Salinity regulates N-methylation of phosphatidylethanolamine in euryhaline crustaceans hepatopancreas and exchange of newly-formed phosphatidylcholine with hemolymph.

Phosphatidylcholine (PC), the main phospholipid in eukaryotes, is synthesized via two different routes, the phosphatidylethanolamine N-methyl transferase (PEMT) and the CDP-choline pathways. We previously showed in euryhaline fish that salinity impacts the relative contribution of the two pathways for PC biosynthesis, with PEMT pathway being activated in the liver of sea water (SW)-adapted animals. To address the occurrence of such phenomenon in other animals we performed in vivo metabolic studies in two crustacean species: the Chinese crab (Eriocheir sinensis) and the green crab (Carcinus maenas).

Uptake of cadmium through isolated perfused gills of the Chinese mitten crab, Eriocheir sinensis.

Using the perfusion method, we compared cadmium accumulation and influx across the gills of the euryhaline Chinese mitten crab Eriocheir sinensis, exposed to 4.8 microM cadmium in the incubation medium (OUT). Cadmium influx was not observed across posterior gills while it ranged from 0.

High pressure and glycolytic flux in the freshwater Chinese crab, Eriocheir sinensis.

The hexose part of glycolysis has been studied in the freshwater Chinese crab Eriocheir sinensis exposed to high pressure (101 ATA, i.e. 1000 m depth) at 14 degrees C and in normoxic conditions.

Effects of ions substitutions and of inhibitors on transepithelial potential difference and sodium fluxes in perfused gills of the crab Pachygrapsus marmoratus.

With the same saline on both sides of the epithelium, a spontaneous inside negative transepithelial potential difference (PD) was measured in perfused posterior gills of the euryhaline crab Pachygrapsus marmoratus acclimated to dilute sea water. The origin of the PD and the transport properties of the epithelium were investigated by ionic substitutions and by application of inhibitors. Diffusion of Na+ and Cl- ions at the apical side contributes to the establishment of the PD.

Perfusion of gills isolated from the hyper-hyporegulating crab Pachygrapsus marmoratus (Crustacea, Decapoda): adaptation of a method.

This paper reports the adaptation of a branchial perfusion technique to the gills of the small hyper-hyporegulating crab, Pachygrapsus marmoratus. The physiological quality of the preparation has been established and preliminary measurements of the transepithelial potential difference (PD) and sodium fluxes were reported. A clear-cut distinction has to be made between anterior and posterior gills.