Protective effects of benfotiamine on cyfluthrin-induced testicular damage and sperm characteristics during the prepubertal period.

Cyfluthrin, a widely used synthetic pyrethroid insecticide, poses potential risks to both human health and the environment due to its extensive application in residential, agricultural, and outdoor settings. Conversely, benfotiamine, a fat-soluble derivative of vitamin B1, offers versatile therapeutic potential. This experimental study aimed to investigate the impact of cyfluthrin exposure during the prepubertal period on sperm characteristics and testicular tissue integrity in male rats, as well as to assess the protective effects of benfotiamine. A total of 32 4-week-old Wistar albino male rats were divided into four groups. Group I received daily oral gavage of 1 ml/kg/day of olive oil (control). Group II was administered cyfluthrin (54 mg/kg/day) dissolved in 1 ml of olive oil. Group III received both cyfluthrin (54 mg/kg/day) and benfotiamine (100 mg/kg/day) in olive oil. Group IV was given benfotiamine (100 mg/kg/day) in olive oil. After 5 weeks of treatment, the rats underwent evaluations for sperm motility, epididymal sperm density, and abnormal sperm rates. Additionally, their testicular tissues were examined histologically and immunohistochemically. This study underscores the potential hazards of cyfluthrin exposure on male reproductive health and highlights the protective role of benfotiamine in mitigating these effects. It emphasizes the importance of careful pesticide usage and dosage considerations to prevent potential public health issues, including infertility, associated with long-term exposure to pesticides like cyfluthrin.

Protective effects of L-arginine against aluminium chloride-induced testicular damage in rats.

Aluminium (Al) is a toxic metal with frequent exposure because it is a common element in nature and is found in many products used in daily life. L-arginine is a semi-essential amino acid that is involved in many biochemical pathways in the body and has antioxidant effects. The current research evaluated the possible protective effects of L-arginine against aluminium chloride (AlCl3 ) induced testicular damage. In this animal-based experimental study, 28 male Wistar Albino rats were separated into four groups: control, Al (20 mg/kg/day Al), Al + L-arginine (20 mg/kg/day Al + 50 mg/kg/day L-arginine), and L-arginine (50 mg/kg/day L-arginine). All applications were carried out intraperitoneally (i.p.) for 4 weeks. The histopathological changes caused by exposure to Al in the testicular tissue and the protective effects of L-arginine were investigated by using biochemical, histochemical, immunohistochemical [4-hydroxynonenal (4-HNE) and 8-hydroxy-2'-deoxyguanosine (8-OHdG)] and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay techniques. The testicles in the AlCl3 group showed increased 4-HNE, 8-OHdG expressions, apoptotic index, and abnormal sperm content, while serum testosterone levels, sperm motility, and sperm number were decreased (p < 0.05). Furthermore, histomorphometric examinations of testicular tissue indicated significant structural impairments such as vacuolization in the seminiferous tubule epithelium, edema, and vascular congestion in the interstitial area (p < 0.05). However, the structural alterations were largely ameliorated in the Al + L-arginine group (p < 0.05). Thus, L-arginine, which is an antioxidant, may protect against the harmful effects of Al and may help improve male fertility.

Effects of Low- and High-Dose Valproic Acid and Lamotrigine on the Heart in Female Rats.

Epilepsy is a chronic neurological disease that affects more than 50 million people worldwide. Antiepileptic drugs (AEDs) are the mainstay of treatment for most patients with epilepsy. However, AEDs have been reported to be associated with adverse cardiac effects. In this study, it was aimed to investigate the possible cardiac effects of low-dose (LD) and high-dose (HD) treatment of valproic acid (VPA) and lamotrigine (LTG), which are commonly used AEDs, in rats without epilepsy. Rats were randomly grouped as control, LD-VPA, HD-VPA, LD-LTG, and HD-LTG. The cardiac effects of AEDs were evaluated using immunohistological, biochemical, and hemodynamic parameters. A dose-dependent increase in the intensity of caspase-3 staining was detected in the VPA and LTG groups. The intensity of connexin-43 and troponin-T staining in the VPA groups and desmin staining in the LTG groups was significantly reduced. Biochemically, HD-VPA and HD-LTG administrations caused a significant increase in MDA level in myocardial tissue. In addition, as a result of hemodynamic evaluations, cardiac functions were found to be affected and blood pressure increased in HD-LTG group. The results of present study support that VPA and LTG treatment can increase cardiac risk markers.

