Ismail Zararsiz

Effect of formaldehyde inhalation on Hsp70 in seminiferous tubules of rat testes: an immunohistochemical study

One parameter which might provide an insight into the underlying mechanism of the effect of formaldehyde (FA) inhalation on testicular tissue, is the assessment of heat shock protein 70 (Hsp70), which increases promptly in cells exposed to stress caused by chemical toxicity. Thus, following subchronic exposure at cytotoxic concentrations, we studied the immunohistochemical effect of FA inhalation on changes in Hsp70 content in testicular tissue. We used 18 albino Wistar rats divided into three groups, exposed to 0 (control), 5 and 10 ppm FA gas for a total of 91 days, 8 h/day, five days a week. Serum testosterone levels were determined using a chemiluminescent enzyme immunoassay. Testicular tissues were stained with Hematoxylin-Eosine and Hsp70 immunohistochemically performed. Diameters of seminiferous tubules and serum testosterone levels in animals inhaling FA were significantly decreased. In seminiferous epithelium stained for Hsp70, compared to those in the control group, the spermatogenetic cells in the experimental groups demonstrated an obvious increase in immunoreaction spermatides in the adluminal region and especially in the cytoplasm of spermatocytes. Immunoreaction of Hsp70 was detected in the spermatogonias of animals exposed to FA inhalation as opposed to those of the control group. Compared to the control, there was a significant increase in the immunoreactions observed not only in the cytoplasm of primary spermatocytes, but also spermatides in the adluminal region of the seminiferous tubules. In conclusion, FA gas may damage spermatogenetic cells and increase Hsp70 synthesis.

Hypothalamic superoxide dismutase, xanthine oxidase, nitric oxide, and malondialdehyde in rats fed with fish ω-3 fatty acids

Phospholipids located in the cellular membrane play a critical role in the fluid-mosaic model of membrane structure and membrane function. Evidence is mounting for the role of abnormal phospholipid metabolism in some neuropsychiatric disorders including schizophrenia. As an important essential fatty acid (EFA), omega-3 (omega-3) fatty acid series are found in large amounts in fish oil. The aim of this experimental study was to assess the changes of some of the oxidant and antioxidant parameters in the hypothalamus of rats fed with omega-3 EFA diet (0.4 g/kg/day) for 30 days. Eight control rats and nine rats fed with omega-3 were decapitated under ether anesthesia, and hypothalamus was removed immediately. Malondialdehyde (MDA) and nitric oxide (NO) levels as well as superoxide dismutase (SOD) and xanthine oxidase (XO) enzyme activities in the hypothalamus were measured. SOD activity was significantly decreased in omega-3 EFA treated group compared to control group (p < 0.014). Tissue MDA and NO levels were also decreased in omega-3 EFA treated group compared to control rats (p < 0.0001). Xanthine oxidase activity was found to be increased in omega-3 EFA treated rats when compared to the control group (p < 0.0001). Taken together, this preliminary animal study provides strong support for a therapeutic effect of omega-3 EFA in some neuropsychiatric disorders in which reactive oxygen species (ROS) are recently accused to be an important physiopathogenetic factor.

Effects of v-3 essential fatty acids against formaldehyde-induced nephropathy in rats:

The aim of this study was to examine the toxicity of formaldehyde (FA) on the kidney and the protective effects of v-3 essential fatty acids against these toxic effects. Twenty-one male Wistar rats were divided into three groups. Rats in Group I comprised the controls, while the rats in Group II were injected every other day with FA. Rats in Group III received v-3 fatty acids daily while exposed to FA. At the end of the 14-day experimental period, all rats were killed by decapitation and the kidneys removed. Some of the kidney tissue specimens were used for determination of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities, and malondialdehyde (MDA) levels. The remaining kidney tissue specimens were used for light microscopic evaluation. The levels of SOD and GSH-Px were significantly decreased, and MDA levels were significantly increased in rats treated with FA compared with those of the controls. Furthermore, in the microscopic examination of this group, glomerular and tubular degeneration, vascular congestion and tubular dilatation were observed. However, increased SOD and GSH-Px enzyme activities, and decreased MDA levels were detected in the rats administered v-3 fatty acids while exposed to FA. Additionally, kidney damage caused by FA was decreased and structural appearance was similar to that of the control rats in this group. In conclusion, it was determined that FA-induced kidney damage was prevented by administration of v-3 essential fatty acids.

