Antithrombin III pretreatment reduces neutrophil recruitment into the lung and skeletal muscle tissues in the rat model of bilateral lower limb ischemia and reperfusion: a pilot study

The effect of astaxanthine on ischemia-reperfusion injury in a rat model

BACKGROUND

We aimed to compare biochemical and histopathological findings of astaxanthin's potential effects on oxidative stress in ischemia/reperfusion damage (I/R).

METHODS

Thirty-two rats were randomly divided into four groups: control group; I/R group; I/R + treatment group; drug group. Astaxanthin was orally administered to groups C and D for 14 days. In groups B and C, the femoral artery was clamped for 2 h to form ischemia. The clamp was opened, and reperfusion was performed for 1 h. In all groups, 4 ml of blood sample through intracardiac puncture and gastrocnemius muscle tissue samples were collected. Serum and tissue samples were analyzed by measuring malondialdehyde (MDA), superoxide dismutase (SOD), total antioxidant capacity (TAC), and total oxidative level (TOL). Necrosis, inflammation, and caspase-3 in muscle tissue collected for histopathological examination were evaluated.

RESULTS

Tissue MDA, SOD and TOL values significantly differed between groups. Serum MDA, SOD, TOL and TAC values significantly differed between groups. On necrosis examination, there was a significant difference between groups B and C. Although signs of inflammation significantly differed between groups, there was no significant difference between groups A and C and groups A and D. Although there was a significant difference in caspase-3 results between groups, there was no significant difference between groups A and C.

CONCLUSIONS

The use of astaxanthin before and after surgery showed preventive or therapeutic effects against I/R damage.

Low-molecular-weight heparin calcium attenuates the tourniquet-induced ischemia-reperfusion injury in rats

Ischemia-reperfusion injury (IRI) is a common postoperative complication of the tourniquet used surgery; low-molecular-weight heparin calcium (LMWH) is frequently used postoperatively to prevent the formation of deep venous thrombosis. However, subcutaneous hemorrhage can usually be seen in patients who underwent lower limb surgery, especially in total knee arthroplasty, the influence of LMWH on IRI remains controversial. In this experiment, we designed an animal model to observe the influence of LMWH on the skeletal muscle injury induced by tourniquets. Sprague-Dawley (SD) rats underwent either 2 h of unilateral hindlimb ischemia or anesthesia alone, at different time points of reperfusion interval, animals received either 4mg/kg LMWH or normal saline subcutaneously twice a day. The levels of inflammatory markers in serum, the expression of apoptosis proteins, as well as histological examination of skeletal muscles, were detected at 48-h reperfusion. We found that the injury of skeletal muscle and the systemic inflammatory response was less severe in LMWH-treated animals, indicating that LMWH could attenuate the tourniquet-induced IRI. In conclusion, LMWH given postoperatively after limb surgery may be clinically beneficial.

The effects of amantadine on lung tissue in lower limb ischemia/reperfusion injury model in rats

Background

This study aims to evaluate the effect of amantadine on lung tissue of after lower limb ischemia/reperfusion injury in rats.

Methods

A total of 24 Wistar rats were divided into four equal groups including six rats in each: sham group (Group S), amantadine group (Group A), ischemia/reperfusion group (Group I/R), and ischemia/reperfusion + amantadine group (Group I/R-A). All groups underwent a midline abdominal incision. In Groups I/R and I/R-A, the infrarenal abdominal aorta was clamped for 120 min and, then, reperfused for 120 min after removal of the clamp. Amantadine hydrochloride 45 mg/kg was administered intraperitoneally to the rats of Groups A and Group I/R-A 15 min before surgery. At the end of reperfusion period (240 min), all rats were sacrificed, and their lung tissues were obtained. Lung tissue catalase and superoxide dismutase activities and glutathione S-transferase and malondialdehyde levels were analyzed. Lung tissues were examined histopathologically.

Results

Catalase activity was lower in Groups A, I/R, and I/R-A compared to Group S. Superoxide dismutase activity was higher in Group I/R than Group S. Superoxide dismutase activity in Groups I/R-A and A decreased, compared to Groups S and I/R. Glutathione S-transferase levels decreased in Groups I/R and A, compared to Group S. Glutathione S-transferase levels in Group I/R-A were higher than Groups I/R and A. The highest level of malondialdehyde was found in Group I/R and the lowest level was found in Group I/R-A. According to histopathological examination, infiltration scores were significantly lower in Group S than Groups I/R and I/R-A (p=0.009 and p=0.011, respectively). The alveolar wall thickening scores in Group I/R were also significantly higher than Groups S and Group A (p=0.001 and p=0.001, respectively).

