Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2007 Oct;26(5):658-61.
doi: 10.1016/j.clnu.2007.07.003. Epub 2007 Sep 27.

Antiproteolytic effects of plasma from hibernating bears: a new approach for muscle wasting therapy?

Affiliations

Antiproteolytic effects of plasma from hibernating bears: a new approach for muscle wasting therapy?

Gemma Fuster et al. Clin Nutr. 2007 Oct.

Abstract

Background & aims: In rodents and humans, inactivity or starvation leads to atrophy of skeletal muscle including a decrease in the number and size of muscle cells and in the myofibrillar protein content. It has previously been described that in overwintering bears the inactivity does not provoke any loss of skeletal muscle cell number or size. Taking all these into account, the aim of this study is to test if hibernating bear plasma has any antiproteolytic effect on incubated rat skeletal muscle.

Methods: Rat skeletal extensor digitorum longus (EDL) muscles were incubated in the presence of hibernating, non-hibernating and control bear plasma. After that, proteolytic rate was evaluated as levels of tyrosine released to the medium and muscle mRNA content for different proteolytic systems were measured by Northern blot.

Results: Rat skeletal EDL muscles incubation in the presence of hibernating bear plasma resulted in a 40% decrease of the net proteolytic rate. This inhibition of proteolysis was accompanied by decreases in the expression of both lysosomal (cathepsin B) and ubiquitin-dependent (ubiquitin) proteolytic systems.

Conclusions: The results suggest that during hibernation the bear is able to produce a powerful proteolytic inhibitor which is released to the circulation and blocks muscle wasting associated with immobilization.

PubMed Disclaimer

Similar articles

Cited by

Publication types

Substances

LinkOut - more resources