Animals ; Diethylnitrosamine/toxicity* ; Liver ; Liver Neoplasms/chemically induced* ; Rats

To explore the renal metabolic markers relavant to the renal toxicity of diethylnitrosamine and the metabolic pathways involved in the renal metabolic markers.
 Methods: Nineteen Sprague Dawley rats were assigned into 2 groups: A normal control group (n=9) and a diethylnitrosamine (DEN) administration group (n=10). The rats in the normal control group were given sterilized water for free drinking. The rats in the DEN administration group were given 0.1 mg/mL DEN solution for free drinking. After 18 weeks, the kidney tissues were collected and tested for nuclear magnetic resonance detection and pathological examination.
 Results: The content of kidneys metabolites in the rats with the DEN administration was changed significantly. The levels of alanine, taurine, pyruvate, acetate, and choline were significantly reduced compared with rat in the normal control group, while the levels of creatine, glycine, TMAO, methionine, proline, lactate, valine, leucine and isoleucine were significantly increased.
 Conclusion: Metabolicomics studies have revealed significant differences in five metabolic pathways, including valine, leucine and isoleucine biosynthesis, glycine serine and threonine metabolism, pyruvate metabolism, glycolysis or gluconeogenesis, cysteine and methionine metabolism.
Alkylating Agents ; toxicity ; Animals ; Diethylnitrosamine ; toxicity ; Glycine ; Kidney ; drug effects ; physiology ; Metabolic Networks and Pathways ; drug effects ; Rats ; Rats, Sprague-Dawley

The modifying potential of capsaicin (CAP) on lesion development was examined in a rat multiorgan carcinogenesis model. Groups 1 and 2 were treated sequentially with diethylnitrosamine (DEN) (100 mg/kg, ip, single dose at commencement), N-methylnitrosourea (MNU) (20 mg/kg, ip, 4 doses at days 2, 5, 8, and 11), and N,N-dibutylnitrosamine (DBN) (0.05% in drinking water during weeks 3 and 4). Group 3 received vehicles without carcinogens during the initiation period. Group 4 served as the untreated control. After this initiating procedure, Groups 2 and 3 were administered a diet containing 0.01% CAP. All surviving animals were killed 20 weeks after the beginning of the experiment and the target organs examined histopathologically. The induction of GST-P+ hepatic foci in rats treated with carcinogens was significantly inhibited by treatment with CAP. CAP treatment significantly decreased the incidence of adenoma of the lung but increased the incidence of papillary or nodular (PN) hyperplasia of the urinary bladder. The tumor incidence of other organs, such as the kidney and thyroid, was not significantly different from the corresponding controls. These results demonstrated that concurrent treatment with CAP not only can inhibit carcinogenesis but can also enhance it depending on the organ. Thus, this wide-spectrum initiation model could be used to confirm organ-specific modification potential and, in addition, demonstrate different modifying effects of CAP on liver, lung, and bladder carcinogenesis.
Animals ; Capsaicin/pharmacology/*toxicity ; Cocarcinogenesis ; Diethylnitrosamine ; Liver Neoplasms, Experimental/chemically induced/prevention & control ; Lung Neoplasms/chemically induced/prevention & control ; Male ; Methylnitrosourea ; Neoplasms, Experimental/*chemically induced/prevention & control ; Nitrosamines ; Rats ; Rats, Inbred F344 ; Urinary Bladder Neoplasms/chemically induced

