Influence of Acute Nutritional Stress on Polyribosomes and Protein Synthesis in Brain and Liver of Young Rats

Abstract

Polyribosomal patterns and protein synthesis of brain and liver were studied in 10-day-old suckling rats fasted for 6 to 12 hours and in 35-day-old post-weanling rats fasted for 3 days or force-fed a threonine-devoid diet for 3 days. Fasting in either the 10- or 35-day-old rats resulted in disaggregation of polyribosomes and a decrease in protein synthesis of liver as measured in vitro whereas polyribosomes and in vitro assay of protein synthesis of brain were unaffected. Force-feeding of a threonine-devoid diet for 3 days, which has been shown to induce kwashiorkor-like lesions in pancreas, salivary glands and liver along with enhanced hepatic protein synthesis, had no effect on brain polyribosomes and on brain protein synthesis when measured in vivo or in vitro.