Medical ozone therapy reduces shock wave therapy-induced renal injury.

OBJECTIVES: Extracorporeal shock wave (ESW) lithotripsy is the preferred treatment modality for uncomplicated kidney stones. More recently free oxygen radical production following ESW application has been considered to be crucial in shock wave-induced renal damage. It has been shown that ozone therapy (OT) has ameliorative and preventive effects against various pathological conditions due to increased nitro-oxidative stress. In current study, we aimed to evaluate the efficacy of OT against ESW-induced renal injury. METHODS: Twenty-four male Sprague-Dawley rats were divided into three groups: sham-operated, ESW, and ESW + OT groups. All groups except sham-operated group were subjected to ESW procedure. ESW + OT group received 1 mg/kg/day of oxygen/ozone mixture intraperitoneally at 2 h before ESW, and OT was continued once a day for consecutive three days. The animals were killed at the 4th day, and kidney tissue and blood samples were harvested for biochemical and histopathologic analysis. RESULTS: Serum ALT and AST levels, serum neopterin, tissue nitrite/nitrate levels, and tissue oxidative stress parameters were increased in the ESW group and almost came close to control values in the treatment group (p < 0.05, ESW vs. ESW + OT). Histopathological injury scores were significantly lower in treatment group than the ESW group (p < 0.05, ESW vs. ESW + OT). Immunohistochemical iNOS staining scores in ESW group were higher than those of sham-operated group (p < 0.05, ESW vs. sham-operated), iNOS staining scores in OT group were significantly lower than the ESW group (p < 0.05, ESW + OT vs. ESW). CONCLUSION: OT ameliorates nitro-oxidative stress and reduces the severity of pathological changes in the experimental ESW-induced renal injury of rat model.

Poly-ADP-ribose polymerase inhibition provides protection against lung injury in a rat paraquat toxicity model.

OBJECTIVES: Paraquat (PQ) is a widely used herbicide. Exposure to PQ at toxic doses can result in fatal acute lung injury. Inhibition of the poly-(ADP-ribose) polymerase (PARP) enzyme alleviates inflammation and necrosis in various pathologies. Here we aimed to evaluate the effects of PARP inhibition on PQ-induced lung damage in a rat experimental model. METHODS: Female Sprague-Dawley rats (n = 24) were allocated into three groups: sham, PQ and PQ + 3-aminobenzamide (3-AB) that is a PARP inhibitor, groups. Experimental lung injury was induced by administration of 15 mg/kg PQ intraperitoneally in PQ and PQ + 3-AB groups. 3-AB (10 mg/kg twice per day) was administered to the PQ + 3-AB group for four consecutive days. The animals were killed on the fifth day following PQ administration. Lung tissue and blood samples were collected and stored until analysis. RESULTS: Serum lactate dehydrogenase (LDH) and neopterin levels, tissue oxidative stress parameters, transforming growth factor-beta1 (TGF-ß) levels and histological injury scores in the PQ + 3-AB group were significantly lower than in the PQ group (P < 0.05, PQ vs. PQ + 3-AB). Total antioxidant capacity in the PQ + 3-AB group was significantly higher than in the PQ group (P < 0.05, PQ + 3-AB vs. PQ). CONCLUSION: Our results suggested that the use of PARP inhibitors following PQ toxicity might be useful for minimizing lung injury due to paraquat toxicity.

Evaluation and comparison of the effect of hypothermia and ozone on ischemia-reperfusion injury of skeletal muscle in rats.