Protective effect of melatonin against formaldehyde-induced kidney damage in rats:

This study was undertaken to investigate the protective effects of melatonin against formaldehyde-induced renal damage in rats. For this purpose, 21 male Wistar rats were divided into three groups. The animals in Group I were used as a control, whereas the rats in group II were injected every other day with formaldehyde. The rats in group III received melatonin daily while exposed to formaldehyde. At the end of the 14-day experimental period, all rats were killed by decapitation, and the kidneys were removed. Some of the renal tissue specimens were used for determination of superoxide dismutase, glutatione peroxidase enzyme activities, and malondialdehyde levels. The remaining kidney tissue specimens were used for light microscopic evaluation. The renal tissue activities of superoxide dismutase and glutatione peroxidase were significantly decreased, and malondialdehyde levels were significantly increased in rats treated with formaldehyde compared with those of the control animals. In the light microscopic evaluation of this group, degenerative glomerules, vacuolization and dilatation of distal tubules, and vascular congestion were detected. However, an increase was observed in activities of superoxide dismutase and glutatione peroxidase enzymes, and a decrease of malondialdehyde levels in animals treated with formaldehyde plus melatonin was observed. Furthermore, the histopathological changes caused by formaldehyde were disappeared except for minimal tubular dilatation in this group. In conclusion, the biochemical and histological findings of our study suggest that melatonin administration prevents formaldehyde-induced oxidative renal damage in rats.

Effects of melatonin on carbon tetrachloride-induced changes in rat serum

Carbon tetrachloride (CCl4) is a volatile organic chemical, which causes tissue damage, especially to the liver and kidney. In experimental animals it has been shown to be carcinogenic. This study was designed to evaluate the effects of exogenous melatonin administration on the CCl4-induced changes of some biochemical parameters in rat blood. Twenty-four male Wistar rats were randomly divided into three equal groups: Control, CCl4 and CCl4 plus melatonin (CCl4+MEL). Rats in CCl4 group were injected subcutaneously with CCl4 0.5 ml/kg in olive oil while rats in CCl4+MEL group were injected with CCl4 (0.5 ml/kg) plus melatonin (25 mg/kg in 10% ethanol) every other day for one month. Control rats were treated with olive oil. Serum urea, creatinine, total protein, albumin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total and conjugated bilirubin, alkaline phosphatase (ALP), gamma-glutamyl transferase (γ-GT), total iron, and magnesium levels were determined. Serum AST, ALT, total and conjugated bilirubin, ALP, γ-GT, and total iron levels were significantly higher in CCl4-treated rats than in the controls, while urea, total protein, and albumin levels were significantly lower. Melatonin treatment did not cause a significantly change in serum urea, total protein, and albumin levels. However, the elevations in AST, ALT, total and conjugated bilirubin, ALP, γ-GT, and total iron levels induced by CCl4 injections were significantly reduced by melatonin. On the other hand, melatonin administration significantly decreased serum magnesium levels. These results indicate that melatonin could be a protective agent against the CCl4 toxicity in rats, most likely through its antioxidant and free radical scavenger effects.ResumenEl tetracloruro de carbono (CCl4) es un agente cancerígeno que causa daños orgánicos, especialmente en hígado y riñón. En este trabajo se evalúan los efectos de la administración de melatonina sobre los cambios inducidos por CCl4 de algunos parámetros bioquímicos en suero de rata. Para ello, 24 ratas Wistar macho se dividieron en tres grupos (n=8): Control, CCl4 y CCl4 más melatonina (CCl4+MEL). A las ratas del grupo CCl4 se les inyectó diariamente CCl4 (0,5 ml/kg, sc en aceite de oliva) durante un mes y a las ratas CCl4+MEL se les inyectó además melatonina (25 mg/kg, sc en etanol al 10%) en días alterno. Las ratas control recibieron sólo aceite de oliva por vía subcutánea. Al final del tratamiento, se determinaron los niveles séricos de urea, creatinina, proteína total, albúmina, aspartato aminotransferasa (AST), alanina aminotransferasa (ALT), bilirrubina total y conjugada, fosfatasa alcalina (ALP), gamma-glutamil transpeptidasa (γ-GT), hierro total y magnesio. Los valores de AST, ALT, bilirrubina total y conjugada, ALP, γ-GT, y de hierro total fueron significativamente mayores en suero de ratas tratadas con CCl4 que en los controles, mientras que los niveles de urea, proteína total, albúmina fueron significativamente menores. El tratamiento de melatonina no modificó significativamente los cambios en la urea, proteína total y albúmina sérica. Sin embargo, los increamentos en los niveles de AST, ALT, bilirrubina total y conjugada, ALP, γ-GT y hierro total en suero inducidos por CCl4 se redujeron significativamente por la hormona. Además, la administración de melatonina provocó disminución de los niveles de magnesio. Los resultados indican que la melatonina puede ser un protector contra la intoxicación por CCl4 en ratas, probablemente por sus efectos antioxidantes.

