Changes in amniotic fluid cathepsins with gestational age.

Activities of the cysteine proteinases cathepsins B and H and of the chymotrypsin-like cathepsin G were determined in amniotic fluid of rats during the last third of gestation. Activities of cathepsins B and G were found to significantly increase with increasing gestational age while cathepsin H activity decreased. It was concluded that cathepsins may participate in the destabilization of fetal membranes and therefore may contribute to their rupture