Localization of acetylcholinesterase in normal human fibroblasts and in a human fibrosarcoma cell line.

A modified histochemical procedure was used to detect specific acetylcholinesterase localization in cultured human cells. Enzymic activity was found in cytoplasm in the perinuclear zone and in the plasma membrane of 20% to 40% of HT-1080 human fibrosarcoma cells. The presence of pseudocholinesterase was excluded using specific substrates and inhibitors.