood glucose and enhanced lung damage. In addition, levels of serum HMGB1, tumor necrosis factor-α, and interleukin-6 were increased in diabetic rats. Diabetes may exacerbate systemic inflammation as evidenced by higher serum HMGB1 and cytokine levels and enhanced lung damage in the rat systemic inflammation model.

Filtration leukocytapheresis therapy ameliorates lipopolysaccharide-induced systemic inflammation in a rat model.

BACKGROUND: Systemic inflammation, which is associated with various conditions such as sepsis, pneumonia, and trauma, can lead to multiple organ dysfunction syndrome. Systemic inflammation can be life-threatening and is often associated with conditions seen in the intensive care unit. Leukocytes exert a proinflammatory effect and damage various tissues during systemic inflammation. The purpose of this study was to determine whether leukocytapheresis therapy can prevent lipopolysaccharide (LPS)-induced systemic inflammation in a rat model. MATERIALS AND METHODS: Male Wistar rats weighing 250 to 300 g were used for all experiments. Rats received an LPS injection, followed 6 h later by filtration leukocytapheresis or mock treatment for 30 min under sevoflurane anesthesia. Systemic inflammation was induced in rats by intravenous LPS injection (7.5 mg/kg) followed by filtration leukocytapheresis. Following blood filtration, we evaluated lung and liver histology, serum cytokine levels, and survival rate of rats for each treatment group. RESULTS: Histologic examination revealed markedly reduced inflammatory injury in lung and liver tissue harvested from rats 24 h after leukocytapheresis therapy compared with mock treatment. LPS-induced tumor necrosis factor (TNF)-α and interleukin (IL)-6 secretion was also inhibited by leukocytapheresis therapy. Moreover, survival was significantly increased in rats treated with high-efficiency leukocytapheresis compared to mock-treated rats (P<0.05). CONCLUSIONS: Taken as a whole, our findings indicate that filtration leukocytapheresis therapy protects against LPS-induced systemic inflammation. Therefore, leukocytapheresis shows potential as a new therapy for various systemic inflammatory diseases.

ETS-GS, a new anti-oxidative drug, protects against lipopolysaccharide-induced acute lung and liver injury.

BACKGROUND: Sepsis is a major health threat that remains refractory to treatment. Impairment of normal cellular function due to oxidative stress is implicated in organ injury during systemic inflammatory responses. We investigated whether the new anti-oxidative drug, ETS-GS, could inhibit secretion of cytokines and mono-nitrogen oxides, thus reducing organ damage in a rat model of lipopolysaccharide-induced sepsis. MATERIALS AND METHODS: Lipopolysaccharide was administered intravenously to male Wistar rats in order to establish a rat model of systemic inflammation. These rats were challenged with or without intravenous ETS-GS. Mouse macrophage RAW264.7 cells were stimulated with lipopolysaccharide, with or without simultaneous ETS-GS treatment, in order to elucidate the mechanism of action. RESULTS: Histologic examination revealed that ETS-GS markedly reduced lipopolysaccharide-induced interstitial edema and leukocytic infiltration in lung tissue, and lipopolysaccharide-induced bleeding and leukocytic infiltration in liver tissue harvested 12 h after treatment. Cytokine (interleukin-6 and tumor necrosis factor-α) secretion was strongly induced by lipopolysaccharide; this induction was similarly inhibited by ETS-GS treatment. Likewise, lipopolysaccharide-induced secretion of mono-nitrogen oxides was inhibited by ETS-GS. In the in vitro studies, ETS-GS administration inhibited IκB phosphorylation. CONCLUSION: ETS-GS blocked the lipopolysaccharide-induced inflammatory response and protected against acute lung and liver injury normally associated with endotoxemia in this rat model of systemic inflammation. Further, this protection may be mediated through the inhibition of nuclear factor κ-light-chain-enhancer of activated B cells activation. Our results suggest that ETS-GS is a potential therapeutic agent for sepsis.

Continuous hemodiafiltration therapy ameliorates LPS-induced systemic inflammation in a rat model.

