233 Cholecystokinin expression in the developing and regenerating pancreas and intestine G Liu, S V Pakala, D Gu, T Krahl, L Mocnik and N Sarvetnick Department of Immunology, Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA (Requests for offprints should be addressed to N Sarvetnick; Email:
[email protected]) Abstract In developmental terms, the endocrine system of neither NOD mice continued this pattern. By contrast, in IFN- the gut nor the pancreatic islets has been characterized transgenic mice, CCK expression was suppressed from fully. Little is known about the involvement of cholecysto- birth to 3 months of age in the pancreata but not intestines. kinin (CCK), a gut hormone, involved in regulating the However, by 5 months of age, CCK expression appeared secretion of pancreatic hormones, and pancreatic growth. in the regenerating pancreatic ductal region of IFN- Here, we tracked CCK-expressing cells in the intestines transgenic mice. In the intestine, CCK expression per- and pancreata of normal mice (BALB/c), Non Obese sisted from fetus to adulthood and was not influenced Diabetic (NOD) mice and interferon (IFN)- transgenic by IFN-. Intestinal cells expressing CCK did not mice, which exhibit pancreatic regeneration, during em- co-express glucagon, suggesting that these cells are bryonic development, the postnatal period and adulthood. phenotypically distinct from CCK-expressing cells in We also questioned whether IFN- influences the expres- the pancreatic islets, and the effect of IFN- on sion of CCK. The results from embryonic day 16 showed CCK varies depending upon the cytokine’s specific that all three strains had CCK in the acinar region of microenvironment.