High-fat diet effects on contractile performance of isolated mouse soleus and extensor digitorum longus when supplemented with high dose vitamin D

Research output: Contribution to journalArticlepeer-review

6 Downloads (Pure)

Abstract

Evidence suggests vitamin D3 (VD) supplementation can reduce accumulation of adipose tissue and inflammation and promote myogenesis in obese individuals, and thus could mitigate obesity-induced reductions in skeletal muscle (SkM) contractility. However, this is yet to be directly investigated. This study, using the work-loop technique, examined effects of VD (cholecalciferol) supplementation on isolated SkM contractility. Female mice (n = 37) consumed standard low-fat diet (SLD) or high-fat diet (HFD), with or without VD (20,000 IU/kg−1) for 12 weeks. Soleus and EDL (n = 8–10 per muscle per group) were isolated and absolute and normalized (to muscle size and body mass) isometric force and power output (PO) were measured, and fatigue resistance determined. Absolute and normalized isometric force and PO of soleus were unaffected by diet (P > 0.087). However, PO normalized to body mass was reduced in HFD groups (P < 0.001). Isometric force of extensor digitorum longus (EDL) was unaffected by diet (P > 0.588). HFD reduced EDL isometric stress (P = 0.048) and absolute and normalized PO (P < 0.031), but there was no effect of VD (P > 0.493). Cumulative work during fatiguing contractions was lower in HFD groups (P < 0.043), but rate of fatigue was unaffected (P > 0.060). This study uniquely demonstrated that high-dose VD had limited effects on SkM contractility and did not offset demonstrated adverse effects of HFD. However, small and moderate effect sizes suggest improvement in EDL muscle performance and animal morphology in HFD VD groups. Given effect sizes observed, coupled with proposed inverted U-shaped dose-effect curve, future investigations are needed to determine dose/duration specific responses to VD, which may culminate in improved function of HFD SkM.
Original languageEnglish
Pages (from-to)283-301
Number of pages19
JournalExperimental Physiology
Volume109
Issue number2
Early online date20 Nov 2023
DOIs
Publication statusPublished - 1 Feb 2024

Bibliographical note

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Keywords

  • fatigue
  • force
  • high-fat diet
  • muscle function
  • obesity
  • power output
  • work loop

Fingerprint

Dive into the research topics of 'High-fat diet effects on contractile performance of isolated mouse soleus and extensor digitorum longus when supplemented with high dose vitamin D'. Together they form a unique fingerprint.

Cite this