Pancreatic islet immunoreactivity to the Reg protein INGAP

J Histochem Cytochem. 2008 Feb;56(2):183-91. doi: 10.1369/jhc.7A7365.2007. Epub 2007 Nov 12.


The Reg-related protein family member INGAP (islet neogenesis-associated protein) is a pleiotropic factor enhancing islet neogenesis, neurite growth, beta-cell protection, and beta-cell function. Using an antibody to the N-termini of INGAP, we have identified that immunoreactivity to INGAP localized to the pancreatic endocrine cells in mouse. INGAP- and insulin-immunoreactive cells are mutually exclusive, with INGAP-immunoreactive cells being preserved after streptozotocin-mediated destruction of beta-cells. Glucagon- and INGAP-immunoreactive cells colocalize, although respective antigen expression occurs in different intracellular locations. These data suggest that INGAP-immunoreactive cells include alpha-cells; however, detection of single INGAP-immunoreactive/glucagon-negative cells indicates that this may not be exclusive. In addition to mouse, detection of islet endocrine cells that were INGAP immunoreactive/glucagon immunoreactive/insulin negative was also observed in islets from human, monkey, and rat. These findings reveal that INGAP and/or related group 3 Reg proteins have a conserved expression in the pancreatic islet.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigen-Antibody Reactions
  • Antigens, Neoplasm / metabolism*
  • Biomarkers, Tumor / metabolism*
  • Cell Line
  • Cross Reactions
  • Diabetes Mellitus, Experimental / metabolism
  • Glucagon / metabolism
  • Glucagon-Secreting Cells / metabolism
  • Haplorhini
  • Humans
  • Immunohistochemistry
  • Insulin / metabolism
  • Intracellular Space / metabolism
  • Islets of Langerhans / metabolism*
  • Lectins, C-Type / metabolism*
  • Male
  • Mice
  • Pancreatitis-Associated Proteins
  • Protein Transport
  • Proteins / metabolism*
  • Rats
  • Recombinant Proteins / metabolism
  • Species Specificity


  • Antigens, Neoplasm
  • Biomarkers, Tumor
  • Insulin
  • Lectins, C-Type
  • Pancreatitis-Associated Proteins
  • Proteins
  • REG3A protein, human
  • Recombinant Proteins
  • Reg3b protein, mouse
  • Reg3b protein, rat
  • Glucagon