BACKGROUND: Systemic inflammation can result in multiple organ dysfunction syndrome, a potentially life-threatening condition. Some reports suggest that continuous hemodiafiltration can effectively remove proinflammatory cytokines from circulation during systemic inflammation. In the present study, we investigated whether continuous hemodiafiltration therapy could prevent LPS-induced systemic inflammation and improve survival in a rat model. MATERIALS AND METHODS: Male Wistar rats were injected with lipopolysaccharide (LPS; 7.5 mg/kg body weight), and 6 h later were treated with either single-pass hemofiltration (C group), continuous hemofiltration (CHF group), continuous hemodiafiltration (CHDF group), or mock filtration (Control group). We performed histologic examinations of lung and liver tissues, determined serum cytokine levels, and survival rates for each treatment group, and compared cytokine removal between CHF and CHDF therapies. RESULTS: Histologic examination revealed significant reduction in inflammation in lung and liver tissues harvested 24 h after CHDF compared with the Control group. Likewise, LPS-induced serum TNF-α and IL-6 levels decreased with continuous hemodiafiltration along with a significant improvement in survival. After 30 min of treatment, both CHF and CHDF removed significant amounts of TNF-α and IL-6 from the blood. However, serum cytokine levels measured before and after filtration were not significantly different. CONCLUSIONS: Continuous hemodiafiltration therapy lowered inflammatory cytokines and increased survival rates in a rat model of systemic inflammation. Therefore, continuous hemodiafiltration may be a potential therapy for use against various systemic inflammatory diseases.

Danaparoid sodium attenuates the effects of heat stress.

BACKGROUND: Heat stroke is a condition characterized by high body temperature that can lead to hemorrhage and necrosis in multiple organs. Anticoagulants, such as danaparoid sodium (DA), inhibit various types of inflammation; however, the anti-inflammatory mechanism of action is not well understood. Given that heat stroke is a severe inflammatory response disease, we hypothesized that DA could inhibit inflammation from heat stress and prevent acute heat stroke. MATERIALS AND METHODS: Male Wistar rats were given a bolus injection of saline or DA (50 U/kg body weight) into the tail vein just prior to heat stress (42 °C for 30 min). Markers of inflammation were then determined in serum and tissue samples. RESULTS: In rats pretreated with DA, induction of cytokines (interleukin [IL]-1ß, IL-6, and tumor necrosis factor [TNF]-α), nitric oxide (NO), and high mobility group box 1 (HMGB1) protein were reduced compared with saline-treated rats. Histologic changes observed in lung, liver, and small intestine tissue samples of saline-treated rats were attenuated in DA-treated rats. Moreover, DA pretreatment improved survival in our rat model of heat stress-induced acute inflammation. CONCLUSION: Collectively, our findings demonstrate that DA pretreatment may have value as a new therapeutic tool for heat stroke.

ETS-GS, a new antioxidant, ameliorates renal ischemia-reperfusion injury in a rodent model.

BACKGROUND: Ischemia-reperfusion (I/R) contributes to acute kidney injury (AKI). On the other hand, anti-oxidative drugs help to prevent renal injury caused by I/R. The current study examined whether a new antioxidant, ETS-GS, inhibits reactive oxygen species (ROS) generation and thereby prevents renal I/R injury in rodent models. METHODS: Rats with experimentally-induced renal I/R injury were treated concurrently with an intravenous injection of either ETS-GS or saline. Anesthesia was induced with sevoflurane. RESULTS: Histologic examination revealed marked reduction of interstitial congestion, edema, inflammation, and hemorrhage in kidney tissue harvested 24 h after ETS-GS treatment. Renal I/R-induced secretion of nitric oxide (NO) in serum was inhibited by ETS-GS treatment. Furthermore, malondialdehyde (MDA) levels in the kidney were significantly lower in ETS-GS-treated rats with renal I/R. Moreover, when murine macrophage-like RAW264.7 cells were stimulated with antimycin A in the presence or absence of simultaneous ETS-GS treatment, ETS-GS decreased ROS levels. CONCLUSIONS: Thus, ETS-GS lowered ROS levels in cultured cells, reduced serum NO levels, decreased renal MDA levels, and protected rats against I/R-induced kidney injury. Given these in vitro and in vivo findings, ETS-GS is a strong candidate for future exploration of therapeutic potential in various human I/R diseases.

