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1.
This study is devoted to the analysis of DNase activity and DNA fragmentation level in liver cells nuclei of rats with transplanted Guerin's carcinoma on irradiation background. Was shown, that in an organism of previously irradiated rat with tumor the dominance of neoplasm development over the consequences of the irradiation is observed on the initial stages of the experiment. The alignment of gamma-irradiation influencing already takes place from the first stages after Guerin's carcinoma transplantation, which is testified by the decrease of DNase activity of liver cells nuclei and the decrease of a degree of nuclear DNA fragmentation. On the stationary stages of tumor growth the general action of the factors causes differences in the parameters of the investigated animal groups. It shows that together with the constant reduced level of DNase activity the processes of DNA fragmentation strengthen and their intensity reaches maximum during this period. The nature of the fragmented DNA accumulation is similar to the irradiated organism on the first days after the radiation factor removal. Thus, the radiation-induced signal in the organism with tumor is leveled under the conditions of active neoplasm growth; nevertheless, the consequents of its operating do not disappear, and only move away in time.  相似文献   

2.
Radiosensitizing effects of combination of a minor groove DNA ligand, Hoechst-33342, with the glucose analogue and inhibitor of glycolysis, 2-deoxy-D-glucose (2-DG) have been investigated in Ehrlich ascites tumour (EAT) bearing mice following focal irradiation of the tumour with 60Co gamma-rays. Treatment-induced tumour growth delay and tumour free animal survival were evaluated as parameters of radiation response. Focal irradiation of the tumour with a single fraction of 10 Gy induced a moderate delay in tumour growth but did not lead to complete regression in any of the tumours. Intravenous administration of H-342 1 hr before irradiation enhanced radiation-induced growth delay in a dose dependent manner. Complete regression of the tumour was observed only at a dose of 10 mg/kg body wt, leading to a cure (tumour free survival for more than 100 days) rate of 55%. Administration of 2-DG (2 g/kg body wt; i.v.), immediately before irradiation significantly enhanced radiation-induced growth delay and resulted in a cure rate of 45%. In combination with this dose of 2-DG (2 g/kg body wt), H-342 at a lower dose (5 mg/kg body wt) significantly enhanced the cure rate to 66%. H-342 or 2-DG given alone or in combination at the doses investigated here did not show any significant effects on the unirradiated tumour.  相似文献   

3.
The fractionated X-ray irradiation resulted in accumulation of malonic dialdehyde (MDA) in chromatin of the cells of rat liver and activation of nuclear endogenous histon-specific proteases. Seven days after the termination of irradiation, the activity of the nuclear proteases returned to the control level and the MDA level remained 10% above the control parameter. The correlation (r = 0.71) of the processes of MDA accumulation in chromatin and activation of histon-specific proteases in the cells of rat liver after the termination of irradiation showed that these processes were coupled. Transplantation of Guerin's carcinoma to the irradiated animals caused the changes in nuclear proteolysis of the histones and MDA level in chromatin of the tumor-carrier liver cells, which lessened the influence of preliminary X-ray irradiation on rats.  相似文献   

4.
Diallyl sulfide (DAS) is a flavor compound derived from garlic and is active in the inhibition of chemically induced cytotoxicity and carcinogenicity in animal models. This study was conducted to examine the effects of the treatment of DAS and garlic homogenates on the activities of catalase, glutathione peroxidase, and superoxide dismutase. Male Sprague-Dawley rats were treated with DAS i.g. at daily doses of 50 or 200 mg/kg for 8 days, causing the hepatic catalase activity to decrease by 55 and 95%, respectively. Such a decrease in hepatic catalase activity was also observed when the DAS treatment was extended to 29 days. Western blot analysis showed that the DAS treatments resulted in corresponding decreases in the liver catalase protein level. No significant change in the catalase activity in the kidney, lung, and brain was observed with the treatments, but a slight decrease in heart catalase activity was observed. These treatments did not cause significant changes in superoxide dismutase and glutathione peroxidase activities in these tissues. Treatment with DAS at a daily dose of 200 mg/kg for 1-7 days resulted in a gradual decrease in the liver catalase activity to 5% of the control level, but it did not decrease the erythrocyte catalase activity. Treatment of rats with fresh garlic homogenates (2 or 4 g/kg, i.g., daily for 7 days) caused a 35% decrease in liver catalase activity. A/J mice treated with DAS and garlic homogenates also showed a decrease in the liver catalase activity. Diallyl sulfone (DASO2), a DAS metabolite, however, did not effectively decrease catalase activity in mice. The catalase activity was not inhibited by either DAS or DASO2 in vitro. The present results demonstrate that treatment with DAS and garlic homogenates decrease the hepatic catalase level in rats and mice.  相似文献   

