Swimming training modulates lung injury induced by ovariectomy in diabetic rats: involvement of inflammatory and fibrotic biomarkers.

CONTEXT: Previous studies have noted that the incidence of inflammatory and fibrotic diseases is higher in diabetic menopausal women. OBJECTIVE: In the present study, we evaluated effects of swimming training on inflammatory and fibrotic biomarkers in the lung of ovariectomized diabetic rats. MATERIALS AND METHODS: Forty female rats were assigned into four groups: sham; rats underwent surgery without ovariectomies, OVX: rats that underwent ovariectomies, OVX.Dia: ovariectomized rats with high-fat diet, OVX.Dia. Exe: ovariectomized diabetic rats with 8 weeks of swimming training. At the end of experiment, protein expressions were assessed with western blot. Lung sections were subjected to immunohistochemical and haematoxylin eosin staining. RESULTS: There was a significant difference in the protein expressions between exercise and ovariectomized diabetic groups (p < .05). CONCLUSION: The present study showed strong potential of swimming training on oestrogen deficient diabetic lung. These data encourage further investigation into the inclusive effects of exercise in menopausal diabetic women.

Fibrotic and apoptotic markers alteration in ovariectomised rats: addition of swimming training preserves lung architecture.

CONTEXT: The important role of exercise in pulmonary function during menopause is not well known. Oestrogen deficiency in ageing female mice is accompanied by increase in apoptotic markers such as caspase3 in the lung. OBJECTIVE: The present study was designed to investigate whether swimming training will ameliorate fibrosis and apoptosis resolution in the ovariectomy-induced lung injury rats. MATERIAL AND METHOD: Thirty female rats were assigned to three groups (n = 10 in each group): sham; rats underwent bilateral laparotomy without ovariectomy, OVX; rats underwent bilateral ovariectomy, OVX.Exe; ovariectomised rats that underwent swimming training for eight weeks. At the end of eight weeks, the lungs were harvested and protein expressions in whole lung tissues were analysed by western blotting technique. RESULT: Analysis of proteins expression in the lung showed significant differences between exercise and ovariectomised group (p < .05). CONCLUSION: The present study indicates strong potential of exercise in experimental oestrogen deficiency-induced lung damage.

Genistein preserves the lungs of ovariectomized diabetic rats: addition to apoptotic and inflammatory markers in the lung.

OBJECTIVES: The role of isoflavones in pulmonary structure and function during menopause is not well studied. Moreover, the important role of estrogen in the physiological function of respiratory system has been revealed. Genistein, as an isoflavone, mimics estrogenic in diabetic and ovariectomized rats. Here, we hypothesized that genistein would reverse changes in the protein expression levels related to estrogen deficiency in the lung of ovariectomized diabetic rats. MATERIALS AND METHODS: Wistar female rats were assigned to four experimental groups (n=10 in each group): sham, rats underwent laparotomy without removing the ovaries; OVX, rats that underwent ovariectomy; OVX.D, rats underwent bilateral ovariectomy and were fed a high-fat diet (HFD); OVX.D.G, ovariectomized diabetic rats with genistein administration (1 mg/kg /day). After ovariectomy, rats continued to feed HFD for a 4-week period. After 4 weeks of HFD feeding, a single dose of 30 mg/kg of streptozotocin was administered in the diabetic group. Genistein was administered for eight weeks. At the end of the experiment, lung tissue was removed and Western blotting technique and hematoxylin-eosin staining were used for evaluation of the lung. RESULTS: Treatment with genistein significantly decreased inflammatory and apoptotic biomarkers in the ovariectomized diabetic rats compared to non-treated animals (P<0.05). Also, genistein exerted a protective effect in the lung architecture. CONCLUSION: Genistein partly reversed ovariectomy-induced changes in apoptotic and inflammatory biomarkers in the lung. Our data suggest that genistein treatment as a natural replacement therapy may prevent the estrogen deficiency effects in the lung of diabetic menopausal women.

