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Protective effects of simvastatin administered in the experimental hepatic ischemia-reperfusion injury rat model

BACKGROUND Hepatic ischemia-reperfusion (I/R) injury is a major complication in clinical practice. Previous studies suggest that statins have pleiotropic effects in addition to cholesterol-lowering effects. In this study, we aimed to investigate the hepatoprotective role of two different doses of simvastatin (SV) pretreatment in rats with experimental hepatic I/R injury. METHODS Adult male Sprague-Dawley rats were divided into four groups (n = 7 in each group) :control, I/R, I/R with 2.5-mg/kg SV, and I/R with 5.0-mg/kg SV. Before hepatic I/R was induced, SV was injected intraperitoneally at doses of 2.5 and 5.0 mg/kg. After 45-min ischemia and a 60-min reperfusion period, the animals were euthanized, and liver tissues were excised. Tissue levels of malondialdehyde and nitric oxide, and activities of superoxide dismutase, glutathione peroxidase, and catalase were measured. Liver tissues were also evaluated histopathologically and immunohistochemically. RESULTS Histopathologic evaluation showed that 5.0-mg/kg SV reduced hepatic damage and apoptosis. Pretreatment with 5.0-mg/kg SV reduced malondialdehyde and nitric oxide levels (P < 0.01) and increased superoxide dismutase, glutathione peroxidase, and catalase activities significantly (P < 0.001, P < 0.01) in I/R with 2.5-mg/kg SV compared with I/R group. In addition, SV decreased Kupffer cell activation, and hypoxia-inducible factor-1α and vascular endothelial growth factor protein levels. CONCLUSIONS The results of this study suggest that 5.0-mg/kg SV pretreatment may be protective against hepatic I/R injury. This effect can be achieved by antioxidant and antiapoptotic activities.

Topical effects of nebivolol on wounds in diabetic rats

OBJECTIVE Recently, it has reported that nebivolol might be useful in the treatment of diabetes mellitus foot ulcers. The aim of this study was to examine treatment of the wounds in streptozotocin-induced diabetic rats with topical nebivolol. METHODS Two 15 × 15 mm-sized wounds were created in 56 streptozotocin-induced rats. A total of 56 diabetic wounds were studied in eight groups (n=7). No treatment was administered to the first and second groups. The third and fourth groups consisted of diabetic rats that were administered 1:1 mixture of lanolin and vaseline for 7 and 14 days, respectively. Five percent nebivolol plus 1:1 mixture of lanolin and vaseline was administered to rats in the fifth and sixth groups for 7 and 14 days, respectively, and 10% nebivolol plus 1:1 mixture of lanolin and vaseline was administered to rats in the seventh and eighth groups for 7 and 14 days, respectively. On days 7 and 14, wound healing was observed, and the percent of wound healing was determined by measuring its size and histopathologic examination. The ratio was calculated by the formula, healing ratio (%)=100 ×(1-wound area/initial wound area). Statistical analysis was performed by ANOVA with Tukeys HSD test and Mann-Whitney U test, using SPSS 15.0 software. RESULTS On days 7 and 14, rates of wound healing in the fifth, sixth, seventh, and eighth groups were 57.42%, 89.16%, 60.80%, and 91.80%, respectively. Multiple comparison showed that rates of wound healing were significantly higher in rats administered 5% and 10% nebivolol than those in rats administered a mixture of lanolin and vaseline and in the untreated group (P<0.05). CONCLUSION Topical nebivolol therapy may be useful for wound healing in diabetic rats. Further studies are needed to support these data.

Different dose-dependent effects of ebselen in sciatic nerve ischemia-reperfusion injury in rats

Ebselen is an organoselenium compound which has strong antioxidant and anti-inflammatory effects. We investigated the neuroprotective role of ebselen pretreatment in rats with experimental sciatic nerve ischemia-reperfusion (I/R) injury. Adult male Sprague Dawley rats were divided into four groups (N = 7 in each group). Before sciatic nerve I/R was induced, ebselen was injected intraperitoneally at doses of 15 and 30 mg/kg. After a 2 h ischemia and a 3 h reperfusion period, sciatic nerve tissues were excised. Tissue levels of malondialdehyde (MDA) and nitric oxide (NO), and activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were measured. Sciatic nerve tissues were also examined histopathologically. The 15 mg/kg dose of ebselen reduced sciatic nerve damage and apoptosis (p<0.01), levels of MDA, NO, and inducible nitric oxide synthase (iNOS) positive cells (p<0.01, p<0.05, respectively), and increased SOD, GPx, and CAT activities (p<0.001, p<0.01, p<0.05, respectively) compared with the I/R group that did not receive ebselen. Conversely, the 30 mg/kg dose of ebselen increased sciatic nerve damage, apoptosis, iNOS positive cells (p<0.01, p<0.05, p<0.001) and MDA and NO levels (p<0.05, p<0.01) and decreased SOD, GPx, and CAT activities (p<0.05) compared with the sham group. The results of this study suggest that ebselen may cause different effects depending on the dose employed. Ebselen may be protective against sciatic nerve I/R injury via antioxidant and antiapoptotic activities at a 15 mg/kg dose, conversely higher doses may cause detrimental effects.