BACKGROUND: Tourniquet-induced ischemia-reperfusion, which affects local and distant organs, is very common in orthopedic surgery. Hypothermia is used in traumatic tissue during ischemic period commonly. Ozone (O3) has been recommended as a novel therapeutic agent in various medical conditions. The objective of the study was to evaluate and compare the effect of hypothermia (H) and O3 on ischemia-reperfusion injury of skeletal muscle in rats by measuring oxidative parameters and inducible nitric oxide synthase (iNOS) levels. MATERIALS AND METHODS: Eighteen rats (Wistar albino) were separated into five groups randomly (sham, IR, IR + H, IR + O3, IR + H + O3; n = 6). The lower right extremity of all rats was subjected to 2 h of ischemia and 22 h of reperfusion clamping the common iliac artery and using the rubber-band technique at the level of the lesser trochanter under general anesthesia. Two hours of hypothermia were applied during the first 2 h of reperfusion in two groups. O3 was applied in two groups. All rats were sacrificed after the IR period with high dose of anesthesia. The tibialis anterior muscle and blood were saved. Levels of superoxide dismutase, glutathione peroxidase, MDA, NOx, and interleukin-1ß were measured in the muscle. Creatinine kinase, lactate dehydrogenase, aspartate aminotransferase, urea, creatinine, and electrolytes were measured in serum. Immunohistochemical iNOS staining was performed on muscle samples. RESULTS: The levels of MDA, NOx, and interleukin-1ß in muscle were raised in the IR group compared with those in the sham group. The same parameters were lower in the groups of IR + H, IR + O3, and IR + H + O3 compared with those in the IR group. Superoxide dismutase and glutathione peroxidase activities in muscle were lower in the IR group compared with those in the sham group; however, same parameters were higher in the groups of IR + H, IR + O3, and IR + H + O3 compared with those in the IR group. Score and intensity of iNOS staining in skeletal muscle in the IR group was increased compared with that in the sham group and decreased in the groups of IR + H, IR + O3, and IR + H + O3 compared with that in the IR group. Levels of creatinine kinase, aspartate aminotransferase, and K in the three treatment groups decreased compared with those in the IR group. CONCLUSIONS: These findings showed that hypothermia, which has more affect, and O3 decreased the tourniquet-induced IR injury in the rat's muscle-skeletal system by reducing the levels of oxidative and nitrosative stress parameters and enhancing antioxidant enzymes. Hypothermia and O3 had no synergistic effect. Hypothermic reperfusion and O3 preconditioning might be beneficial in skeletal muscle IR injury-associated tourniquet.

Efficacy of poly(adenosine diphosphate-ribose) polymerase inhibition in extracorporeal shock wave-induced renal injury.

OBJECTIVES: Extracorporeal shock wave lithotripsy (ESW) induces renal damage by excessive production of free oxygen radicals. Free Oxygen radicals cause cellular injury by inducing nicks in DNA. The enzyme poly(adenosine diphosphate-ribose) polymerase (PARP) involved in the process of repair of DNA in damaged cells. However, its activation in damaged cells can lead to adenosine triphosphate depletion and death. Thus, we designed a study to evaluate the efficacy of 3-aminobenzamide (3-AB), a PARP inhibitor, against extracorporeal shock wave induced renal injury. METHODS: Twenty-four Sprague-Dawley rats were divided into three groups: control, ESW, ESW + 3-AB groups. All groups except control group were subjected to ESW procedure. ESW + 3-AB group received 20 mg/kg/day 3-aminobenzamide intraperitoneally at 2 h before ESW and continued once a day for consecutive 3 days. The surviving animals were sacrificed at the 4th day and their kidneys were harvested for biochemical and histopathologic analysis. Blood samples from animals were also obtained. RESULTS: Serum ALT and AST levels, serum neopterin and tissue oxidative stress parameters were increased in the ESW group and almost came to control values in the treatment group (p < 0.05, ESW vs. ESW + 3-AB). Histopathological injury score were significantly lower in treatment group than the ESW group (p < 0.05, ESW vs. ESW + 3-AB). CONCLUSION: Our data showed that PARP inhibition protected renal tissue against ESW induced renal injury. These findings suggest that it would be possible to improve the outcome of ESW induced renal injury by using PARP inhibitors as a preventive therapy.

Inhibition of inducible nitric oxide synthase prevents shock wave therapy induced renal injury.

