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

ABSTRACT

OBJECTIVE: We visualized and investigated the intracellular calcium waves propagated by platelet-activating factor (PAF) in cultured human myometrial cells. STUDY DESIGN: Myometrial cells were stimulated with PAF ranging between 10(-8) and 10(-15) M. For the observation of calcium waves, calcium green-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 induced intracellular calcium waves. Mean wave speed was 16.1+/-5.6 microm/s. Wave speeds were independent of the PAF concentration. Similar results were observed in the absence of added calcium, with the exception that the wave speeds were significantly slower (7.3+/-3.3 microm/s). CONCLUSIONS 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.