[Study on the changes in the distribution and chemical states of the hepatic intra-and extra-cellular sodium ion in the rats with severe burns at early stage]

To investigate the changes in the distribution and chemical states of the hepatic intra- and extra-cellular sodium ion in the rats with severe burns, so as to provide guidance for fluid resuscitation at early postburn stage.Nineteen adult male Sprague-Dawley (SD) rats were employed in the study and were randomly divided into control (n = 12) and burn (n = 7) groups. The changes in the longitudinal (T1) and transverse (T2) relaxation times of hepatic intra-cellular and extra-cellular sodium in the two groups were studied with 23Na NMR spectroscopy and a shift reagent.After infusion of the shift reagent,the extra-cellular sodium content in rat liver decreased by 17%, with obvious increase in fast T2 component (P0.01), indicating an increase in the fraction of Na+ binding sites in the extra-cellular space. The characteristics of relaxation of intra-cellular sodium remained unchanged despite a 57% increment in intra-cellular sodium content.The deficiency of sodium as a permeable molecule might be related to the postburn movement of hypertonic sodium from extra-cellular to intra-cellular space. The results indicated that it is reasonable to administer high concentration of sodium in fluid resuscitation during the first 24 postburn hours.