Effect of Decorin and Bevacizumab on oxygen-induced retinopathy in rat models: A comparative study.

Purpose: The aims of this study were to evaluate the effects of decorin (DCN) in rat oxygen-induced retinopathy (OIR) model and to compare the results with those of bevacizumab. Methods: Twenty-eight newborn Sprague-Dawley rats were randomly divided into four groups. Group I (control): normoxia plus intraperitoneal (ip) normal saline (NS), Group II (sham): OIR plus ip NS, Group III (DCN): OIR plus ip 0.1 mg/kg DCN, and Group IV (bevacizumab): OIR plus ip 2.5 mg/kg bevacizumab. The OIR model was induced by cycling the oxygen concentration between 50% and 10% every 24 h for 14 days following their birth. In all groups, injections were administered on postnatal day (PD) 15. All animals were sacrificed and their right eyes were enucleated on PD 18. The nuclei of neovascular endothelial cells on the vitreal side of the inner limiting membrane were counted, and vascular endothelial growth factor (VEGF) and tumor necrosis factor-alpha (TNF)-α immunoreactivity were detected in histopathological and immunohistochemical examinations. One-way analysis of variance and post hoc Tukey tests were used for statistical analyses of the data. Results: In Groups II, III, and IV, the mean neovascular cell nuclei counts were 13.14 ± 1.34, 6.57 ± 1.51, and 6.71 ± 1.49, respectively. The mean neovascular cell nuclei count was significantly reduced in treatment groups compared with sham group (P < 0.001). In immunohistochemical staining, the immunoreactivity of VEGF was 0.07 ± 0.02, 0.97 ± 0.21, 0.37 ± 0.12, and 0.23 ± 0.17, respectively. Likewise, immunoreactivity of TNF-α was 0.02 ± 0.02, 1.11 ± 0.36, 0.37 ± 0.13, and 0.62 ± 0.21, respectively. VEGF and TNF-α immunoreactivity increased markedly in the sham group compared with those in the control group (P < 0.001). VEGF and TNF-α immunoreactivity of treatment groups decreased significantly compared to sham group (P < 0.001). Conclusion: The beneficial effects obtained by DCN administration in OIR model were comparable to the effects of bevacizumab.

Anti-inflammatory effect of cortistatin in rat endotoxin-induced uveitis model.

PURPOSE: To evaluate the anti-inflammatory effect of cortistatin (CST) in endotoxin-induced uveitis (EIU) model and to compare the results with corticosteroid treatment. METHODS: A total of 35 healthy Wistar albino rats were randomly divided into five groups. EIU was induced by a single subcutaneous injection of lipopolysaccharide (LPS). Group I received intraperitoneal (ip) normal saline (NS), Group II received ip 150 µg LPS plus NS, Group III received ip 150 µg LPS plus 250 µg/kg CST, Group IV received ip 150 µg LPS plus 1mg/kg dexamethasone, and Group V received ip 250 µg/kg CST only. The aqueous humor was collected 24 h after injection and the infiltrating cells were determined. Moreover, histopathological and immunohistochemical examinations were also performed. RESULTS: The clinical score and infiltrated cell count were reduced in Groups III and IV compared with Group II (P < 0.001). The pathological findings of Groups III and IV were significantly reduced compared with Group II (P < 0.001). These findings were similar between Groups III and IV (P = 1.000). Tumor necrosis factor-alpha (TNF-α) and interleukin 1 beta (IL-1ß) immunoreactivity in the ciliary body of Group III and Group IV were significantly reduced compared with Group II (P < 0.001). TNF-α and IL-1ß immunoreactivity in the ciliary body of Group III and Group IV were similar compared with Group I and Group V (range of P values was 0.539-0.958). CONCLUSION: CST administration as a therapeutic agent might ameliorate the severity of intraocular inflammation in uveitis patients. In conclusion, effect of CST and dexamethasone in EIU model was comparable.

Chronic exposure to paroxetine or bupropion modulates the pubertal maturation and the reproductive system in female rats.