OBJECTIVES: Shock wave lithotripsy treatment (SWT) is not completely free from side effects; one of the accused mechanisms for renal injury during SWT is oxygen- and nitrogen-derived free radical productions. Therefore, we aimed to evaluate the effect of inhibition of nitric oxide (NO) production by N-[3(aminomethyl) benzyl) acetamidine] (1400W), highly selective inducible nitric oxide synthase (iNOS) inhibitor, at SWT-induced kidney damage. MATERIALS AND METHODS: Twenty-four rats those underwent right nephrectomy procedure were divided equally into three groups as control, SWT, and SWT + 1400W. 1400W was administered at a dose of 10 mg/kg at 2 h prior to SWT procedure and at the beginning of SWT procedure via intraperitoneal route and continued daily for consecutive 3 days. At the end of the fourth day, animals were killed via decapitation and trunk blood and the left kidneys were taken for biochemical and histopathologic evaluation. RESULTS: SWT caused renal tubular damage and increased lipid peroxidation and antioxidant enzyme activities and SWT also significantly increased nitro-oxidative products. Inhibition of iNOS via administration of 1400W ameliorated renal injury and decreased tissue lipid peroxidation (malondialdehyde), superoxide dismutase, glutathione peroxidase and nitrite/nitrate levels (NOx). In addition, it was seen that histolopathological changes were attenuated in the SWT + 1400W group when compared to SWT group. CONCLUSION: SWT-induced renal injury might be due to excessive production of oxygen free radicals and NO production. Inhibition of iNOS attenuates renal injury following SWT treatment. It can be concluded that iNOS inhibitors or peroxynitrite scavengers might be used to protect the kidneys against SWT-induced morphological and functional injuries.

Beneficial effects of Etanercept on experimental necrotizing enterocolitis.

PURPOSE: Tissue damage in necrotizing enterocolitis (NEC) of infants occurs as a result of an uncontrolled inflammatory response. The aim of this study was to investigate any potential anti-inflammatory effects that Etanercept may have on the inflammatory response in an experimental NEC model in newborn rats. METHODS: Newborn pups were randomized into three groups immediately after birth (Control, NEC + Placebo and NEC + Etanercept). Pups in the NEC + Placebo and NEC + Etanercept groups were subjected to an NEC-inducing protocol (hypercarbia, hypothermia and hyperoxia) twice a day for 3 days. Pups in the NEC + Etanercept group were given an intraperitoneal injection of Etanercept. Rats were harvested for biochemical and histopathological examinations. RESULTS: The histopathological injury score of rats in the NEC + Placebo group was significantly higher compared to the NEC + Etanercept and Control groups (p < 0.05 for both comparisons). Tissue levels of tumor necrosis factor-α, interleukin-1ß, and malondialdehyde were higher in the placebo group compared to the Etanercept group. CONCLUSION: Our results suggest that Etanercept attenuates intestinal tissue damage in NEC by reducing inflammation and blocking the production of free-oxygen radicals, while also reducing tissue levels of tumor necrosis factor-α and interleukin-1ß.

Protective effects of colchicine in an experimental model of necrotizing enterocolitis in neonatal rats.

BACKGROUND: The pathophysiology of necrotizing enterocolitis (NEC) includes the massive production of endogenous cytokines with exaggerated activation of inflammatory pathways. Colchicine has been used as an anti-inflammatory agent. The aim of this study was to investigate the possible beneficial effects of colchicine in a neonatal rat model of NEC. MATERIALS AND METHODS: We randomly divided rat pups into three groups: a control group, a saline-treated NEC group, and a colchicine-treated NEC group. We induced NEC by hyperosmolar enteral formula feeding and exposure to hypoxia/reoxygenation after cold stress. Intestinal samples were harvested for biochemical and histopathologic analyses. RESULTS: The grade of intestinal injury of pups in the saline-treated NEC group was significantly higher than in the control and colchicine-treated groups (P < 0.001 and 0.003, respectively). The median level of intestinal malondialdehyde was significantly higher in the saline-treated NEC group compared with the control group (P = 0.006) or the colchicine-treated NEC group (P = 0.015). We observed significantly higher activity levels of intestinal superoxide dismutase and glutathione peroxidase in the colchicine-treated NEC group compared with the saline-treated NEC group (P = 0.033 and 0.030, respectively). The tissue levels of tumor necrosis factor-α and interleukin-1ß were significantly higher in the saline-treated NEC group compared with the colchicine-treated NEC group (P < 0.001 and 0.003, respectively). CONCLUSIONS: We observed that in this model of NEC, colchicine had favorable effects on intestinal histologic and biochemical changes.

