Hypothalamic changes in diabetic Chinese hamsters. A semiquantitative, light and electron microscopic study.

Eight male congenitally diabetic Chinese hamsters (DCH) and eight heterozygotic controls were studied for a period of about 20 months. Final glycemia and body weight were significantly higher in DCH (p less than 0.001). After whole body perfusion brains were removed and processed for light and electron microscopy. Qualitative and quantitative light microscopic studies of semithin sections of hypothalami revealed significant changes in DCH. Accumulation of lipid droplets was found in the external layer of the median eminence (p less than 0.001). Cell bodies of beta-tanycytes (p less than 0.01) and of arcuate nucleus neurons (p less than 0.001) were hypotrophic. By electron microscopy, the lipid droplets were localized in beta-tanycyte processes. Apical surfaces of alpha- and beta-tanycytes of DCH had fewer digitations. Intracytoplasmic organelles of arcuate nucleus neurons were reduced in number and size. These findings suggest a primary pathogenetic role of the hypothalamic-hypophyseal axis in diabetes of Chinese hamsters.