Ionic regulation in Antarctic teleosts

This work reports recent data on mechanisms of cold adaptation exhibited by the Antarctic teleosts Trematomus bernacchii and Cbionodraco bamatus. Anal ysis of fatty acid in intestinal mucosa brush border suggested that an incr ease in unsaturated fatty acid could be a mechanism for the preservation of cell membrane integrity and functionality. The investigation of several tr ansporters involved in the regulation of cell homeostasis (Na+/K+-ATPASE, N a+-D-glucose cotransport, Na+/H+ exchanger and Ca++-ATPASE) showed kinetic characteristics that could explain part of the adaptation of these proteins to work at low temperature. The activity of carbonic anhydrase, involved i n pH control both at intracellular and systemic level, was related to plasm a buffer capacity.