Hepatopancreas gluconeogenesis during hyposmotic stress in crabs Chasmagnathus granulata maintained on high-protein or carbohydrate-rich diets

摘要

The incorporation of [~14C]-alamine or [~14C]-lactate into glucose was measured in heptopancreas fractions from Chasmagnathus granulata adapted to a high protein or a carbohydrate-rich diet and submitted or not (control group) to hyposmotic stress. Gluconeogenic capacity and phosphoenolpyruvate carboxykinase (PEPCK) activityincreased during acclimation to a dilute medium in C. granulata hepatopancreas. In intact animals, high hemolymph urea levels occured for the high-protein regimen and for crabs fed both diets and submitted to hyposmotic stress. It could be that the amino acids released during hyposmotic stress are deaminated in the hepatopancreas, and that the carbon chains are used as substrate for gluconeogenesis. Hepatopancreas gluconogenesis seems to be one of the pathways implicated in the metabolic adjustment of the amino acid pool during hyposmotic stress in C. granulata.