[Expression of the small molecular weight matrix metalloproteinase in adenomyosis of the mouse uterus].

The etiology and the pathogenesis of adenomyosis, which is a benign disease featuring ectopic proliferation and invasion of the endometrial stromas and glands into the myometrium, as seen with malignant tumor cells, are still unknown. Adenomyosis induced in mice by intrauterine pituitary isografts was analyzed to study the relationship between adenomyosis and matrix metalloproteinase. Under zymography, adenomyosis showed a gelatiolytic band of 20-30kDa, which was inhibited by EDTA. We then compared matrix metalloproteinase, which is a small protein, with the known pump-1 (MMP7) utilizing RT-PCR and southern blotting hybridization. The PCR product from pump-1 mRNA was clearly detected in both adenomyosis and normal uterus, as in postpartum uterus and kidney in which pump-1 is expressed. These results were confirmed by southern blotting hybridization, and closely resembled the results obtained with RT-PCR. Our study suggests that the small molecular weight matrix metalloproteinase, which is virtually identical to pump-1, may play important roles in adenomyosis at the level of gene transcription, activation, inhibition or otherwise.