Collagenase activity in oral submucous fibrosis.

Oral submucous fibrosis (OSF) is characterized by an abnormal accumulation of collagen fiber in oral submucosa. OSF is a collagen disease and is also regarded as a precancerous lesion. In the previous study, we discovered that the collagen content in oral mucosa of OSF is statistically higher than in normal mucosa. This research examined the relationship between the fibrosis and collagenase activity. Collagenase activity was determined by using soluble 14C-glycine-labeled collagen (9813 cpm/200 micrograms/tube) as a substrate in a solution incubated for 30 hours at 35 degrees C. The results showed that the collagenase activity of the OSF was much lower than that of normal oral mucosa (65.23 +/- 19.49 units/g tissue in normal mucosa vs. 29.48 +/- 5.69 units/g tissue in OSF). Furthermore, the cleavage pattern revealed by SDS-Polyacrylamid gel electrophoresis (SDS-PAGE) confirmed that the partially purified OSF collagenase was likely to be typical mammalian collagenase, with a molecular weight of about 68.0 kDa.