Premium
Does short‐term nutritional deprivation (ND) affect protein synthesis in different organs differently?
Author(s) -
Balagopal Prabhakaran,
Sweeten Shawn,
Bruno Brice,
Fournier Mario,
Lewis Michael
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.lb61-b
Subject(s) - medicine , protein turnover , endocrinology , metabolism , protein metabolism , chemistry , protein biosynthesis , biology , biochemistry
Proteins are integral components of all tissues and they play crucial pathophysiological roles in preserving the function of various organs. Recent studies have suggested alterations in protein metabolism in the diaphragm muscle (DM) due to short‐term ND. However, the impact of ND on protein metabolism in different organs, such as gastracnemius muscle (GM), DM, liver and heart remains unclear. In the current study we measured the rate of protein synthesis in GM, DM, liver and heart in ND and control rats. Male rats were divided into 2 groups: 20% of usual food intake for 4 days (ND) with water provided ad libitum and free‐eating control. [U‐13C]leucine was continuously infused through the jugular vein for 3.5 h after a priming dose of the isotope. Blood samples were collected from the carotid artery at baseline and every 30 min at precursor pool plateau. GM, DM, liver and heart were excised at the end of the infusion. The rate of incorporation of 13C‐leucine into mixed protein in each tissue was measured using gas‐chromatography‐combustion‐isotope ratio mass spectrometry and protein synthetic rates calculated. Results suggest that short‐term ND results in an overall reduction in protein synthesis in GM, DM, liver and heart. Compared to ND‐induced reductions in protein synthesis in GM and DM (~70% for both), the reductions in heart (~50%) and liver (~30%) appear to be much less. It is unclear if protein turnover in the vital organs compensates for the drastic reductions in protein turnover in muscle, in the longer term, by sparing amino acid substrates for protein remodeling in other tissues.