Pancreatic and Intestinal Processing of Proglucagon in Man

Diabetologia. 1987 Nov;30(11):874-81. doi: 10.1007/BF00274797.

Abstract

We developed antisera and radioimmunoassays against synthetic replicas of glucagon-like peptide-1 (1-36) and -2, predicted products of the glucagon precursor, and against glucagon-like peptide-1 (7-36) identical to the sequence of glucagon-like peptide-1, but lacking its first six N-terminal amino acids. With these tools, we studied the localisation and molecular nature of glucagon-like immunoreactivity in human pancreas, small intestine and plasma. By immunohistochemistry glucagon-like peptide-1, and glucagon-like peptide-2 immunoreactivity coexisted with glucagon in pancreatic islet cells and with enteroglucagon in small intestinal enteroglucagon-producing cells. By chromatography of tissue extracts we found that glucagon-like peptide-1 and glucagon-like peptide-2-immunoreactivities in the human pancreas (307 +/- 51 and 107 +/- 37 pmol/g tissue) were mainly contained in a large peptide, whereas in the small intestine glucagon-like peptide-1 and glucagon-like peptide-2 immunoreactivities were found in separate smaller molecules (49 +/- 21 and 77 +/- 28/g tissue). By isocratic high pressure liquid chromatography of the large pancreatic glucagon-like peptide we found that this peptide is heterogeneous. By chromatographic analysis glucagon-like peptide-1 immunoreactivity in fasting plasma was mainly found in a large peptide corresponding to the pancreatic form, while after a meal a smaller molecular form coeluting by gel filtration with glucagon-like peptide-1 predominated.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Amino Acid Sequence
  • Chromatography, Gel
  • Chromatography, High Pressure Liquid
  • Gastrointestinal Hormones / analysis*
  • Glucagon / analysis*
  • Glucagon / blood
  • Glucagon-Like Peptide 1
  • Glucagon-Like Peptide 2
  • Humans
  • Ileum / analysis
  • Intestine, Small / analysis*
  • Pancreas / analysis*
  • Pancreatic Hormones / analysis*
  • Peptides / analysis*
  • Peptides / blood
  • Proglucagon
  • Protein Precursors / analysis*
  • Protein Precursors / blood
  • Radioimmunoassay

Substances

  • Gastrointestinal Hormones
  • Glucagon-Like Peptide 2
  • Pancreatic Hormones
  • Peptides
  • Protein Precursors
  • Proglucagon
  • Glucagon-Like Peptide 1
  • Glucagon