a parallel loss of water and electrolyte, they do

THE CHANGES IN THE DISTRIBUTION OF BODY WATERACCOMPANYING INCREASE AND DECREASE IN

EXTRACELLULAR ELECTROLYTE

By DANIEL C. DARROW AND HERMAN YANNET

(From the Department of Pediatrics, Yale University Medical School, New Haven)

(Received for publication November 21, 1934)

Considerable attention has been given the rela-tion of body water to the metabolism of fixedbase. Gamble, Ross and Tisdall (1) have pointedout that loss or gain of sodium is usually accom-panied by an increase or decrease in extracellularwater sufficient to keep the extracellular sodiumconstant in concentration. Furthermore, sincenearly all of the potassium of the body is intra-cellular and variations in the concentration ofpotassium in serum are relatively small, a loss orgain in potassium is usually accompanied by anincrease or decrease in cellular water sufficient tokeep the osmotic pressure of cellular fluid in equi-librium with that of blood plasma. These authorshave estimated the probable loss of water fromintracellular and extracellular spaces which ac-companies the losses of sodium and potassiumduring starvation. Gamble, Blackfan and Hamil-ton (2) have described the probable mechanismof the diuretic effect of acidifying salts by similarreasoning. Analogous studies have been made indiabetic coma (3) and infantile diarrhea (4).Since such studies are based on the premise ofa parallel loss of water and electrolyte, they donot take into account the redistribution of bodywater which must take place when electrolyte islost or gained without a corresponding loss orgain in water. The present study describes thechanges in concentration of water and electrolytein serum and erythrocytes when the amount ofextracellular electrolytes is altered with littlechange in total body water. The probable shiftsof body water which explain these changes arediscussed.The experimental procedure used to produce

variation in extracellular electrolyte without sig-nificant alteration in total body water is based onexperiments described by Schechter, Cary, Car-pentieri and Darrow (5). These experimentsdemonstrated that when a watery solution wasplaced in the peritoneal cavity, it tended to assumethe composition of a fluid in ionic and osmotic

equilibrium with blood plasma. Thus when " iso-tonic glucose solution " (5 per cent) was placedin the peritoneal cavity, sodium, chloride, and bi-carbonate diffused into the fluid while glucose dif-fused into the blood. At first the rate of diffusionof electrolyte into the peritoneal fluid was so rapidthat water also passed into the peritoneal cavity.However, after four to six hours the amount offluid in the peritoneal cavity was approximatelythat injected, but the composition approached thatof a fluid in equilibrium with plasma. In guineapigs about twenty-four hours was required forcomplete absorption; the interval in dogs, mon-keys and rabbits was not determined, but is prob-ably between twelve and twenty-four hours.Since the fluid in the peritoneal cavity was notimmediately available throughout the tissues, thebody may be considered to have lost temporarilythe amount of electrolyte present in the peritonealcavity, while the total amount of body water re-mained relatively unaltered. The interpretationof the results is simplified by the fact that anuriaaccompanies these experiments and the only lossof water is by evaporation and the only gain, fromcellular oxidations, which for the present purposescould be neglected.

In order to increase the amount of extracellularelectrolyte, saline of double physiological strength(1.8 per cent NaCl) was injected into the peri-toneal cavity. In these experiments after aboutfour hours, the fluid in the peritoneal cavity wasin approximate equilibrium with the blood plasmaand the total volume was approximately that in-jected. In this case the total amount of extra-cellular electrolyte was increased with relativelysmall change in total body water.

EXPERIMENTAL PROCEDURE

Healthy dogs, rabbits and monkeys (Macacus rhesus),maintained on an adequate diet, were used as the experi-mental animals. The last feeding occurred about eight-een hours before the experimental procedure. Food andwater were removed from the cages during the courseof the experiments.

