Glycemic Regulation and Insulin Secretion Are Abnormal in Cystic Fibrosis Pigs Despite Sparing of Islet Cell Mass

Diabetes is a common and significant comorbidity in cystic fibrosis (CF). The pathogenesis of CF-related diabetes (CFRD) is incompletely understood. Because exocrine pancreatic disease is similar between humans and pigs with CF, the CF pig model has the potential to contribute significantly to the understanding of CFRD pathogenesis. We determined the structure of the endocrine pancreas in fetal,newbornand older CF and non-CF pigsand assessed endocrine pancreas function by intravenous glucose tolerance test (IV-GTT). In fetal pigs, pancreatic insulin and glucagon density was similar between CF and non-CF. In newborn and older pigs, the insulin and glucagon density was unchanged between CF and non-CF per total pancreatic area, but increased per remnant lobular tissue in CF reflecting exocrine pancreatic loss. Although fasting glucose levels were not different between CF and non-CF newborns, CF newborns demonstrated impaired glucose tolerance and increased glucose area under the curve during IV-GTT. Second phase insulin secretion responsiveness was impaired in CF newborn pigs and significantly lower than that observed in non-CF newborns. Older CF pigs had elevated random blood glucose levels compared to non-CF. In summary, glycemic abnormalities and insulin secretion defects were present in newborn CF pigs and spontaneous hyperglycemia developed over time. Functional changes in CF pig pancreas were not associated with a decline in islet cell mass. Our results suggest that functi...
Source: Clinical Science - Category: Biomedical Science Authors: Source Type: research