Effects of long-term exposure to 101 ATA hydrostatic pressure on blood, gill and muscle composition and on some enzyme activities of the FW eel ( Anguilla anguilla L.)

Abstract

1. 1. The study was set up to investigate the effects of long-term exposure (30 days) at 101 ATA of hydrostatic pressure (HP), in normoxic conditions and at constant temperature, on enzyme activities involved in energy production and ionic transfers. 2. 2. Measurements of activities of LDH, PFK, IDH and CPK in liver, red and white muscle seem to show that HP induces an improvement of aerobic pathway in red muscle and anaerobic pathway in white muscle; in liver no significant change is observed. 3. 3. At the same time, there appears an increase of plasma Na +, Cl − and Mg 2+ contents; in muscle and gill, only Na + and Cl − increase under pressure. Concomitantly with the changes in ion contents, there is a decrease in maximum activity of gill (Na + + K +)ATPase and Mg 2+ ATPase activity. 4. 4. The results agree with a Na + balance impairment occurring at the tissue level at the same time when a new state of energetic metabolism results from adjustments of intertissue coupling of anaerobic and aerobic metabolisms induced by a long-term exposure to hydrostatic pressure.