QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Reilly, M. E. Articles by Preedy, V. R. Search for Related Content PubMed PubMed Citation Articles by Reilly, M. E. Articles by Preedy, V. R.

---

Articles

In Vivo Rates of Skeletal Muscle Protein Synthesis in Rats Are Decreased by Acute Ethanol Treatment but Are Not Ameliorated by Supplemental -Tocopherol¹

Matthew E. Reilly^*,, Vinood B. Patel, Timothy J. Peters and Victor R. Preedy^*,2

Departments of ^* Nutrition and Dietetics and Clinical Biochemistry, King’s College, London, UK

²To whom correspondence should be addressed.

Some studies have shown that reductions in tissue protein synthesis, under a variety of cytotoxic conditions, are ameliorated by -tocopherol (ATC) supplementation. We have also shown evidence of increased oxidative stress and reduced protein synthesis rates in alcohol-exposed muscle. Serum levels of ATC fall and rates of muscle protein synthesis are reduced in patients with alcoholic myopathy. We therefore tested the hypothesis that treatment with ATC could ameliorate the ethanol-induced changes in muscle protein synthesis, a contributory event in the pathogenesis of alcoholic muscle disease. Studies were carried out on gastrocnemius (Type II fiber-predominant and usually considered representative of the musculature as a whole), soleus (Type I fiber-predominant) and plantaris (Type II fiber-predominant) muscles. For comparative purposes, we also investigated the liver. Young male Wistar rats (90 g body weight) were injected intraperitoneally (i.p.) daily with ATC (30 mg/kg body weight) in Intralipid fat emulsion (0.1 mL/100 g body, i.p.) for 5 d. Controls were similarly injected with the Intralipid vehicle alone. After ATC supplementation, rats were given ethanol (75 mmol/kg body weight, i.p., 2.5 h) or saline (0.15 mol/L NaCl, i.p.). Fractional rates of tissue protein synthesis (i.e., the percentage of the tissue protein pool renewed each day, k_s, %/d) and RNA activities [i.e., the amount of protein synthesis each day per unit RNA, k_RNA, mg protein/d/mg RNA)] were then measured. Supplementation increased ATC concentrations in plasma, gastrocnemius and liver. There was no effect of ATC supplementation alone on k_s in any of the tissues. ATC supplementation in the absence of alcohol increased k_RNA in the plantaris muscle. In nonsupplemented groups, acute ethanol treatment reduced skeletal muscle (soleus, plantaris and gastrocnemius) k_s. Hepatic k_s was not altered by ethanol, although ATC concentrations in this tissue increased due to ethanol. However, none of the changes in muscle k_s or k_RNA due to ethanol were significantly affected by ATC supplementation. In conclusion, ATC supplementation does not appear beneficial in ameliorating acute alcohol toxicity in skeletal muscle as defined by reductions in protein synthesis.

KEY WORDS: • -tocopherol • muscle • liver • protein synthesis • rats • alcohol

This article has been cited by other articles:

				J. M. McClung, M. A. Whidden, A. N. Kavazis, D. J. Falk, K. C. DeRuisseau, and S. K. Powers Redox regulation of diaphragm proteolysis during mechanical ventilation Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2008; 294(5): R1608 - R1617. [Abstract] [Full Text] [PDF]