Antidepressant drugs are globally used to treat several psychiatric disorders in pediatric patients and their prescription has continued to increase in recent years, especially among girls. In addition to its well-known metabolic and gastrointestinal side effects, antidepressants can cause sexual dysfunction in adults. However, the effects of the antidepressants on puberty onset and reproductive system remain unclear in children and adolescents. Therefore, the goal of this study is to examine the effects of chronic postnatal antidepressant drugs, paroxetine or bupropion, treatments on puberty onset and reproductive system components in female rats weaned at postnatal day (PND) 21. Female rats (n = 10 for each group) were exposed to vehicle (0.2 mL of saline), paroxetine (3.6 mg/kg in 0.2 mL of saline) or bupropion (17 mg/kg in 0.2 mL of saline) daily by oral gavage from the PND 21 to PND 90-93. Chronic paroxetine or bupropion treatments advanced the puberty onset, but the difference was statistically significant in only the paroxetine group. The exposure to bupropion significantly decreased the serum anti-Müllerian hormone (AMH) levels and luteinizing hormone (LH) levels. There were increases in serum estradiol levels by both antidepressant treatments and the significance was found in only the paroxetine group. Consistent with these results, histopathologic changes were observed in the ovary and uterus tissues taken from both antidepressant-treated rats. The obtained results of chronic postnatal exposure to paroxetine or bupropion may change the timing of puberty onset and lead to disruption of reproductive functions in females.

Effects of long-term paroxetine or bupropion treatment on puberty onset, reproductive and feeding parameters in adolescent male rats.

Antidepressant use in adolescents has become more common in recent years. We have found several studies stating that prenatal antidepressant exposure can lead to delayed or earlier puberty onset but there was no study on postnatal paroxetine or bupropion. The main aim of this study was to investigate the effect of postnatal exposure to bupropion or paroxetine on puberty onset, reproductive and feeding results. The male rats (n = 8/group) aged 21 days were exposed to paroxetine (3.6 mg/kg) or bupropion (17 mg/kg) orally by gastric gavage every day from postnatal day 21-90. Also, control group received only saline orally as a vehicle. Postnatal exposure to bupropion or paroxetine delayed puberty onset compared to control group, but it was not significant. Sperm counts were significantly lower in the paroxetine and bupropion groups compared to control group. Sperm motility was significantly lower in only bupropion group. In addition, sperm motility was lower in paroxetine group, but it was not significant. In the histopathological examination, there was damage to the testicular structure in both treatments. Taken together, our result indicates that postnatal paroxetine or bupropion exposure may affect puberty onset and contribute to the impairment in fertility in male rats.

Effects of benfotiamine and coenzyme Q10 on kidney damage induced gentamicin.

OBJECTIVE: Gentamicin (GM) is an effective antibiotic against severe infection but has limitations related to nephrotoxicity. In this study, we investigated whether benfotiamine (BFT) and coenzyme Q10 (CoQ10), could ameliorate the nephrotoxic effect of GM in rats. METHODS: Rats were divided into five groups. Group 1 and 2 served as control and sham respectively, Group 3 as GM group, Group 4 as GM+CoQ10 and Group 5 as GM+BFT for 8days. At the end of the study, all rats were euthanized by cervical decapitation and then blood samples and kidneys were collected for further analysis. Serum urea, creatinine, cytokine TNF-a, oxidant and antioxidant parameters, as well as histopathological examination of kidney tissues were assessed. RESULTS: Gentamicin administration caused a severe nephrotoxicity which was evidenced by an elevated serum creatinine, urea and KIM-1 level as compared with the controls. Moreover, a significant increase in serum malondialdehyde, reduced glutathione. Histopathological examination of renal tissue in gentamisin administered group, there were extremly pronounced necrotic tubules in the renal cortex and hyalen cast accumulation in the medullar tubuli. BFT given to GM rats reduced these nephrotoxicity parameters. Serum creatinine, urea, and KIM-1 were almost normalized in the GM+BFT group. Benfotiamin treatment was significantly decreased necrotic tubuli and hyalen deposition in gentamisin plus benfotiamin group. CoQ10 given to GM rats did not cause any statistically significant alterations in these nephrotoxicity parameters when compared with GM group but histopathological examination of renal tissue in GM+CoQ10 administered group, CoQ10 treatment was decreased necrotic tubuli rate and hyalen accumulation in tubuli. CONCLUSION: The results from our study indicate that BFT supplement attenuates gentamicin-induced renal injury via the amelioration of oxidative stress and inflammation of renal tubular cells.

Protective effects of vitamin D3 against d-galactosamine-induced liver injury in rats.

