Effects of sodium nitroprusside on blood glucose concentration, B-cell morphology and islet glutamate dehydrogenase activity in mice.
Mice injected with sodium nitroprusside (NaNP) exhibited a marked, transient hyperglycemia and enhanced activity of glutamate dehydrogenase in the pancreatic islets. Ultrastructurally, the islet B-cells of NaNP-treated mice showed expanded granular endoplasmic reticulum, prominent Golgi complex, increased amount of secretory granules, mitochondrial enlargement and vacuolation, and mitochondrion-secretory granule complexes. Stereological analyses disclosed increased volume of endoplasmic reticulum, Golgi complex and mitochondria, and increased number of secretory granules in the B-cells 1 h after the injection of NaNP. Isolated mouse islets exposed to NaNP showed stimulated activity of glutamate dehydrogenase both in the presence of 2 and 18 mM glucose, whereas the release of insulin was stimulated at 2 mM glucose, but inhibited at 18 mM glucose. The observations demonstrate that NaNP induces transiently altered structure and function in mouse islet B-cells.
Boquist
L
L
Institute of Pathology, University of Umeå, Sweden.
D000818:Animals; D001786:Blood Glucose / Q000032:analysis*; D006152:Cyclic GMP / Q000032:analysis; D005260:Female; D005292:Ferricyanides / Q000494:pharmacology*; D005969:Glutamate Dehydrogenase / Q000032:analysis*; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects* / Q000201:enzymology / Q000648:ultrastructure; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009599:Nitroprusside / Q000494:pharmacology*
D001786:Blood Glucose; D005292:Ferricyanides; D007328:Insulin; D009599:Nitroprusside; D005969:Glutamate Dehydrogenase; D006152:Cyclic GMP