Immunohistochemical localization of gastrin C-terminus, gastric inhibitory peptide (GIP) and endorphin in the pancreas of lizards with special reference to the hibernation period.

Gastrin C-terminus and GIP immunoreactive cells were observed in the pancreas of the desert lizard (Uromastyx aegyptia) captured during the hibernation period, but not in those collected in the active period. These cell types were encountered among the exocrine parenchyma, especially around ducts and among the ductal epithelial cells. Occasionally a few GIP cells were seen to occupy the islet periphery. No gastrin C-terminus or GIP immunoreactive cells were observed in the pancreas of the grass lizard (Mabuya quinquetaeniata)--which does not hibernate--collected in winter and in summer. In both species of lizards endorphin-like immunoreactivity was localized in the pancreatic PP-cells in specimens collected in winter and summer. It was assumed that the presence of the gastrin C-terminus and GIP cells in the desert lizard pancreas represents a response to the peculiar physiological state through which these lizards pass in hibernation.