266

DISTRIBUTION OF BODY WATER

Blood specimens (about 30 cc. in dogs and 20 cc. inrabbits and monkeys) were taken from the externaljugular vein in dogs, directly from the heart in rabbitsand from the femoral vein in monkeys. About 10 cc. ofthe blood were immediately transferred to a tube con-taining a small amount of mercury and securely stop-pered. The size of the tube and the amount of mercuryused were such that the blood completely filled the tube.Defibrination was accomplished by gentle inversion ofthe stoppered tube for about five minutes. The remain-der of the blood was delivered under mineral oil, allowedto clot at room temperature, centrifuged and the clearserum removed.Soon after withdrawal of the first specimen of blood,

a five per cent solution of glucose was injected into theperitoneal cavity in one series of animals. iThe glucosesolution was freshly prepared and sterile, and theamounts injected were approximately 100 cc. per kgm.of body weight in most of the experiments. The secondseries of animals received similar quantities of freshlyprepared, sterile 1.8 per cent solution of sodium chlorideintraperitoneally. In both cases the solutions werewarmed to body temperature before injection and gaveno evidence of being irritating. In the experiments ondogs the urine was collected in cages equipped for meta-bolic studies. In the experiments on rabbits and monkeysclean dry pans were placed under the wire cages. Aboutfour to six hours later, a second specimen of blood wasobtained and treated in the same way as the first speci-men. Samples of the peritoneal fluid were obtained atthis time in the dogs, but in the monkeys and rabbits itwas usually impossible to obtain peritoneal fluid withoutkilling the animals and this was deemed unnecessary inmost of the experiments.

In order to determine the amount of fluid remaining inthe peritoneal cavity after approximate equilibrium hadbeen established, fourteen animals were sacrificed and theperitoneal fluid drained and measured. These animalswere also carefully examined for gross pathologicalchanges. In four of the animals a measure of the totalvolume of material in the gastro-intestinal tract wasmade. No histological studies were carried out.

CHEMICAL METHODS

The volume of the blood cells was determined on thedefibrinated blood by centrifuging at high speed for 20minutes in capillary tubes. Measurements of the heightsof the columns of blood and cells were made with cali-pers. The following chemical determinations weremade: protein, by macro-Kjeldahl (6) method usingsuperoxol to insure complete digestion; sodium, by But-ler and Tuthill's modification of the method of Barberand Kolthoff (7), without removal of phosphate onserum but with removal of phosphate on whole blood;chloride, by Patterson's (8) method, using 0.5 cc. sam-ples; water, by weighing before and after drying over-night at a temperature of 105° C. All determinationswere made in duplicate. The concentrations in the cellswere calculated from the hematocrit values and the con-

centrations in whole blood and serum by the following

formula: C B S(I-V) where C represents cell

concentration; B, whole blood concentration; S, serumconcentration and V, the proportion of red cells in wholeblood.

EXPERIMENTAL RESULTS

During the course of the experiments, datawere collected which permitted estimation of thechanges in concentration of electrolyte and waterin serum and erythrocytes. The present paperpresents such data as bear on the probable changesin distribution of water produced by the experi-ments. In a second paper (14) the changes inthe concentration of electrolytes and water inerythrocytes will be discussed. Mention of thelatter findings will be made in the present paperonly inasmuch as the changes found in this ac-cessible cell are used to explain the clinical symp-toms of the animals and the probable changes indistribution of water in the body.

A. Amount of fluid remaining in the peritonealcavity

Table I shows the amount of fluid recovered atautopsy after a lapse of time comparable to that

TABLE I

Volume of fluid remnaining in the peritoneal cavity

Experi- Aonment ~Solution Amount Amount uTimeAnimal ment Weight inletinjected recov- elapsed Urineher

kgm. cc. cc. hours cc.Dog 1... 1 6.4 Glucose 500 467 6.0 5Dog 6... 16 6.6 Glucose 500 587 5.0 8Dog 3... 7 6.1 Glucose 550 570 4.5 0Dog 7... 17 11.4 Glucose 500 542 6.0 0Monkey 2 8 2.8 Glucose 250 228 3.7 0Monkey 3 9 6.5 Glucose 430 400 3.0 0Rabbit 3. 18 2.5 Glucose 250 260 4.0 30Rabbit 4. 14 2.0 Glucose 200 186 4.0 0Rabbit S. 15 3.0 Glucose 275 240 4.0 0Rabbit 9. 16 2.6 NaCl 260 250 4.2 8Rabbit 10 17 2.6 NaCl 260 225 4.2 5Rabbit 11 18 3.8 NaCl 370 415 4.0 5Rabbit 12 19 2.9 NaCl 280 255 4.5 0Rabbit 13 20 3.4 NaCl 330 310 4.0 5

used in the experiments. The data show thatfour to six hours after the injection of either afive per cent solution of glucose or a 1.8 per centsolution of sodium chloride into the peritonealcavity, the amount of fluid remaining is approxi-mately that injected. In both the " glucose " and" saline" experiments the changes in the totalamount of peritoneal fluid amounted to an in-crease or decrease of less than ten per cent of

