NITRIC OXIDE-MEDIATED CALCIUM SIGNALING IS INVOLVED IN HEXAVALENT CHROMIUM-INDUCED CELL DEATH IN YEAST CELLS

Hexavalent chromium is a ubiquitous pollutant in the environment, and its toxic mechanisms have long been the focus of research studies. In this study, the mechanism through which hexavalent chromium affects yeast cell death was examined. The results show that the presence of hexavalent chromium can cause yeast cell death and that with an increase in the concentration of hexavalent chromium over time, the rates of yeast cell death gradually increase. We also found that relative to the control group, after using 3mM Cr (VI) to treat yeast cells for 9 h, the intracellular nitric oxide (NO) and calcium ion levels increased. However, NO scavenger and calcium antagonists can inhibit yeast cell death due to hexavalent chromium exposure, and c-PTIO can inhibit the increase in NO and production of calcium ions induced by hexavalent chromium. However, EGTA can only prevent the increase in calcium ions induced by hexavalent chromium and cannot inhibit the increase in NO induced by hexavalent chromium. These results show that NO contributes to Cr(VI) by inducing yeast cell death by regulating intracellular Ca2+.