Serum amylase and isoamylases and their origins in healthy dogs and dogs with experimentally induced acute pancreatitis.

Agarose-gel electrophoresis was used to study isoamylases in tissues and sera of healthy dogs and the sera of dogs with experimentally induced acute pancreatitis. Three or 4 isoamylases were found in the serum of healthy dogs; they were numbered 1 to 4 with respect to their degree of anodal migration. Peak 4 isoamylase, the slowest migrating (most cathodal), was the major isoamylase fraction in sera and tissues of healthy dogs. Peak 3 was identified as a pancreas-specific isoamylase. Absolute total serum amylase and total isoamylase concentrations increased significantly in dogs with pancreatitis compared with values for control dogs (sham-operated). The relative increase in peak 3 isoamylase was greater than that seen with total amylase or the other isoamylases. The decrease in total serum amylase and isoamylase concentrations paralleled each other; however, peak 3 remained proportionally high longer than did total amylase and the other isoamylase fractions. These findings indicate that measurement of peak 3 isoamylase concentrations may be of diagnostic value in dogs with suspected pancreatitis with normoamylasemia and in dogs with extrapancreatic hyperamylasemia.