Apoptosis and Histopathology of the Heart after Renal Ischemia-Reperfusion in Male Rat Running title: Ischemia-Reperfusion Injury

ABSTRACT Ischemia-reperfusion injury was seen in strokes, myocardial infarctions, acute kidney injury, mesenteric ischemia, liver and systemic shock. Renal ischemia-reperfusion is more importance in the setting of kidney transplantation that affects distant organs. In this study forty Male Albino Wistar rats (200-250g) were randomly divided in four group (n=10) including control, sham operation group, nephrectomy and IRI group. All rats anesthetized with intraperitoneal injection of ketamine (50 mg/kg) and xylazine (10 mg/kg) and maintained the core body temperature at approximately 37°C. For inducing IRI group, it was performed right nephrectomy, and in continuing, the left kidney pedicle occluded to 45 min via nontraumatic microvascular clamp for making ischemia that followed 24 hours reperfusion. TUNEL assay was used to detect the cardiac apoptotic cells. Hematoxylin-Eosin staining and periodic acid-Schiff (PAS) procedure was used to histopathological assessment and glycogen accumulation respectively. There was more heart damage at 24 h reperfusion in IRI group. Renal IRI group showed myocardial degeneration, necrosis and increasing connective tissue in myofibril. There were apparent hypertrophy and swelling of myofibril, fragmentation and vacuolization of sarcoplasm. In addition, it was shown elevated apoptotic cell at 24 hours reperfusion in renal IRI group than sham group. There were increases of glycogen accumulation in cardimyocyte of renal IRI group. Our findings suggest that renal IRI-induced cardiac damage, accompanied by an accumulation of glycogen granules, induced apoptosis and histological changes in cardiomyocytes.

Effect of renal ischemia-reperfusion on lung injury and inflammatory responses in male rat.

OBJECTIVES: Acute kidney injury (AKI), a syndrome characterized by decreased glomerular filtration, occurs in every 1 of 5 hospitalized patients. Renal ischemia-reperfusion, one of the main causes of AKI, is of particular importance in the setting of kidney transplantation. MATERIALS AND METHODS: Sixty male rats were divided into four groups including control, nephrectomy, sham surgery and renal ischemia-reperfusion (IRI) group. The rats were anesthetized with intraperitonealketamin and xylazin. For making IRI group, right nephrectomywas performed, and after a week, the left kidney pedicle was occluded for 45 min for making ischemia that followed by 24 hr reperfusion. At the end of reperfusion phase, the lung tissues were isolated to be used in immunohistochemical and histological assays. Immunohistochemical assay was used to evaluate Bcl-2 and TNF-α, and hematoxylin-eosin staining assay was used to histopathology. RESULTS: lung tissues injury after renal ischemia-reperfusion was revealed by immunohistochemistry analysis to increase TNF-α level and decrease Bcl-2 (an anti-apoptotic protein) level. Lung injury and necrosis was discovered by hematoxylin-eosin staining to be more evident in IRI group than sham and control groups. CONCLUSION: The results demonstrated that increase in TNF-α and decrease in Bcl-2 levels in lungs induces the pulmonary inflammatory damage in renal IRI model.

The additive effects of ischemic postconditioning and cyclosporine-A on nitric oxide activity and functions of diabetic myocardium injured by ischemia/reperfusion.