In this study, we examined liver damage induced by d-galactosamine (d-GaIN) and the protective effects of vitamin D3 in relation to d-GaIN toxicity. Twenty Wistar albino rats were used in this study. The rats were divided into four groups. Group I rats were used as the control group. Group II rats were given a single intraperitoneal injection of d-GaIN. Group III rats were given a single intraperitoneal injection of d-GaIN, intramuscular vitamin D3 for five days. Group IV rats were given intramuscular vitamin D3 for five days. All of rats were euthanized by cervical decapitation on the fifth day of experiment. Upon completion of the experiment, a midsaggital incision was performed, and the livers of all rats were removed and fixed. The livers were processed to perform TUNEL technique and histochemical staining. During the microscope examination, we observed inflamatory cell infiltration, sinusoidal dilatation, and apoptotic bodies due to d-GaIN exposure. In addition, glycogen content of the group II hepatocytes was significantly decreased. Vitamin D3 treatment provided better structural apperance of the livers in group III. TUNEL positive cells were extremly pervasive in the group II livers. The study found group III TUNEL positive cells at a reduced rate in relation to group II due to vitamin D3 treatment. This findings indicate that d-GaIN causes inflamation in the liver. This inflamation triggers the apoptotic process gradually. Vitamin D3 has potency to decrease the severity of d-GaIN-caused structural liver damage.

A comprehensive immunohistochemical examination of the distribution of the fat-burning protein irisin in biological tissues.

Irisin was first identified in skeletal muscle cells, but its precise location has not yet been demonstrated, and there is limited information about irisin protein in other human and rat tissues. The present immunohistochemical study was undertaken to screen skeletal muscle and other tissues for irisin immunoreactivity. Irisin staining was found in the brain (neurons and neuroglia), cardiac and skeletal muscle (fibers) and skin (sebaceous glands) tissues in male rats. In both human adult and fetal skeletal muscle, the most intense immunohistochemical staining was in the perimysium and endomysium, in the peripheral nerve (epineurium) and axon and nerve sheaths spreading among the cells, in the sarcoplasma and subendomysium. Irisin was also demonstrated in the testis (seminiferous tubules, some spermatogenic cells in fetal and Leydig cells in fetal and adult testis, ductus epididymis in fetal human epididymis); pancreas (islets of Langerhans, serous acini cells, intralobular and intralobular ducts cells); liver (hepatocytes; Kupffer cells and sinusoidal endothelial cells); spleen (subcapsular region and periarterial lymphatic sheets); the stomach (gastric parietal cells, tunica muscularis cells). We conclude that the fat-burning protein irisin locally produced in peripheral and central tissues could act as a gatekeeper of metabolic energy regulation in those tissues, since this myokine converts white into brown adipose tissue, enhancing energy expenditure.

Prenatally exposure to exogenous glucocorticoids and stress may affect the inner ear.

OBJECTIVES: This study aims to investigate the effect of exogenous glucocorticoid exposure in the prenatal period on hearing and to evaluate the effectiveness of caffeic acid phenethyl ester (CAPE), an antioxidant, on the prevention of the inner ear injury. MATERIALS AND METHODS: Dexamethasone was given to half of twelve Sprague-Dawley pregnant rats and the distilled water was given to the remaining half. The real subjects were obtained by born of the offsprings. When the all subjects were two months of age, they were exposed to 110 dB noise during four hours as a stressor effect. These subjects were divided into three groups. Group 1: subjects to whose mothers were given distilled water; Group 2: subjects to whose mothers were given dexamethasone; Group 3: subjects to whose mothers were given dexamethasone and CAPE. RESULTS: While there was no statistical significance in hearing thresholds which exposed and not exposed to exogenous dexamethasone before noise exposure (p>0.05) between the groups, the elevation of hearing thresholds of subjects which exposed to exogenous dexamethasone was statistically significant after noise exposure (p<0.05). CONCLUSION: Prenatally exposure to exogenous glucocorticoids may cause the inner ear susceptible to the effect of noise, and CAPE is effective to prevent the possible damage.

Evaluation of the effect of methylprednisolone and N-acetylcystein on anastomotic degeneration and regeneraton of the facial nerve.

