Human serum amylase: a brief biochemical evaluation

Preparation and application of Procion Yellow starch for amylase assay

A new starch derivative for the determination of amylase activity has been synthesized by coupling Procion Yellow dye with starch. The product of this reaction is intensely yellow and is easily suspended in water, in neutral buffer solution, and also in acidic solution. Amylase from pancreatin, saliva, urine and serum readily hydrolyzes this chromogenic substrate. A method for determining amylase activity based on the use of Procion Yellow Starch substrate is described. The procedure requires 0.1 ml of sample and an incubation time of 30 min. The soluble chromogen, which is liberated by enzymatic hydrolysis, is measured at 420 nm and the amylase activity-absorbance relationship at this wavelength is linear. The normal range for this method is 50--150 Somogyi units/dl.

Antiserum raised against human pancreatic alpha-amylase

Isozymes of human pancreatic alpha-amylase were used as immunogens to raise antisera in rabbits. These antisera were unable to differentiate between the two isoamylases but produced an almost total inhibition of serum amylase activity when used at a dilution of 1 : 5000. Similar inhibition patterns were produced with the salivary and urinary enzymes as well as with serum from a patient with acute pancreatitis. No cross reactivity of the antisera with hog pancreatic amylase was observed and only at antiserum concentrations of 1 : 5000 and above was ther any inhibition of monkey serum amylase. The degree of inhibition observed varied with the size of the substrate but was not increased by the use of a second antibody.