期刊名称：Journal of Nutritional Science and Vitaminology
印刷版ISSN：0301-4800
电子版ISSN：1881-7742
出版年度：1974
卷号：20
期号：6
页码：437-449
DOI：10.3177/jnsv.20.437
出版社：Center for Academic Publications Japan
摘要：The effects of protein and/or energy deficiency on 14C incorporation into body constituents and 14C output in expired air and urine were investigated in adult rats using 14C-Chlorella protein hydrolysate. Rats were given a protein-free diet (PFD) for 2 weeks and control rats were fed ad libitum or pair-fed with the PFD group on a 12% lactalbumin diet (LA and Pair-fed, respectively). On the 15th day, animals received 14C-Chlorella protein hydrolysate with 5g of their respective diet. One group of PFD animals was given tracer by stomach tube without food (PFD-fast). Normal control rats ate about twice as much diet as the PFD group. The respiratory 14C output in the PFD group was identical with those in the LA and Pair-fed groups and was less than that in the PFD-fast group, The rate of protein synthesis, provisionally expressed as relative specific radioactivity, was more in the PFD group than in the normal group in the liver and less than the latter in the muscle. The LA group retained less total radioactivity in the body than the Pair-fed or PFD group, indicating high capability to hold the body protein in protein deficiency. In addition, decreased conversion of amino acids to lipids and glycogen was observed in the PFD group. All these differences are interpreted as adaptations to protein shortage. On prolonged fasting (PFD-fast group), gluconeogenesis in the liver increased to provide energy, despite the protein deficiency. The relative importances of protein and energy for tissue protein synthesis are briefly discussed.
