Related Experiment Videos
Marked nitrosation by stimulation with lipopolysaccharide in ascorbic acid-deficient rats
H Kosaka1, M Tsuda, Y Kurashima
1Division of Environmental Health Research, Osaka Prefectural Institute of Public Health, Japan.
Carcinogenesis
|October 1, 1990
Summary
Ascorbic acid deficiency in rats (ODS rats) leads to increased N-nitrosothioproline formation after LPS stimulation. Supplementing ascorbic acid significantly reduces this nitrosamine production, highlighting its protective role.
Area of Science:
- Biochemistry
- Toxicology
- Nutrition
Background:
- Ascorbic acid (vitamin C) is a crucial antioxidant and cofactor.
- Escherichia coli lipopolysaccharide (LPS) is a potent immune stimulator.
- N-nitrosothioproline (N-nitrosothiazolidine-4-carboxylic acid) is a nitrosamine of toxicological interest.
Purpose of the Study:
- To investigate the role of ascorbic acid in the formation of N-nitrosothioproline induced by LPS.
- To evaluate the impact of ascorbic acid deficiency on nitrosamine production in vivo.
Main Methods:
- Utilized osteogenic disorder syndrome (ODS) rats, a mutant strain unable to synthesize ascorbic acid.
- Administered thioproline and measured urinary nitrate and N-nitrosothioproline excretion.
- Compared LPS-stimulated ODS rats with and without ascorbic acid supplementation.
Main Results:
- LPS significantly increased urinary nitrate excretion in both supplemented and unsupplemented ODS rats.
- Urinary N-nitrosothioproline excretion increased sixfold in ascorbic acid-deficient ODS rats post-LPS.
- Ascorbic acid supplementation markedly reduced N-nitrosothioproline excretion following LPS stimulation.
Conclusions:
- Ascorbic acid deficiency potentiates the formation of N-nitrosothioproline induced by LPS.
- Ascorbic acid plays a critical protective role against LPS-induced nitrosamine formation.
- These findings underscore the importance of adequate ascorbic acid levels in mitigating endotoxin-related nitrosative stress.