267

DANIEL C. DARROW AND HERMAN YANNET

the amount injected. Since the amount of fluidinjected was ten per cent of the body weight andsince total body water is about seventy per centof the body weight, the experiments would changeavailable body water by less than 1.5 per cent.Because blood plasma, interstitial fluid and intra-cellular fluid are all in osmotic equilibrium, theeffects of this change in body water will be dis-tributed throughout all body fluids and be ofminor importance in explaining changes found inthe blood. In other words the chief changes pro-duced in " the glucose " experiments are broughtabout by withdrawal of extracellular electrolyteand the chief changes of the "saline" experi-ments are the result of the increase in extracel-lular electrolyte (NaCl).The preponderant effect of loss or gain of so-

dium and chloride becomes apparent when oneconsiders the losses or gains of these ions in rela-tion to their total amounts in normal animals.The approximate losses of chloride and sodiumin the " glucose " experiments may be estimatedby multiplying the original volumes (or the finalvolume when this was determined) by the finalconcentrations of these ions in the peritoneal fluid.These calculated losses of chloride and sodiumhave been compared to the total amounts of chlor-ide and sodium found in a normal dog, a normalmonkey and two normal rabbits (unpublished datafrom this laboratory). In the " glucose " experi-ments the losses of chloride are about 25 per centof total body chloride; the losses of sodium, about20 per cent of total body sodium. In the " saline "experiments the effective increases in body sodiumand chloride are more uncertain, especially inthose animals excreting considerable quantities ofurine. Neglecting excretion in the urine whichwas negligible in most of the experiments, similarcalculations show that the increases in body chlor-ide were about 50 per cent of total body chlorideand the increases in sodium, about 30 per cent.

It was not deemed necessary to sacrifice dogsand monkeys in order to determine the amountof fluid remaining in the peritoneal cavity afterthe injection of 1.8 per solution of sodium chlor-ide since the behavior of the various animals wassimilar and the appearance of the abdomen andthe ease with which fluid could be withdrawn fromthe peritoneal cavity was the same in the " saline"and " glucose " experiments.

B. Clinical aspects of animals subjected to re-moval of extracellular electrolyte with little

alteration in total body water

Following the intraperitoneal injection of glu-cose solutions, the animals suffered no local signsof pain or irritation. However, in all animals(8 dogs, 5 rabbits and 5 monkeys) signs of mildto severe dehydration developed which were com-parable to those observed in dehydrated patients.The tongue and mucous membranes were dry; theskin showed loss of turgor; the animals becamelanguid and looked sick. In the monkeys andrabbits greyish pallor such as is seen in "ali-mentary intoxication " could be distinguished. Inabout 24 hours the animals recovered completely.

Following the injection of isotonic glucose, nourine was passed by any of the animals duringthe periods of experimental observation whichwere four to six hours. In view of the clinicalevidences of dehydration it was interesting to notethat the animals were not thirsty. Autopsies onthe animals listed in Table I confirmed the drynessof the mucous membranes, for only 5 cc. of mu-coid material could be recovered from the stomachand small intestines in the dogs and monkeys.The small intestines of the rabbits contained littlefluid but, as is the rule in this species, the stomachand colon were filled with considerable materialwhich, however, was not very moist.

C. Changes in the blood in the " glucose" experi-ments

Data which concern the distribution of waterin serum and erythrocytes are given for repre-sentative experiments in Table II. As waspointed out previously, the various data may beregarded as exemplifying the changes producedby the losses of extracellular electrolyte with littlealteration in body water.

