Microassay of an arylamidase in needle biopsies of human liver

Area of Science:

• Biochemistry
• Enzymology
• Clinical Diagnostics

Background:

• Liver function tests are crucial for diagnosing hepatic injury.
• Assessing enzyme activity in small tissue samples presents analytical challenges.

Purpose of the Study:

• To develop a microdetermination method for liver arylamidase activity.
• To enable enzyme activity assessment from small human and animal liver biopsy samples.

Main Methods:

• A novel method for determining liver arylamidase activity in tissue homogenates.
• Utilized small tissue samples (5-15 mg wet wt.) obtained via needle biopsy.
• Quantified enzyme activity based on benzylhydrazine formation per microgram of protein per hour.

Main Results:

• Established normal liver arylamidase activity range: 0.2 to 0.6 nmoles benzylhydrazine formed/mug protein/hr.
• Demonstrated the feasibility of assaying enzyme activity in minimal tissue amounts.
• Reported protein content in human liver: 90-130 mug/mg wet wt.

Conclusions:

• The described microdetermination method is suitable for liver arylamidase activity assessment.
• This assay is a valuable tool for the diagnosis of hepatic injury.
• The method's utility is enhanced by its requirement for only small biopsy samples.