OBJECTIVES: This study was aimed to determine the effects of methylprednisolone and N-acetylcystein on nerve healing in facial nerve anastomosis. METHODS: Thirty rabbits were randomly divided into 3 groups: Group I: control group received no medication; Group II: 50mg/kg/day N-acetylcystein administered group; Group III, 1mg/kg/day Methylprednisolone administered group. All rabbits underwent the same standard surgical procedure. A 1mm segment was resected from the facial nerve and the free ends were anastomosed. The drugs were administered for two months twice a day. At the end of the second month, the anastomosed regions were dissected and examined under electron and light microscopy. RESULTS: Best nerve regeneration was observed in the N-acetylcystein and the control groups, respectively, whereas the weakest regeneration was determined in the methylprednisolone group. In the N-acetylcystein group, due to Schwann cell and glial cell proliferation, the increased regeneration rate was significantly higher compared to that of the methylprednisolone group. In the methylprednisolone group, no significant regeneration was observed despite the presence of degenerative signs of significant axonal withdrawal and an increase in the number of myelin debris. CONCLUSION: In the present study, we demonstrated that methylprednisolone had no beneficial effect in nerve regeneration after facial nerve anastomosis. It further caused increased degeneration. On the contrary, N-acetylcystein administration significantly increased the extent of regeneration, whereas it decreased the extent of degeneration compared to the control and the methylprednisolone groups.

Dietary vitamin C and E modulates oxidative stress induced-kidney and lens injury in diabetic aged male rats through modulating glucose homeostasis and antioxidant systems.

Diabetes induces oxidative stress in aged human and rat, although daily supplementation of vitamins C and E (VCE) can be beneficial to aged diabetic rats by reducing free radical production. The aim of the present study was to evaluate whether dietary VCE supplementation relieves oxidative stress in streptozotocin (STZ)-induced diabetic in aged rats. Thirty aged rats were randomly divided into three groups. The first group was used as a control. The second group was made diabetic using a single dose of intraperitoneal STZ. VCE-supplemented feed was given to aged diabetic rats constituting the third group. On the 21st day of the experiment, blood, lens and kidney samples were taken from all animals. Glutathione peroxidase (GSH-Px) activity in lens and kidney, reduced glutathione (GSH), vitamin E and ß-carotene concentrations in kidney were lower in the diabetic group than in the control whereas plasma glucose, urea and creatinine, and kidney and lens peroxidation (LP) levels were higher in the diabetic group than in the control. However, kidney and lens LP levels, and plasma glucose, urea and creatinine values were decreased by VCE supplementation. Lens and kidney GSH-Px activity, kidney GSH, vitamin E and ß-carotene concentrations and erythrocyte counts were increased by VCE treatment. Kidney weights, vitamin A, haemoglobin, hematocrit, leukocyte and platelets values were not changed by diabetes and/or VCE supplementation. VCE ameliorated also diabetes-induced histopathological changes in kidney. In conclusion, we observed that VCE supplementation is beneficial towards kidney and lens of aged diabetic rats by modulating oxidative and antioxidant systems.

Protective effects of CAPE on liver injury induced by CCL4: an electron microscopy study.

This study was designed to investigate the protective effects of caffeic acid phenethyl ester on carbon tetrachloride-induced liver damage in rats. Twenty-four male Wistar rats were divided in three groups. Group I was used as control. Rats in group II were injected with carbon tetrachloride every other day for 1 month, whereas rats in group III were injected with carbon tetrachloride and caffeic acid phenethyl ester every other day for 1 month. At the end of the experiment, all animals were killed by decapitation and their livers were removed. Liver tissues were processed for electron microscopy. Histopathologically, hepatocytes of rats treated with carbon tetrachloride had damage in the cytoplasmic organelles and nuclei membranes as well as an excessive lipid accumulation in the hepatocytes. However, those histopathological changes were reduced with the coadministration of carbon tetrachloride and caffeic acid phenethyl ester. We conclude that caffeic acid phenethyl ester treatment has the capability to prevent carbon tetrachloride-induced liver damage in rats.

Protective effect of the thoracic cage on parenchyma in response to trauma direction in blunt thoracic trauma: an experimental study.

