The coupling of metabolic to secretory events in pancreatic islets. The cytosolic redox state.
NADP-linked isocitrate dehydrogenase and malic enzyme [malate dehydrogenase (decarboxylating) (NADP)] activities were characterized in the cytosol of pancreatic islet cells. D-Glucose and L-leucine augmented the cytosolic NADPH/NADP+ ratio, as judged from the isocitrate/2-oxoglutarate and malate/pyruvate islet contents. The flow rate through the malic enzyme was judged from the output of labelled pyruvate by islets exposed to either L-[U-14C]glutamine or L-[U-14C]leucine. The cytosolic generation of NADPH, e.g. at the level of the malic enzyme, may play a role in the coupling of metabolic to secretory events in the process of nutrient-stimulated insulin release.
D000818:Animals; D003600:Cytosol / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D066298:In Vitro Techniques; D007515:Islets of Langerhans / Q000201:enzymology / Q000378:metabolism*; D007521:Isocitrate Dehydrogenase / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000378:metabolism; D008293:Malates / Q000378:metabolism; D009249:NADP / Q000378:metabolism*; D010084:Oxidation-Reduction; D011773:Pyruvates / Q000096:biosynthesis; D019289:Pyruvic Acid; D051381:Rats
D008293:Malates; D011773:Pyruvates; D005973:Glutamine; D009249:NADP; C030298:malic acid; D019289:Pyruvic Acid; D008291:Malate Dehydrogenase; D007521:Isocitrate Dehydrogenase; D007930:Leucine