Islet NO-Synthases, extracellular NO and glucose-stimulated insulin secretion: Possible impact of neuronal NO-Synthase on the pentose phosphate pathway.

ABSTRACT: The impact of islet neuronal nitric oxide synthase (nNOS) on glucose-stimulated insulin secretion (GSIS) is less understood. We investigated this issue by performing simultaneous measurements of the activity of nNOS versus inducible NOS (iNOS) in GSIS using isolated murine islets. Additionally, the significance of extracellular NO on GSIS was studied. Islets incubated at basal glucose showed modest nNOS but no iNOS activity. Glucose-induced concentration-response studies revealed an increase in both NOS activities in relation to secreted insulin. Culturing at high glucose increased both nNOS and iNOS activities inducing a marked decrease in GSIS in a following short-term incubation at high glucose. Culturing at half-maximal glucose showed strong iNOS expression revealed by fluorescence mic

SUBMITTER: Lundquist I 

PROVIDER: S-EPMC11760571 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature