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Protein metabolism in the small intestine of the ethanol‐fed rat
Author(s) -
Preedy Victor R.,
Peters Timothy
Publication year - 1989
Publication title -
cell biochemistry and function
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 61
eISSN - 1099-0844
pISSN - 0263-6484
DOI - 10.1002/cbf.290070402
Subject(s) - ethanol , chemistry , medicine , small intestine , phenylalanine , metabolism , endocrinology , zoology , biochemistry , biology , amino acid
Abstract The effects of chronic ethanol feeding on the small intestine were investigated in young rats. Rats were fed a nutritionally‐adequate liquid diet, containing 36 per cent of total energy as ethanol (treated, n = 7), or isovolumetric amounts of the same diet in which ethanol was substituted by isocaloric glucose (controls, n = 7). After six weeks the wet weight and total tissue contents of protein, RNA and DNA were significantly reduced by 21 per cent, 23 per cent, 16 per cent and 28 per cent respectively, ( p < 0·014). Rates of protein synthesis were measured with L[4 3 H]phenylalanine and fractional rates (defined as the percentage of constituent tissue protein synthesised each hour, i.e. k s , % h −1 ) were calculated from the specific radioactivity of free phenylalanine in both tissue homogenates and plasma. Ethanol‐feeding reduced k s by approx 10 per cent ( p < 0·181). The amount of protein synthesized unit −1 RNA was also reduced by approx 15 per cent ( p < 0·059) but the amount of protein synthesis unit −1 DNA was unaffected by ethanol‐feeding ( p < 1·000). In contrast, the absolute rates of protein synthesis were reduced by approximately 30 per cent ( p < 0·022). It was concluded that, as the small intestine contributes to approx. 20–25 per cent of whole body synthesis these results may have an important effect on whole body nitrogen homeostasis and may have implications for the gastrointestinal effects of ethanol seen during chronic alcoholic abuse.