Inhibition of respiratory growth and survival in yeast by dopamine and counteraction with ascorbate or glutathione

Dopamine is a key monamine neurotransmitter, yet it can also exhibit toxicity to neuronal cells. There are suggestions that dopamine may be neurotoxic due to its propensity to induce the formation of reactive oxygen species, which may in turn adversely affect mitochondrial function and cell viability. In this study, the effects of dopamine or a dopamine reaction product on yeast growth and survival have been explored. Yeast is ideal for such a study because, unlike mammalian cells, yeast cells can be grown even when respiratory function is totally absent. Indeed, dopamine was found to be inhibitory to yeast growth in media where respiratory function was required and cytotoxic to yeast cells suspended in water. The inhibitory effects of dopamine were reduced greatly by the antioxidants ascorbate and glutathione, suggesting the involvement of reactive oxygen species in dopamine-mediated toxicity. It would appear that yeast may offer a convenient model to perform screens for further compounds that may provide protection against dopamine-mediated growth inhibition and toxicity