Bone as a Sodium and Potassium Reservoir 12

Abstract

Gamble, Ross, and Tisdall (1) originally pointed out that electrolytes and water were lost from the body during fasting in a manner which could be reasonably predicted from the concentration of salts in the body fluids. This concept is the basis for the study of changes in body composition by examination of electrolyte balance and weight changes. Darrow, Da Silva, and Stevenson (2) elaborated the method of calculation and showed that shifts of sodium between extracellular and intracellular fluid could be inferred in certain conditions from balance measurements. In this laboratory, studies in both man and animals (3, 4) have frequently demonstrated losses or gains of sodium which cannot be reasonably explained on the basis of shifts so calculated. Two possible explanations are: (a) Unmeasured skin losses may lead to the calculation of erroneously large retentions, or (b) Electrolyte may be sequestered in the body in an osmotically inactive form quickly available to the body fluids. Flanagan, Davis, and Overman (5), studying both balances and composition of tissues in dogs with adrenal insufliciency, noted such discrepancies and suggested that bone might serve as a sodium reservoir.The early work of Gabriel (6) demonstrated the presence of substantial amounts of sodium in the chloride-free residue of bone extracted with alkaline glycol solutions. Harrison, Darrow, and Yannet (7) showed that the ratio of sodium to chlonde in the skeleton is greatly in excess of that found in a plasma ultrafiltrate, and defined this as "extra" bone sodium. Subsequent investigators have confirmed these findings (8, 9), and Kaltreider, Meneely, Allen, and Bale (8), Stern, Cole, Bass, and

The Disposition of Acid Administered to Sodium-Depleted Subjects: The Renal Response and the Role of the Whole Body Buffers 12

“…In two of the preshydrogen buffering might occur. This probably includes not only muscle and other soft tissues, but also bone, which has been demonstrated to have a large labile store of sodium and potassium (11). ent cases and in Folling's experiment, the estimated loss of intracellular potassium was considerably less than the calculated uptake of hydrogen (Table III), indicating that some other cellular cation, probably sodium, was also exchanged.…”

Electrolyte Composition of Bone and the Penetration of Radiosodium and Deuterium Oxide Into Dog and Human Bone 12

“…The corrected exchangeable sodium is only reduced by some 10 per cent on the assumption that all of Until recently, direct evidence of displacement of sodium from bone to circulating extracellular fluid has been lacking. Bergstrom (40) observed that in rats acute sodium and potassium depletion resulted in a mobilization of both of these cations from bone. Other investigators (25) could not demonstrate any significant changes in bone sodium content in adrenalectomized dogs although the rate of bone sodium exchange using Na24 as a tracer appeared to be depressed in the adrenal insufficient animals as compared to the controls.…”

Influence of Sodium Intake on Exchangeable Sodium in Normal Human Subjects*

“…On the basis of reported animal studies, however, it can be predicted that the extracellular fluid compartment would show the greatest changes followed by the exchangeable fraction of bone sodium (32)(33)(34)(35)(36)(37) 2. Body sodium exchanging after the first 24 to 48 hours was not a significant fraction of the metabolically active sodium pool, nor did it interfere with long-term measurements of this pool by isotope dilution methods.…”