Showing papers by "Alain Junod published in 1970"

REMARKS ON PANCREATIC β-CELLS IN SPONTANEOUS AND EXPERIMENTAL DIABETES IN SMALL LABORATORY RODENTS

Abstract: Publisher Summary This chapter discusses remarks on pancreatic s-cells in spontaneous and experimental diabetes in small laboratory rodents. In reviewing the metabolic sequences that appear to be related to the spontaneous occurrence of inappropriate hyperglycemia in these rodents, it was suggested that decreased responsiveness to insulin might be the primary event, either spontaneous or diet induced. A decreased effectiveness of insulin was almost invariably associated with hyper-insulinemia, although this may be a very transient event, as in Chinese hamsters, or a rather long-lasting one, as in obob mice. Both hypertrophy and hyperplasia of the β cells of the islets of Langerhans are frequently present at least at some point during the life history of most of these syndromes with the notable exception of the syndrome in Chinese hamsters and that in dbdb mice. In the principal ultrastructural characteristics of the pancreatic β cells, it was found that the normal appearance of β cells in normoglycemic spiny mice do not differ from the β cells of other species, except that the average electron density of β granules is rather low, although the characteristic variability in β-granule density is maintained. The most important feature of β cells from hyperglycemic, and particularly from hyperglycemic and ketotic animals, is, of course, that of the frequent occurrence of mixed exocrine–endocrine cells. The spontaneous syndromes associated with inappropriate hyperglycemia and anomaly of the insulin producing β- cells increase the number and alter the relative activity of these reaction patterns and should certainly contribute to the understanding of both normal and deranged β-cell metabolism.