In all experiments the proportions of red cellsin blood and the concentrations of serum proteinswere increased. The increases in the proportionof red cells were considerable. If one take noaccount of the blood withdrawn for analyses, onemay calculate the apparent loss of plasma whichwould produce the given change in the proportionof erythrocytes. Because loss of blood tends tobe replaced by interstitial fluid, the calculationprobably underestimates the diminution of plasma

268


TABLE II

Changes in the blood following intraperitoneal injection of 5 per cent glucose

Experi-Animal ment Weight Fluid Time Cell Serum Serum Serum Serum Cell Cell Peritoneal Peritonealnum- in- elapsed volume protein water Na Cl water protein Na C1

ber jected

kgm. cc. hours Per cent per cent per cent m. Eq. m. Eq. per cent per cent m. Eq. m. Eq.perL. perL. per L. Per L.

Dog 3...... 4 6.0 500 0.0 39.6 4.8 143.3 112.4 33.64.5 52.2 5.8 130.7 92.6 28.9 114.3 96.2

Dog 1 .. . 1 6.4 500 0.0 48.7 6.4 147.3 106.1 32.86.0 57.2 8.4 132.5 86.8 30.3 115.0 91.1

Dog 3..... 5 5.5 500 0.0 34.0 5.7 144.1 112.6 31.94.5 44.8 6.9 124.4 91.8 29.1 107.8 91.8

Dog 3..... 7 6.1 550 0.0 44.9 5.8 92.4 147.5 111.1 74.4 30.34.0 54.4 8.0 90.3 131.7 91.2 75.4 28.6 105.3 88.2

Monkey 4.. 10 3.8 400 0.0 43.7 6.8 90.9 144.6 104.5 76.7 29.04.5 55.2 8.0 88.9 125.2 82.9 78.8 25.9

Monkey 4.. 11 3.5 300 0.0 41.8 7.7 90.6 150.2 108.5 75.9 30.84.0 46.8 8.3 89.8 131.4 90.4 76.5 28.2 125.8 99.4

Monkey 2.. 8 2.8 250 0.0 47.0 7.4 90.8 165.9 109.3 75.4 29.73.5 58.5 9.5 88.2 145.3 96.2 76.5 28.9 92.9 75.6

Monkey 3.. 9 6.5 430 0.0 50.0 7.5 90.6 154.5 110.1 76.4 28.54.0 55.0 8.6 89.7 133.5 92.3 76.5 28.9 125.1 98.8

Rabbit 4 ... 14 2.0 200 0.0 35.5 6.1 92.5 137.5 95.4 76.3 29.6l l 1 4.0 1 38.3 6.8 91.8 1 19.3 85.3 1 79.4 1 25.9 98.4 78.7

volume which would otherwise have been pro-duced by the loss of extracellular electrolytes.Roughly, by this calculation, the losses of plasmavolume varied from 8 to 27 per cent of the totalblood volume, or 18 to 49 per cent of the plasmavolume. Similar calculations of the apparentlosses of plasma water from the changes in concen-tration of serum proteins gave values roughlyagreeing with those calculated from the changes inthe proportion of red cells. Although changes inplasma volume are not the only factors affectingthe concentration of cells in blood or proteins inserum, in experiments of short duration, changesof the magnitude shown in Table II could hardlyoccur without being due chiefly to losses of waterfrom plasma.The water of red cells increased as is evidenced

by reductions in the concentration of cell proteins.Reductions in concentration of cell proteins oc-curred in all experiments except in the case ofMonkey 3, Experiment 9, when the changes wereso slight as to be within the error of the methods.The increases in erythrocytic water amounted to1.4 to 7.3 per cent of the original cellular water.

Since total body water changed relatively little,this water was presumably derived from extra-cellular spaces.

In all cases considerable reductions were foundin the concentrations of chloride and sodium inthe serum. It is obvious that these reductionswere chiefly brought about by migration of so-dium and chloride into the peritoneal cavity.

D. Clinical aspects of animals subjected to in-crease of extracellular electrolyte with little

alteration of body waterThe intraperitoneal injection of 1.8 per cent

solution of sodium chloride produced few clinicalsymptoms. The animals retained their appetitesand did not look ill although two dogs vomited.They became thirsty but no loss of skin turgoroccurred. Grossly the rabbits which were ex-amined postmortem revealed nothing abnormalexcept the fluid in the peritoneal cavity. No illeffects were noted after 24 hours.

