Effect of endostatin on 1,2-dimethylhydrazine-induced colon tumor in mice

Endostatin, one of the most potent negative regulators of angiogenesis, is naturally occurring as an inhibitor of angiogenesis capable of inhibiting tumor growth and their metastases. We aimed to investigate the in vivo activities of low dose of recombinant human endostatin on 1,2-dimethylhydrazine (DMH)-induced mice colon cancer. Thirty male Balb-c mice were injected with DMH (20 mg/kg/week) subcutaneously once a week for 12 weeks to induce colon cancer. Twelve weeks after the last DMH injection, 7 mu g rh-endostatin was injected every day for 6 weeks. The animals were killed after 30 weeks for histopathological examination. The weight of the animals, tumor inhibition rates, death rates and the distribution of the lesions in colon were evaluated after the mice were killed. The mean colonic lesions incidence in single tumor bearing mice was 11 +/- 4.0 in those treated with DMH and 8.1 +/- 3.7 in those treated with endostatin. When we look at the distribution of lesions in the colon, they occurred in the distal colon. At the end of our study, we noticed that the number of lesions decreased by 25% in the group of endostatin, considering the number of the lesions in the group of DMH. But there was no statistical difference between the mice treated with endostatin and those treated with DMH. It will be very significant to identify endostatin therapeutic effects as long as proper dose of endostatin is administrated at the proper time, duration and proper tumor model

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

Immunohistochemical, histological and ultrastructural evaluation of the effects of leptin on testes in mice

This study was undertaken to examine the effects of leptin on testes in mice. For this purpose, 12 male mice were divided into two groups. Animals in Group I were designated as control. Mice in Group II were injected daily with leptin for 5 days. All animals were decapitated at the end of the experiment. The testes were removed and weighed out. Testicular tissue specimens were processed for light and electron microscopic examination and semi-quantitative evaluation of immunohistochemical testosterone staining. Intensity of immunostaining was determined on a scale between 0 (no staining) and 5 (heavy staining). For morphometric comparison, diameters of seminiferous tubules from each group were measured. In the leptin injected group, testicular weights and diameters of seminiferous tubules were significantly increased in comparison to control values. In light microscopic examination, an increase in secretory granules in the cytoplasm of Leydig cells was observed after leptin treatment. In the same group, distinct changes indicative of increased cell activation were seen in the ultrastructure of Leydig cells. Amount of mitochondria, lysosomes and cytoplasmic secretory granules were increased. Furthermore, an increase in extensiveness of rough endoplasmic reticulum was noted in this group. Immunohistochemical testosterone staining of the cytoplasm of Leydig cells was heavy (5+) in the leptin treated mice compared to mild score (2+) in the control mice. Additionally, heavy immunostaining of testosterone was also observed in the interstitial space after injection of leptin. The present findings indicate that testicular functions and synthesis of testosterone increase after administration of leptin. Copyright © Taylor & Francis Inc

The changes of Zinc, Copper, and Iron levels in lung tissue after formaldehyde inhalation during the early postnatal period of Rats

Aim: In this study, effects of inhaled formaldehyde (FA) gas, during early postnatal period on the levels of zinc, copper and iron elements and activity of total superoxide dismutase (t-SOD) enzyme in lung tissue and also the reversibility of effects of formaldehyde were examined. Methods: For this purpose newly born albino Wistar rats were exposed to 0 (control), 6 or 12 ppm FA gas for 30 days. After the treatment, rats were decapitated in 30th and 90th days. Activities of t-SOD and the levels of zinc, copper and iron were measured in lung samples. Results: A decrease in the t-SOD activity, copper and iron levels and increase in zinc levels were found in the treatment groups in comparison with control group at both 30th and 90th days measurements. Conclusion: It was thought that exposure to FA may alter the trace element levels of lung tissue including copper, zinc and iron, and induce further oxidative damage on lung tissue

Effects of omega-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 omega-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 omega-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 omega-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 omega-3 essential fatty acids

Effects of Formaldehyde Inhalation on Zinc, Copper and Iron Concentrations in Liver and Kidney of Male Rats

In the present study, adult Wistar albino male rats were exposed to formaldehyde at different periods (subacute and subchronic) and concentrations (5.0 and 10.0 ppm) in order to figure out the changes in the concentration of Zn, Cu and Fe. It was observed that the formaldehyde inhalation caused gradual decline of body weights in the experimental groups when compared with control groups. It was found that subacute (4-week) or subchronic (13-week) exposure to formaldehyde for rats may cause growth retardation. After inhalation procedure, concentration of copper, zinc and iron were determined in liver and kidney tissues of rats using atomic absorption spectrophotometer. In addition, concentrations of Cu, Zn and Fe changed by the effect of formaldehyde in subacute and subchronic groups