Remifentanil and glucose suppress inflammation in a rat model of surgical stress.

PURPOSE: Postoperative stress produces an inflammatory response. Recent studies have shown that narcotic analgesics suppress the immune system. Nutritional management during perioperative care has also been reported to affect inflammation. We therefore examined whether remifentanil or glucose administration could ameliorate postsurgical inflammatory responses using a rat model of surgical stress. METHODS: We divided male Wistar rats randomly into five groups: (1) control, (2) sevoflurane+lactated Ringer's solution, (3) sevoflurane+lactated Ringer's solution with 1% glucose, (4) sevoflurane+remifentanil+lactated Ringer's solution, and (5) sevoflurane+remifentanil+ lactated Ringer's solution with 1% glucose. In all groups, serum samples were obtained at various time points after surgery, and secreted cytokine concentrations were determined. In addition, we assessed the activation of protein kinase B (Akt) and forkhead/winged helix box class O (FOXO3), which play a role in gluconeogenesis/stress responses. RESULTS: Surgical stress increased the serum concentrations of tumor necrosis factor-α and interleukin-6. Groups receiving remifentanil with anesthesia showed an attenuated inflammatory response. The inflammatory response was also reduced by administering 1% glucose. Furthermore, 1% glucose induced Akt and FOXO3 phosphorylation in the quadriceps femoris muscle 12 h after surgery. CONCLUSIONS: Anesthesia based on remifentanil and perioperative administration of lactated Ringer's solution containing 1% glucose may be able to control inflammatory responses caused by surgical stress.

Anti-inflammatory effects of perioperative intensive insulin therapy during cardiac surgery with cardiopulmonary bypass.

PURPOSE: Recent studies have reported that controlling blood glucose with insulin can suppress systemic inflammation. In the present study, we evaluated how perioperative intensive insulin therapy (IIT) influences the inflammatory response in an artificial pancreas during cardiac surgery with cardiopulmonary bypass. METHODS: We randomly divided the patients undergoing cardiac surgery with cardiopulmonary bypass into two groups: an IIT group (n = 13) and a conventional treatment (CT) group (n = 12). For the IIT group, blood glucose control was initiated with an artificial pancreas at initiation of surgery. Blood glucose was maintained at 100 mg/dl until 24 h postoperatively. Blood samples were collected to determine changes in serum cytokine levels over time. RESULTS: Patients' characteristics did not differ significantly between groups. Blood glucose levels were significantly higher in the CT group after surgery. Serum levels of tumor necrosis factor-α, interleukin-6, and high-mobility group box 1 were higher in the CT group than in the IIT group. CONCLUSIONS: Use of IIT in the artificial pancreas during the perioperative period significantly decreased the inflammatory response. Moreover, we did not find evidence of hypoglycemia in those treated with IIT. This suggests that use of IIT in an artificial pancreas can be safe and effective for critically ill patients.

Total parenteral-nutrition-mediated dendritic-cell activation and infiltration into the small intestine in a rat model.

PURPOSE: Total parenteral nutrition (TPN) is commonly carried out in the clinical setting. However, effects of TPN on the immune system, including dendritic cells (DC), are not well understood. The purpose of this study was to determine whether TPN affects DC activation and infiltration into the intestinal barrier. METHODS: Male Wistar rats were given conventional nutrition (CN) or TPN for 7 days. DCs were visualized by immunohistochemistry. Levels of nucleotide-binding oligomerization domain protein 2 (NOD2) and high-mobility group box 1 (HMGB1) protein were assessed by Western blot. RESULTS: The number of DCs at the small intestinal barrier was significantly increased in the TPN group (9.2 ± 3.1 cells/microscopic field) compared with the CN group (0.5 ± 0.6 cells/microscopic field; p < 0.05), as were protein expression levels of NOD2 and HMGB1. CONCLUSION: These results suggest that TPN increases activation and infiltration of DCs into the small intestine, potentially involving an increase in NOD2 and HMGB1 levels in the small intestine.