In three of the experiments on dogs a definitediuresis occurred, resulting in the loss of about 25per cent of the fluid injected (see Table III). In

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TABLE III

Chatnges in the blood folowing intraperitoneal injection of 1.8 per cent NaCi

mExperi Fluid Time Cell Serum Serum Serum Serum Cell Cell P n -UAnimal num- Weight ine-d elapsed volume protein water Na Cl water proteinber jetdNa Cl Vol- Na Cl

ume

kgm. cc. hours Per cent per cent per cent m. Eq. m. Eq. per cent per cent m. Eq. m. Eq. cc. m. Eq. m.Eq.per L. per L. per L. per L. perL. pcrL.

Dog 3 ..... 4 6.5 600 0.0 45.1 6.7 140.1 108.2 31.64.5 38.5 6.1 157.6 132.0 32.6 165.1 160.0 0 - -

Dog 3 ..... 1 5.3 500 0.0 38.5 6.0 146.2 110.8 32.74.5 35.0 5.6 162.7 131.4 34.2 168.8 153.0 0 - -

Dog4 ..... 5 11.6 1000 0.0 64.4 5.9 142.0 111.0 31.85.0 56.1 5.9 152.9 135.0 32.9 156.0 360 218 206

Dog 4..... 3 11.2 1000 0.0 37.5 6.2 147.1 112.2 34.14.0 34.8 6.3 161.4 130.6 34.2 240 - 380

Dog 5 ..... 8 7.0 700 0.0 48.1 6.2 91.9 145.8 111.6 74.3 31.74.0 45.3 6.2 92.1 161.1 129.8 74.2 32.7 166.6 150.1 180 319 339

Monkey 4 . 10 3.7 350 0.0 36.0 7.4 90.7 148.2 107.4 76.9 27.24.0 27.4 6.1 91.9 165.1 130.7 74.5 29.4 i

Monkey 3. 9 5.8 425 0.0 46.2 7.6 90.6 147.2 104.9 76.2 29.45.0 40.2 7.3 91.1 163.9 125.0 74.0 31.9 164.7 140.9 i

Monkey 5. 11 2.6 260 0.0 41.9 7.5 91.1 144.9 107.5 75.0 32.54.5 35.0 6.5 91.9 169.4 142.1 73.4 33.6 4t

Monkey 5 12 2.5 225 0.0 38.8 6.9 91.3 147.0 107.4 75.3 31.73.8 29.3 6.1 91.4 165.3 132.2 74.5 34.8

Rabbit 7 .. 14 2.5 250 0.0 30.8 4.9 93.7 138.7 103.3 74.7 31.94.0 26.5 4.4 94.3 152.0 121.8 73.3 32.6 4

Rabbit 8 .. 15 1.9 180 0.0 40.4 7.7 90.8 152.8 123.1 76.3 29.94.0 27.0 6.2 92.2 175.6 154.0 74.8 31.5 182.4 172.1 4

*l indicates less than 5 cc. of urine.

these cases the urine contained 200 to 350 milli-equivalents of sodium and chloride per liter. Inthe other experiments practically no urine waspassed during the first 4 to 6 hours.

E. Changes in the blood in the " saline"experiments

The results of the examination of the blood inrepresentative experiments are given in Table III.As was pointed out previously, the variouschanges may be regarded as exemplifying thealterations produced by an increase in extracel-lular electrolyte with little alteration in total bodywater. In both experiments on Dog 3 and in allexperiments on rabbits and monkeys, only minimalamounts of urine were excreted. Since in bothexperiments on Dog 4 and the one on Dog 5,about one fourth of the salt and water injected

into the peritoneal cavity was recovered in theurine, these experiments gave less striking butqualitatively similar changes.

