Serum amylases, isoenzymes, and pancreatitis. I. Effect of substrate variation.

Four plant starches were used to study human amylase activity in normal serum and urine, “pancreatitis” serum,duodenal fluid (secretin stimulated),saliva, and pancreatic extract. The starches were derived from waxy maize, high amylosecorn, potato, and corn (pearl), and were lintnerized. It was shown that the rate of digestion of starch by each of the fluids tested dependson the plant starch selected as substrate. Digestion of waxy maize was most rapid. The advantagesof using waxy maize as a substrate are indicated as a means of markedly enhancing the sensitivity of serum amylasedetermination. It was also found that normal serum, urine, and saliva digested potato starch at a greater rate than corn starch with few exceptions,while pancreatitis serum, secretin-stimulated duodenalfluid, and pancreatic extract digestedcorn starch at a greater rate than potato. These findings suggest that organ-specific amylases exist, and that plant starchesmight be used to distinguishthem.