Clinical Chemistry, Vol 14, 1176-1184, Copyright © 1968 by the American Association for Clinical Chemistry

Serum Amylases, Isoenzymes, and Pancreatitis I. Effect of Substrate Variation

¹ Children’s Hospital, the Children’s Hospital Research Foundation, and the Department of Pediatrics, The Ohio State University College of Medicine, 561 S. 17th St., Columbus, Ohio 43205; and The Research Laboratory, The Keever Starch Division, The Keever Company, Columbus, Ohio.

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 amylose corn, potato, and corn (pearl), and were lintnerized. It was shown that the rate of digestion of starch by each of the fluids tested depends on the plant starch selected as substrate. Digestion of waxy maize was most rapid. The advantages of using waxy maize as a substrate are indicated as a means of markedly enhancing the sensitivity of serum amylase determination. 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 duodenal fluid, and pancreatic extract digested corn starch at a greater rate than potato. These findings suggest that organ-specific amylases exist, and that plant starches might be used to distinguish them.