The ultrastructure changes of pancreatic islets alpha cells in rats with impaired glucose tolerance / 中华内分泌外科杂志

ABSTRACT

Objective To investigate the ultrastructure changes of pancreatic islets alpha cells in rats with impaired glucose tolerance.Methods 16 Wistar rats were randomly assigned into normal glucose tolerance group(NGT group,n =8)and impaired glucose tolerance group(IGT group,n =8).NGT group were fed with routine diet and IGT-group were fed with high-sugar high-fat diet.At the 12th week,IGT models were considered successful if the level of 2-hour peripheral blood glucose(2 h PG)was between 7.8 and 11.1 mmol/L in oral glucose tolerance test and continued for more than a week.The pancreas tail of animals in the NGT group and IGT group rats was removed for ultrastructure observation.Alpha cells were observed under transmission electron microscope.Results The big-plump secretory granule with aureole appeared in pancreatic islets alpha cells of NGT group,and it contained a round dense core.The nuclear chromatin and contents were evenly distributed.Mitochondria and en-doplasmic reticulum arranged tightly and orderly.Compared with NGT group,the quantities of secretory granule increased significantly in IGT group.The gap between dense core and membrane was narrower.The quantities of mitochondria and rough endoplasmic reticulum increased significantly.There was no significant change for the structure of the other cell organelle.Conclusion The pathogenesis of IGT is associated with ultrastructural changes and dysfunction of pancreas islets alpha cells.