5.
Rats were fed selenium-deficient (less than 0.005 mg selenium/kg) or selenium-supplemented diets (0.1 mg selenium/kg, as Na2SeO2) for up to five wks from weaning to assess the effects of developing selenium deficiency on the metabolism of thyroid hormones. Within two wks 3:5,3'-triiodothyronine (T3) production from thyroxine (T4) in liver homogenates from selenium-deficient rats was significantly lower compared with the activity in liver homogenates from selenium-supplemented rats. This decreased activity was probably responsible, in part, for the higher T4 and lower T3 concentrations in plasma from the selenium-deficient rats after 3, 4, and 5 weeks of experiment. Repletion of selenium-deficient rats with single intra-peritoneal injections of 200 micrograms selenium/kg body wt. (as Na2SeO3) 5 days before sampling reversed the effects of the deficiency on thyroid hormone metabolism and significantly increased liver and plasma glutathione peroxidase activities. However a dose of 10 micrograms selenium/kg body wt given to rats of similar low selenium status had no effect on thyroid hormone metabolism or glutathione peroxidase activity but did reverse the increase in hepatic glutathione S-transferase activity characteristic of severe selenium deficiency. Imbalances in thyroid hormone metabolism are an early consequence of selenium deficiency and are probably not related to changes in hepatic xenobiotic metabolizing enzymes associated with severe deficiency.  相似文献   

6.
Nicotinamide and arabinoside cytosine mixed with hydroxyurea were shown to influence the relative amount of double-stranded DNA in Ehrlich ascites tumor cells in vitro subjected to single irradiation (10-30-52 Gy) and in Guerin's carcinoma in rat lungs exposed to fractionated 6 MeV neutron-radiation (1.25 Gy X 4). The DMF values for Ehrlich ascites tumor were a function of a dose range and the duration of the drugs' effect. Guerin's carcinoma DNA was found to be affected more readily when treated with radiation and drugs than when exposed to neutron radiation alone.  相似文献   

7.
During radiotherapy, ionizing irradiation interacts with biological systems to produce free radicals, which attacks various cellular components. The hematopoietic system is well-known to be radiosensitive and its damage may be life-threatening. Melatonin synergistically acts as an immunostimulator and antioxidant. In this study we used a total of 120 rats with 20 rats in each group. Group 1 did not receive melatonin or irradiation (Control group), Group 2 received only 10 mg/kg melatonin (Mel group), Group 3 exposed to dose of 2 Gy irradiation (2 Gy Rad group), Group 4 exposed to 8 Gy irradiation (8 Gy Rad group), Group 5 received 2 Gy irradiation plus 10 mg/kg melatonin (Mel +2 Gy Rad group) and Group 6 received 8 Gy irradiation plus 10 mg/kg melatonin (Mel+8 Gy Rad group). Following exposure to radiation, five rats from each group were sacrificed at 4, 24, 48 and 72 h. Exposure to different doses of irradiation resulted in a dose-dependent decline in the antioxidant enzymes activity and lymphocyte count (LC) and an increase in the nitric oxide (NO) levels of the serum. Pre-treatment with melatonin (10 mg/kg) ameliorates harmful effects of 2 and 8 Gy irradiation by increasing lymphocyte count(LC) as well as antioxidant enzymes activity and decreasing NO levels at all time-points. In conclusion 10 mg/kg melatonin is likely to be a threshold concentration for significant protection against lower dose of 2 Gy gamma irradiation compared to higher dose of 8 Gy. Therefore, it seems that radio-protective effects of melatonin are dose-dependent.  相似文献   