BACKGROUND: The interaction of diabetes with cardioprotection by postconditioning in ischemia/reperfusion injury remains unclear. The aim of this study was to investigate the concomitant effects of ischemic postconditioning (IPostC) and cyclosporine-A (CsA) on nitric oxide (NO) content and parameters of cardiac function of the diabetic myocardium injured by ischemia/reperfusion. METHODS: Diabetes was induced by single injection of streptozotocin (50 mg/kg; intraperitoneally [ip]) in Wistar rats (250-320 g) and the diabetic period was 8 weeks. The hearts (n = 96) were removed quickly, mounted on Langendorff apparatus, and then subjected to 30-minute regional ischemia followed by 45-minute reperfusion. Ischemic postconditioning was induced by 3 cycles of 30-second reperfusion/ischemia at the onset of reperfusion. Myocardial function was measured throughout the experiment, and infarct size (IS) was identified by triphenyltetrazolium chloride (TTC) staining. Total amounts of NO metabolites were determined using Griess method and enzyme-linked immunosorbent assay (ELISA) reader. RESULTS: Administration of either IPostC or CsA alone in nondiabetic animals significantly improved myocardial function and reduced the ISs (28% ± 1.9% or 23% ± 2.0% vs 41% ± 2.9% of the risk zone [RZ], respectively; P < .01), but they had no effect on diabetic hearts (35% ± 1.8% or 32% ± 2.1% vs 39% ± 3.1%, respectively). In addition, myocardial NO level was significantly increased by IPostC only in nondiabetic animals (P < .01). However, after administration of CsA (5 minutes before and 10 minutes after the onset of reperfusion) in postconditioned animals, the cardioprotective and NO-enhancing effects of IPostC were restored in diabetic rats (IS: 21% ± 1.1% vs 39% ± 3.1%), similar to those in nondiabetic controls (19% ± 1.3% vs 41% ± 2.9%; P < .01). CONCLUSION: The present study indicated that IPostC or CsA failed to affect NO levels and failed to protect the diabetic myocardium against ischemia/reperfusion injury. Moreover, concomitant administration of CsA and IPostC at reperfusion can increase NO content and protect the diabetic myocardium.

Effects of exercise on memory consolidation and retrieval of passive avoidance learning in young male rats.

PURPOSE: Previous studies have shown that physical activity improves learning and memory. Present study was performed to determine the effects of short term and long term treadmill exercise on learning, memory consolidation and retrieval of passive avoidance learning in an animal model. METHODS: In this study fifty male Wistar rats with 3-4 months of age were randomly divided into five groups (n=10 in each group). Control group was trained in passive avoidance box and was tested 10 min, 24 hr, 10 days and 3 months later. Two groups exercised on treadmill one hour at 17 m. min for 10 days and 3 months respectively and then were trained in passive avoidance box and were tested 10 min and 24 hr later. The other two groups were trained and were tested 10 days and 24 hr later and then exercised on treadmill as same as other exercised groups. RESULTS: Obtained results showed that short-term (10 days) and long-term (3 months) treadmill running before training by passive avoidance test had significant (P=0.006 and P=0.001 respectively) effects on memory consolidation. However, no significant difference was observed between latency time of rats before and after exercise in exercised groups retrieval (P>0.05). CONCLUSION: Our results showed that physical activity promoted learning and memory consolidation but it did not affect retrieval memory performance.

Long-term exercise training affects age-induced changes in HSP70 and apoptosis in rat heart.

The aim of this study was to test the effects of age and long-term exercise training on antioxidant, heat shock protein 70 (HSP70) expression and apoptosis by comparing the hearts of sedentary and trained rats. Training groups went under 3-, 6- and 9-months of regular exercise (25 m/min with a 0% slope, 60 min/day and 6 days/week). Level of glutathione increased with age in trained and sedentary control rats but level of this factor unchanged by training. Activity of mitochondrial superoxide dismutase (mtSOD) increased in heart homogenates of 6- and 9-months trained animals as compared with their sedentary. The rates of apoptosis were increased with age but level of apoptosis in 9-months trained group was significantly lower than corresponding sedentary. Levels of HSP70 expression were significantly decreased with age while long-term training induced marked increase in HSP70 expression levels. These results show that a long-term regular exercise affects age-induced changes in mtSOD, HSP70 and apoptosis as it increases mtSOD activities and HSP70 expression levels and elicits a marked reduction in apoptosis rate in rat myocardium. However, a shorter training program is not effective.