Ultrastructure of the adrenal medulla of normal and insulin-treated hamsters.
Fine structural characteristics of the chromaffin cells both in normal and insulin-administered hamster adrenal gland were studied. Exocytosis occurs in 5 per cent of nonstimulated cells especially on the apical cell surfaces. At the same time the occurrence of a great number of closely attached secretory granules was conspicuous on the lateral plasma membrane in the untreated hamster adrenal medulla. Following insulin treatment (10 IU/100 g/body weight), characteristic was the development of large intercellular vacuoles between the lateral plasma membrane, in which electron-dense secretory material was frequently present. On the basis of this observation it is suggested that in the case of insulin-induced hormone secretion, exocytosis preferentially occurs on the lateral plasma membrane, and may play an important role in the discharge of secretory materials from the cells.
D000313:Adrenal Medulla / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D000818:Animals; D002395:Catecholamines / Q000378:metabolism; D002462:Cell Membrane / Q000648:ultrastructure; D006224:Cricetinae; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D005089:Exocytosis / Q000187:drug effects; D005260:Female; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D014617:Vacuoles / Q000648:ultrastructure
D002395:Catecholamines; D007328:Insulin