Stimulation of phospholipid hydrolysis and cell death by mercuric chloride: evidence for mercuric ion acting as a calcium-mimetic agent.

Mercuric chloride stimulates phospholipid hydrolysis and prostaglandin release in 3T3 mouse fibroblasts. This response is distinctly different from that stimulated by other sulfhydryl-reactive agents, but it exhibits a variety of characteristics similar to the phospholipid hydrolysis response stimulated by Ca2+ plus ionophore A23187. Also, the additivity of phospholipid hydrolytic responses stimulated by Hg2+, Ca2+ and A23187 is consistent with Hg2+ interacting with a Ca2+-dependent enzyme(s). These results are consistent with Hg2+ acting by a novel, Ca2+-mimetic mechanism; i.e., with it entering cells and activating cell processes that are activated by Ca2+ in calcium-dependent cell death.