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Elastatinal and leupeptin: effects on u.v.-induced mutation and sister-chromatid exchanges in Chinese hamster cells
Abstract:
Microbial protease inhibitors elastatinal and leupeptin were tested for cytotoxicity and for effects on spontaneous and u.v.-induced 6-thioguanine-resistant (6TGr) mutation and sister-chromatid exchange (SCE) in V79 Chinese hamster cells. Continuous treatment with elastatinal exhibited marked cytotoxicity, while leupeptin was almost non-cytotoxic. Elastatinal rapidly induced cytotoxic effects as a function of its concentration and time of exposure. Near maximum cytotoxicity was reached after exposure of 6-8 h and this was partially abolished by the presence of 2.5 micrograms cycloheximide per ml. Concentrations of either protease inhibitor which gave 60-80% survival had no appreciable effects on u.v. survival and frequencies of spontaneous and u.v.-induced 6TGr mutation and SCE. However, reconstruction experiments revealed that pretreatments of 6TGr and 6TGs (wild-type) cells with these inhibitors for 6 days tended to block metabolic co-operation in their co-cultures. Thus, elastatinal and leupeptin are neither clastogenic mutagenic by themselves, and do not alter mutation fixation and expression.
Insights
Microbial protease inhibitors elastatinal and leupeptin were evaluated for their effects on V79 Chinese hamster cells. Elastatinal showed cytotoxicity, while neither inhibitor affected mutation or sister-chromatid exchange frequencies.
Area of Science:
- Cell Biology
- Toxicology
- Molecular Genetics
Background:
- Protease inhibitors are crucial in biological research and therapeutics.
- Understanding the cellular effects of microbial protease inhibitors like elastatinal and leupeptin is important.
- V79 Chinese hamster cells are a standard model for genotoxicity testing.
Purpose of the Study:
- To assess the cytotoxicity of elastatinal and leupeptin.
- To investigate their effects on spontaneous and UV-induced 6-thioguanine-resistant (6TGr) mutation.
- To determine their impact on sister-chromatid exchange (SCE) and metabolic cooperation in V79 cells.
Main Methods:
- Cytotoxicity assays were performed on V79 cells.
- Mutation induction assays for 6-thioguanine resistance (6TGr) were conducted.
- Sister-chromatid exchange (SCE) analysis was performed.
- Metabolic cooperation assays were utilized.
Main Results:
- Elastatinal exhibited significant cytotoxicity in a dose- and time-dependent manner, partially reversed by cycloheximide.
- Leupeptin demonstrated minimal cytotoxicity.
- Neither elastatinal nor leupeptin affected UV-induced 6TGr mutation or SCE frequencies at non-cytotoxic concentrations.
- Both inhibitors blocked metabolic cooperation between V79 cells after prolonged treatment.
Conclusions:
- Elastatinal and leupeptin are not directly clastogenic or mutagenic.
- These protease inhibitors do not influence mutation fixation or expression.
- Elastatinal and leupeptin can interfere with intercellular communication (metabolic cooperation).