N-acetylcysteine protects testicular tissue against ischemia/reperfusion injury via inhibiting endoplasmic reticulum stress and apoptosis.

BACKGROUND: In animal models, endoplasmic reticulum (ER) stress has been reported to play a vital role in mediating ischemia/reperfusion (I/R) injury in certain organs, such as brain, liver, and intestine. However, there are a limited number of studies examining the relationship between ER stress and torsion and detorsion (T/D)-induced testicular injury. OBJECTIVE: To investigate the effects of N-acetylcysteine (NAC) on ER-stress and apoptosis in an experimental testicular I/R injury model. DESIGN: A non-blinded experimental study with three arms. Rats were divided into three groups: control group, T/D group, and NAC group. In the pretreatment of the NAC group, 20 mg/kg NAC was given intraperitoneally 30 min before detorsion. Tissue 4-hydroxynonenal (4-HNE), 78-kDa glucose-regulated protein (GRP78), and activating transcription factor 6 (ATF6) levels were determined using enzyme-linked immunosorbent assay. The apoptosis levels were evaluated using terminal deoxynucleotide transferase-mediated dUTP nick-end label assay. RESULTS: In T/D group, tissue 4-HNE, GRP78, ATF6, and apoptotic index levels were significantly higher than control group. These increases were significantly reversed with NAC pretreatment. DISCUSSION: There are some potential drugs that have been shown to reduce ER stress in the experimental ischemia model, and it is questioned that these drug candidates can be used as a therapeutic agent in the treatment of ischemic diseases in the near future. This study was not without limitations. First, the authors applied NAC only 20 mg/kg. In a future study, a dose-dependent assay should be performed to assess the likelihood of an additional testicular protective effect. One limitation of this research is also that in vivo studies cannot be extrapolated to possible effect in clinics. More experiments therefore need to be conducted to extrapolate the study findings to humans. CONCLUSION: The study results showed that, after testicular torsion (TT), the ER stress-related apoptotic pathway plays a pivotal role in testicular injury. Further studies of other experimental models of TT may prove that NAC is a useful agent as an adjunctive treatment in surgical repair in human cases.

Biochemical and morphological evaluation of the effects of propolis on cisplatin induced kidney damage in rats.

Cisplatin (CP) is a chemotherapeutic agent used to treat various types of cancer; nephrotoxicity is the most common adverse effect of the drug. We investigated the protective effects of propolis against CP induced kidney injury. Thirty-six male rats were divided into six equal groups: untreated control group, 50 mg/kg/day propolis group, 100 mg/kg/day propolis group, single-dose 7 mg/kg CP group, 7 mg/kg CP + 50 mg/kg/day propolis and 7 mg/kg CP + 100 mg/kg propolis. Rats were sacrificed after 14 days and kidneys were removed for histopathological and biochemical analyses. We used hematoxylin & eosin and periodic acid-Schiff staining to evaluate kidney histopathology and we used the TUNEL technique to assess apoptosis. We also measured total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), ischemia-modified albumin (IMA) and malondialdehyde (MDA) levels in tissue and blood specimens. Normal morphology was observed in the control, 50 mg/kg/day propolis and 100 mg/kg/day propolis groups by light microscopy. Degeneration of tubule cells, edema and tubule dilation were increased in the CP group compared to the control group. Degeneration of tubule cells and dilation of Bowman's spaces were decreased in the CP + 50 mg/kg/day propolis and CP + 100 mg/kg/day propolis groups compared to the CP group. Tubule dilation decreased significantly in the CP + 100 mg/kg propolis group compared to the CP group. Also, the 7 mg/kg CP group exhibited altered proximal tubule epithelial cells, loss of brush border and thickening of the parietal layer of Bowman's capsule in glomeruli and basal laminae of tubules. A normal brush border was observed in the CP + 50 mg/kg/day propolis and CP + 100 mg/kg/day groups. Serum OSI and MDA levels were increased in the CP group compared to the control group. Serum MDA levels decreased significantly in the CP + 50 mg/kg/day propolis and 100 mg/kg CP + propolis groups compared to the CP group. CP caused significant damage to kidney tissue; propolis exhibited dose-dependent prevention of tissue damage.

Effects of prenatal exposure to a 900 MHz electromagnetic field on 60-day-old rat testis and epididymal sperm quality.

