Deniz Unal

The effects of high-fat diet on the renal structure and morphometric parametric of kidneys in rats

To characterize the kidney in a high‐fat‐induced obesity model, we examined the renal structure of adult Sprague–Dawley rats fed a control diet or a high‐fat diet for 3 months. Ten adult female Sprague–Dawley rats were fed a diet consisting highly of fat (30%) for a period of 3 months. Ten control rats were maintained with standard rat chow. All animals were weighed every 10 days for 3 months. At the end of the experiment, the naso‐anal length of the anaesthetized rats was measured to calculate body mass index, and subsequently whole kidneys of intracardially formalin‐perfused animals were removed. Quantitative features of the kidney were analysed with the Cavalieri and physical dissector methods applied to serial paraffin sections. Kidney samples were also examined histologically. The body mass indices of the control and treatment groups were 4.528 ± 0.242 and 5.876 ± 0.318 kg m−2, respectively. The difference between the body mass indices of the two groups was statistically significant (P < 0.01, Mann–Whitney U‐test), suggesting that the animals fed with a high‐fat diet may be overweight. Stereological examination of the kidneys revealed differences in kidney weight, total kidney volume, volume of cortex, medulla, glomeruli, proximal and distal tubules, and numerical density of glomeruli and glomerular height in the treatment group compared with the control group. Light microscopic investigation showed a dilatation in blood vessels and Bowmans space, mononuclear cell infiltration, degeneration in nephrons, including glomerulosclerosis and tubular defects, and an increase in the connective tissue in the kidneys in the treatment group. We concluded that a fatty diet is responsible for the rats’ obesity and may lead to renal deformities as a result of histopathological changes such as dilatation, tubular defects, inflammation and connective tissue enlargement of the kidney.

Sildenafil treatment attenuates lung and kidney injury due to overproduction of oxidant activity in a rat model of sepsis: a biochemical and histopathological study

Sepsis is a systemic inflammatory response to infection and a major cause of morbidity and mortality. Sildenafil (SLD) is a selective and potent inhibitor of cyclic guanosine monophosphate (cGMP)‐specific phosphodiesterase PDE5. We aimed to investigate the protective effects of sildenafil on caecal ligation and puncture (CLP)‐induced sepsis in rats. Four groups of rats were used, each composed of 10 rats: (i) 10 mg/kg SLD‐treated CLP group; (ii) 20 mg/kg SLD‐treated CLP group; (iii) CLP group; and (iv) sham‐operated control group. A CLP polymicrobial sepsis model was applied to the rats. All groups were killed 16 h later, and lung, kidney and blood samples were analysed histopathologically and biochemically. Sildenafil increased glutathione (GSH) and decreased the activation of myeloperoxidase (MPO) and of lipid peroxidase (LPO) and levels of superoxide dismutase (SOD) in the septic rats. We observed a significant decrease in LPO and MPO and a decrease in SOD activity in the sildenafil‐treated CLP rats compared with the sham group. In addition, 20 mg/kg sildenafil treatment in the sham‐operated rats improved the biochemical status of lungs and kidneys. Histopathological analysis revealed significant differences in inflammation scores between the sepsis group and the other groups, except the CLP + sildenafil 10 mg/kg group. The CLP + sildenafil 20 mg/kg group had the lowest inflammation score. Sildenafil treatment decreased the serum tumour necrosis factor (TNF)‐α level when compared to the CLP group. Our results indicate that sildenafil is a highly protective agent in preventing lung and kidney damage caused by CLP‐induced sepsis via maintenance of the oxidant–anti‐oxidant status and decrease in the level of TNF‐α.

Protective effects of lithium: a new look at an old drug with potential antioxidative and anti-inflammatory effects in an animal model of sepsis.

Sepsis is the systemic response of an organism against microorganisms and toxins. Lithium is a therapeutic agent used for bipolar disorder and neurodegenerative disease, and it exerts pleiotropic effects on various cellular processes. The present study aimed to determine the effect of lithium on cecal ligation and puncture (CLP)-induced tissue injury in the lungs, by inhibiting the pro-inflammatory cytokine response, and the generation of reactive oxygen species (ROS) triggered by polymicrobial sepsis. Five groups of 20 rats each were used: 1) sham-operated control group; 2) CLP group; 3) 50mg/kg lithium-treated control healthy group; 4) 25 mg/kg lithium-treated CLP group; and 5) 50 mg/kg lithium-treated CLP group. A CLP polymicrobial sepsis model was applied to the rats. All rat groups were killed 16 h later, and lung and blood samples were analyzed histopathologically and biochemically. The 25 and 50 mg/kg of lithium decreased the level of interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and the tumor necrosis factor-α (TNF-α) in the serum, and the 8-iso-prostaglandin F2α (8-ISO) level in lung tissue. The lithium also increased the activity of superoxide dismutase (SOD) and the total levels of glutathione (GSH) in the lung tissues of rats. The histopathological scores and examinations were in accordance with the biochemical results, and revealed significant differences in the inflammation scores between the sepsis group and the other groups. The CLP+lithium 50mg/kg group had the lowest inflammation score among the CLP groups. Our results indicated that the therapeutic administration of lithium prevented oxidative stress changes and cytokine changes, and also protected vital tissues.