8.
The effect of oral ubiquinone (Q10) intake on thein vivo response of tumors to single dose radiotherapy was examined. The human small-cell lung cancer (SCLC) line CPH 054A, which is sensitive to relatively low doses of X-radiation, was grown as subcutaneous transplants in the flanks of nude nu/nu mice. When macroscopical growth was established, groups of mice received either 10, 20 or 40 mg/kg Q10 in 30 mL soy oil intragastrically daily on 4 consecutive days. Controls received either 30 mL of pure soy oil or nothing. Three h after the last dose half of the tumors in each group received a single radiation dose of 5 Gy, using a 300 kV therapeutic unit. The macroscopic growth pre- and posttreatment was analyzed according to a transformed Gompertz algorithm using the software program GROWTH. Treatment with Q10 or soy oil alone had no effect on tumor growth compared with untreated controls. Groups of tumors that received Q10 and radiotherapy had a significantly lower specific growth delay (SGD) than the radiotherapy-only groups. This effect was significant at 40 mg/kg and borderline at 20 mg/kg, whereas at 10 mg/kg no radioprotection was seen. We conclude that systemic Q10 reduces the response to single dose tumor irradiation inxenotransplanted human SCLC tumors.  相似文献   

9.
Increased oxidative stress and impaired antioxidant defense mechanisms are important factors in the pathogenesis and progression of diabetes mellitus and other oxidant-related diseases. This study was designed to determine whether alpha-lipoic acid, which has been shown to have substantial antioxidant properties, when administered (10 mg/kg ip) once daily for 14 days to normal and diabetic female Sprague-Dawley rats would prevent diabetes-induced changes in biomarkers of oxidative stress in liver, kidney and heart. Serum glucose concentrations, aspartate aminotransferase activity, and glycated hemoglobin levels, which were increased in diabetes, were not significantly altered by alpha-lipoic acid treatment. Normal rats treated with a high dose of alpha-lipoic acid (50 mg/kg) survived but diabetic rats on similar treatment died during the course of the experiment. The activity of glutathione peroxidase was increased in livers of normal rats treated with alpha-lipoic acid, but decreased in diabetic rats after alpha-lipoic acid treatment. Hepatic catalase activity was decreased in both normal and diabetic rats after alpha-lipoic acid treatment. Concentrations of reduced glutathione and glutathione disulfide in liver were increased after alpha-lipoic acid treatment of normal rats, but were not altered in diabetics. In kidney, glutathione peroxidase activity was elevated in diabetic rats, and in both normal and diabetic animals after alpha-lipoic acid treatment. Superoxide dismutase activity in heart was decreased in diabetic rats but normalized after treatment with alpha-lipoic acid; other cardiac enzyme activities were not influenced by either diabetes or antioxidant treatment. These results suggest that after 14 days of treatment with an appropriate pharmacological dose, alpha-lipoic acid may reduce oxidative stress in STZ-induced diabetic rats, perhaps by modulating the thiol status of the cells.  相似文献   

10.
An intramuscular administration of ethonium in a dose of 5 and 10 mg/kg 4-6 h later decreases the level of the reduced glutathione and increases that of oxidized glutathione and the glutathione peroxidase activity in the liver and kidneys of albino rats. The duration of the preparation effect depends on the dose and organ, changes in the glutathione reductase activity in the liver, kidneys, lungs, spleen and heart are not found. Participation of ethonium in formation of peroxides in the organism tissues is shown possible.  相似文献   

