Effect of acetylosalicylic acid and naproxen on collagen solubility and heterogeneity in the rat liver.

Rats were treated acetylosalicylic acid (150 mg/kg b.w.) or naproxen (125 mg/kg b.w.) during 6 weeks. An increase of collagen content, elevated solubility of collagen and changes in the ratio of type I to type III collagen were observed in animals receiving acetylosalicylic acid, and only slight alterations were found in these treated with naproxen. A rise of indices of the liver injury in blood serum was shown after treatment with acetylosalicylic acid. It is suggested that changes of collagen metabolism in the liver of rats receiving anti-rheumatic drugs are caused by direct action of the drugs on collagen biosynthesis and catabolism as well as resulted from the toxic action of the drugs on the liver.