sodium-nitrite and Lung-Neoplasms

The objective of this study is to investigate the risk of esophageal carcinoma in a cohort with long-term occupational exposure to sodium nitrite. The method used was a retrospective cohort study. A small wood screw manufacturer was founded in 1977 and closed down in 2000. In their production process, the sodium nitrite solution was used to serve as anticorrosive and coolant fluid. One hundred sixty workers in turning and milling shops had direct exposure to sodium nitrite through skin, mouth, and airway because of lack of occupational protective knowledge (study group), whereas 255 workers from other workshops without direct contact with sodium nitrite served as control group. The incidence, diagnosis, and treatment of esophageal carcinoma as well as other malignant tumors in these two groups were followed until the end of 2007. The sodium nitrite exposure time in the study group ranged from 16 to 23 years, with an average of 22.1 years. During 30 years of follow-up, there were 11 esophageal carcinomas and 10 other malignant tumors (4 hepatic cell carcinomas, 3 lung cancers, 2 breast cancers, and 1 leukemia) documented in the study group, while no cancer developed in the control group. The risk for esophageal carcinoma was significantly increased in the study group compared with the control group (relative risk = 1.26, 95% confidence interval = 1.08-1.46, chi-square = 116.83, P < 0.001). Long-term exposure to sodium nitrite markedly increases the risk of esophageal carcinoma in human body.

Topics: Adolescent; Adult; Aged; Breast Neoplasms; Carcinoma; Chi-Square Distribution; China; Construction Materials; Esophageal Neoplasms; Female; Follow-Up Studies; Humans; Incidence; Kaplan-Meier Estimate; Leukemia; Liver Neoplasms; Lung Neoplasms; Male; Middle Aged; Occupational Exposure; Retrospective Studies; Risk; Sodium Nitrite; Young Adult

This study aims to compare Ki-67 antigen expression and K-ras mutation in lung tumours induced by the interfering effects of urethane followed by sodium nitrite, sodium chloride and vitamin D3.. The samples were classified into six groups: control (C) group; urethane only (U) group; urethane and vitamin D (U+D) group which received 3.5 mg/kg vitamin D3 for four weeks; urethane and sodium nitrite (U+NS) group which was given sodium nitrite (50 mg/L); urethane and physiological serum (U+NaCl) group; and sodium nitrite and physiological serum (NS+NaCl) group which was given 50 mg/L sodium nitrite and physiological serum, instead of water. The four carcinogen groups receiving urethane were injected intraperitoneally with 600 mg/kg of urethane three times. After 20 weeks of intervention, the mice were killed; the tissues were removed and examined for histopathological changes and comparison of Ki-67 antigen expression and mutations in the exon 1 of the K-ras gene in lung tumours.. There were significant differences in the Ki-67 index between the C group and the U (p-value is less than 0.006, 95 percent confidence interval [CI] -432.9 to -55.6), U+D (p-value is less than 0.05, 95 percent CI -408.3 to -4.6), U+NS (p-value less than 0.02, 95 percent CI -415.7 to -27.2), U+NaCl (p-value less than 0.002, 95 percent CI -478.8 to -90.3) groups. There was no difference between the C and NS+NaC1 groups. There was no mutation in the exon 1 of K-ras gene of the lung tumours.. The expression of Ki-67 antigen was found to be increased by urethane in the present study. However, a study on a larger sample size may show anti-tumourogenic effect of vitamin D3. However, the K-ras exon 1 mutations do not play any role in the interfering effects of urethane followed by sodium nitrite and sodium chloride.

Topics: Animals; Cholecalciferol; Exons; Female; Gene Expression Regulation, Neoplastic; Genes, ras; Ki-67 Antigen; Lung Neoplasms; Male; Mice; Mice, Inbred BALB C; Mutation; ras Proteins; Sodium Chloride; Sodium Nitrite; Urethane; Vitamin D

Combined effects of sodium nitrite (NaNO2) and 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) on liver, colon and Zymbal's gland carcinogenesis were assessed using a rat two-stage carcinogenesis model, with a focus on involvement of oxidative stress. Male 6-week-old F344 rats were given a single intraperitoneal injection of 200 mg/kg of diethylnitrosamine and 4 subcutaneous injections of 40 mg/kg of 1,2-dimethylhydrazine for initiation. Then, they were administered 0 or 300 ppm IQ in the diet or 0, 0.1 or 0.2% NaNO2 in their drinking water for 27 weeks. The treatment with NaNO2+IQ significantly enhanced colon and Zymbal's gland carcinogenesis and tended to enhance hepatocarcinogenesis. The incidence of lung tumors in the IQ-treated groups was significantly increased as compared with the initiation alone group. In a second experiment, male rats were given IQ or NaNO2 under the same conditions as before for 1 week, and at sacrifice, their liver and colon tissue or mucosa were collected for analysis of 8-hydroxydeoxyguanosine (8-OHdG), thiobarbituric acid reactive substances (TBARS), acrolein-modified protein and the bromodeoxyuridine-labeling index (BrdU-LI) (in the colon). In the colon, 8-OHdG, acrolein-modified protein levels and BrdU-LI were significantly increased by the combined treatment. These results indicate that the treatment with NaNO2 enhances IQ-induced colon and Zymbal's gland carcinogenesis in rats and that oxidative DNA damage and lipid peroxidation may partly be involved, especially in the colon. In addition, this experiment showed that IQ can act as a potent lung carcinogen in rats.