The effects of ethyl alcohol and pig serum administration on the development of preneoplastic hepatic enzyme-altered foci were examined in an in vivo mid-term assay system. Rats were initially given a single dose (200 mg/Kg) intraperitoneal injection of diethylnitrosamine (DEN). Two weeks later, treatment was started with 10% ethanol + 10% sucrose solution, 10% sucrose solution, or tap water as drinking water for 6 weeks with or without intraperitoneal injection of porcine serum twice a week. All rats were subjected to a two-thirds partial hepatectomy at week 3. The modification potentials were evaluated by comparing the number and area per cm2 of glutathione S-transferase placental form-positive (GST-P+) foci in the liver of each group. As a result, ethanol significantly enhanced the development of GST-P+ foci. Unfortunately, the porcine serum injection produced no hepatic fibrosis and no significant alteration in GST-P+ foci.
Animals ; Diethylnitrosamine/*toxicity ; Ethanol/*pharmacology ; Glutathione Transferase/*metabolism ; Immune Sera/pharmacology ; Liver Cirrhosis, Alcoholic/enzymology ; Male ; Placenta/drug effects/*enzymology ; Precancerous Conditions/*chemically induced/enzymology ; Rats ; Rats, Inbred F344 ; Survival Rate ; Swine

With the aim of establishing bio-indices for the development of multistep hepatotumorigenesis, rats were fed water containing 0.01% diethylnitrosamine (DEN) ad libitum for 13 weeks. This treatment with DEN only made it possible to induce hepatic tumors in 100%. After the DEN administration, several clinical symptoms were observed including minor behavioral changes, brittleness of hair and a decrease in water and food intake. The concentration of total serum protein and albumin in all treated groups was significantly lower than in non-treated controls (p<0.05). Increase of specific enzyme (AST, ALT and GGT) activity (p<0.05), variable tumor size and hepatomegaly of the liver was observed in all rats treated with DEN for 10 weeks. Both hepatocellular carcinoma and cholangiocarcinoma were found in the same livers at the same time, and were prominently developed after 12 weeks. In case of carcinoma, some of the livers showed more or less advanced states over the 12-15 weeks period. In the present study, hepatocellular carcinoma was developed by treating DEN in only the drinking water, without any other carcinogens or without partial hepatectomy. These results indicate that DEN is a new carcinogen that acts directly on it the liver, moreover, it might be very useful for investigating hepatotumorigenesis.
Alanine Transaminase/blood ; Animals ; Aspartate Aminotransferases/blood ; Biological Markers/blood ; Carcinogens ; *Cell Transformation, Neoplastic ; Diethylnitrosamine/toxicity ; Liver/drug effects/*pathology ; Liver Neoplasms/blood/chemically induced/*pathology ; Liver Neoplasms, Experimental/blood/*pathology ; Male ; Rats ; Rats, Sprague-Dawley ; gamma-Glutamyltransferase/blood

BACKGROUNDIt is generally accepted that spleen plays a complex role in the tumor immunity, which would change in the different periods of cancer. In this study, we investigated the changes in the function of splenic macrophage (Mphi) in different stages of liver cancer induced by diethylnitrosamine (DEN) in rats. The aim was to support the characteristics of "two-way" and "phase" of spleen in tumor immunity.

METHODSThe model of pulmonary metastasis of liver cancer was established in forty male SD rats by DEN. In the 8th, 13th and 16th week, 10 rats were randomly chosen and sacrificed, and divided into cirrhosis, liver cancer and pulmonary metastasis groups depending on the pathological result, respectively. The other 10 rats were taken as control group. The Mphi was isolated by anchoring cultivation. The changes in ultrastructure, phagocytosis, cytokine secretion, antigen processing and presenting, and viability of splenic Mphi were detected by transmission electron microscopy, Vybrant(TM) Phagocytosis Assay, DQ(TM) Ovalbumin, and rat TNF-alpha ELISpot kits.

