IMMUNOCYTOCHEMICAL LOCALIZATION OF GASTRIC INHIBITORY PEPTIDE AND GLUCAGON IN THE ALIMENTARY TRACT OF RUMINANTS

Cells containing gastric inhibitory peptide (GIP) and glucagon immunoreactivity were localized in the alimentary tract of the adult sheep, young lamb, calf and goat kid by indirect immunocytochemistry, using antisera raised to the porcine peptides. GIP and glucagon were localized in two distinct cell populations. Cells containing immunoreactive GIP were confined to the mucosa of the duodenum, jejunum and ileum and were not observed in the forestomachs, abomasum, large intestine and pancreas. Cells containing immunoreactive glucagon were distributed widely throughout the alimentary tract but were most numerous in the pancreatic islets and the ileum. Neither GIP nor glucagon‐containing cells were observed in the forestomachs. The distribution of the peptides was similar in adult and young animals. Both cell types appeared to possess an apical projection into the glandular lumen of the alimentary tract. Pre‐absorption of the primary antisera with the appropriate peptide antigen abolished the staining.