Pathological effects of prenatal exposure to a 900 MHz electromagnetic field on the 21-day-old male rat kidney

Abstract We investigated the effects on kidney tissue of 900 megahertz (MHz) EMF applied during the prenatal period. Pregnant rats were exposed to 900 MHz EMF, 1 h/day, on days 13–21 of pregnancy; no procedure was performed on control group pregnant rats or on mothers or newborns after birth. On postnatal day 21, kidney tissues of male rat pups from both groups were examined by light and electron microscopy. Malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione levels also were investigated. Light microscopy revealed some degenerative changes in the tubule epithelium, small cystic formations in the primitive tubules and large cysts in the cortico-medullary or medullary regions in the experimental group. Electron microscopy revealed a loss of peritubular capillaries and atypical parietal layer epithelial cells in the experimental group. Biochemical analysis showed significantly increased MDA levels in the experimental group and decreased SOD and CAT levels. EMF applied during the prenatal period can caused pathological changes in kidney tissue in 21-day-old male rats owing to oxidative stress and decreased antioxidant enzyme levels.

The effects of prenatal exposure to a 900-MHz electromagnetic field on the 21-day-old male rat heart

Abstract The growing spread of mobile phone use is raising concerns about the effect on human health of the electromagnetic field (EMF) these devices emit. The purpose of this study was to investigate the effects on rat pup heart tissue of prenatal exposure to a 900 megahertz (MHz) EMF. For this purpose, pregnant rats were divided into experimental and control groups. Experimental group rats were exposed to a 900 MHz EMF (1 h/d) on days 13–21 of pregnancy. Measurements were performed with rats inside the exposure box in order to determine the distribution of EMF intensity. Our measurements showed that pregnant experimental group rats were exposed to a mean electrical field intensity of 13.77 V/m inside the box (0.50 W/m2). This study continued with male rat pups obtained from both groups. Pups were sacrificed on postnatal day 21, and the heart tissues were extracted. Malondialdehyde, superoxide dismutase and catalase values were significantly higher in the experimental group rats, while glutathione values were lower. Light microscopy revealed irregularities in heart muscle fibers and apoptotic changes in the experimental group. Electron microscopy revealed crista loss and swelling in the mitochondria, degeneration in myofibrils and structural impairments in Z bands. Our study results suggest that exposure to EMF in the prenatal period causes oxidative stress and histopathological changes in male rat pup heart tissue.

Inflammation and peripheral 5-HT7 receptors: The role of 5-HT7 receptors in carrageenan induced inflammation in rats

The aim of this study was: (1) to investigate possible role for 5-HT7 receptors in carrageenan induced inflammatory paw oedema in rats; (2) to determine the presence of 5-HT7 receptors in rat paw tissue; (3) to observe the effects of 5-HT7 receptor agonist and antagonist administration on inflammation; and (4) to determine a unique mechanism for inflammatory processes via 5-HT7 receptors. Effects of 5-HT7 receptor agonist, antagonist and indomethacin were investigated in carrageenan induced paw oedema in rats. Blood and tissue samples were collected and evaluated biochemically for serum cytokine levels, tissue oxidant-antioxidant balance and histopathologically for inflammatory cell accumulation. We performed Real Time PCR analyses for tissue 5-HT7 receptor and COX mRNA expressions. The 5-HT7 receptor agonist AS-19 exerted significant anti-inflammatory effect both alone and in combination with indomethacin. Antagonist, SB269970, did not affect inflammation alone but decreased the effects of agonist when co-administered. 5-HT7 mRNA levels were higher in the carrageenan group than healthy control. Carrageenan+indometacin group decreased the mRNA expression of 5-HT7 when compared to carrageenan group. While agonist administration decreased 5-HT7 mRNA expression when compared to carrageenan group. Agonist decreased paw COX expression. Agonist also decreased serum cytokine levels and tissue oxidative stress. In conclusion, this study demonstrated for the first time that 5-HT7 receptors are expressed in rat paw tissue and that this expression responds to inflammatory stimuli. The 5-HT7 receptor may be a promising new therapeutic target for prevention of inflammation and inflammatory disorders and may also provide a new glimpse into inflammation pathophysiology.

The effects of polymicrobial sepsis with diabetes mellitus on kidney tissues in ovariectomized rats

Objectives: Sepsis model was used to understand the role of sustained hyperglycemia and ovariectomy, either separately or concomitantly, on the response of the activity of the nuclear factor kappa B (NF-κB) and the oxidative response in kidney. Subjects: Polymicrobial sepsis was induced by cecal ligation and puncture (CLP). Diabetes was induced in female rats using administration of alloxan. The rats were divided into five groups: sham control (group 1), ovariectomy (group 2), ovariectomy + sepsis (group 3), ovariectomy + diabetes (group 4), and ovariectomy + diabetic + sepsis (group 5). Results: In kidney tissues, the levels of lipid peroxidation (LPO) and glutathione (GSH) and the activity of catalase (CAT) were higher for groups 3, 4, 5 than the control groups. Superoxide dismutase (SOD) activity was lower for groups 3, 4, 5 than the control groups. We determined that CLP produced injury evident in the kidneys of rats when compared to the control group, whereas the severity of the injury was higher in the diabetes + ovariectomy + CLP group when compared to the CLP group. In immunohistochemical staining, we determined that CLP operation increased NF-κB activation. In the ovariectomized, septic, and diabetic group, NF-κB activation was significantly higher than other groups. Conclusions: Hyperglycemia and ovariectomy severely increased NF-κB activation and oxidant levels with the stages of our sepsis model. Ovariectomy resulted in general changes in metabolism, which are seen in the kidney with diabetes under sepsis conditions.