Conclusion

Lung tissue can be affected histopathologically by ischemia/ reperfusion injury and this injury can be reversed by amantadine administration.

Health Benefits of Fennel, Rosemary Volatile Oils and their Nano-Forms in Dyslipidemic Rat Model

BACKGROUND AND OBJECTIVE

Dyslipidemia is a major health problem that may lead to cardiovascular diseases (CVDs). In the present research, a biological experiment was run on dyslipidemic rats to study the health benefits of the volatile oils (VOs) of fennel and rosemary in its original and nano-form using chitosan as carrier.

MATERIALS AND METHODS

Rats were divided into 6 groups; normal control, dyslipidemic control and 4 test groups with dyslipidemia and treated by VOs of fennel and rosemary and their respective nano-forms separately. Glucose tolerance test was carried out after 4 weeks. Parameters reflecting oxidative stress/antioxidant plasma catalase, malondialdehyde (MDA) and blood uric acid, were assessed. Plasma lipid profile and tumor necrosis factor alpha (TNF-α) as inflammatory biomarker were determined. Liver and kidney function were assessed as determinant of the safety of the different VO forms. Twenty four hour urinary volume was measured to assess creatinine clearance and to evaluate the possible diuretic activity of the VOs.

RESULTS

Dyslipidemic control rats showed dyslipidemia, increased CVDs risk, liver dysfunction, elevated MDA and TNF-α with marked increase in blood sugar after half an hour of glucose ingestion compared to normal control. Treatment with the four VOs forms improved the majority of the biochemical parameters.

CONCLUSION

All treatment showed cardio and hepato- protective effect and safety towards kidney and blood sugar. Oxidative stress and inflammatory biomarkers were significantly improved by the different treatments; both VO forms of fennel were more efficient in ameliorating inflammation.

Effect of picroside II on hind limb ischemia reperfusion injury in rats

Introduction

Many structural and functional damages are observed in cells and tissues after reperfusion of previously viable ischemic tissues. Acute ischemia reperfusion (I/R) injury of lower extremities occurs especially when a temporary cross-clamp is applied to the abdominal aorta during aortic surgery. Research regarding the treatment of I/R injury has been increasing day-by-day. In this study, we aimed to investigate the effect of picroside II on skeletal muscle of rats experiencing simulated I/R.

Materials and methods

Twenty-four male Wistar albino rats weighing between 210 and 300 g were used in this study. Rats were randomly divided into 4 groups of 6 rats each (control, I/R, control + picroside II, and I/R + picroside II). The infrarenal section of the abdominal aorta was occluded with an atraumatic microvascular clamp in I/R group. The clamp was removed after 120 minutes and reperfusion was provided for a further 120 minutes. Picroside II (10 mg kg⁻¹) was administered intraperitoneally to the animals in control + picroside II and I/R + picroside II groups. At the end of the study, skeletal muscle tissue was obtained for the determination of total oxidant status (TOS) and total antioxidant status (TAS) levels. Apoptosis was evaluated by TUNEL experiment.

Results

TOS levels were significantly higher in I/R group than that of control and I/R + picroside II groups (P=0.014, P=0.005, respectively). TAS levels were significantly higher in I/R group than that of control and I/R + picroside II groups (P=0.007 P=0.005, respectively). TUNEL assay revealed that picroside II reduced cell necrosis.

Conclusion

The results of this study demonstrated that picroside II plays a critical role to prevent I/R injury. Even though our results were found to be satisfactory, it should be encouraging to those who want to conduct future research on this topic.

