Changes in the human uterine cervical collagenase with special reference to cervical ripening

Abstract Changes in the human cervical collagenase activity of three different types, free active enzyme, a complex with α 2 -macroglobulin, and inactive form activated by 4-aminophenylmercuric acetate, were examined by using fluorescein-labeled collagen and 2,4-dinitrophenyl-Pro-Gln-Gly-Ile-Ala-Gly-Gln- d -Arg. Both active collagenase and the complex of collagenase with α 2 -macroglobulin were found to increase more significantly in pregnancy at term than those in nonpregnant control group. This tendency was also observed in chromatographic profiles on Sephadex G-150. However, the inactive enzyme estimated by activation did not change during the course of pregnancy.