Betaine is the principal counteracting osmolyte in tissues of the elephant fish, Callorhincus millii (Elasmobranchii, Holocephali)

Analysis of the organic constituents of tissues of the elephant fish, Cailorhincus millii, using both NMR and HPLC, revealed that trimethylamine oxide (TMAO) was present in only low concentrations in all tissues. The principal counteracting osmolyte in the elephant fish was the methylamine glycine betaine, which occurred at a concentration of 50-70 mmol kg(-1) fresh weight in those tissues analysed. The compatible osmolyte taurine was found to be in high concentration (39 mmol kg(-1) fresh weight) in heart muscle, and significant amounts of serine were found in both heart and brain. (C) 1998 Elsevier Science Inc. All rights reserved.