RESULTSUnder the electron microscope, the Mphi in the control group had some pseudopodium-like prominences, and mitochondria, ribosome, rough endoplasmic reticulum, lysosome can be found in the cytoplasm, and phagocytized RBC. In the liver cirrhosis and liver cancer group, Mphi had more prominences, meanwhile much more mitochondria, ribosome, rough endoplasmic reticulum, lysosome can be found in the cytoplasm, especially in the liver cancer group. In the pulmonary metastasis group, the Mphi was swelling, with few organelle. As compared to the control group, the function of splenic Mphi increased in cirrhosis and cancer groups, but decreased in metastasis group (phagocytosis rate: (84.7 +/- 1.9)%, (89.5 +/- 3.1)%, and (36.0 +/- 2.6)% vs (75.6 +/- 1.7)%, P < 0.05, P < 0.01; viability: (1.53 +/- 0.15)%, (1. +/- 0.14)%, and (1.12 +/- 0.29)% vs (1.48 +/- 0.17)%, P < 0.05, P < 0.01; TNF-alpha secretion: (741.0 +/- 52.9)%, (1126.2 +/- 174.5)%, and (313.8 +/- 50.8)% vs (626.6 +/- 24.6)%, P < 0.05, P < 0.01; positive cell rate of antigen processing and presenting: (24.03 +/- 1.87)%, (27.95 +/- 2.63)%, and (10.46 +/- 2.16)% vs (16.45 +/- 1.86)%, P < 0.01).

CONCLUSIONSIn the stage of cirrhosis and early cancer, the immune functions of splenic Mphi were reinforced. It may promote the non-specificity tumor immunity. On opposite, in the stage of pulmonary metastasis, the immune functions of splenic Mphi were impaired. It may lead to the decrease of tumor immunity.

Animals ; Cells, Cultured ; Diethylnitrosamine ; toxicity ; Disease Models, Animal ; Liver Cirrhosis ; immunology ; pathology ; Liver Neoplasms, Experimental ; chemically induced ; complications ; immunology ; ultrastructure ; Lung Neoplasms ; immunology ; secondary ; ultrastructure ; Macrophages ; pathology ; ultrastructure ; Male ; Microscopy, Electron, Transmission ; Rats ; Rats, Sprague-Dawley ; Spleen ; pathology ; ultrastructure

AIM: A decoction of Elephantopus scaber (Asteraceae) root is used to treat liver disorders in Indian and Chinese traditional medicine. The study was designed to examine the dose response effects of E. scaber methanolic extract on rats exposed to N-nitrosodiethylamine (NDEA) induced hepatotoxicity (0.02% NDEA in water five days per week, per oral) in preventive and curative models. METHODS: In preventive groups, NDEA was administered for six weeks. Daily doses of E. scaber methanolic extract (200 and 100 mg·kg-1) started one week before the onset of NDEA intoxication and continued for six weeks. In curative animals, NDEA was administered for six weeks followed by treatment with the methanolic n-hexane extract of E. scaber (200 and 100 mg·kg-1) for ten days. RESULTS: E. scaber extract treatment significantly (P ≤ 0.05) reduced the levels of AST, ALT, and MDA in both experimental groups. The extract also enhanced the antioxidant enzyme and protein levels in rats intoxicated with NDEA. Treatment with the extract dose dependently protected the liver from NDEA-induced hepatotoxicity with normal hepatocytes and uniform sinusoids, but in some areas showed degenerating hepatic cells in both treatment groups. CONCLUSION E. scaber methanolic extract dose dependently prevented and reversed the hepatotoxicity induced by NDEA in both experimental models.
Alanine Transaminase ; metabolism ; Animals ; Aspartate Aminotransferases ; metabolism ; Asteraceae ; chemistry ; Diethylnitrosamine ; toxicity ; Dose-Response Relationship, Drug ; Female ; Humans ; Liver ; drug effects ; enzymology ; Liver Function Tests ; Plant Extracts ; administration & dosage ; isolation & purification ; Rats ; Rats, Wistar

OBJECTIVETo investigate the dynamic expression and its relation of gelatinase A (MMP-2), its natural inhibitor (TIMP-2) and DNA index (DI) changes during carcinogenesis, invasion and metastasis in Wistar rats.

METHODSSquamous cell carcinoma of lung was induced with 3-methylcholanthrene (MCA) and diethyinitrosamine (DEN) in iodized oil by left intra-bronchial instillation in 80 Wistar rats. Immrno histochemistay (IHC) and in situ hybridigation were used in the monitor of MMP-2, TIMP-2 proteins and mRNA expression during invasion and metastasis of lung cancer in these rats, DNA index (DI) value was measured by guantitatove image analysis on feulgen stained sections.