Proteomics Analysis to Identify and Characterize the Biomarkers and Physical Activities of Non-Frail and Frail Older Adults

Globally, the proportion of older adults is increasing. Older people face chronic conditions such as sarcopenia and functional decline, which are often associated with disability and frailty. Proteomics assay of potential serum biomarkers of frailty in older adults. Older adults were divided into non-frail and frail groups (n = 6 each; 3 males in each group) in accordance with the Chinese-Canadian Study of Health and Aging Clinical Frailty Scale. Adults were measured for grip power and the 6-min walk test for physical activity, and venous blood was sampled after adults fasted for 8 h. Ultra-high-performance liquid chromatography-tandem mass spectrometry was used for proteomics assay. The groups were compared for levels of biomarkers by t test and Pearson correlation analysis. Non-frail and frail subjects had mean age 77.5±0.4 and 77.7±1.6 years, mean height 160.5±1.3 and 156.6±2.9 cm and mean weight 62.5±1.2 and 62.8±2.9 kg, respectively. Physical activity level was lower for frail than non-frail subjects (grip power: 13.8±0.4 vs 26.1±1.2 kg; 6-min walk test: 215.2±17.2 vs 438.3±17.2 m). Among 226 proteins detected, for 31, serum levels were significantly higher for frail than non-frail subjects; serum levels of Ig kappa chain V-III region WOL, COX7A2, and albumin were lower. The serum levels of ANGT, KG and AT were 2.05-, 1.76- and 2.22-fold lower (all p < 0.05; Figure 1A, 2A and 3A) for non-frail than frail subjects and were highly correlated with grip power (Figure 1B, 2B and 3B). Our study found that ANGT, KG and AT levels are known to increase with aging, so degenerated vascular function might be associated with frailty. In total, 226 proteins were revealed proteomics assay; levels of angiotensinogen (ANGT), kininogen-1 (KG) and antithrombin III (AT) were higher in frail than non-frail subjects (11.26±2.21 vs 5.09±0.74; 18.42±1.36 vs 11.64±1.36; 22.23±1.64 vs 9.52±0.95, respectively, p < 0.05). These 3 factors were highly correlated with grip power (p < 0.05), with higher correlations between grip power and serum levels of ANGT (r = -0.89), KG (r = -0.90), and AT (r = -0.84). In conclusion, this is the first study to demonstrate a serum proteomic profile characteristic of frailty in older adults. Serum ANGT, KG and AT levels could be potential biomarkers for monitoring the development and progression of frailty in older adults.

Effect of dexmedetomidine on acute lung injury in experimental ischemia-reperfusion model

PURPOSE

Ischemia-reperfusion injury is one of the consequences of tourniquet application for extremity surgery. The aim of the study was to establish the effect of dexmedetomidine on the acute lung injury following lower extremity experimental ischemia-reperfusion model in rats.

METHODS

Twenty-eight Wistar-Albino breed Rats were recruited after Ethics Committee approval and allocated into 4 groups, each with 7 subjects. Group 1 (SHAM) received only anesthesia. Group 2 (IR) had experienced 3h of ischemia and 3h of reperfusion using left lower extremity tourniquet after anesthesia application. Groups 3 (D-50) and 4 (D-100) had undergone the same procedures as in the Group 2, except for receiving 50 and 100mg·kg^-1, respectively, dexmedetomidine intraperitoneally 1h before the tourniquet release. Blood samples were obtained for the analysis of tumor necrosing factor-α and interleukin-6. Pulmonary tissue samples were obtained for histological analysis.

RESULTS

No significant difference regarding blood tumor necrosing factor-α and interleukin-6 values was found among the groups, whereas pulmonary tissue injury scores revealed significant difference. Histological scores obtained from the Group 2 were significantly higher from those in the Groups 1, 3 and 4 with p-values 0.001 for each comparison. Moreover, Group 1 scores were found to be significantly lower than those in the Groups 3 and 4 with p-values 0.001 and 0.011, respectively. No significant difference was observed between the Groups 3 and 4.

CONCLUSION

Dexmedetomidine is effective in reduction of the experimental ischemia-reperfusion induced pulmonary tissue injury in rats, formed by extremity tourniquet application.

Effect of picroside II on erythrocyte deformability and lipid peroxidation in rats subjected to hind limb ischemia reperfusion injury

Background

Ischemia reperfusion injury (I/R) in hind limb is a frequent and important clinical phenomenon. Many structural and functional damages are observed in cells and tissues in these kinds of injuries. In this study, we aimed to evaluate the effect of picroside II on lipid peroxidation and erythrocyte deformability during I/R in rats.