The Effects of Inhaled Formaldehyde on Oxidant and Antioxidant Systems of Rat Cerebellum During the Postnatal Development Process

ABSTRACT The aim of this study was to examine the effects of formaldehyde (FA) inhalation during the early postnatal period on some oxidant and antioxidant systems of rat cerebellum in the developmental process and to determine whether the changes were reversible or not. After birth, 0 (control), 6, or 12 ppm FA5 was given to the neonatal rats throughout 30 days. This was done by placing them for 6 h/day and 5 day/week in a glass chamber containing FA vapor. After cessation of the FA exposing process, seven rats from each group were decapitated on postnatal day (PND) 30 and the remaining seven rats were decapitated on the PND 90, and all cerebellums were removed immediately. On samples, levels of malondialdehyde (MDA) and nitric oxide (NO) and activities of total superoxide dismutase (t-SOD) and glutathione peroxidase (GSH-px) enzymes were measured. We found that activity of GSH-Px and levels of MDA and NO increased; on the other hand, activity of t-SOD decreased significantly in the rats treated with FA compared to control rats at PND 30. In general, the findings at PND 90 were similar to PND 30. Additionally, we observed that the 12-ppm FA-inhaling rats were more affected than the 6-ppm FA-inhaling rats, especially at PND 30. As a result, the present findings suggest that inhalation of FA during the early postnatal period affects the oxidant and antioxidant systems and increases some free radicals in the rat cerebellum in a dose-related manner. We think that these changes were carried on for a long time or may cause irreversible toxicity and oxidative damage.

Protective effects of omega-3 essential fatty acids against formaldehyde-induced cerebellar damage in rats

This study aimed to investigate changes in the cerebellum of formaldehyde-exposed rats and the effects of omega-3 fatty acids on these changes. The study involved 21 male Wistar-Albino rats which were divided into three groups. The rats in Group I comprised the control group. The rats in Group II were injected with intraperitoneal 10% formaldehyde every other day. The rats in Group III received omega-3 fatty acids daily while exposed to formaldehyde. At the end of the 14-day experimental period, all rats were killed by decapitation and the cerebellum removed. The activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), xanthine oxidase (XO), and malondialdehyde (MDA) levels were determined in cerebellum specimens by using spectrophotometric methods. In our study, levels of SOD and CAT were significantly decreased, and GSH-Px, XO, MDA levels were significantly increased in rats treated with formaldehyde compared with those of the controls. Whereas, it was seen that there was an increase in SOD and CAT enzyme activities and decrease in MDA, XO, and GSH-Px levels in rats administered to omega-3 fatty acids with exposure of formaldehyde. It was determined that exposure of formaldehyde increased free radicals in cerebellum of rats and this increase was prevented by administration of omega-3 fatty acids.

