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

This Article 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 Google Scholar Google Scholar Articles by Samuels, S. E. Articles by Baracos, V. E. Search for Related Content PubMed PubMed Citation Articles by Samuels, S. E. Articles by Baracos, V. E.

Tissue Protein Turnover is Altered during Catch-Up Growth Following Escherichia coli Infection in Weanling Rats^1,2,3,

Department of Animal Science, University of Alberta, Edmonton, Alberta T6G 2P5 Canada

Infection in young growing animals is manifested by poor tissue protein accretion; during subsequent catch-up growth this is reversed. To account for these changes, protein synthesis and degradation were measured in vivo in skeletal muscle, skin, liver and small intestine in weanling rats during catch-up growth after Escherichia coli infection. Observations were made at d 4, 6, 8, 11 and 14, when infected rats had elevated nitrogen balance. Liver protein mass and turnover were not affected by treatment. Although protein mass of small intestine fell during infection, catch-up was achieved before d 4, suggesting a high priority for protein repletion in this tissue. On d 4, protein mass was lower (P < 0.05) in muscle (-19%) and skin (-23%) in infected vs. control rats. Thereafter growth rates of skeletal muscle and skin were higher (P < 0.001) in infected rats compared with controls. Catch-up growth was most pronounced early, but continued throughout the study. During catch-up growth, protein synthesis (mg/d) in muscle and skin was not different between control and infected animals. Protein synthesis was maintained in muscle because RNA mass was maintained. During catch-up growth in muscle and skin of infected rats, there was lower protein degradation (mg/d) than in controls (P < 0.05). We conclude that alterations in protein turnover during catch-up growth are tissue and time dependent and are different from those described in other hyperanabolic states.

KEY WORDS: • catch-up growth • protein degradation • protein synthesis • infection • rats

¹ Presented in part at the 35th Annual Meeting of the Canadian Federation of Biological Societies (CFBS), June 1992, Victoria, British Columbia, Canada [Samuels, S. E. & Baracos, V. E. (1992) Skeletal muscle protein turnover during catch-up growth following E. coli infection in weanling rats. (abs.)].

² This research was made possible by grants from Natural Sciences and Engineering Research Council (NSERC) of Canada.

³ The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 USC section 1734 solely to indicate this fact.

⁴ To whom correspondence should be addressed.

Manuscript received 17 May 1994. Revision accepted 23 August 1994.