Lysosomal hydrolases in cystic fibrosis livers.

The specific activity of several lysosomal hydrolases in normal and cystic fibrosis (CF) livers has been investigated. Neuraminidase activity with respect to two natural substrates (fetuin and bovine submaxillary mucin) is normal in CF livers. No significant differences were found between CF and normal livers in 4-methylumbelliferyl-alpha-D-mannosidase specific activities determined at three different pH values (4.3, 5.65 and 6.5) corresponding to lysosomal, golgi and cytosolic components of the enzyme, respectively. The specific activities of p-nitrophenyl-beta-D-mannosidase and 4-methylumbelliferyl-beta-N-acetylglucosaminidase were also both similar in CF and normal livers.