In Dog 3 and in the rabbits and monkeys theconcentration of serum protein and the propor-tion of red cells in blood decreased. The appar-ent increases in plasma volume were 16 to 52 percent when calculated from the changes in theproportion of red cells in blood while the apparentincreases were 4 to 24 per cent when calculatedfrom the changes in concentration of serum pro-teins. In each experiment the former calculationled to a greater value than the latter. However,so many factors may influence the concentrationof serum proteins or the proportion of red cellsin blood that a close correlation is unlikely. Thechanges are sufficiently great to indicate consid-erable increases in plasma volume.

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The concentrations of proteins in the red cellsincreased owing to losses of erythrocytic water.The losses of cellular water varied from 2 to 7per cent of the original water. Because bodywater remained relatively constant, the waterwhich left the red cells presumably migrated tothe extracellular spaces.

In Dogs 4 and 5, the results were much thesame as in the other experiments, if considerationbe given the large amount of salt and water ex-

creted. The changes in the proportion of redcells indicate considerable increases in plasmavolume. However, for some reason which is notapparent, the concentrations of serum proteinsdid not change. The proteins of the red cellsbecame concentrated owing to losses of cellularwater, except in Dog 4, Experiment 8. Thechanges in serum sodium and chloride in Dogs 4and 5 are of the same order of magnitude as

those of the other experiments.In all cases considerable increases in the con-

centration of chloride and sodium in serum oc-

curred owing to migration of these ions from thefluid injected into the peritoneal cavity. Theapparent means which the body uses to maintainosmotic equilibrium in both types of experimentwill be brought out in the discussion.

DISCUSSION

Since the principal phenomena exhibited by theexperiments must fit into the concepts of thephysiological behavior of water, a tentative de-scription of the factors affecting the distributionof water in the body will be given. Almostseven-tenths of the body is made up of waterwhich moves between intracellular and extracel-lular spaces in such a manner as to maintain os-

motic equilibrium between the fluid of the cellsand that in the extracellular spaces. Since aboutnine-tenths of the osmotic pressure of body fluidsis maintained by electrolytes, the distribution ofbody water is largely determined by the distribu-tion of electrolytes. Furthermore, as the concen-

tration of anions equals the concentration ofcations, the approximate osmotic relations are

given by the concentrations of the total base inmilliequivalents per liter of water. Because thepreponderant bases are the univalent ions, sodiumand potassium, the concentrations of these cationsdetermines roughly the osmotic pressure. One

may, therefore, surmise that the factors control-ling the distribution of sodium and potassium alsogovern the distribution of water.From analyses of blood plasma, lymph, edema

fluid and cerebrospinal fluid it is fairly well es-tablished that all extracellular fluids have approxi-mately the composition of plasma, except thatlittle protein is present in the extracellular fluidsoutside of the vascular system. The actualamount of extracellular fluid is unknown, butanalyses of muscles (9) and whole bodies (10,11) indicate that about two-tenths of the bodyweight must be due to extracellular fluid. Thisestimate is obtained by assuming all but negligiblequantities of sodium and chloride are extracellularand that their concentrations in extracellular fluidsare essentially those of blood plasma when ex-pressed in concentrations per kilogram of water.Assuming this to be true, about five-tenths of thebody weight is made up of intracellular water.The chemical composition of intracellular fluid isnot known, but from analyses of red cells (12,13, 14), muscles (9) and whole bodies (10, 11),one may surmise that the chief anions are proteinsand phosphate (chiefly organic) and the chiefcation, potassium. This particular distribution ofions with sodium and chloride1 on one side ofthe cellular membrane and potassium and phos-phate on the other is usually assumed to indicaterelative impermeability of cellular membranes tothese ions.The probable changes in distribution of body

water which fit in with the concepts briefly out-lined above can most readily be brought out withthe aid of a diagram (Figure 1). On the or-dinate, the concentrations of electrolyte are indi-cated in milliequivalents per liter of water, whileon the abscissa, the volumes of body water arerepresented in liters. The areas bounded by theselines, therefore, represent the total amount ofelectrolyte in intracellular and extracellular com-partments. The original distribution of bodywater is given by the continuous lines; the dis-tribution of body water after removal of 100milliequivalents of extracellular electrolyte is rep-resented by the lines which are made up of dots

1 The chloride of the erythrocytes is apparently anexception to the rule that intracellular fluids containlittle or no chloride.

