Dataset Information

Enhancement of muscle mitochondrial function by growth hormone.

ABSTRACT:

Context

Although GH promotes growth and protein anabolism, which are ATP-dependent processes, the GH effect on mitochondrial regulation remains to be determined.

Objective

Our objective was to determine the acute effect of GH on mitochondrial oxidative capacity in skeletal muscle of healthy subjects.

Design and setting

The study was a randomized crossover design at an academic medical center.

Participants

Nine healthy men and women completed the study.

Intervention

GH (150 microg/h) or saline was infused for 14 h on separate days, and muscle biopsies were obtained.

Main outcome measures

Outcome measures included mitochondrial function, gene expression, and protein metabolism.

Results

The 4-fold increase in plasma GH caused elevations in plasma IGF-I, insulin, glucose, and free fatty acids and a shift in fuel selection, with less carbohydrate (-69%) and leucine (-43%) oxidation and 29% more fat oxidation. Muscle mitochondrial ATP production rate and citrate synthase activity were increased 16-35% in response to GH. GH also resulted in higher abundance of muscle mRNAs encoding IGF-I, mitochondrial proteins from the nuclear (cytochrome c oxidase subunit 4) and mitochondrial (cytochrome c oxidase subunit 3) genomes, the nuclear-derived mitochondrial transcription factor A, and glucose transporter 4. Although GH increased whole-body protein synthesis (nonoxidative disposal of leucine), no effect on synthesis rate of muscle mitochondrial proteins was observed.

Conclusions

These results demonstrate that acute GH action promotes an increase in mitochondrial oxidative capacity and abundance of several mitochondrial genes. These events may occur through direct or indirect effects of GH on intracellular signaling pathways but do not appear to involve a change in mitochondrial protein synthesis rate.

SUBMITTER: Short KR

PROVIDER: S-EPMC2243230 | biostudies-literature | 2008 Feb

REPOSITORIES: biostudies-literature

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Publications

Enhancement of muscle mitochondrial function by growth hormone.

Short Kevin R KR Moller Niels N Bigelow Maureen L ML Coenen-Schimke Jill J Nair K Sreekumaran KS

The Journal of clinical endocrinology and metabolism 20071113 2

<h4>Context</h4>Although GH promotes growth and protein anabolism, which are ATP-dependent processes, the GH effect on mitochondrial regulation remains to be determined.<h4>Objective</h4>Our objective was to determine the acute effect of GH on mitochondrial oxidative capacity in skeletal muscle of healthy subjects.<h4>Design and setting</h4>The study was a randomized crossover design at an academic medical center.<h4>Participants</h4>Nine healthy men and women completed the study.<h4>Interventio ...[more]

PMID: 18000087

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Dataset Information

Enhancement of muscle mitochondrial function by growth hormone.

Context

Objective

Design and setting

Participants

Intervention

Main outcome measures

Results

Conclusions

Publications

Enhancement of muscle mitochondrial function by growth hormone.

Similar Datasets

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