Protective effects of melatonin and S-methylisothiourea on mechlorethamine induced nephrotoxicity.

BACKGROUND: In this study, we aimed to investigate the protective effects of melatonin (MEL) and S-methylisothiourea (SMT) on mechlorethamine (MEC) induced nephrotoxicity. MATERIALS AND METHODS: A total of 36 male Sprague-Dawley rats were divided into four groups: control, MEC, MEC+MEL, and MEC+SMT. Three groups received single dose of MEC (3.5 mg/kg) via transdermal route. Control animals were given saline only via transdermal route. MEL (100 mg/kg) was administered intraperitoneally 30 min after the application of MEC, and after the same dose of MEL was given every 12 h for a total of six doses. SMT (50 mg/kg) was also given intraperitoneally 30 min after the application of MEC. RESULTS: The tissue TNF-α, IL-1ß, and NOx levels were found significantly different for all groups (P < 0.001). MEC application resulted in severe histopathological changes. Melatonin showed meaningful protection against kidney damage. But protection by SMT was weaker. TNF-α and IL-1ß levels increased significantly with MEC application, and MEL and SMT ameliorated these increases in kidney tissue. MEC also elevated NOx levels in kidney tissue. CONCLUSIONS: Both inflammation and oxidative stress may have an important role in the MEC induced nephrotoxicity. MEL and SMT may also have anti-inflammatory properties, as well as anti-oxidant properties.

Medical ozone therapy decreases postoperative uterine adhesion formation in rats.

PURPOSE: Various studies have been performed to find out novel treatment strategies to prevent postoperative adhesion formation. Ozone therapy (OT) is shown to reduce inflammation in several pathological conditions. Therefore, we aimed to evaluate the efficacy of OT in a rat model of experimental uterine adhesion (EUA). METHODS: Thirty female Wistar rats (200-250 g) were divided into three groups: sham, EUA and EUA+OT. EUA and EUA+OT groups were subjected to the postoperative adhesion procedure by bipolar coagulation on the uterine horns and corresponding pelvic sidewall parietal peritoneum. EUA+OT group received 0.7 mg/kg daily single dose for 3 days of ozone/oxygen mixture intraperitoneally after adhesion induction. All animals were killed on the 7th day and uterine adhesions were scored. Uterine tissues and peritoneal washing fluid were harvested for all analyses. RESULTS: Uterine malondialdehyde levels in the EUA group were significantly higher compared to the other groups. However, in the EUA group, uterine superoxide dismutase and glutathione peroxidase activities were lower than in other groups. Peritoneal fluid TNF-α levels were found to be significantly different for all groups (p < 0.001). Macroscopic total adhesion score was significantly higher in the EUA group compared to the other groups (p < 0.001). But, total score in the EUA+OT group was lower than in the EUA group (p = 0.006). CONCLUSIONS: Medical OT prevents postoperative uterine adhesions by modulating TNF-α levels and oxidative/antioxidative status in an experimental uterine adhesion model.

The effects of medical ozone therapy on renal ischemia/reperfusion injury.

INTRODUCTION: This study was designed to investigate the possible beneficial effects of medical ozone therapy (OT), known as an immunomodulator and antioxidant, on the renal function, morphology, and biochemical parameters of oxidative stress in kidneys subjected to ischemia/reperfusion injury (IRI). MATERIALS AND METHODS: Thirty male Sprague-Dawley rats were classified into three groups: control, renal IRI, and renal IRI + OT. The IRI group was induced by bilateral renal ischemia for 60 min, followed by reperfusion for 6 h. After reperfusion, the kidneys and blood of rats were obtained for histopathologic and biochemical evaluation. RESULTS: Renal IRI increased the tissue oxidative stress parameters (lipid peroxidation, protein oxidation, and nitrite plus nitrate) and decreased the antioxidant enzyme activities (superoxide dismutase and glutathione peroxidase). The serum neopterin levels showed correlation with oxidative stress parameters. All these parameters were brought to control values in the treatment group. Histopathologically, the kidney injury in the treatment group was significantly lesser than in the renal IRI group. CONCLUSIONS: Our results clearly showed that OT has beneficial effect to protect kidney against IRI. The serum neopterin levels might be used as a marker to detect the degree of renal IRI.