RESULTSAlong with the carcinogenis, the average poritive MNP-2 and TIMP-2 expressions increased, with positive rates of 8.5% - 85.7% and 6.4% - 35.7%. DI value also underwent the same changes (1.47 +/- 0.54) - (2.87 +/- 0.55). The difference of MMP-2 expression in carcinoma in situ versus early carcinoma and early carcinoma versus metastatic carcinoma are statistically significant (P < 0.05). Companing lung carcinome, the contrel group and non-cancerous lesions, the elevation of MNP-2 and TIMP-2 expressions were also sigmificant (P < 0.01). The DI elevation in carcinoma in situ and dysplasia were obviously significant (P < 0.05). Meanwhile a negative relation was noted in TINP-2 and MMP-2 expressions during carcinogenesis. There was a positive relation between MMP-2 expression and DNA poikiloidy (P < 0.01), which was related to the close relationship between MMP-2 and metastasis in advanced rat lung carcinoma (P < 0.05).

CONCLUSIONThe excess degradation and disruption of basement membranes by activated MMP-2 may be a key step in inducing lung cancer invasion and metastasis. The imbalance between MMP and TIMP may be a critical factor which affects biologic behavior of lung carcinogenesis, invasion and metastasis.

Alkylating Agents ; toxicity ; Animals ; Carcinoma, Squamous Cell ; chemically induced ; genetics ; pathology ; Diethylnitrosamine ; toxicity ; Female ; Gene Expression Regulation, Neoplastic ; Lung ; drug effects ; metabolism ; pathology ; Lung Neoplasms ; chemically induced ; genetics ; pathology ; Male ; Matrix Metalloproteinase 2 ; genetics ; metabolism ; Methylcholanthrene ; toxicity ; Neoplasm Invasiveness ; Neoplasm Metastasis ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar ; Tissue Inhibitor of Metalloproteinase-2 ; genetics ; metabolism

OBJECTIVEThe present paper aims to investigate the effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and N-nitrosodiethylamine (DEN) on tumorigenesis and its potential mechanism.

METHODSThe potentials of TCDD and DEN in separation or in combination to induce malignant transformation were tested in Balb/c 3T3 cells by using a cell transformation assay method. The possible mechanism of observed effects was studied further by adding α-naphthoflavone (α-NF), a competitive binding agent of TCDD, to the Aryl hydrocarbon receptor (AhR) pathway. The mRNA expressions of Cyp1a1 and Cyp2a5 gene in Balb/c 3T3 cells treated by DEN and TCDD in separation or in combination with or without presence of α-NF were measured with fluorescence quantification RT-PCR technique.

RESULTSThe cell transformation frequency (TF) was significantly higher in case of induction with TCDD in combination with DEN, as compared to that with either TCDD or DEN alone. These effects were not inhibited via α-NF. The mRNA expression levels of both Cyp1a1 and Cyp2a5 were enhanced by TCDD treatment alone, but this inducible effect was blocked in cells treated by TCDD and DEN in combination.

CONCLUSIONTCDD and DEN had a significant synergistic effect on tumorigenesis when they were used in combination. AhR pathway may not be the key mechanism of this synergistic effect. Thus, it is necessary to further test the potential mechanism involved in cancer development.

3T3 Cells ; Animals ; Base Sequence ; Carcinogens ; toxicity ; Cell Transformation, Neoplastic ; Cytochrome P-450 Enzyme System ; genetics ; DNA Primers ; Diethylnitrosamine ; toxicity ; Drug Synergism ; Mice ; Mice, Inbred BALB C ; Polychlorinated Dibenzodioxins ; toxicity ; RNA, Messenger ; genetics ; Real-Time Polymerase Chain Reaction ; Receptors, Aryl Hydrocarbon ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction