Regulation of the Superoxide Releasing System in Human Fibroblasts

Fibroblasts release low amounts of reactive oxygen intermediates (ROIs) upon contact with appropriate stimuli, which have regulatory functions in inter- and intracellular signal transduction. Ca2+/calmodulin are involved in the activation process of the ROI-generating system. A rise of intracellular Ca2+ is necessary, but not sufficient to trigger the release of ROIs. As a second signal, protein phosphorylation seems to be involved in the activation process.