Monoi H
Biophys J. 1974 Sep;14(9):645-51. doi: 10.1016/S0006-3495(74)85941-2.
The ability to depress the resonance intensity of (23)Na in rat liver tissue was not found in the supernatant fraction. It was exclusively localized in particulate fractions. The intensity and saturation behavior of the (23)Na signal was examined in suspensions containing various amounts of the particulate fraction of rat liver homogenate. The results strongly suggest that the (23)Na signal of tissue reflects quadrupole interactions and does not result from a slow exchange between the free and bound fractions of Na(+). The activity coefficient of Na(+) in rat liver homogenate (no medium was added) was 0.59, about 20% less than that in the isotonic saline. Available evidences and discussion indicate that the bound Na(+) in the homogenate is much less than the so-called "NMR-invisible" fraction of Na(+).
在上清液部分未发现降低大鼠肝脏组织中(23)Na共振强度的能力。它仅定位于颗粒部分。在含有不同量大鼠肝脏匀浆颗粒部分的悬浮液中检测了(23)Na信号的强度和饱和行为。结果有力地表明，组织中的(23)Na信号反映了四极相互作用，并非源于Na(+)自由部分和结合部分之间的缓慢交换。大鼠肝脏匀浆（未添加介质）中Na(+)的活度系数为0.59，比等渗盐水中的活度系数约低20%。现有证据和讨论表明，匀浆中结合的Na(+)远少于所谓的Na(+)“NMR不可见”部分。
