Exocrine pancreatic dysfunction in guinea pigs with diabetes mellitus

In this study, 37 guinea pigs were classified, on the basis of histologic examination of the pancreas, into three categories: nondiabetic, latent diabetic, and overt diabetic. In order to compare the exocrine pancreatic function in these three groups of animals, pancreatic secretion was collected from each animal following an intravenous infusion of secretin and pancreozymin. Pancreatic enzyme activity, bicarbonate concentration, and the total volume of pancreatic secretion were all significantly decreased in guinea pigs with overt diabetes, but not in those with latent diabetes mellitus. Pancreatic histologic changes characteristic of both latent and overt diabetes were beta-cell hyperplasia and generalized fatty degeneration of the acini. Only the animals with overt diabetes showed total degranulation and severe vacuolation of theta-cells. The same type of exocrine pancreatic dysfunction observed in guinea pigs with spontaneous overt diabetes mellitus is found in human diabetics, and is particularly common in the juvenile type. The guinea pig, therefore, appears to be a suitable animal model for the study of human juvenile diabetes mellitus.