Methods

Rats were randomly divided into four groups – each containing six animals (sham, I/R, sham + picroside II, and I/R + picroside II). The infrarenal section of the abdominal aorta was occluded with an atraumatic microvascular clamp in I/R groups. The clamp was removed after 120 minutes and reperfusion was provided for a further 120 minutes. Picroside II (10 mg·kg⁻¹) was administered intraperitoneally to the animals in the appropriate groups (sham + picroside II, I/R + picroside II groups). All rats were euthanized by intraperitoneal administration of ketamine (100 mg·kg⁻¹) and taking blood from the abdominal aorta. Erythrocytes were extracted from heparinized complete blood samples. Buffer (P_T) and then erythrocytes (P_E) were passed through the filtration system and the changes in pressure were measured to investigate the role of serum malondialdehyde and nitric oxide (NO) in lipid peroxidation and erythrocyte deformability index.

Results

Deformability index was significantly increased in the I/R group compared to groups sham, sham + picroside-II, and I/R + picroside-II (P<0.0001, P<0.0001, and P=0.007). Malondialdehyde (MDA) and NO levels were evaluated. MDA level and NO activity were also higher in the I/R group than in the other groups. Picroside II treatment before hind limb I/R prevented these changes.

Conclusion

These results support that deformability of erythrocytes is decreased in I/R injury and picroside II plays a critical role to prevent these alterations. Further experimental and clinical studies are needed to evaluate and clarify the molecular mechanisms of action and clinical importance of these findings.

Serpin induced antiviral activity of prostaglandin synthetase-2 against HIV-1 replication. PLoS One. 2011;6:e18589. [PMID: 21533265 DOI: 10.1371/journal.pone.0018589]

The serine protease inhibitors (serpins) are anti-inflammatory proteins that have various functions. By screening a diverse panel of viruses, we demonstrate that the serpin antithrombin III (ATIII) has a broad-spectrum anti-viral activity for HIV-1, HCV and HSV. To investigate the mechanism of action in more detail we investigated the HIV-1 inhibition. Using gene-expression arrays we found that multiple host cell signal transduction pathways were activated by ATIII in HIV-1 infected cells but not in uninfected controls. Moreover, the signal pathways initiated by ATIII treatment, were more than 200-fold increased by the use of heparin-activated ATIII. The most up-regulated transcript in HIV-1 infected cells was prostaglandin synthetase-2 (PTGS2). Furthermore, we found that over-expression of PTGS2 reduced levels of HIV-1 replication in human PBMC. These findings suggest a central role for serpins in the host innate anti-viral response. Host factors such as PTGS2 elicited by ATIII treatment could be exploited in the development of novel anti-viral interventions.

Ischemic postconditioning attenuates lung reperfusion injury and reduces systemic proinflammatory cytokine release via heme oxygenase 1

OBJECTIVE

Systemic inflammatory response following ischemia-reperfusion injury (IRI) to a specific organ may cause injuries in multiple remote organs. The emergence of ischemic postconditioning (IPO) provides a potential method for experimentally and clinically attenuating various types of organ postischemic injuries. We have shown that IPO can attenuate lung IRI by up-regulating the protein expression of heme oxygenase-1(HO-1). This study tested the hypothesis that IPO attenuates systemic inflammatory responses following lung IRI by activating HO-1.

METHODS

Anaesthetized and mechanically ventilated adult Sprague-Dawley rats were randomly assigned to one of the following groups (n = 8 each): the sham-operated control group, the ischemia-reperfusion (IR) group (40 min of left-lung ischemia and 120 min of reperfusion), the IPO group (three successive cycles of 30-s reperfusion per 30-s occlusion before restoring full perfusion), and the zinc protoporphyrin IX (ZnP) plus IPO group (ZnP, an inhibitor of HO-1, was injected intraperitoneally at 20 mg/kg 24 h prior to the experiment, and the rest of the procedures were similar to that of the IPO group). Lung injury was assessed by arterial blood gas analysis, wet-to-dry lung weight ratio and tissue histologic and biochemical changes. The lung tissue and plasma levels of lipid peroxidation were determined by measuring the contents of malondialdehyde (MDA) production. Protein expression of HO-1 was determined by Western blotting. Pulmonary neutrophil was counted. Lung tissue myeloperoxidase (MPO) activity as well as plasma levels of proinflammatory cytokines tumor necrosis factor-α (TNF-α), interleukines 6 and 8 (IL-6, IL-8) were determined by spectrophotography.

RESULTS

Lung ischemia-reperfusion led to severe lung pathologic morphologic changes and increased pulmonary MDA production, neutrophil count, and MPO activity and reduced arterial oxygen partial pressure (all P < 0.05 IR versus sham), accompanied with a compensatory increase in HO-1 protein and activity. Plasma levels of TNF-α, IL-6, and IL-8 were increased in the IR group (all P < 0.05 versus sham). IPO attenuated or prevented all the above changes, except that it further increased lung HO-1 activity. Treatment with ZnP abolished all the protective effects of postconditioning.