11.
Withania somnifera is a medicinal plant used in the treatment of a variety of ailments in the Ayurvedic system. Alcoholic extract of the root of the plant was injected(ip) at daily doses of 200 to 1000 mg/kg body wt for 15 days starting from 24 hr after intradermal inoculation of 5 x 10(5) cells of S-180 in BALB/c mice. Solid tumor growth was monitored for 100 days. Doses of 400 mg/kg and above produced complete regression of tumor after an initial growth, the percentage of complete response (CR) increasing with increasing drug dose. A 55% CR was obtained at 1000 mg/kg drug administration, but this dose also produced some mortality among the animals. A significant increase in the volume doubling time and growth delay was seen when the drug dose was increased from 500 to 750 mg/kg body wt, but further increase in drug dose to 1000 mg/kg did not produce any significant increase in these responses. Cumulative doses of 7.5 to 10 g at daily doses of 500 or 750 mg/kg seems to produce a good response in this tumor.  相似文献   

12.
NLCQ-1 (NSC 709257), a hypoxia-selective cytotoxin that targets DNA through weak intercalation, was investigated for efficacy in combination with single or fractionated radiotherapy of human head and neck xenografts. A staged tumor experiment was performed in tumor-bearing female athymic nude mice that were locally irradiated with or without NLCQ-1. Tumor hypoxia was assessed by immunohistochemistry for pimonidazole adducts in tumors of varying weight. Fractionated radiation, depending on the dose, was administered either once daily for 4 days or once daily for 4 days followed by a 7-day rest and repeat. NLCQ-1 was administered i.p. at 15 mg/kg alone or 45 min before each radiation dose. Hypoxia (1-52%) was detected in all tumors and was positively correlated with tumor size. NLCQ-1 alone resulted in about 10 days of tumor growth delay, measured at sixfold the tumor's original size, without causing toxicity. All combination treatments with NLCQ-1 were more effective than treatments with radiation alone. Radiation at 1 Gy given once daily for 4 days on days 20 and 30 caused 3.5 days of tumor growth delay, whereas in combination with NLCQ-1 it caused 14.5 days of growth delay. Radiation at 5 Gy given in two doses 10 days apart resulted in 3.5 days of tumor growth delay, whereas more than 20 additional days of delay were observed in combination with NLCQ-1. Radiation given as a single dose of 10 Gy resulted in about 7 days of tumor growth delay, whereas in combination with NLCQ-1 about 30 additional days of delay were seen. These results suggest a significant advantage in combining radiation with NLCQ-1 in treatment of human head and neck tumors, which are known to have hypoxic areas.  相似文献   

13.
Erythrocyte glutathione peroxidase activity and alkane production in exhaled air of growing rats were studied as a measure of lipid peroxidation in vivo. When 4-weeks-old, rats were fed a low-selenium (0.05 mg/kg) refined soy concentrate-based diet but adequate in vitamin E and other nutrients. Rats of control groups were fed the same diet supplemented with varying amounts of selenium as sodium selenite. After 10 weeks, erythrocyte glutathione peroxidase activity in the group fed the low selenium diet had decreased to about 40% of the original level. Feeding this diet for a longer period resulted in a slow increase of the glutathione peroxidase level. After about 37 weeks, this level was equal to the initial level. During the same period of rapid growth, ethane and pentane production in the exhaled air of a group of similar animals on the diet containing 0.05 mg Se per kg was slightly although significantly higher compared with the levels of animals on a supplemented (0.4 mg Se per kg) diet. Differences were highest when glutathione peroxidase activity levels in the erythrocytes were lowest and negligible at the start of the experiment and after the period of rapid growth. These results support the view that the seleno-enzyme glutathione peroxidase is active in the defense mechanism of the cell against lipid proxidation.  相似文献   

14.
Administration of cadmium (2.5 mg/kg, sc on alternate days for 3 weeks) to male albino rats led to significant accumulation of cadmium and metallothionein in the liver and kidneys. The activity of glutathione peroxidase was significantly decreased whereas, the concentration of glutathione was increased in these organs. Glycine-l-14C incorporation studies showed enhanced synthesis of glutathione in kidney but not in the liver. Selenium supplementation (1 mg/kg/day orally) failed to prevent these cadmium-induced changes, although it resulted in very high accumulation of selenium in these organs indicating the formation of cadmium-selenium complex.  相似文献   