Role of cyclooxygenase 2 and endothelial nitric oxide synthetase in preclinical atherosclerosis.

Cyclooxygenase-2 and endothelial nitric oxide (NO) synthase enzymes may have a role in developing preclinical atherosclerosis. Designed groups were as follows: smoke exposed rats before and during pregnancy, only before pregnancy, and controls. Cross-sectional samples of abdominal aorta were examined immunohistochemically. Cyclooxygenase-2 and eNOS expression was evaluated semi-quantitatively through staining extent (focal, diffuse) and staining intensity. Diffuse COX-2 expression was detected in study groups. Endothelial NO synthase expression was diffuse in study groups. COX-2 and eNOS may contribute to the formation of preatherosclerotic lesions in offspring of rats exposed to cigarette smoke through inflammatory response.

Passive smoke exposure of female rats caused aortic atherosclerotic precursor lesions in their offspring.

The aim of this study was to evaluate the presence and degree of preclinical atherosclerosis in pups of pregnant rats exposed to cigarette smoke. Abdominal aorta examined for atherosclerotic lesions and intimal medial thickness of the abdominal aorta was measured by image analysis. The study groups showed endothelial cellular losses, marked intimal injuries, elastic fiber damages, mononuclear cellular infiltration, and irregularities in internal elastic membrane, with pronounced damages as integrity losses and local fragmentations. The results provide evidence for development of an atherosclerotic process in the neonatal period, even in prenatal stage, long before the formation of smoke-related cardiovascular diseases.

Efficacy of melatonin, mercaptoethylguanidine and 1400W in doxorubicin- and trastuzumab-induced cardiotoxicity.

Doxorubicin (DOX) and Trastuzumab (TRAST) are effective agents for the treatment of many neoplastic diseases. Cardiotoxicity is a major side effect of these drugs and limit their use. In this study, the possible protective effects of melatonin (MEL), mercaptoethylguanidine (MEG), or N-(3-(aminomethyl) benzyl) acetamidine (1400W) against the cardiotoxicity of DOX and TRAST were tested. Male Sprague-Dawley rats received an injection of DOX (20 mg/kg) alone or in combination with TRAST (10 mg/kg) to induce cardiotoxicity; daily treatments with MEL (10 mg/kg × 2), MEG (10 mg/kg × 2), or 1400W (10 mg/kg × 2) were begun 36 hr before and continued for 72 hr after DOX and TRAST administration. Oxidant/antioxidant indices of the cardiac tissue, namely, malondialdehyde, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), as well as serum levels of creatine phosphokinase (CK-MB) were measured. Additionally, the injury scores were evaluated histopathologically. Malondialdehyde levels were significantly higher, while SOD and GSH-Px activities were significantly reduced in rats with DOX- or DOX+TRAST-induced cardiotoxicity compared to normal values. All three treatment agents significantly reversed oxidative stress markers. Serum CK-MB levels were significantly increased after treatment with DOX and DOX+TRAST; these changes were also reversed by each of the treatments and resulted in near normal levels. Both the DOX- and DOX+TRAST-treated rats presented similar histopathologic injuries; in the animals treated with the protective agents, histologic protection of the cardiac tissue was apparent. These results suggested that MEL, MEG, as well as 1400 W are effective in preventing DOX- or DOX+TRAST-induced cardiotoxicity.

Ozone therapy and hyperbaric oxygen treatment in lung injury in septic rats.

