Cell motility and invasion are crucial events for endometrial cells, not only for the establishment of pathological states but also during the physiological tissue remodelling that occurs during the menstrual cycle and embryo implantation. We have characterized these phenomena in endometrial stromal cells evaluating cell migration-specific stimuli and the biochemical pathways involved. Ability of endometrial cells to migrate on collagen type IV substrate was evaluated by means of chemotaxis experiments. Modulation of this phenomenon by different growth factors and steroid hormones and their ability to activate extracellular signal-regulated protein kinase (ERK) and phosphatidylinositol 3 kinase (PI3K)/Akt signalling in this context were examined. Platelet-derived growth factor (PDGF)-BB, epidermal growth factor and fibroblast growth factor-2 as chemoattractant agents stimulated basal migration of endometrial stromal cells through the rapid activation of both ERK1/2 and PI3K/Akt signalling pathways. Experiments using wortmannin and PD98059, specific inhibitors of the PI3K/Akt and ERK1/2 activity, respectively, showed that the activation of both pathways is required for growth-factor-induced cell motility responses. Similarly, 17beta-estradiol (10(-6)-10(-8) M) could enhance both constitutive and PDGF-induced migration of the cells and their rapid treatment with the hormone significantly increased phosphorylation of ERK1/2 and Akt. Conversely, progesterone did not interfere with the basal migration but inhibits the PDGF-induced motility of this cell type. Rapid activation of intracellular signalling cascades ERK1/2 and PI3K/Akt by growth factors and estrogens is involved in the migration of normal endometrial stromal cells.