CONCLUSION

Postconditioning attenuated pulmonary neutrophil accumulation and activation and lung IRI and reduced systemic inflammatory responses by activating HO-1.

Effect of renal and non-renal ischemia/reperfusion on cell-mediated immunity in organs and plasma

Acute renal failure (ARF) is a common morbidity factor among patients in the intensive care unit, reaching an incidence from 3% to 30% depending on the definition of ARF and the population. Although the majority of the patients with ARF are treated with continuous renal replacement therapy, the mortality rate still remains above 50%. The causes of death are primarily extra-renal and include infection, shock, septicemia, and respiratory failure. We wanted to evaluate the cell-mediated inflammatory response of renal ischemia-reperfusion (I/R) and non-renal I/R, in blood and in distant organs. In our study, 80 mice were divided into four groups. The following surgeries were performed on the groups compared: bilateral renal I/R by clamping, unilateral renal ischemia, anesthesia only, and unilateral hind leg I/R. Half of the animals were killed after 2 h and the other half after 24 h. To assess the inflammatory response, we measured myeloperoxidase (MPO) in the organs, and CD 11b and major histocompatibility complex (MHC) II-positive cells in the blood. Non-renal I/R elicited the most elevated levels of MPO in extra-renal tissue such as the lungs. There was a trend toward higher MPO levels in the kidney following renal I/R. All kinds of I/R induced an upregulation of the adhesion molecule CD 11b and a downregulation of MHC II. Renal and non-renal I/R induced neutrophil infiltration in distant organs. Renal I/R does not induce a larger cell-mediated inflammatory response in blood and organs than non-renal I/R.

Effects of simvastatin on lung injury induced by ischaemia-reperfusion of the hind limbs in rats

We investigated whether simvastatin reduces lung injury caused by ischaemia-reperfusion of the hind limbs in rats. The control group underwent dissection of bilateral femoral arteries; another group (I/R group) underwent ischaemia of bilateral hind limbs for 2 h followed by 3 h reperfusion; and two other groups were pretreated with 5 or 10 mg/kg per day simvastatin for 3 days and then underwent ischaemia-reperfusion. The control and I/R group rats received placebo (water) instead of simvastatin. The lungs of the I/R rats showed marked histopathological changes compared with the other groups. Lung tissue myeloperoxidase, malondialdehyde, neutrophil count and lung injury scores in both simvastatin groups were significantly lower than in the I/R group; 10 mg/kg per day simvastatin significantly reduced lung water content although 5 mg/kg per day did not. Expression of haem oxygenase-1 (HO-1) protein in lung tissue was significantly greater in the simvastatin groups than in the I/R group. Simvastatin protects against lung injury associated with lower extremity ischaemia-reperfusion by reduction of neutrophil aggregation and oxidative damage, and upregulation of HO-1 expression in the injured lung.

Microcirculatory disorders in sepsis and transplantation: therapy with natural coagulatory inhibitors antithrombin and activated protein C

PURPOSE OF REVIEW

Modern technologies allow visualization of microcirculatory disorders. This review describes how the coagulatory inhibitors antithrombin and activated protein C (APC) can improve microcirculation in sepsis and transplantation.

RECENT FINDINGS

The effects of antithrombin and APC on microcirculatory disorders in ischemia reperfusion and experimental sepsis have been reported recently. In addition, antithrombin has recently been clinically used to reduce graft pancreatitis after pancreas-kidney transplantation, and to improve kidney perfusion. It was demonstrated that septic capillary perfusion failure as well as leukocyte-endothelial cell interactions can be reversed by high-dose prophylactic antithrombin application. APC was also highly effective in this context. Thus, APC could improve microcirculatory blood flow in septic patients as recently measured by in-vivo orthogonal polarization spectral imaging techniques. For antithrombin, comparable measurements in humans are currently not available.

SUMMARY

Microcirculatory dysfunction plays a key role in the development of organ dysfunction in septic patients and after solid organ transplantation. The exogenous application of coagulatory inhibitors may provide a new important strategy for prevention and treatment of microcirculatory disorders. This mode of action may be the reason why coagulatory inhibitors could improve mortality in septic patients without directly influencing inflammatory mediator concentrations.