Protein synthesis rate in liver and muscle of rats following four days of overfeeding.
Protein synthesis rate in liver and in muscle were determined in control and in 4-day overfed rats. Both the control and the overfed rats received their entire food (liquid diet) by a continuous intragastric infusion through permanently implanted cannulas. Each of the control rats received a daily quantity of the liquid diet which matched its own mean voluntary (ad libitum) intake as determined prior to the experiment. Each of the overfed rats received a daily excess of 35% over its mean daily voluntary intake. Protein synthesis rate was determined using a continuous intravenous infusion of 14C tyrosine. Overfeeding resulted in a 24% reduction (P less than 0.02) in the fractional rate of protein synthesis in the liver, and in a 16% reduction in the muscle. Overfeeding also resulted in a reduction in the ratio of RNA/protein amounting to 11% in the liver (P less than 0.05) and 21% in the muscle (P less than 0.02). These significant reductions ins RNA/protein indicate a relative loss of ribosomes that overnutrition can be associated with a reduced rate of protein synthesis.
D000818:Animals; D001835:Body Weight; D002149:Energy Intake; D005260:Female; D005526:Food, Formulated; D008099:Liver / Q000378:metabolism* / Q000473:pathology; D009124:Muscle Proteins / Q000096:biosynthesis; D009132:Muscles / Q000378:metabolism* / Q000473:pathology; D009929:Organ Size; D014176:Protein Biosynthesis; D051381:Rats; D013270:Stomach
D009124:Muscle Proteins