[Collagen metabolism in ethionine induced rat chronic pancreatic injury]

Under low choline diet, chronic pancreatic injury was induced by the intraperitoneal administration of ethionine of 10 mg/100 g body weight, 3 times a week for sequential 8 weeks in rats and histological changes, pancreatic hydroxyproline and collagenase activity were studied. Histologically, acute inflammatory changes were observed mainly in the early days, and infiltration of fibroblastoid cells was increased on the 28th day. Then, fat droplets deposition became remarkable. Though hydroxyproline concentration increased gradually after the injection of ethionine and showed maximal level on the 28th day when the slight fibrosis was noticed, it was decreased on the 56th day when collagenous tissue was replaced by fat droplets. On the other hand, collagenase activity showed two peaks, in the early phase and on the 56th day, and it showed bottom level on the 28th day. Collagen synthesis relatively dominated over degradation on the 28th day. It is suggested that the unbalance of collagen metabolism between synthesis and degradation may result in fibrosis.