Platelet-activating factor-induced intracellular calcium waves in human uterine myometrial cells

Objective: We visualized and investigated the intracellular calcium waves p ropagated by platelet-activating factor (PAF) in cultured human myometrial cells. Study design: Myometrial cells were stimulated with PAF ranging betw een 10(-8) and 10(-15) M. For the observation of calcium waves, calcium gre en-1 and a confocal laser microscopy were used. Cells were also stimulated with 10(-9) M of PAF in a calcium-free solution. Results: In physiological solution, PAF at concentrations ranging between 10(-9) and 10(-15) M induce d intracellular calcium waves. Mean wave speed was 16.1 +/- 5.6 mum/s. Wave speeds were independent of the PAF concentration. Similar results were obs erved in the absence of added calcium, with the exception that the wave spe eds were significantly slower (7.3 +/- 3.3 mum/s). Conclusion: This is the first study to demonstrate the calcium waves propagated by PAF stimulation in human myometrial cells. These observations further support the proposed role of PAF in parturition. (C) 2000 Elsevier Science Ireland Ltd. All righ ts reserved.