[Changes in lysosomal enzymes and cell damage of the liver in obstructive jaundiced rats].

The changes of hepatic lysosomal enzymes and the hepatic cellular damage were investigated in rats with obstructive jaundice, phospholipase A2 (PL-A2) which is a strong labilizer of lysosomal membrane was added in the lysosomal fraction of rat's liver with various concentration. The activities of cathepsin D and beta-glucuronidase those were released by PL-A2 from lysosomal fraction were measured. The values of both lysosomal enzyme activities showed positive relation to the concentration of PL-A2, and were remarkably increased in obstructive jaundiced rats than in normal rats. We also measured the activity of cathepsin D released by Triton X-100 from lysosomal fraction of normal and jaundiced rat liver. The amount of lysosomal enzyme was more increased in obstructive jaundiced liver than in normal liver. Fragility score as the indicator for lysosomal membranous fragility was calculated as the ratio of cathepsin D released by PL-A2 to that released by Triton X-100. Fragility score was more increased in obstructive jaundiced rats than in normal rats. In conclusion, these data suggest that the fragility of lysosomal membrane could be enhanced in obstructive jaundiced liver.