Topics: 1,2-Dimethylhydrazine; Administration, Oral; Alkylating Agents; Animals; Carcinogens; Cell Transformation, Neoplastic; Colonic Neoplasms; Diethylnitrosamine; DNA Damage; Drug Interactions; Indicators and Reagents; Injections, Subcutaneous; Lipid Peroxidation; Liver Neoplasms; Lung Neoplasms; Male; Oxidative Stress; Quinolines; Rats; Rats, Inbred F344; Sodium Nitrite

Chronic sodium nitrite (SN) treatment potentiated spontaneous and 1,2-dimethylhydrazine (DMH)-induced carcinogenesis. Mice injected with SN alone showed a higher incidence of leukemia and lung cancer than in controls. Combined treatment with DMH and SN induced most of benign and malignant tumors (hepatic hemangioendothelioma, hepatocarcinoma, renal adenoma, etc.). The difference in the numbers of DMH- and SN-induced tumor bearers was not significant until a concentration of 500 mg/l was reached (64.7%). The level of multiple tumor incidence increased when SN 50 and 500 mg/l was used. Unlike DMH alone, cumulative incidence of DMH-specific tumors and leukemia after combined treatment was higher. An evaluation of cumulative incidence and relative risk established an indirect but positive correlation between SN dose, on the one hand, and spontaneous and induced carcinogenesis, on the other. The strongest carcinogenic effect was reported when DMH was used in combination with SN 500 mg/l. Our data confirmed the carcinogenic hazard of chronic exposure to SN which increased when in combination with that to a specific carcinogenic substance.

Topics: 1,2-Dimethylhydrazine; Animals; Carcinogens; Cocarcinogenesis; Drug Synergism; Leukemia; Lung Neoplasms; Male; Mice; Mice, Inbred C57BL; Mice, Inbred CBA; Sodium Nitrite

It was shown in experiments on 186 mice that formation of tumors of the lung and fore-stomach induced by injection of sodium nitrite in combination with aminopyrine or methylurea is inhibited following treatment with ascorbic acid, hexamethylenetetramine or sodium metabisulfite.

Topics: Aminopyrine; Animals; Ascorbic Acid; Cocarcinogenesis; Female; Lung Neoplasms; Male; Methenamine; Methylurea Compounds; Mice; Mice, Inbred Strains; Nitrites; Sodium Nitrite; Stomach Neoplasms; Sulfites

Topics: Animals; Cocarcinogenesis; Drug Synergism; Female; Lung Neoplasms; Mammary Neoplasms, Experimental; Nitrates; Nitrites; Rats; Sodium Nitrite; Tritium; Water; Water Intoxication

Cimetidine (CM), a drug widely prescribed for ulcers, readily undergoes nitrosation to form nitrosocimetidine (NCM), a genotoxic agent. In a test of the chronic effects of NCM in mice, (C57BL/6 X BALB/c)F1 mice were exposed chronically to NCM (113 or 1130 ppm) in the drinking water from preconception through prenatal and neonatal development and adult life. Each group consisted of 40 to 80 mice of each sex, and median survival time was 27 months. Other groups were given CM alone or in combination with NaNO2 (184 or 1840 ppm), or NaNO2 alone. None of the chemical treatments had large effects on reproductive parameters, survival, or incidence of nonneoplastic lesions. CM treatment was associated with a small but significant increase in incidence of lymphomas in females, 41 of 59 (69%), compared with 31 of 66 controls (47%, P = 0.01). No females receiving either dose of NCM developed mammary carcinomas (0 of 91), compared with an incidence of four of 66 controls (6%, P = 0.03). Males given the high-dose combination of CM and NaNO2 showed a higher incidence of lung tumor bearers than controls (71 of 79 versus 30 of 52, P less than 0.01) and also experienced a significant, dose-dependent increase in numbers of large lung tumors (greater than 1 cm in diameter), lung carcinoma, and metastatic lung tumors. Females given the higher dose of NCM had significantly greater incidence of mice with large lung tumors than controls (nine of 41 versus three of 66, P = 0.009). The possibility of carcinogenicity of cimetidine, nitrosocimetidine, and cimetidine plus nitrite is discussed.

Topics: Animals; Body Weight; Cimetidine; Dose-Response Relationship, Drug; Female; Fetus; Lung Neoplasms; Male; Mammary Neoplasms, Experimental; Maternal-Fetal Exchange; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Neoplasms, Experimental; Nitrites; Pregnancy; Reproduction; Sex Factors; Sodium Nitrite

Topics: Adenoma, Bile Duct; Aminopyrine; Animals; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Chenodeoxycholic Acid; Cricetinae; Female; Lung Neoplasms; Male; Mesocricetus; Nitrites; Sodium Nitrite

Sodium nitrite has been widely used as one of the most effective food additives to tinge color on cured meat. However, it has been elucidated that this chemical is not merely a precursor of N-nitroso compounds, many of which are strongly carcinogenic, but also a mutagenic substance in biological tests. In order to ascertain the possible tumorigenicity of sodium nitrite itself, chronic toxicity of the agent in mice, by means of daily oral administration as drinking water for more than 18 months, in the concentration of 0.5 (maximum tolerated dose), 0.25, and 0.125%, was tested. As a result, development of various tumors, including thymic lymphoma, nonthymic lymphoid leukemia, pulmonary adenoma and carcinoma, and benign and malignant tumors in soft tissue, was seen in these mice. However, as to the incidence of tumors as well as the developmental time of each histologically classified tumor, no apparent difference was detected between those in the experimental groups and the control group.

Topics: Animals; Carcinogens; Female; Leukemia; Liver Neoplasms; Lung Neoplasms; Male; Mammary Neoplasms, Experimental; Mice; Mice, Inbred ICR; Nitrites; Sodium Nitrite; Soft Tissue Neoplasms; Thymus Neoplasms; Time Factors; Uterine Neoplasms