Various therapeutic protocols were used for the management of sepsis including hyperbaric oxygen (HBO) therapy. It has been shown that ozone therapy (OT) reduced inflammation in several entities and exhibits some similarity with HBO in regard to mechanisms of action. We designed a study to evaluate the efficacy of OT in an experimental rat model of sepsis to compare with HBO. Male Wistar rats were divided into sham, sepsis+cefepime, sepsis+cefepime+HBO, and sepsis+cefepime+OT groups. Sepsis was induced by an intraperitoneal injection of Escherichia coli; HBO was administered twice daily; OT was set as intraperitoneal injections once a day. The treatments were continued for 5 days after the induction of sepsis. At the end of experiment, the lung tissues and blood samples were harvested for biochemical and histological analysis. Myeloperoxidase activities and oxidative stress parameters, and serum proinflammatory cytokine levels, IL-1ß and TNF-α, were found to be ameliorated by the adjuvant use of HBO and OT in the lung tissue when compared with the antibiotherapy only group. Histologic evaluation of the lung tissue samples confirmed the biochemical outcome. Our data presented that both HBO and OT reduced inflammation and injury in the septic rats' lungs; a greater benefit was obtained for OT. The current study demonstrated that the administration of OT as well as HBO as adjuvant therapy may support antibiotherapy in protecting the lung against septic injury. HBO and OT reduced tissue oxidative stress, regulated the systemic inflammatory response, and abated cellular infiltration to the lung demonstrated by findings of MPO activity and histopathologic examination. These findings indicated that OT tended to be more effective than HBO, in particular regarding serum IL-1ß, lung GSH-Px and histologic outcome.

Rosuvastatin, a new generation 3-hydroxy-3-methylglutaryl coenzyme a reductase inhibitor, reduces ischemia/reperfusion-induced spinal cord tissue injury in rats.

BACKGROUND: Severe neurological injury still represents one of the most devastating complications occurring after surgical repair of thoracoabdominal aneurysms. We aimed to investigate the role of rosuvastatin (RSV) against ischemia/reperfusion injury in an experimental model of spinal cord ischemia in rats. METHODS: Experimental groups included control group (n = 8), ischemia/reperfusion group (n = 8) undergoing aortic occlusion without pharmacologic treatment, and RSV-treated group (n = 8) receiving 10 mg/kg/day of RSV orally for 3 days before spinal cord ischemia. Spinal cord ischemia was induced by occlusion of the abdominal aorta between the left renal artery and aortic bifurcation for 45 minutes, followed by reperfusion. Neurological status was assessed before spinal ischemia and at 48 hours postoperatively. Spinal cords were harvested for histopathologic examination with hematoxylin-eosin staining and biochemical analysis for tissue malondialdehyde, superoxide dismutase, and glutathione peroxidase levels. RESULTS: Decreased spinal cord tissue malondialdehyde levels (p = .01) and increased tissue superoxide dismutase (p = .01) and glutathione peroxidase (p = .09) levels were observed in the RSV-treated group, as compared with the ischemia group. Histopathologic analyses demonstrated typical changes of ischemic necrosis in the ischemia group; however, RSV attenuated tissue necrosis. Total injury score in the RSV-treated group was significantly decreased, as compared with the ischemia group (p < .05). The Tarlov scores at 48 hours postoperatively were higher in the RSV group as compared with the ischemia group. CONCLUSION: RSV administration before spinal cord ischemia reduces spinal cord tissue injury by increasing antioxidant enzyme levels and may reduce the incidence of associated neurological dysfunction.

Comparison of hyperbaric oxygen and medical ozone therapies in a rat model of experimental distal colitis.

