The role of leukocyte factors on uterine cervical ripening and dilation.

To clarify the role of leukocytes effused into uterine cervix at term pregnancy, the effect of conditioned medium (MCM) of rabbit peritoneal macrophages on the production of specific collagenase by cervical cells was investigated, in vitro. MCM stimulated uterine cervical cells to induce a 10-fold increase in collagenase production as compared with the control. Similarly, production of gelatinolytic metalloproteinase (an endogenous procollagenase activator) increased to about 4-fold of the control cultures, whereas MCM did not affect [3H]thymidine incorporation into DNA. The enhancement of collagenase production was depressed by the treatment of cells with 10(-6) M cycloheximide. The MCM also contained lymphocyte-activating activity (interleukin-1). These data suggest that rabbit uterine cervical cells are able to produce both specific collagenase and gelatinolytic metalloproteinase in response to interleukin-1, and that leukocytes effused into the cervix may participate in the ripening and dilation of uterine cervix at term pregnancy.