15.
The effects of toremifene, a new triphenylethylene derivative, on the uterus and DMBA-induced mammary tumors in rats were compared to tamoxifen. The ability of toremifene to compete with [3H]estradiol for cytoplasmic estrogen receptor from rat uterus was similar to tamoxifen, the IC50 being 26 and 23 microM respectively. In immature intact rats the two compounds, administered orally for three consecutive days, had similar intrinsic partial estrogenic efficacy, at 50 mg/kg, about 40% of that of estradiol benzoate (EB). However, at doses less than or equal to 10 mg/kg, the estrogenic effect of toremifene was seen at doses about 40 times higher than that of tamoxifen. The two compounds, administered together with a standard dose of EB, expressed the same maximal antiestrogenic efficacy (about 65% inhibition) at 50 mg/kg. However, the minimal effective antiestrogenic dose of toremifene was about 10 times that of tamoxifen and the ratio between antiestrogenic/estrogenic properties was favourable to toremifene. The duration of the antiestrogenic (antiuterotrophic) effect of a single oral dose (10 mg/kg) of the two compounds proved similar: at least 4 days in intact rats and 3 days in ovariectomized rats. In DMBA-induced tumor bearing rats toremifene was administered p.o., 6 times/week for 4 weeks at 0.08, 0.4, 2, 10 and 50 mg/kg. It was effective at the doses of 2, 10 and 50 mg/kg, inducing 39, 35 and 46% tumor regressions. The activity of toremifene at the minimal effective dose of 2 mg/kg was then compared with that of tamoxifen given at the same dose level. The compounds had comparable activity (47 vs 44% tumor regressions).  相似文献   

16.
Because the synthetic trioxolane OZ78 is active against the liver fluke Fasciola hepatica, we were motivated to investigate the in vivo and in vitro activity against another liver fluke, namely Clonorchis sinensis. Rats infected with C. sinensis for 2 and 5 wk were treated orally with single doses of OZ78 (75, 150, or 300 mg/kg). Worm burden reductions were assessed against untreated control rats. Scanning electron microscopy (SEM) was used to observe adult C. sinensis after recovery from rats 1-3 days posttreatment with a single 300 mg/kg oral dose of OZ78 and after in vitro exposure to concentrations of 1, 10, and 100 microg/ml of OZ78. A single 300 mg/kg oral dose of OZ78 resulted in worm burden reductions of 78.5% and 98.5% against juvenile and adult C. sinensis, respectively. SEM observations revealed tegumental surface alterations, including blebbing and sloughing. OZ78 emerges as a new compound with a broad spectrum of activity against major foodborne trematode infections.  相似文献   

17.
Rat intoxication with acetaminophen (APAP) (500–1500 mg/kg body weight, intragastrically) caused a considerable dose-dependent decrease in reduced glutathione (GSH) level in both liver cell cytoplasm and mitochondria (at the dose 1500 mg/kg body weight by 60% and 33%, respectively). The decrease in cytoplasmic GSH level was more pronounced than in mitochondria. Despite of significant mitochondrial GSH depletion we did not observe any inactivation of the mitochondrial enzymes: succinate dehydrogenase, α-ketoglutarate dehydrogenase, glutathione peroxidase, and also any decrease in the respiratory activity of liver mitochondria isolated from APAP-intoxicated rats. We have investigated hepatoprotector properties of tryptophan derivatives, melatonin and N-acetyl-nitrosotryptophan (a nitric oxide donor). The pineal gland hormone, melatonin, a known antioxidant (10 mg/kg body weight), did not prevent intramitochondrial GSH, but decreased the APAP hepatotoxicity evaluated as the decrease in the activity of marker enzymes of hepatic damage, ALT and AST and total bilirubin content in blood plasma of intoxicated rats, whereas NNT did not exhibit any hepatoprotective effects.  相似文献   

