The effect of salinity on the metabolism of nitrogen-containing compounds by Carcinus maenas

Abstract

1. 1. The level of the ninhydrin positive substances in the tissues of Carcinus maenas changed with both environmental salinity and nutritional status. 2. 2. In 40 per cent sea-water compared with 100 per cent sea-water there is an increased rate of utilization of glutamic acid, both in vivo following injection of U- 14C-glutamate and in vitro after its exogenous addition. 3. 3. Glutamine synthesis decreased and U8 production accelerated at the lower salinity from both exogenously added glutamate and endogenously generated glutamate (formed from 2- 14C-sodium acetate). 4. 4. Small increases in U- 14C-alanine and U- 14C-glycine utilization in vitro were observed when the salinity was reduced from 100 to 40 per cent sea-water. 5. 5. Aminotransferase enzymes were not activated by NaCl.