DEPRIVATION OF DIETARY NUCLEOTIDES DECREASES PROTEIN-SYNTHESIS IN THELIVER AND SMALL-INTESTINE IN RATS

Background & Aims: Dietary nucleotides are reported to influence the g rowth and functioning of the liver and small intestine. The aim of thi s study was to examine the mechanism by which nucleotides exert their effects in these tissues by assessing protein synthesis activity and r elated parameters in the presence or absence of dietary nucleotides. M ethods: Rats were fed a purified diet with or without nucleotides far 10 days, Fractional protein synthesis rate, RNA and DNA concentrations , polysome size distribution, and number of ribosomes were assessed, R esults: Fractional protein synthesis rates of the liver and small inte stine were lower in the nucleotide-deprived group than in the control group. In the liver, RNA concentration was also Tower in the nucleotid e-deprived group, but values in the small intestine were similar in th e two groups. In the liver, deprivation of nucleotides resulted in a r eduction in the number of ribosomes and in polysome breakdown, Protein and DNA concentrations did not vary in the liver; however, the concen tration of DNA was lower in the small intestine of the nucleotide-depr ived roup than in the control group, Conclusions: Dietary nucleotides can modulate protein synthesis in the liver and small intestine as a r esult of tissue-specific nucleic acid changes.