Effects of alprostadil and iloprost on renal, lung, and skeletal muscle injury following hindlimb ischemia–reperfusion injury in rats

Objectives To evaluate the effects of alprostadil (prostaglandin [PGE1] analog) and iloprost (prostacyclin [PGI2] analog) on renal, lung, and skeletal muscle tissues after ischemia reperfusion (I/R) injury in an experimental rat model. Materials and methods Wistar albino rats underwent 2 hours of ischemia via infrarenal aorta clamping with subsequent 2 hours of reperfusion. Alprostadil and iloprost were given starting simultaneously with the reperfusion period. Effects of agents on renal, lung, and skeletal muscle (gastrocnemius) tissue specimens were examined. Results Renal medullary congestion, cytoplasmic swelling, and mean tubular dilatation scores were significantly lower in the alprostadil-treated group than those found in the I/R-only group (P<0.0001, P=0.015, and P<0.01, respectively). Polymorphonuclear leukocyte infiltration, pulmonary partial destruction, consolidation, alveolar edema, and hemorrhage scores were significantly lower in alprostadil- and iloprost-treated groups (P=0.017 and P=0.001; P<0.01 and P<0.0001). Polymorphonuclear leukocyte infiltration scores in skeletal muscle tissue were significantly lower in the iloprost-treated group than the scores found in the nontreated I/R group (P<0.0001). Conclusion Alprostadil and iloprost significantly reduce lung tissue I/R injury. Alprostadil has more prominent protective effects against renal I/R injury, while iloprost is superior in terms of protecting the skeletal muscle tissue against I/R injury.

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 (PT) and then erythrocytes (PE) 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.

Assessment of the effects of levosimendan and thymoquinone on lung injury after myocardial ischemia reperfusion in rats

Aim The aim of this study was to investigate the effects of levosimendan and thymoquinone (TQ) on lung injury after myocardial ischemia/reperfusion (I/R). Materials and methods Twenty-four Wistar albino rats were included in the study. The animals were randomly assigned to 1 of 4 experimental groups. In Group C (control group), left anterior descending artery was not occluded or reperfused. Myocardial I/R was induced by ligation of the left anterior descending artery for 30 min, followed by 2 h of reperfusion in the I/R, I/R-levosimendan (24 µg/kg) (IRL) group, and I/R-thymoquinone (0.2 mL/kg) (IRTQ) group. Tissue samples taken from the lungs of rats were histochemically stained with H&E and immunohistochemically stained with p53, Bcl 2, Bax, and caspase 3 primer antibodies. Results Increased expression of p53 and Bax was observed (4+), especially in the I/R group. In IRTQ and IRL groups, expression was also observed at various locations (2+, 3+). H&E staining revealed that that the lungs were severely damaged and the walls of the alveoli were too thick, the number of areas examined was increased during the evaluation. Caspase 3 expression was observed to be at an (1+, 2+) intensity that was usually weak and diffuse in multiple areas. Bcl 2 was not found to be expressed in any of the tissues. H&E staining revealed that that the lungs were severely damaged in the I/R group, with the walls of the channels and alveoli thickened and edematous, and also an intense inflammatory cell migration was observed. Immunohistochemical staining was more prominent in inflammatory areas and structures around the terminal bronchioles. Conclusion The findings in our study have shown that administration of levosimendan and TQ during I/R increases expression of caspase 3, p53, and Bax in lung tissue and has a protective effect on lung as distant organ. We suggest that findings of this study be elucidated with further large-scale clinical studies.

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.

