Evidence for a non-steroidal angiotropic factor from the primate corpus luteum: stimulation of endothelial cell migration in vitro.

After luteal cells from 7 midluteal phase cynomolgus monkeys were cultured for 72 h, luteal conditioned media were found to contain angiotropic activity that stimulated endothelial cell migration in vitro, using a 48-microwell chemotaxis assembly. The number of endothelial cells that migrated through 8 micron-pore polycarbonate membranes in 2 h was three-fold greater (P less than 0.01) with luteal cell-conditioned vs identical unconditioned media. Pre-treatment of luteal cultures with hCG, FSH, or testosterone did not enhance production of the endothelial cell migration stimulating activity (P greater than 0.25). Luteal angiotropic activity was both chemotactic and chemokinetic. Angiotropic activity was retained in steroid-depleted fractions after reversed-phase chromatography. These results demonstrate that monkey luteal cells secrete a non-steroidal factor(s) which directly stimulate(s) migration of endothelial cells in vitro. A luteal angiotropic factor may be an important intraovarian regulator of the formation and lifespan of the primate corpus luteum during the ovarian cycle.