Genotoxicity of Natural and Anthropogenic Agents

The Ministry of Science, Education and Sports of the Republic of Croatia (2002-2006)

Principal Investigator: Vilena Kašuba

Field: Biology
Branch: Biology

SUMMARY
In last few decades, the number and quantity of toxic agents, which are threat to the environment, was rashly increased with the development of industry. Consequently humans are exposed to them directly or by nourishment.

It is long appreciated that environmental mutagens can have clastogenicand/or aneugenic activities. The event, which irreversibly affects the cell-integrity, is double-strand break (DSB) of the DNA molecule. DNA DSBs may arise either spontaneously during cellular processes or as a result of exposure to DNA-damaging agents such as ionizing radiation, or chemical agents.

It is widely accepted that nonrepaired or misrepaired DSB are the main lesions leading to the production of chromosomal aberrations, mutagenesis,oncogenic transformation, and cell death. Studies focusing on this relationship, as well as the possible modulation of DNA repair mechanisms, are currently of major interest. Great characters in these studies have methods that insure quick results with small quantity of the test material. Mutagen effects of ionizing radiation, heavy metals, and some organic combinations present in human environment and work-places, will be studied in human peripheral blood lymphocytes, rat reticulocytes, and in animal cell-cultures.

In our investigations we will use the following methods: comet assay, chromosomal aberration analysis, sister chromatid exchange analysis, micronucleus assay in cytochalasin B blocked human lymphocytes, rat bone-marrow and peripheral blood reticulocytes, and LDH (lactat-dehydrogenase) colorimetric determination in cell culture medium (as a result of the cell membrane damage because of activity of different environmental and professional agents). The results should contribute to better understanding of effects of agents from environment to a genome and cell membrane, and, consequently, to organization and protection exposed subjects.

Keywords:
Genotoxic effects, ionizing radiation, chemical agents, chromosome aberrations, micronucleus assay, sister chromatid exchange, alkali-gel electrophoresis- comet assay, cell membrane.