Establishment of an assay method for human mast cell chymase.

Chymase secreted by mast cells found in fibroblast-containing interstitial connective tissue has been implicated in collagen fiber formation and extracellular matrix production. We established a method for determination of human chymase activity, and applied this technique to measurements in serum and liver tissue. The mean chymase concentration in liver biopsy specimens from 26 patients with chronic hepatitis was 5.