Use of yeast respiratory adaptation test system to detect chemical mutagens/carcinogens in mammals.

An approach to follow distribution of injected DNA-acting chemicals (mutagens/carcinogens) in animal tissues has been described. This is based on the use of respiratory adaptation (mitochondrial biogenesis) process in Saccharomyces cerevisiae during transition from anaerobic to aerobic state. By virtue of specific interaction of such chemicals with mitochondrial DNA associated with promitochondrial structures this process is extremely sensitive to DNA-acting chemicals. Solutions of berylium sulphate, aflatoxin G1, aflatoxin B1, and carbaryl (all known DNA-acting agents) were injected to rats at low concentrations and, after 24 hr, distribution of these chemicals or their metabolites was studied by determining the inhibitory action of appropriately diluted urine and tissue homogenates on respiratory adaptation in S.cerevisiae. Detectable amounts of the chemicals and their DNA-acting metabolites could be analyzed in urine, liver, lungs, kidney and spleen.