Lysosomal Enzyme Activity in Human Liver in Relation to the Age of the Patient and in Cases with Obstructive Jaundice

Abstract

Basal (latent) and maximal (induced by Triton X-100) activity of the enzymes acid phosphatase, aryl sulphatase, beta-glucuronidase, and cathepsin was determined in homogenate of human liver, obtained as biopsy from patients operated on for uncomplicated gallbladder disease and from patients operated on for obstructive jaundice caused by common bile-duct stones.

Maximal activity of acid phosphatase and aryl sulphatase was significantly positively correlated to the age of the patient.

The ratio between maximal and basal activity (an expression of the degree of retention of the enzymes to the lysosomes) of aryl sulphatase was significantly decreased with increasing age of the patient.

In cholestatic liver the degree of retention of acid phosphatase and cathepsin activity to the lysosomes was significantly decreased.

Cholic acid and bilirubin added in vitro to homogenate in concentrations assumed to be within physiological limits, caused a release of lysosomal enzymes.

It is suggested that the retention of bile products in obstructive jaundice causes release of hydrolytic enzymes from liver lysosomes, and that this phenomenon could be responsible for the common occurrence of scattered cellular necrosis in the liver in cholestatic conditions.

Key Words:

• Acid phosphatase
• aging
• bile acids and salts
• bilirubin
• cathepsin
• jaundice
• obstructive
• liver diseases
• lysosomes