Effect of proteinase inhibitors on rabbit uterine ultrastructure

Rabbit uterine epithelium was examined by electron microscopy after treatment with two proteinase inhibitors, aprotinin and antipain, administered as a single injection. Both compounds had similar effects, those of antipain being slighter. After treatment, uterine epithelium showed an increased number of very enlarged cells. Lateral cell membranes were often brocken off; basal cell membrane and basement membrane integrities are impaired. The possible interference of the system proteinase-proteinase inhibitors with the implantation process was discussed.