In:
Diabetes, American Diabetes Association, Vol. 29, No. 6 ( 1980-06-01), p. 431-437
Abstract:
When isolated rat pancreatic islets are exposed to L-leucine (20 mM), the rate of NH4 production is close to the summed rates of L-[1-14 C] leucine decarboxylation and α-ketoisocaproate production, whereas the rates of acetoacetate production and L-[U-14 C] -leucine oxidation are compatible with the conversion of each mole of the amino acid to one mole of acetoacetate and three moles of CO2. ATP content, ATP/ADP ratio, and adenylate charge are maintained at normal values by L-leucine, whereas the NADH/NAD+ ratio (but not the NADPH/NADP+ ratio) is significantly increased. The release of insulin evoked by L-leucine is potentiated by 2-ketoisovalerate, unaffected by L-valine, and inhibited by menadione. L-leucine mimicks the effect of D-glucose on 86Rb+ and 45Ca2+ handling by the islets. However, relative to its rate of oxidation, the insulinotropic effect of L-leucine is less marked than that of D-glucose. This may be due, in part at least, to a decrease in the oxidation of endogenous nutrients. It is concluded that the metabolic, cationic, and secretory effects of L-leucine in isolated islets are not incompatible with the fuel hypothesis for insulin release.
Type of Medium:
Online Resource
ISSN:
0012-1797
,
1939-327X
DOI:
10.2337/diab.29.6.431
Language:
English
Publisher:
American Diabetes Association
Publication Date:
1980
detail.hit.zdb_id:
1501252-9
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