Collagenolytic activity in experimental cirrhosis of the liver

Mechanisms of spontaneous resolution of rat liver fibrosis. Hepatic stellate cell apoptosis and reduced hepatic expression of metalloproteinase inhibitors.

“…These observations are supported by data presented by other groups, which indicate that collagenase activities detected in tissue homogenates initially rise with fibrotic injury but then fall with progression of fibrosis to cirrhosis (17,18,(36)(37)(38) and that fibrotic human liver disease is associated with raised serum TIMP levels, which are inversely correlated to collagenase activity (22)(23)(24). Moreover, serum TIMP levels in patients with liver fibrosis are inversely correlated to collagenase activity, which can be unmasked by removal of the bound TIMP (22)(23)(24).…”

Adenosine reverses a preestablished CCl4-induced micronodular cirrhosis through enhancing collagenolytic activity and stimulating hepatocyte cell proliferation in rats

“…The neutral collagenase activity was assayed as previously reported, using 1 mg of homogenate as source of enzyme activity. 13 In addition, liver collagenolytic ability to use endogenous substrates was determined essentially as described by Pérez-Tamayo et al 27 Here, 10 mg of homogenate protein was used as a source of both enzyme and homologous substrates. The final volume was 2 mL in both cases, incubated at 37°C for 24 hours.…”

Tetrandrine Prevents Tissue Inhibitor of Metalloproteinase‐1 Messenger RNA Expression in Rat Liver Fibrosis

“…Previous studies suggest that collagenase activity becomes deficient during evolution of liver fibrosis in animal models and in humans (Takahashi et al 1980;Maruyama et al 1982;Rerez-Tamayo et al 1987), and the studied described earlier suggest that this may be caused by the tissue inhibitor of metalloproteinase overexpression. Continued inhibition of extracellular matrix degradation by the tissue inhibitor of metalloproteinases may block the ability to recover from fibrosis, even after removal of the injury.…”

“…It has also been shown to exhibit antifibrogenic activity against fibroblasts, particularly pulmonary fibroblasts (Reist et al 1993), strong binding to alveolar macrophages (Ma et al 1991), inhibition of proliferative activity of pulmonary fibroblast, and an inhibitory effect on types I and III collagen gene mRNA level in lung tissue of rats (Liu et al 1994).We have previously reported that tetrandrine has an antifibrotic effect on liver fibrosis in rats induced by bile duct ligation and scission and tetrandrine exert a direct inhibition effect on rat hepatic stellate cell activation (Park et al 2000).Previous studies suggest that collagenase activity becomes deficient during evolution of liver fibrosis in animal models and in humans (Takahashi et al 1980;Maruyama et al 1982;Rerez-Tamayo et al 1987), and the studied described earlier suggest that this may be caused by the tissue inhibitor of metalloproteinase overexpression. Continued inhibition of extracellular matrix degradation by the tissue inhibitor of metalloproteinases may block the ability to recover from fibrosis, even after removal of the injury.…”