Ontogeny and species differences in the pancreatic expression and localization of the CCKA receptors

We have evaluated the presence and localization of the CCKA receptor in rat, mouse, pig and human fetal pancreas by Northern, Western blots and immunofluorescence techniques. In the rat, parallelism exists between development of the CCKA receptor mRNA and protein with maximal peaks of expression during the suckling period. In the course of pancreatitis induction, CCKA receptor mRNA were maximally expressed and sustained during the gland's regeneration. In the rat and mouse pancreas, the CCKA receptor protein is localized around the acinar cells and beta cells of the islets of Langerhans. In the adult pig and fetal human pancreas, the CCKA receptor proteins were detected by Western blot. By immunofluorescence, its detection was possible only in the islet of Langerhans of the pig pancreas. These new findings support the views that CCK plays important and various roles in specific physiological systems of the pancreas of different species. (C) 1999 Academic Press.