Effect of starvation and refeeding on amino acid metabolism in muscle of crab Neohelice granulata previously fed protein- or carbohydrate-rich diets

Abstract The present study assesses the effects of starvation and refeeding on 1-[ 14 C]-methyl aminoisobutyric acid ( 14 C-MeAIB) uptake, 14 C-total lipids, 14 CO 2 production from 14 C-glycine, 14 C-protein synthesis from 14 C-leucine and Na + –K + -ATPase activity in jaw muscle of Neohelice granulata previously maintained on a carbohydrate-rich (HC) or high-protein (HP) diet. In N. granulata the metabolic adjustments during starvation and refeeding use different pathways according to the composition of the diet previously offered to the crabs. During starvation, 14 CO 2 production from 14 C-glycine, and 14 C-protein synthesis from 14 C-leucine were reduced in HC-fed crabs. In crabs maintained on the HP or HC diet, 14 C-total lipid synthesis increased after 15 days of starvation. In crabs fed HP diet, 14 C-MeAIB uptake and Na + –K + -ATPase activity decreased in refeeding state. In crabs refeeding HC diet, 14 C-MeAIB uptake and 14 CO 2 production decreased during the refeeding. In contrast, the 14 C-protein synthesis increased after 120 h of refeeding. In both dietary groups, 14 C-total lipid synthesis increased during refeeding. Changes in the carbon amino acid flux between different metabolic pathways in muscle are among the strategies used by this crab to face starvation and refeeding. Protein or carbohydrate levels in the diet administered to this crab modulate the carbon flux between the different metabolic pathways.