Toxic effects of formaldehyde on the urinary system.

Formaldehyde is a chemical substance with a pungent odor that is highly soluble in water and occurs naturally in organisms. Formaldehyde, when taken into organisms, is metabolized into formic acid in the liver and erythrocytes and is then excreted, either with the urine and feces or via the respiratory system. Form-aldehyde is widely used in the industrial and medical fields, and employees in these sectors are frequently exposed to it. Anatomists and medical students are affected by formaldehyde gas during dissection lessons. Because full protection from formaldehyde is impossible for employees in industrial plants using this chemical and for workers in laboratory conditions, several measures can be implemented to prevent and/or reduce the toxic effects of formaldehyde. In this review, we aimed to identify the toxic effects of formaldehyde on the urinary system.

HSP70 immune reactivity and TUNEL positivity in the liver of toluene-inhaled and melatonin-treated rats.

Toluene is a clear, colorless and volatile hydrocarbon that is metabolized in liver, produced free oxygen radicals and can mediate cellular damage. Melatonin which is a pineal gland hormone is a very potent antioxidant. It can make the cellular membrane more durable against oxidative attacks and protect nuclear DNA from oxidative damage. This study aimed to investigate heat shock protein (HSP)70 immune reactivity and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) positivity (apoptotic activity) in the liver of toluene-inhaled and melatonin-treated rats. A total of 21 adult male Wistar albino rats were divided at random into 3 equal groups. Animals in group I were designated as control. The rats in group II were exposed to toluene (3000 ppm/1 h/day) for 30 days, while the rats in group III were treated with melatonin (10 mg/kg/day, intraperitoneally) plus toluene inhalation. At the end of the 30-day experimental period, all rats were killed by decapitation. Then the liver tissues of rats were removed and tissue specimens were embedded in paraffin blocks. The specimens were stained with periodic acid-schiff (PAS) following routine histological procedures. Sections obtained from paraffin blocks were used for immune detection of TUNEL and HSP70. In light microscopic observations of tissues from toluene-inhaled rats, massive hepatocyte degeneration, ballooning degeneration and decreased PAS positivity were observed. Increased TUNEL positivity and HSP70 immune reactivity were determined in toluene-inhaled group and melatonin treatment decreased all these adverse effects.

The protective effects of caffeic acid phenethyl ester against toluene-induced nephrotoxicity in rats

Caffeic acid phenethyl ester (CAPE) has antioxidant and anti-inflammatory properties. The aim of this study is to examine the negative effects of toluene on kidney tissues and functions and to investigate the protective effects of CAPE against toluene-induced nephrotoxicity in rats. A total of 21 male Wistar rats were divided into three groups of equal number in each. The rats in group I were the controls. Toluene was intraperitoneally injected into the rats in group II with a dose of 500 mg/kg. Rats in group III received CAPE daily while exposed to toluene. After 14 days of experimental period, all rats were killed by decapitation. Enzymatic activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) and malondialdehyde (MDA) levels were studied in the rat kidneys. Blood urea nitrogen (BUN) and serum creatinine levels were measured for renal function. The CAT and SOD enzyme activities and serum creatinine levels were significantly increased in rats treated with toluene when compared with the controls. But GSH-Px activity, MDA, and BUN levels showed statistically nonsignificant changes. However, increased CAT and SOD enzyme activities and decreased serum creatinine levels were detected in the rats that received CAPE while exposed to toluene. The GSH-Px activity and MDA and BUN levels in the same group did not show statistically significant changes. The results of our study demonstrated that toluene damages kidney tissue and is a nephrotoxic substance. CAPE was able to prevent the renal damage as antioxidant, antitoxic, and nephroprotective agent.