BACKGROUND: We aimed to investigate the protective potential of the thoracic cage on the parenchyma in response to blunt trauma from different directions in an animal model. METHODS: Female Wistar albino rats were divided into control, anterolateral, lateral and posterolateral trauma groups, with six rats in each group. A weight of 500 g was dropped from a height of 40 cm on the left hemithorax to produce an energy of 1.96 joules, using a specially designed platform. Respiratory rates and heart rates were noted before and at 0, 1, and 5 minutes after trauma. Twenty-four hours later, the left lungs were excised for wet lung weight measurement, histological examinations and tissue malondialdehyde determination. RESULTS: Severe pulmonary contusion was observed in all trauma groups according to histological parameters. Malondialdehyde was increased in both the lateral and posterolateral groups. Wet lung weight was increased only in the posterolateral trauma group when compared to controls. Histologically, macrophages were increased and mononuclear cell infiltration was significant in the posterolateral trauma group. There were no significant changes in physiological parameters in the groups. CONCLUSION: Lung parenchyma seems to be badly affected after trauma to the posterolateral thoracic wall. Different thoracic regions may respond differently to the same traumatic stress, and this may be related to the biomechanical properties of the thoracic cage.

Ameliorative effect of caffeic acid phenethyl ester on histopathological and biochemical changes induced by cigarette smoke in rat kidney.

It was aimed to investigate the histopathological and biochemical changes in kidney tissues of rats exposed to cigarette smoke and possible protective effects of caffeic acid phenethyl ester (CAPE) on these changes. Twenty one male Wistar albino rats were divided into three equal groups. Animals in group I were used as control. Rats in group II were exposed to cigarette smoke and rats in group III were exposed to cigarette smoke and daily administration of CAPE. At the end of the 60-day experimental period, all the animals were sacrificed by decapitation. The serum samples obtained from the animals were studied for uric acid, creatinine and blood urine nitrogen (BUN) levels. Following routine histological procedures, kidney tissue specimens were examined under a light microscope. In addition, dismutase (SOD) and glutathione peroxidase (GSH-Px) enzyme activities and malondialdehyde (MDA) and nitric oxide (NO) contents were determined spectrophotometrically in tissue samples. It was found that serum uric acid and BUN levels of the rats exposed to cigarette smoke alone were elevated, although serum creatinine levels did not significantly change. Furthermore, renal SOD, GSH-Px, NO and MDA levels were significantly increased. These increases in serum BUN, and renal SOD, GSH-Px, NO and MDA levels were significantly inhibited by CAPE treatment. In light microscopic observations of tissues from rats exposed to smoke, mesangial cell proliferation in the renal corpuscles, dilatation and congestion in the peritubular capillaries and degenerative alterations in the proximal tubules were noted. There were also atrophic renal corpuscles. However, these histopathological changes were partially disappeared in the rats exposed to cigarette smoke plus CAPE. The present findings indicate that cigarette smoke causes impairment in renal structure and function, which can be prevented by CAPE administration.

Immunolocalization of TGF-beta2 in the rat thymus during late stages of prenatal development.

The aim of this study was to investigate the immunolocalization of transforming growth factor beta (TGF-beta2) in rat thymic stromal cells and thymocytes and investigate the roles of TGF-beta2 in thymopoiesis during the late stages of fetal development. Twelve adult pregnant female Wistar rats weighing 250-270 g were used in this study. The rats were killed by cervical dislocation on gestation days 16 (GD16), 18 (GD18) and 20 (GD20). Fetal thymus glands were prepared and examined by an immunohistochemical technique to reveal binding of an anti-TGF-beta2 rabbit polyclonal antibody. The thymic primordium was surrounded with a connective tissue capsule at GD16 and at this stage TGF-beta2 immunoreactivity was not observed. At GD18, the connective tissue capsule had formed septa which subdivided the tissue into lobules and at this stage TGF-beta2 immunolocalization was detected in the capsule and in thymocytes. Lobulation was more evident at GD20 and TGF-beta2 immunoreactivity of thymocytes was more extensive than on GD18. Results indicate that TGF-beta2 may play an important role in the organization or development of thymocytes in the late stages of thymopoiesis.

Effects of pinealectomy and exogenous melatonin on ghrelin and peptide YY in gastrointestinal system and neuropeptide Y in hypothalamic arcuate nucleus: immunohistochemical studies in male rats.

