Metabolic and structural effects of insulin-like growth factor-I and high-protein diet on dystrophic hamster skeletal muscle

Martin M. Zdanowicz, Saul Teichberg, Margaret O'Connor, Jeffrey Moyse, Alfred E. Slonim

Research output: Contribution to journalArticle

10 Scopus citations

Abstract

In muscular dystrophy (MD) there is an imbalance between muscle protein synthesis and protein degradation, which results in a net muscle catabolism, along with muscle wasting and weakness. Using a dystrophic hamster model (BIO 53.58), we examined the chronic (8 weeks) effects of two factors that may enhance muscle protein synthesis and inhibit protein degradation, namely, insulin-like growth factor-I (rhIGF-I) and high-protein diet (HPD). Protein synthesis was determined by measuring the incorporation of 14C phenylalanine into perfused leg muscle, while protein degradation was calculated from the release of tyrosine from the same perfused muscle. Urinary 3-methylhistidine excretion was used as an indicator of myofibrillar degradation. Treatment of dystrophic hamsters with rhIGF-I, HPD, or a combination of the two for 8 weeks resulted in significant decreases in total and myofibrillar degradation when compared with untreated dystrophic animals (P < 0.05) but had minimal effects on protein synthesis. Significant morphologic improvements (P < 0.05), including a normalization and greater uniformity of muscle fibers, were also seen in rhIGF-I- and rhIGF-I + HPD- treated animals. rhIGF-I and HPD were effective in reducing the excessive proteolysis seen in dystrophic muscle, and this reduced proteolysis resulted in improvement of muscle morphology.

Original languageEnglish (US)
Pages (from-to)168-173
Number of pages6
JournalProceedings of the Society for Experimental Biology and Medicine
Volume215
Issue number2
StatePublished - Jun 1 1997
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

Fingerprint Dive into the research topics of 'Metabolic and structural effects of insulin-like growth factor-I and high-protein diet on dystrophic hamster skeletal muscle'. Together they form a unique fingerprint.

  • Cite this