18.
Abstract

Biodistribution and computed tomography (CT) imaging characteristics of iopromide-carrying liposomes were investigated in healthy or tumor-bearing rats. The mean diameter of the liposomes obtained by the ethanol evaporation method was approximately 0.5 urn and the encapsulation amounted to 32 %. In the biodistribution study a significant accumulation of the liposomal contrast medium was observed at both examined doses (250 and 1000 mg total iodine/kg b.w.) in liver and spleen. A dose-dependent enrichment in these organs could be demonstrated. Increasing the iodine and thus lipid dose resulted in a marked increase in blood iodine concentration for prolonged time periods due to saturation of liver uptake. Increasing the injection rate 20-fold at a dose of 250 mg iodine/kg b.w. did not significantly (p > 0.05) change the biodistribution behaviour. In the CT study in healthy rats doses in the range from 100 to 2000 mg iodine/kg were investigated/There was an increase in density in liver and spleen in all animals immediately after the intravenous injection. At lower doses the increase in liver density reached the maximum level within a few minutes and remained almost unchanged during the whole study period (24 h). At doses above 500 mg total iodine or lipid/kg b.w. saturation of liver phagocytosis could be observed. In tumor-bearing rats (Novikoff hepatoma) 150 and 200 mg iodine/kg resulted in a significant increase in density difference between liver and tumor. Liver lesions down to a size of about 5 mm could be clearly delineated over the whole study period (up to 30 minutes).  相似文献   

19.
In this study, we evaluated the anti-tumor potential of luteolin (30mg/kg, p.o.), combined with cyclophosphamide (10mg/kg, i.p.) (LU+CYC) orally administered for 20 days; and CYC individually for 10 days against 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary carcinogenesis in Wistar rats. Combination treatment (LU+CYC) inhibited the incidence rate of tumors and decreased tumor volume significantly without changing the total body weight of the animals. Long-term treatment did not show any apparent toxicity in rats. The CYC-treated group showed potential reduction of tumor volume (74%), severe toxicity, and loss of body weight. In order to elucidate the anticancer mechanism of luteolin, antioxidant activities such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) generation in the liver, kidney and breast, as well as protein profiles, were also examined. Biochemical analysis of the combination-treated group showed significant (P<0.01; P<0.05) inhibition of lipid peroxide (LPx) formation (oxygen-free radicals), the level and the activity of SOD, CAT and GPx were found to be very high than the LU and CYC individually treated rats at a 30mg/kg dose. 2D gel electrophoresis analysis revealed that (56kDa) high molecular weight protein was detected in tumors of rats receiving combination treatment than the cancer controls. The biological significance of that protein involved for the dysfunction of cancer cells and induces apoptosis. Histopathological changes also confirmed the formation of tumor tubules and neovascularization after the treatment. Overall, these results suggest that the combination treatment provided antioxidant defense with strong chemopreventive activity against the genesis of DMBA-induced mammary tumors.  相似文献   

20.
Abhrak bhasma is a commonly used ayurvedic drug against many diseases including hepatitis. It is tested in albino rats using a model of hepatitis induced by a single dose of CCl4 (3 ml/kg body wt). Different doses of abhrak bhasma (10, 20, 30 and 40 mg/kg body wt) were tested to decide the dose related hepatoprotective efficacy. The centrolobular necrosis induced by single dose of CCl4 was reduced significantly by abhrak bhasma (10 mg) and liver histology was also protected by 20 mg dose. Liver acid lipase activity was lowered, while alkaline and lipoprotein lipase activities were elevated due to treatment of single dose of CCl4. Abhrak bhasma counteracted the action of CCl4 on liver lipolytic enzymes. CCl4 did not alter the kidney histologically. Activities of three lipases of rat kidney (acid, alkaline and lipoprotein lipases) were reduced by CCl4 treatment and were reversed by administration of abhrak bhasma. Acid lipase activity of rat adipose tissue was reduced by CCl4 treatment. On the contrary alkaline, lipoprotein and hormone sensitive lipases were enhanced after 24 hr of administration of CCl4. Acid lipase activity was raised by administration of different doses of abhrak bhasma concurrent with CCl4. Abhrak bhasma treatment along with CCl4 enhanced alkaline lipase activity at 10 and 20 mg dose and later it was reduced at 30 and 40 mg doses and came to normal levels. Lipoprotein and hormone sensitive lipases were reduced by the counteraction of increasing doses of abhrak bhasma.  相似文献   

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