Glucokinase is required for high-starch diet-induced β-cell mass expansion in mice.
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ABSTRACT: Aims/introduction
We aimed to determine whether glucokinase is required for β-cell mass expansion induced by high-starch diet (HSTD)-feeding, as has been shown in its high-fat diet-induced expansion.Materials and methods
Eight-week-old male wild-type (Gck+/+ ) or glucokinase haploinsufficient (Gck+/- ) mice were fed either a normal chow (NC) or an HSTD for 15 weeks. The bodyweight, glucose tolerance, insulin sensitivity, insulin secretion and β-cell mass were assessed.Results
Both HSTD-fed Gck+/+ and Gck+/- mice had significantly higher bodyweight than NC-fed mice. Insulin and oral glucose tolerance tests revealed that HSTD feeding did not affect insulin sensitivity nor glucose tolerance in either the Gck+/+ or Gck+/- mice. However, during the oral glucose tolerance test, the 15-min plasma insulin concentration after glucose loading was significantly higher in the HSTD group than that in the NC group for Gck+/+ , but not for Gck+/- mice. β-Cell mass was significantly larger in HSTD-fed Gck+/+ mice than that in NC-fed Gck+/+ mice. In contrast, the β-cell mass of the HSTD-fed Gck+/- mice was not different from that of the NC-fed Gck+/- mice.Conclusions
The results showed that HSTD feeding would increase pancreatic β-cell mass and insulin secretion in Gck+/+ , but not Gck+/- mice. This observation implies that glucokinase in β-cells would be required for the increase in β-cell mass induced by HSTD feeding.
SUBMITTER: Tsuchida K
PROVIDER: S-EPMC8409809 | biostudies-literature |
REPOSITORIES: biostudies-literature
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