It is reported that the pineal gland and its main hormone melatonin may have a role in the regulation of ghrelin synthesis in the brain. Stomach is the place where ghrelin is predominantly expressed and secreted. One aim of this study was to investigate possible effects of pinealectomy and melatonin treatment on gastric ghrelin amount. The studies on the effects of the pineal gland on leptin and ghrelin arises the question whether the pineal gland has also effects on the other energy-regulatory peptides such as peptide YY (PYY) and neuropeptide Y (NPY). Therefore, we also aimed to investigate the changes in the immunohistochemical staining of intestinal PYY and hypothalamic NPY following pinealectomy and melatonin treatment. Serum PYY levels were also investigated. Sprague-Dawley rats were divided into four groups as sham-operated (SHAM), sham-operated with melatonin treatment (SHAM-MT), pinealectomised (PNX) and melatonin-treated PNX (PNX-MT) groups. The cells immunostained for ghrelin were abundant throughout the gastric mucosa in all the groups. Neither pinealectomy nor exogenous melatonin affected significantly immunohistochemical staining of ghrelin in stomach. Pinealectomy resulted in a significant increase in immunohistochemical staining of PYY in ileum. The results of serum PYY measurement corresponded closely to the data obtained by immunohistochemical analysis of PYY in ileum, being significantly lower and higher in SHAM and PNX groups, respectively. Pinealectomy caused a decrease in NPY synthesis in ARC as understood from low immunohistochemical staining of NPY. Melatonin treatment increased NPY synthesis in SHAM rats and restored reduction in NPY synthesis caused by pinealectomy. In conclusion, the pineal gland and its main hormone melatonin can be suggested to have a role in the regulation of NPY synthesis in ARC and PYY in gastrointestinal system.

Ultrastructural changes in the kidney of rats with acute exposure to cadmium and effects of exogenous metallothionein.

Ultrastructural changes in the kidneys of rats after acute cadmium exposure and the effects of exogenous metallothionein (MT) were studied by transmission electron microscopy. Thirty-six adult Wistar rats were divided into three groups. Cadmium chloride (CdCl2) (3.5 mg/kg/day) was injected subcutaneously in the first group. In the second group, 30 micromol/kg MT was administered in addition to CdCl2. Control rats received 0.5 ml subcutaneous saline solution. Four rats from each group were killed on days 1, 3, 5, and 7 after administration of the compounds. Kidney tissues were taken and fixed in 2.5% glutaraldehyde solution for electron microscopic observations. Tissue damage in kidney increased as time passed since the administration of CdCl2 in the first group. Degeneration in the proximal and distal tubules was observed. Increased apoptosis was seen in the proximal tubules epithelium, especially on day 7. Peritubular capillaries became dilated, there was degeneration of the endothelial cells, and the amount of intertubular collagen fibers was increased. On day 1, irregular microvilli in the proximal tubules, deepening of the basal striations, and myelin figures; on day 3, multiple vesicular mitochondria and regions of edema around tubules; on days 5 and 7, increased apoptotic cell in the proximal tubules and widened rough endoplasmic reticulum of the endothelial cells of glomerular capillaries were observed. We observed that the structural alterations that increased depending on the day of Cd administration decreased after exogenous MT administration, the dilation of the peritubular capillaries persisted, and there were degenerated proximal tubules. It was established that cadmium chloride was toxic for kidney cortex and caused structural damage. Exogenous MT partly prevents CdCl2-induced damage.

Comparative evaluation of hepatotoxic and nephrotoxic effects of aroclors 1221 and 1254 in female rats.

Polychlorinated biphenyls (PCBs) are persistent environmental pollutants. This study compared effects of two PCB mixtures, Aroclors 1221 (A1221) and 1254 (A1254) on serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), urea, creatinine and uric acid in female rats. Histopathological changes in the liver and kidney were also examined. A group of adult Wistar rats served as controls. Groups II and III were subcutaneously injected with A1221 and A1254 at 10 mg/kg every other day for 6 weeks. At the end of this period, all animals were decapitated and blood samples were collected. Serum urea, creatinine, uric acid, ALT, AST and ALP levels were determined. Liver and kidney were collected for histopathological examination. They were fixed in formaldehyde and processed for light microscopy. Both A1221 and 1254 significantly elevated serum ALT (p < 0.05) and AST (p < 0.01) levels compared to the control group. Serum ALP values were significantly increased by A1221 (p < 0.05), but they were unaffected in the A1254 group. Treatment with both A1221 and A1254 significantly increased serum levels of urea (p < 0.05), creatinine (p < 0.01) and uric acid (except in the A1221 group; p < 0.005). Distinct histopathological changes including renal corpuscular atrophy, peritubular vascular congestion and dilated cortical tubules, sinusoidal dilatation, congestion and mononuclear cell infiltration were observed. These findings suggest that PCBs may cause nephrotoxicity and hepatotoxicity in female rats.