Neutrophil-mediated nitrosamine formation: role of nitric oxide in rats
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Summary
This summary is machine-generated.Inflammatory neutrophils produce carcinogenic nitrosamines in the gut. This study shows neutrophils generate nitric oxide and nitrosamines, which are inhibited by antioxidants and anti-inflammatory drugs, suggesting a link to colorectal cancer.
Area Of Science
- Gastroenterology
- Oncology
- Immunology
Background
- Chronic inflammation of the colon and rectum is linked to increased colorectal cancer risk.
- Mechanisms linking inflammation to neoplasia are not fully understood.
- Inflammatory neutrophils are implicated in producing carcinogenic compounds.
Purpose Of The Study
- To investigate L-arginine-dependent nitric oxide (NO) formation by inflammatory neutrophils in simulated gut interstitial conditions.
- To characterize neutrophil-mediated N-nitrosation of a model amine into its nitrosamine derivative.
- To explore the role of neutrophils in generating endogenous carcinogens during intestinal inflammation.
Main Methods
- Incubation of elicited neutrophils to measure nitrite production (an indicator of NO).
- Inhibition studies using L-arginine omission and NG-nitro-L-arginine methyl ester (L-NAME).
- Assay of neutrophil-dependent N-nitrosation of 2,3-diaminonaphthalene to 1-naphtho-2,3-triazole.
- Evaluation of inhibitory effects of antioxidants, 5-aminosalicylic acid, and L-NAME.
Main Results
- Elicited neutrophils produced significant nitrite levels in an L-arginine-dependent manner.
- Nitrite production was inhibited by L-arginine omission and L-NAME, indicating NO synthesis.
- Neutrophils catalyzed N-nitrosation of a model amine to its nitrosamine derivative.
- Antioxidants, 5-aminosalicylic acid, and L-NAME significantly inhibited nitrosamine formation.
Conclusions
- Inflammatory neutrophils are a source of nitric oxide (NO) in the gut.
- Neutrophils can mediate the formation of carcinogenic nitrosamines.
- These findings suggest inflammatory neutrophils contribute to endogenous carcinogen production during intestinal inflammation, potentially linking to colorectal cancer risk.