The Penetration of Radioactive Sodium and Phosphorus Into the Extra- And Intracellular Phases of Tissues

Abstract

Sodium has received considerably less attention in the study of tissue electrolytes than chloride, undoubtedly because of the difficulty of sodium micro-chemical methods. It has been generally assumed to be in the extracellular phase because of the evidence that most of the chloride in muscle is cxtracellular (7) and because of the fact that in some tissues the sodium: chloride ratios are the same as in plasma. The tendency to extend to all tissues, concepts which may aptly describe muscle, was criticized by Amberson et al. (1) and by Manery and Hastings (18), the latter showing that the sodium: chloride ratio differed appreciably in many tissues from that in plasma. An %xcess" chloride was reported (18) in rabbits in blood, connective tissues, testes, gastric mucosa and in the liver of rats (13a, and this paper), and an "excess" sodium in cart,ilage, spinal cord and intestinal wall (18) which suggests the existence of both intracellular sodium and chloride. It is of some interest, too, that in certain muscles a small "excess" sodium has been reported but t*his is not true for all muscle tissue. It was located in frog (6) and in dog skeletal muscle (11, 12) but not in the skeletal muscles of the rabbit (11, 18). To conform to the simple morphological division into intra-and extracellular phases, this excess sodium has been allocated to the intracellular phase. In view of these findings and of the fact that the red cells of many species (15) contain sodium instead of potassium, it seems possible for sodium to function as an intracellular ion. This report shows how radioact.ive isotopes were used to investigate such a possibility. The general scheme of dividing the tissues into two phases, intra-and extracellular, has been adopted. The limitations of this simple procedure are fully realized but its lack of complexity makes it useful. The following studies have been carried out and are reported herein: a. The rate and extent of the penetration of radioactive sodium into a JEANNE F, Mr\NERY AND WXLLIrlM F. BALE

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

“…One hundred per cent exchange was noted for the next 14 days. 4. The implications of these data on the calculation of intracellular constituents from multiple dilution studies are discussed.…”

“…Since previous estimates indicate that approximately 30 per cent of the body sodium and 8 per cent of the body water is contained in bone (4,6,7), the role of this tissue with regard to these substances in metabolic emergencies, may prove to be of considerable importance.…”

“…Although bone is the primary rigid supporting tissue of the body, the fact that its individual inorganic components exchange constantly -with like substances in the serum has been established beyond cavil (1)(2)(3)(4)(5). Since previous estimates indicate that approximately 30 per cent of the body sodium and 8 per cent of the body water is contained in bone (4,6,7), the role of this tissue with regard to these substances in metabolic emergencies, may prove to be of considerable importance.…”

An Evaluation of Radiosulfate for the Determination of the Volume of Extracellular Fluid in Man and Dogs 1

“…Radioactive labelling has made possible the use of sodium (18, [20][21][22][23] and chloride (18,24,25).…”

The Relationship of Dehydration and Overhydration of the Blood Plasma to Collapse in the Management of Artificial Fever Therapy 1

“…Without evidence to the contrary, it is probable that the total quantity of circulating plasma protein remains fairly constant (27,24,25) during the treatment period. The plasma chloride and water, on the other hand, are subject to tremendous exchange through ingestion, excretion (sweat and urine), and exchange with the extracellular spaces (23,37). Total protein values indicate at least the trend of concentration of the blood, and over the short period required are thus a relative measure of what is happening to the circulating plasma volume.…”