We investigated the effects of exposure in utero to a 900 megahertz (MHz) electromagnetic field (EMF) on 60-day-old rat testis and epididymis. Pregnant rats were divided into control (CG; no treatment) and EMF (EMFG) groups. The EMFG was exposed to 900 MHz EMF for 1 h each day during days 13 - 21 of pregnancy. Newborn rats were either newborn CG (NCG) or newborn EMF groups (NEMFG). On postnatal day 60, a testis and epididymis were removed from each animal. Epididymal semen quality, and lipid and DNA oxidation levels, apoptotic index and histopathological damage to the testis were compared. We found a higher apoptotic index, greater DNA oxidation levels and lower sperm motility and vitality in the NEMFG compared to controls. Immature germ cells in the seminiferous tubule lumen, and altered seminiferous tubule epithelium and seminiferous tubule structure also were observed in hematoxylin and eosin stained sections of NEMFG testis. Nuclear changes that indicated apoptosis were identified in TUNEL stained sections and large numbers of apoptotic cells were observed in most of the seminiferous tubule epithelium in the NEMFG. Sixty-day-old rat testes exposed to 900 MHz EMF exhibited altered sperm quality and biochemical characteristics.

Effects of resveratrol on methotrexate-induced intestinal injury.

UNLABELLED: Methotrexate (MTX) is an anticancer drug. Many studies have reported that MTX causes oxidative stress-associated damage in the small intestine. The purpose of this study was to investigate the possible protective effect of resveratrol (RES), an antioxidant, against MTX-induced damage in the small intestine. MATERIALS AND METHODS: Twenty-four Spraque Dawley rats were randomly divided into four groups; the control group, the RES group given 20 mg/kg RES for 10 days, the MTX group given single dose 30 mg/kg MTX, MTX+RES group given 20 mg/kg RES i.p. for 7 days and 30 mg/ kg MTX i.p. on the 7th day, RES being maintained for 3 further days. All rats were sacrificed on the 10th day, and small intestinal tissue was removed for histopathological and biochemical analysis. Additionally, mucosal apoptosis was analyzed using the TUNEL method. RESULTS: Histopathologically, villar fusion, atrophic villus epithelium, cystic expansion in crypts, hemorrhage and inflammatory cell infiltration were seen in the small intestine in the MTX group. In the MTX+RES group this histopathological damage decreased significantly. Apoptotic score was significantly higher in the MTX group and significantly lower in the MTX+RES group. Tissue malondialdehyde (MDA) level was significantly higher in the MTX group. Superoxide dismutase (SOD) activity was significantly decreased in the MTX group. The MDA level in the MTX+RES group decreased while SOD and catalase (CAT) activities rose, this was not statistically significant.

Perspective on rhabdomyolysis-induced acute kidney injury and new treatment options.

AIM: The purpose of this study was to assess the role of caspase-dependent apoptosis, caspase 1, calpain 1, inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) and the protective effect of grape seed proanthocyanidin extract (GSPE) in the development of rhabdomyolysis-induced acute kidney injury (AKI). MATERIALS AND METHODS: Twenty-one rats were divided into 3 groups - control, rhabdomyolysis and rhabdomyolysis + GSPE. Rhabdomyolysis was induced in the rhabdomyolysis and rhabdomyolysis + GSPE groups with the injection into both hind limbs of 10 ml/kg hypertonic (50%) glycerol following 24-hour dehydration on the 6th day. The rhabdomyolysis + GSPE group was given GSPE at 100 mg/kg by gavage for 7 days. The experiment was concluded 48 h after glycerol injection. Blood specimens were collected, and kidney tissues were extracted for histopathological examination. RESULTS: We identified an increase in blood urea nitrogen, creatinine, histopathological score, iNOS, caspase 3, caspase 1 and calpain 1 expression in the rhabdomyolysis group compared to the controls and a decrease in eNOS expression. In the rhabdomyolysis + GSPE group, however, there was a decrease in these mediators, together with an increase in eNOS expression. CONCLUSION: This study shows for the first time in the literature that calpain 1 is involved in the pathogenesis of rhabdomyolysis-induced AKI, and that GSPE may have a renoprotective effect.

Hormonal and histological changes in the ovaries with high-doses of methylprednisolone administration for acute spinal cord injury: an experimental study.

This study was conducted to investigate the hormonal and histological changes in the ovaries with high doses of methylprednisolone administration for acute spinal cord injury (SCI). Group I (trauma group, eight rats) were subjected to laminectomy and SCI but received no treatment. Group II (steroid group, eight rats) were subjected to SCI and received methylprednisolone (30 mg/kg, intraperitoneally). Group III (control group, six rats) underwent a sham operation without trauma and treatment. Malondialdehyde (MDA) levels were significantly decreased in Group II (p < 0.05). The scores of histopathological damage of the ovaries in the three groups were found to be statistically comparable (p > 0.05). Serum anti-Müllerian hormone (AMH) levels in the steroid group was significantly lower compared with the control group (p < 0.05). High-dose methylprednisolone administration may effect ovarian reserve with reversible ovarian damage and can resolve lipid peroxidation in rats with spinal cord injury.