OBJECTIVES: Previous studies have shown that hyperbaric oxygen (HBO) is effective in reducing the severity of acute distal colitis (ADC). Ozone therapy (OT) reduces inflammation in several pathological conditions. We aimed to compare the effects of HBO therapy and OT in an experimental ADC rat model. MATERIALS AND METHODS: Forty rats were randomly divided into four groups: Sham, ADC, ADC + HBO, and ADC + OT. Rats in the sham group were given isotonic saline. In the remaining groups, ADC was created by intracolonic administration of 4% acetic acid. No treatment was given to the ADC group. The rats in the ADC + HBO and ADC + OT groups were given HBO and ozone treatments, respectively. The administration of acetic acid caused an inflammatory response in all animals. Distal colons and blood samples were obtained. RESULTS: The histopathological score was significantly higher in the ADC group compared to the other groups. The histopathological scores in the ADC + HBO and ADC + OT groups were significantly lower compared to the ADC group (both p < 0.001). The most pronounced therapeutic effect was observed in the ADC + OT group. Malondialdehyde and neopterin levels and superoxide dismutase and glutathione peroxidase activities in the ADC group were significantly higher compared to the other groups (p < 0.001). CONCLUSION: Our data showed that the therapeutic effect of OT is more pronounced than that of HBO therapy. Its possible effect is by means of decreasing inflammation, edema, and oxidative stress. These findings also suggest that it is possible to improve the outcome of ADC by using ozone therapy as an adjuvant therapy.

Inhibition of iNOS reduces the therapeutic effects of ozone in acute necrotizing pancreatitis: an in vivo animal study.

OBJECTIVE: Previously, it was shown that ozone and S-methylthiourea (SMT) treatments had ameliorative effects on experimental models of acute necrotizing pancreatitis (ANP). It is possible that the combination of ozone and SMT may be more effective than either therapy. Therefore, we investigated the efficacy of combination therapy with ozone and SMT in an experimental rat model of ANP. MATERIAL AND METHODS: Sprague-Dawley rats were divided into five experimental groups. Groups were designed as Sham-operated, ANP, ANP + Ozone, ANP + SMT and ANP + Ozone + SMT. A model of ANP was induced by injection of sodium taurocholate into the common biliopancreatic duct. Four days after induction, blood and tissue samples were obtained for biochemical, microbiological and histopathological analysis. RESULTS: Survival rates, serum amylase, lipase and neopterin levels, tissue oxidative stress parameters, bacterial translocation and tissue injury scores were better in the ozone and SMT groups than in the ANP group. There was no bacterial translocation in the ozone-treated groups. Tissue injury scores in the ozone group were better compared to all ANP induced groups. Ozone and SMT treatment in combination did not have better biochemical, microbiological and histological data compared to ozone or SMT treatments separately in experimental ANP. CONCLUSIONS: The combination of ozone and SMT did not provide any therapeutic advantage in ANP possibly because SMT inhibited nitric oxide synthesis which was needed for ozone action.

Long-term exposure to repetitive hyperbaric oxygen results in cumulative oxidative stress in rat lung tissue.

CONTEXT: Despite its known benefits, hyperbaric oxygen (HBO) is also reported to enhance the production of reactive oxygen species and can cause oxidative stress in several tissues. Previous studies had shown that HBO-induced oxidative stress is directly proportional to both its exposure pressure and duration. Nevertheless, these studies were usually performed with single-session HBO exposure but its clinical use commonly depends on long-term exposure periods. OBJECTIVE: To clarify the oxidative effect of long-term repetitive HBO in the lung tissue of rats. MATERIALS AND METHODS: Male Sprague-Dawley rats were divided into six study groups exposed to consecutive HBO sessions (2.8 atm/90 min) for 5, 10, 15, 20, 30, and 40 days. Animals were sacrificed 24 h after the last HBO session. An additional control group was set to obtain normal data. Lung malondialdehyde (MDA) and carbonylated protein (PCC) levels were determined as measures of oxidative stress along with the activities of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase. RESULTS: None of the measured parameters showed any changes among the groups exposed to 5-15 HBO sessions. However, MDA, PCC, and SOD were found to be significantly increased in the 20 to 40 session groups. DISCUSSION AND CONCLUSION: These results indicate that repetitive treatment with HBO may cause oxidative stress in critical tissues including the lung. Although HBO-mediated free radicals are accepted to be responsible for the benefits of this therapeutic modality, especially in cases with prolonged exposure, possible injurious effects of supranormal values of bio-oxidative products need to be considered.

Cilostazol, a type III phosphodiesterase inhibitor, reduces ischemia/reperfusion-induced spinal cord injury.

