ASSOCIATION OF IMMUNOLOCALIZATION OF MATRIX METALLOPROTEINASE-1 WITH OVULATION IN HCG-TREATED RABBIT OVARY

Matrix metalloproteinase 1, MMP-1, which.was previously called interst itial collagenase, is necessary for extracellular matrix reconstructio n. The immunolocalization of the latent form of MMP-1 (proMMP-1) was e xamined in the ovulatory process in hCG-treated (100 iu per animal) ra bbit ovaries. Immunoreactive products of proMMP-1 were identified by t he avidin-biotin peroxidase complex formation using an anti-rabbit pro MMP-1 polyclonal antibody. ProMMP-1 was distributed in the cytoplasm o f theca interna cells, theca externa cells, interstitial glands and ge rminal epithelium throughout ovulation. However, at 9 or 10 h after hC G treatment, this enzyme was identified in several capillary lumina ar ound the apex of preovulatory follicles. In addition, the staining den sity of immunoreactive products apparently increased in granulosa cell s and theca interna cells around the orifice of the ruptured follicle 10 h after the stimulation. These results indicate that the spatiotemp oral appearance of proMMP-1 in ovulation may be closely associated wit h the initiation of rupture of the follicle.