Protective effects of dexmedetomidine in pneumoperitoneum-related ischaemia-reperfusion injury in rat ovarian tissue.

OBJECTIVES: To determine the effects of dexmedetomidine on pneuomoperitoneum-related ischaemia-reperfusion (I/R) injury in rat ovarian tissue. STUDY DESIGN: Animals were randomized into three groups: Group S (n=8), no pneumoperitoneum; Group C (n=8), pneumoperitoneum; and Group D (n=8), 100µg intraperitoneal dexmedetomidine 30min before pneumoperitoneum. Ovarian tissue was collected from all rats 30min after desufflation, and fresh frozen for histological and biochemical evaluation. RESULTS: Body weight was similar in all three groups (202.62±28.86, 211.00±14.45 and 212.87±15.71g in Groups S, D and C, respectively). The mean malondialdehyde level was higher in Group C than the other groups (p<0.03). When the histological samples of ovarian tissue were compared, vascular congestion, haemorrhage, follicular cell degeneration and infiltrative cell infiltration scores were higher in Group C compared with the other groups (p<0.05). Significantly lower scores for the histological parameters were found in Group D compared with Group C (p<0.05). Similar scores for follicular cell degeneration and inflammatory cell infiltration were found in Group D and Group S (p>0.05). Although vascular congestion and haemorrhage scores were significantly lower compared with Group C, higher scores were found for Group D compared with Group S (p<0.05). CONCLUSION: Pneumoperitoneum caused oxidative injury in rat ovarian tissue. Dexmedetomidine reduced oxidative stress and histological injury related to I/R.

The Effect of High Dose Methylprednisolone on Experimental Ovarian Torsion/Reperfusion Injury in Rats.

Purpose: Aim of the study was to evaluate the effects of high dose methylprednisolone on experimental ovarian torsion-detorsion injury in rats. Materials and Methods: Twenty-two Sprague-Dawley rats were randomly divided into three groups. Group 1 (ischemia group, 8 rats) were subjected to left adnexal torsion for 2 h but received no treatment. Group 2 (methylprednisolone group, 8 rats) were subjected to left adnexal torsion for 2 h and received methylprednisolone (30 mg/kg, administered intraperitoneally) at the end of a 2-hour ischemic period followed by 24-hour reperfusion. Group 3 (control group, 6 rats) underwent a sham operation with no adnexal torsion and no treatment. Results: Serum malondialdehyde (MDA), ischemia-modified albumin (IMA), total oxidant status (TOS) and tissue MDA levels were increased in Group 1 rats; total antioxidant status (TAS) levels and oxidative stress index (OSI) were significantly decreased compared with rats in Groups 2 and 3 (p < 0.05). MDA, IMA, TOS and tissue MDA levels were lower and TAS levels and OSI were higher in Group 3 compared to Group 2. Ovarian damage scores in Group 1 were significantly higher compared with Groups 2 and 3 (p < 0.05). Conclusion: This study demonstrated that high dose methylprednisolone reduces ovarian ischemia/reperfusion injury.

Myocardial perfusion alterations observed months after radiotherapy are related to the cellular damage.

AIM: Myocardial perfusion scintigraphy (MPS) is one of the widely used tools to follow developing radiation-induced heart disease (RIHD). But the clinical significance of MPS defects has not been fully understood. We have investigated the biodistribution alterations related to perfusion defects following radiotherapy (RT) and showed coexisting morphologic changes. ANIMALS, METHODS: A total of 18 Wistar rats were divided into three groups (1 control and 2 irradiated groups). A single cardiac 20 Gy radiation dose was used to induce long term cardiac defects. Biodistribution studies with technetium (99mTc) sestamibi and histological evaluations were performed 4 and 6 months after irradiation. The percent radioactivity (%ID/g) was calculated for each heart. For determination of the myocardial damage, positive apoptotic cardiomyocytes, myocardial cell degeneration, myocardial fibrosis, vascular damage and ultrastructural structures were evaluated. RESULTS: Six months after treatment, a significant drop of myocardial uptake was observed (p < 0.05). Irradiation-induced apoptosis rose within the first 4 months after radiation treatment and were stayed elevated until the end of the observation period (p < 0.05). Also, the irradiation has induced myocardial degeneration, perivascular and interstitial fibrosis in the heart at the end of six and four months (p < 0.01). The severity and extent of myocardial injury has became more evident at the end of six month (p < 0.05). At ultrastructural level, prominent changes have been observed in the capillary endothelial and myocardial cells. CONCLUSION: Our findings suggest that the reduced rest myocardial perfusion, occurring months after the radiation, indicates a serious myocard tissue damage which is characterized by myocardial degeneration and fibrosis.