The Effects of Testosterone on Intestinal Ischemia/Reperfusion in Rats

ABSTRACT Ischemic injury to the gut is believed to occur in many serious clinical conditions. Our aim was to investigate the postischemia/reperfusion (I/R) effects of exogenously administered testosterone on the intestines of normal and orchiectomized rats.Forty-eight rats were divided into eight groups of six animals: (1) Sham-operated control group; (2) Sham-operated + testosterone-treated group; (3) I/R group: Rats were subjected to the surgical procedures and underwent intestinal ischemia for 60 min followed by reperfusion for 60 min; (4) I/R + testosterone-treated group: Rats were subjected to the surgical procedures and received testosterone 100 mg/kg (i.p.); (5) I/R + orchiectomy group: Rats were subjected to the surgical procedures as well as orchiectomy; (6) orchiectomy group: Rats were subjected to the surgical procedures as well as orchiectomy; (7) orchiectomy + testosterone-treated group: Rats were subjected to the surgical procedures as well as orchiectomy and received testosterone 100 mg/kg (i.p.); and (8) I/R + orchiectomy + testosterone-treated group. The histological findings of this study paralleled the observed degree of lipid peroxidation (LPO) and protein oxidation. Intestinal mucosal injury was extensive in the I/R, I/R + orchiectomy, and I/R + orchiectomy + testosterone groups, but was less in the I/R + testosterone group. Histopathological injury also paralleled the degree of oxidative stress. Apoptotic enterocytes were more numerous in the I/R, I/R + orchiectomy, and I/R + orchiectomy + testosterone groups. Administration of testosterone in the presence of testes significantly protected intestinal tissue against I/R mucosal injuries, while administration of testosterone in the absence of testes did not significantly protect intestinal tissue against I/R mucosal injuries.

Effects of diabetes and ovariectomy on rat hippocampus (A biochemical and stereological study)

Oxidative stress is one of the main reasons of both menopause and diabetes. So, it plays crucial role in the pathogeneses of that condition and disease. Therefore, the objective of the present study was to investigate the effects of menopause and diabetes upon the hippocampus using a rat model. Adult female Sprague Dawley rats (n = 24) were allocated randomly as follows; control (C group) ovariectomized (O group), diabetic (D group) and ovariectomy plus diabetic groups (DO group) (n = 6; in each group), respectively. For evaluating the results, tissue biochemistry and stereological analysis were made. Biochemistry results (lipid peroxidase (LPO); catalase (CAT); superoxide dismutase (SOD); total glutatyon (GSH); and myeloperoxidase (MPO) values) in Group C-DO were determined as 12.27, 21.88, 23.08 and 29.90 nmol/gr tissue; 59.3, 70.06, 69.7 and 78.1 mmol/min/mg tissue; 174.2, 156.4, 159.7 and 154.6 mmol/min/mg tissue; 3.63, 3.61, 4.21 and 3.97 nmol/mg tissue; and 5.05, 5.68, 5.58 and 6.19 µmol/min/mg tissue, respectively. Moreover, both menopause and diabetes led to change of lipid profiles. There were significant differences between the control and other groups (Group C and D-DO) (p < 0.01) and among experimental groups (p < 0.01) in terms of neuron number. When the volumes of the hippocampus were compared, there were no significant differences between the all groups (P > 0.05). At this point, we suggested that diabetes could aggravate deleterious effects of ovariectomy.

A Stereological Assessment Method for Estimating the Surface Area of Cycloids

OBJECTIVE In this study, we sought to determine differences in estimations of surface area made by classical vertical uniform random (VUR) section series and vertical section series obtained perpendicular to a fixed horizontal plane. MATERIALS AND METHODS One volunteer subject (male, 25 years of age) with no neurological deficit was chosen at random from a bank of controls in the magnetic resonance (MR) image data library of the Department of Radiology. First, a soccer ball with known geometrical features (radius: 9.75 cm) was imaged using a T1-weighted MR scanner at 5-mm thickness (total 40 sections) to test the validity and reliability of surface area and volume measurements obtained via stereological methods. Second, T1-weighted MR section profiles were obtained from a volunteer individual. Surface area and volume estimation procedures were carried out using the Stereo Investigator 6, MicroBright-Field, Inc., USA. CONCLUSIONS We determined that there are no differences in either surface area or volume estimations made using VUR sections and direct vertical sections. We have performed an exhaustive series analysis with a variety of objects.