The effect of acclimation salinity and salinity changes on the concentration of high-energy @entity1391 metabolites and @entity369 kinase (AK) flux was examined in vivo in juvenile @entity11061 using 31P-nuclear magnetic resonance (NMR). Crabs were acclimated for 7 days to a salinity of 5 or 35 per thousand and then placed in a flow apparatus that could sustain the animals while NMR spectra were acquired. Crabs were subjected to either hyperosmotic salinity changes, where an animal acclimated to 5 per thousand was exposed to a salinity of 35 per thousand, or hyposmotic changes, which involved the reciprocal exchange. Neither acclimation salinity nor salinity change had a significant effect on the concentrations of @entity49174 , inorganic @entity1391 or @entity855 . 31P-NMR saturation transfer experiments were used to determine the effect of salinity on the forward and reverse flux of the AK reaction. There was no significant effect of acclimation salinity or salinity change on the flux rate through this reaction. This is in contrast to previous results, which showed that AK flux in isolated muscle was sensitive to prevailing osmotic conditions (Holt and Kinsey, J. Exp. Biol. 205 (2002) 1775-1785). The present study indicates that the integrated osmoregulatory capacity of the intact animal is sufficient to preserve cellular energy status and enzyme function during acute salinity changes.

The effects of rapid salinity change on in vivo @entity369 kinase flux in the juvenile @entity11061 , XXXX .

@entity11061 :: ('6763', 'Species') :: ['blue crabs'] @entity1391 :: ('CHEBI:26020', 'Chemical') :: ['phosphate'] @entity49174 :: ('MESH:C015441', 'Chemical') :: ['arginine phosphate'] @entity369 :: ('CHEBI:29016', 'Chemical') :: ['arginine'] @entity855 :: ('MESH:D000255', 'Chemical') :: ['ATP']
@entity11061 :: (6763,Species) :: ['Callinectes sapidus']
