18] Radioimmunoassay of human pancreatic amylase

Abstract

Publisher Summary This chapter discusses the radioimmunoassay of human pancreatic amylase. Serum amylase determination has been the most commonly used test for the diagnosis of pancreatic inflammation. Radioimmunoassay is applicable to the determination of an enzyme-inhibitor complex or products of enzyme degradation. The development of a radioimmunoassay for human pancreatic amylase was sought to measure the serum enzyme levels in terms of their concentration. The standard curve for the radioimmunoassay of human pancreatic amylase, together with the dilution curves for normal serum and urine are discussed in the chapter. These dilution curves were parallel to the standard curve, indicating that the protein detected in human sera and urines can be measured immunologically at different dilutions. The immunoreactivities of human pancreatic and salivary amylase isoenzymes were too similar to permit the differential determination of amylase isoenzymes. The heat stability of immunological and enzymatic activity of amylase in human pancreatic juice is also discussesd in this chapter. The measurement of enzymatic activity of serum amylase provides a direct assessment of its concentration, suggesting that rapid decline in the enzymatic activity of serum amylase in acute pancreatitis should be attributed to the other factors, such as change in metabolic turnover rather than binding of amylase to inhibitors or the breakdown of the enzymes.