BACKGROUND: Spinal cord injury is still a devastating complication after surgical repair of thoracoabdominal aortic pathologies. In this study, we investigated the protective effect of cilostazol, a type III phosphodiesterase inhibitor, against ischemia/reperfusion (I/R)-induced spinal cord injury in rats. METHODS: Twenty-four rats were assigned to 3 experimental study groups: the control group (sham operation, n = 8); the ischemia group (nontreated, n = 8), which underwent aortic occlusion without pharmacologic intervention; and the cilostazol-treated group (n = 8), which received 20 mg/kg cilostazol per day orally for 3 days before spinal ischemia. All animals underwent a 45-minute period of spinal cord ischemia via clamping of the abdominal aorta between the left renal artery and the aortic bifurcation; removal of the aortic clamp was followed by reperfusion. Neurologic status was assessed before spinal ischemia and at 48 hours after the operation. All animals were sacrificed at 48 hours after the operation. Spinal cords were harvested for histopathologic examination and biochemical analyses for the malondialdehyde (MDA) level and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities. RESULTS: Tarlov scores at postoperative hour 48 tended to be higher in the cilostazol-treated group than in the nontreated ischemia group (mean ± SD, 3.66 ± 0.40 versus 2.32 ± 0.80; P = .08). Spinal cord tissue MDA levels (per gram protein) were lower in the cilostazol-treated group than in the nontreated ischemia group (0.27 ± 0.01 mmol/g versus 0.33 ± 0.04 mmol/g, P = .026), and the cilostazol-treated group had higher activities of tissue SOD (519.6 ± 56.3 U/g versus 438.9 ± 67.4 U/g, P = .016) and GSH-Px (4.07 ± 1.37 U/g versus 3.21 ± 1.02 U/g, P = .47) than the nontreated ischemia group. Histopathologic analyses demonstrated that cilostazol treatment attenuated I/R-induced cellular damage. CONCLUSION: Administration of cilostazol before spinal cord ischemia reduced neurologic injury and produced clinical improvement by attenuating oxidative stress in this rat spinal cord I/R model.

Protective effects of angiotensin II type-1 receptor blockade with olmesartan on spinal cord ischemia-reperfusion injury: an experimental study on rats.

BACKGROUND: Spinal cord injury is a major complication of thoracoabdominal aortic operations. We aimed to investigate neuroprotective role of olmesartan administered to rats before ischemia against ischemia-reperfusion (I-R) injury. METHODS: Twenty-four Wistar albino rats were randomly divided into three groups (n = 8 per group): group I (control group, the sham-operation group), group II (the I-R group undergoing aortic occlusion without pharmacologic treatment), and group III (olmesartan-treated group receiving 3 mg/kg/d olmesartan for 14 days before ischemia). Spinal cord ischemia was induced by infrarenal aortic clamping for 45 minutes, followed by reperfusion. Neurological status was assessed by using modified Tarlov score preoperatively and at 48 hours postoperatively. Spinal cords were harvested for histopathologic examination with hematoxylin-eosin staining and biochemical analysis for tissue malondialdehyde, superoxide dismutase, and glutathione peroxidase levels. RESULTS: The rats in the ischemia group had severe deficits including paraplegia after surgery, and they had a worse neurological status compared with the sham group (p < 0.05). The mean Tarlov scores in the ischemia and olmesartan-treated groups at 48 hours postoperatively were 1.6 +/- 0.4 and 2.2 +/- 0.9, respectively (p < 0.05). Histopathologic analyses demonstrated typical changes of ischemic necrosis in the ischemia group; however, olmesartan attenuated tissue necrosis. Decreased spinal cord tissue malondialdehyde (p = 0.047) and increased tissue superoxide dismutase (p = 0.001) and glutathione peroxidase (p = 0.009) levels were measured in the olmesartan-treated group compared with the ischemia group. CONCLUSION: Olmesartan may protect the spinal cord from I-R injury and reduce the incidence of associated neurological dysfunction after temporary aortic occlusion.