A New Method for the Determination of Sialic Acid Using Sialidase combined with NANA-Aldolase, and its Clinical Application

Abstract

We have established a new method for the determination of sialic acid using sialidase combined with NANA-aldolase. Sialic acid was cleaved to N-acetyl-D-mannosamine and pyruvic acid, following pyruvate was measured by means of LDH with NADH as a change of absorbance at 366 nm. Sialic acid concentration was determined with N-acetyl-neuranimic acid as a standard.
Sensitivity and precision are excellent, linearity extend to 200mg/dl of sialic acid concentration in serum. The result of this method were paralleled with those of manual sialidase-thiobarbituric acid procedure.
Serum sialic acid concentrations in various diseases were observed. In the patient with acute myocardial infarction, high levels of sialic acid in sera had kept until 34 days after the attack.
These data clearly indicate that the following determination of sialic acid provides a more sensitive index of the presence of histologically acute myocardial infarction than the other biochemical tests such as CPK and LDH.