Exenatide reduces oxidative stress and cell death in testis in iron overload rat model

Glucagon-like peptide-1 (GLP-1) has been demonstrated to affect the oxidative stress status in several in vitro, in vivo and clinical studies. The aim of the present study was to evaluate the effect of a GLP-1 analogue, exenatide, on oxidative stress parameters and apoptotic markers in testicular cells in an iron overload rat model. To obtain this model, the animals were randomly divided into three groups (n=6/group). Rats in the control group received intraperitoneal injections of saline. Intraperitoneal iron dextran (60 mg/kg/day) was given to Group FE for 5 days a week for 4 weeks. The third group (Group Fe +E) was given subcutaneous injections of 10 µg/kg exenatide in two divided doses for 4 weeks in addition to iron dextran. Testes of all rats were immediately removed for immunohistochemical staining and to measure the malondialdehyde level and superoxide dismutase enzyme activity. A significant reduction was observed in caspase-8 and −3 enzyme staining in testicular stromal and endothelial cells in exenatide injected iron overloaded rats when compared with controls. Oxidative stress markers malondialdehyde levels and superoxide dismutase enzyme activities were also significantly lower in exenatide-injected rats when compared with controls. These findings indicate that exenatide may be protective against the harmful effects of iron accumulation in testis. Further studies are required to evaluate how exenatide reduces oxidative stress and cell death in iron overloaded testis tissue.

Effects of hydroxyethyl starch 130/0.4 on the kidney tissue of rats with ureteral obstruction

Objective This study was conducted since the effects of colloid solutions on the renal system remain controversial and need to be adequately studied in animals. We aimed to evaluate the effects of hydroxyethyl starch (Voluven) on the kidney tissue of rats with late renal failure due to ureteral obstruction. Materials and methods Rats were divided into four groups: Group C, control; Group HES, hydroxyethyl starch solution (HES) 130/0.4 (Voluven®); Group UUO, unilateral ureteral obstruction (UUO); and Group UUO-HES, UUO-HES 130/0.4 (Voluven®). In the groups with ureteral obstruction, the distal part of the right ureter was accessed and sutured through a lower abdominal incision under ketamine anesthesia. Any signs of late-stage renal failure were evaluated after three weeks. Rats in the HES group and the renal failure-HES group were administered with HES 130/0.4 as a single intravenous dose of 20 mL/kg. After a follow-up of 24 hours, intra-abdominal blood sample was collected, and the rats were sacrificed. Biochemical and histopathological parameters were then evaluated. Results Ureteral obstruction significantly increased urea and creatinine levels. In addition, when the UUO-HES and HES groups were compared, the administration of HES increased urea and creatinine levels in the UUO-HES group. Nitric oxide enzyme activity and malondialdehyde levels have significantly increased in the UUO groups. In addition, HES significantly increased nitric oxide activity and malondialdehyde levels in the UUO-HES group, in comparison with the HES group. The activity of caspases 3 and 8 was significantly increased in the UUO groups. In addition, HES significantly increased the activity of caspases 3 and 8 in the UUO-HES group, in comparison with the HES group. Light microscopy revealed significant changes in the UUO groups, especially in the obstructed kidneys. Conclusion If indicated, HES should be used with caution in cases of UUO, but not in the cases of bilateral ureteral obstruction. Other aspects of these findings, including the clinical significance and practical applications, merit further experimental and clinical investigation.

Effects of lornoxicam and intravenous ibuprofen on erythrocyte deformability and hepatic and renal blood flow in rats

Background Change in blood supply is held responsible for anesthesia-related abnormal tissue and organ perfusion. Decreased erythrocyte deformability and increased aggregation may be detected after surgery performed under general anesthesia. It was shown that nonsteroidal anti-inflammatory drugs decrease erythrocyte deformability. Lornoxicam and/or intravenous (iv) ibuprofen are commonly preferred analgesic agents for postoperative pain management. In this study, we aimed to investigate the effects of lornoxicam (2 mg/kg, iv) and ibuprofen (30 mg/kg, iv) on erythrocyte deformability, as well as hepatic and renal blood flows, in male rats. Methods Eighteen male Wistar albino rats were randomly divided into three groups as follows: iv lornoxicam-treated group (Group L), iv ibuprofen-treated group (Group İ), and control group (Group C). Drug administration was carried out by the iv route in all groups except Group C. Hepatic and renal blood flows were studied by laser Doppler, and euthanasia was performed via intra-abdominal blood uptake. Erythrocyte deformability was measured using a constant-flow filtrometry system. Results Lornoxicam and ibuprofen increased the relative resistance, which is an indicator of erythrocyte deformability, of rats (P=0.016). Comparison of the results from Group L and Group I revealed no statistically significant differences (P=0.694), although the erythrocyte deformability levels in Group L and Group I were statistically higher than the results observed in Group C (P=0.018 and P=0.008, respectively). Hepatic and renal blood flows were significantly lower than the same in Group C. Conclusion We believe that lornoxicam and ibuprofen may lead to functional disorders related to renal and liver tissue perfusion secondary to both decreased blood flow and erythrocyte deformability. Further studies regarding these issues are thought to be essential.