co-relation between carcinogenicity and mutagenicity mutation frequency

CARCINOGENICITY: ABILITY TO CAUSE CANCER ABILITY TO DAMAGE THE GENOME OR THE DISTRUPTION OF CELLULAR METBOLISM CAN BE CAUSED BY A RADIONUCLITIDE, SUBSTANCE OR RADIATION EXAMPLE:UV RAYS,GAMMA RADIATIONS, ALDOSES etc

MUTAGENICITY: CAPACITY TO INDUCE MUTATIONS CAUSED BY A MUTAGEN WHICH CHANGES THE GENETIC MATERIAL,USUALLY DNA. THUS INCREASES THE CHANCES OF MUTATIONS ABOVE THE NATURAL BACKGROUND LEVEL. MUTAGENS ARE LIKELY TO BE CARCINOGENS

RELATIONSHIP BETWEEN CARCINOGENICITY AND MUTAGENICITY: INTRODUCTION: Ames and his colleges developed a technique by which large number of chemicals and other agents can be screened for mutagenicity. A particular strain of salmonella tryphrium is used.

EXPERIMENT FOR ESTIMATION OF MUTAGENICITY: The reversion of these auxotrophic mutants to prototrophic or induced mutants is monitored by placing the auxotrophic cells in petriplate containing medium supplemented with growth factor required by the auxotroph. The number of colonies after an appropriate period of incubation are counted.

RESULT IS ESMTIMATED BY: The frequency of a reversion induced by a particular substance is compared directly with spontaneous reversion frequency to obtain an estimate of it’s mutagenicity.

THEORIES OBTAINED FROM THE EXPERIMENT: Greater then 90% co-relation between mutagenicity and carcinogenicity of substances have been found. Some potent carcinogen were found non- mutagenic to the tester strains. Carcinogens were metabolized to strongly mutagenic substances in the eukaryotic cell. example-nitrates.

MUTATION FREQUENCY: Average Frequency with which a particular mutation occurs in a population Can be increased by chemicals such as mustard gas or hydrogen peroxide