Islet Endocrine-Cell Behavior From Birth Onward in Mice With the Nonobese Diabetic Genetic Background

Glucagon-producing α cells play a crucial role during the perinatal period. Because of their peri-islet localization near the early dendritic and macrophage cell infiltration, we thought it pertinent to investigate α cells in greater depth in nonobese diabetic (NOD) mice, a well-recognized spontaneous model for human type I diabetes. We determined α-cell distribution (glucagon immunohistochemistry and image analysis) and activity (real-time reverse transcriptase polymerase chain reaction [RT-PCR] and glucagon radioimmunoassay [RIA]), in relationship to glycemia in NOD and lymphocyte-deficient NODscid mice as compared to control mice (C57BL/6) from birth onward. NOD and NODscid mice, particularly at 1 day of age, had twice as many very small islets (