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Reduced insulin action in muscle of high fat diet rats over the diurnal cycle is not associated with defective insulin signaling

Version 3 2024-06-18, 14:34
Version 2 2024-06-04, 03:33
Version 1 2019-05-02, 10:54
journal contribution
posted on 2024-06-18, 14:34 authored by L Small, AE Brandon, BL Parker, V Deshpande, AF Samsudeen, Greg KowalskiGreg Kowalski, J Reznick, DL Wilks, E Preston, Clinton BruceClinton Bruce, DE James, N Turner, GJ Cooney
OBJECTIVE: Energy metabolism and insulin action follow a diurnal rhythm. It is therefore important that investigations into dysregulation of these pathways are relevant to the physiology of this diurnal rhythm. METHODS: We examined glucose uptake, markers of insulin action, and the phosphorylation of insulin signaling intermediates in muscle of chow and high fat, high sucrose (HFHS) diet-fed rats over the normal diurnal cycle. RESULTS: HFHS animals displayed hyperinsulinemia but had reduced systemic glucose disposal and lower muscle glucose uptake during the feeding period. Analysis of gene expression, enzyme activity, protein abundance and phosphorylation revealed a clear diurnal regulation of substrate oxidation pathways with no difference in Akt signaling in muscle. Transfection of a constitutively active Akt2 into the muscle of HFHS rats did not rescue diet-induced reductions in insulin-stimulated glucose uptake. CONCLUSIONS: These studies suggest that reduced glucose uptake in muscle during the diurnal cycle induced by short-term HFHS-feeding is not the result of reduced insulin signaling.

History

Journal

Molecular Metabolism

Volume

25

Pagination

107-118

Location

Germany

Open access

  • Yes

ISSN

2212-8778

eISSN

2212-8778

Language

English

Publication classification

C1 Refereed article in a scholarly journal

Copyright notice

2019, The Authors

Publisher

ELSEVIER SCIENCE BV