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.