The antinociceptive effects of estradiol on adjuvant-induced hyperalgesia in rats involve activation of adrenergic and serotonergic systems.

PURPOSE: Estradiol is a female hormone required for maintaining pregnancy and developing follicles in the ovary. Estradiol has been shown to perform a variety of physiological activities, including pain reduction. In this study, we tested the hypothesis that estradiol exerts antinociceptive effects in a rat model of inflammatory hyperalgesia. METHODS: We established a subacute hyperalgesia model using plantar injection of Freund's complete adjuvant (FCA) in Sprague-Dawley rats. We administered estradiol every 24 h, beginning 12 h after FCA administration, and used the plantar test to determine its effect on hyperalgesia. To determine the mechanism of action of estradiol, we evaluated the role of the opioid antinociceptive system using naloxone and the role of the descending pain inhibitory system using the α-2-receptor antagonist yohimbine and the serotonin receptor antagonist methysergide. RESULTS: Administration of FCA induced hyperalgesia, which was significantly reduced by estradiol treatment compared to controls. Moreover, this effect was not antagonized by naloxone, but was attenuated by α-2-receptor and serotonin-receptor antagonists. CONCLUSION: Estradiol is known to perform a variety of physiological functions. Our findings suggest that one such function is antinociception via an interaction with α-2 receptors and serotonin receptors.

Effects of preoperative oral carbohydrates and trace elements on perioperative nutritional status in elective surgery patients.

PURPOSE: In order to enhance postoperative recovery, preoperative consumption of carbohydrate (CHO) drinks has been used to suppress metabolic fluctuations. Trace elements such as zinc and copper are known to play an important role in postoperative recovery. Here, we examined the effects of preoperatively consuming a CHO drink containing zinc and copper. METHODS: Subjects were 122 elective surgery patients divided into two groups (overnight fasting and CHO groups); each group was further divided into morning or afternoon surgery groups. Subjects in the CHO group consumed 300 mL of a CHO drink the night before surgery, followed by 200 ml before morning surgery or 700 ml before afternoon surgery (> or =2 hours before anesthesia induction). Blood levels of glucose, nonesterified fatty acids (NEFA), retinol-binding protein, zinc, and copper were determined. RESULTS: One subject in the CHO group was excluded after refusing the drink. There were no adverse effects from the CHO drink. NEFA levels increased in the fasting groups. Although zinc levels increased in the CHO group immediately after anesthesia induction, no group differences were observed the day after surgery. CONCLUSION: Preoperative consumption of a CHO drink containing trace elements suppressed preoperative metabolic fluctuations without complications and prevented trace element deficiency. Further beneficial effects during the perioperative period can be expected by adding trace elements to CHO supplements.

An electron spin resonance study for real-time detection of ascorbyl free radicals after addition of dimethyl sulfoxide in murine hippocampus or plasma during kainic acid-induced seizures.

Electron spin resonance (ESR)-silent ascorbate solutions generate a detectable, likely concentration-dependent signal of ascorbyl free radicals (AFR) immediately upon addition of a molar excess of dimethyl sulfoxide (DMSO). We aimed to perform quantitative ESR analysis of AFR in real time after addition of DMSO (AFR/DMSO) to evaluate ascorbate concentrations in fresh hippocampus or plasma following systemic administration of kainate in mice. Use of a special tissue-type quartz cell allowed immediate detection of AFR/DMSO ESR spectra in fresh tissues from mice. AFR/DMSO content was increased significantly in fresh hippocampus or plasma obtained during kainate-induced seizures of mice, reaching maximum levels at 90 min after intraperitoneal administration of 50 mg/kg kainic acid. This suggests that oxidative injury of the hippocampus resulted from the accumulation of large amounts of ascorbic acid in the brain after kainic acid administration. AFR/DMSO content measured on an ESR spectrometer can be used for real-time evaluation of ascorbate content in fresh tissue. Due to the simplicity, good performance, low cost and real-time monitoring of ascorbate, this method may be applied to clinical research and treatment in the future.