271


- ------ - - -- I

100 I

tr I NTRACE LLULAR COM PARTMENT EXTRACELLULAR: I | COMPARTMENT

0.

(I X I I I

zILi 50

...L,|,,I I .

0 2 3 4 5 6 7

VO LUME OF FLUID IN LI TE RS OF WA TE R

FIG. 1. DIAGRAMMATIC REPRESENTATION OF THE DISTRIBUTION OF BODY WATER AND ELECTROLYTE.

The areas bounded by the lines representing volume and concentration indicate the total amount of intracellularor extracellular electrolyte. The solid lines give the distribution under normal conditions; the lines made up ofdots and dashes indicate the distribution after removal of 100 m. Eq. of extracellular electrolyte; the lines madeup of dashes represent the distribution after addition of 100 m. Eq. of extracellular electrolyte.

and dashes; the distribution of body water afteraddition of 100 milliequivalents of extracellularelectrolyte is illustrated by the lines made up ofdashes. Since by assumption the total amount ofintracellular electrolyte does not change, the threeareas representing intracellular electrolyte areequal. However, in order to maintain osmoticequilibrium between the intracellular fluid con-taining a fixed amount of electrolyte and theextracellular fluid containing variable amounts ofelectrolyte, the volume of intracellular water and

the concentration of intracellular electrolyte mustvary as indicated in the diagram. The relationof the changes in amount of extracellular electro-lyte to the total body fluid is represented in thediagram in quantities and concentrations com-parable to those which the experiments present.The areas in the diagram representing the shift

in water accompanying loss of extracellular elec-trolyte indicate the probable changes occurring inthe "glucose" experiments. This part of thediagram will be discussed first together with the

272


assumptions on which the diagram is based andthe reasons for making these assumptions.

Conceivably osmotic equilibrium between intra-cellular and extracellular fluids might be broughtabout by transfer of water across cellular mem-

branes, by transfer of ions across cellular mem-

branes, or by both processes. However, previouswork (12, 13) and data obtained in these ex-

periments which will be discussed more fullyelsewhere (14) indicate that transfer of wateris the chief means of adjusting the osmotic equi-librium between plasma and erythrocytes. Sincemost cellular membranes are likewise commonlyregarded as relatively impermeable to cations,shift of water across cellular membranes is prob-ably the chief means of maintaining osmotic equi-librium between intracellular and extracellularfluids. The diagram represents transfer of wateras the sole means of adjusting osmotic relation-ships.The experimental observations indicate that

shift of water across cellular membranes is prob-ably the chief means of maintaining osmotic equi-librium between body fluids. As was pointed outpreviously, in the "glucose" experiments thechanges in concentration of proteins in serum andred cells in blood indicate apparent losses ofplasma volume of 18 to 49 per cent of the originalvolumes. Loss of skin turgor signifies diminutionof extracellular fluids elsewhere than in the blood.The symptoms and signs of dehydration are thosewhich one is accustomed to associate with loss ofextracellular fluid. Furthermore, the losses of so-

dium and chloride are equal to about one fourthof the amounts of these ions in normal animals.If the sodium and chloride remaining in the extra-cellular fluid had not been concentrated by trans-fer of water from extracellular to intracellularspaces, the concentrations of serum sodium andchloride would have shown greater reductionsthan those found. Indication of transfer of ex-

tracellular water is given directly by the decreasesin concentration of erythrocytic proteins. The" glucose " experiments as a whole fit in with theconcepts represented in the diagram and indicatethat loss of extracellular electrolyte with little or

no change in body water leads to hydration ofintracellular fluids and dehydration of extracellu-lar fluids.

In the diagram the loss of extracellular electro-

lyte produces a ten per cent increase in intracellu-lar water and a twenty-five per cent decrease inextracellular fluids. With a given loss of extra-cellular electrolyte accompanied by a dispropor-tionate loss of water, or, as in the " glucose " ex-periments by little change in body water, the mag-nitude of the reduction in concentration of extra-cellular electrolyte will be dependent, not on thevolume of extracellular fluid but rather on totalvolume of body water.2 This deduction followsfrom the fact that the change in osmotic pressureproduced by loss of extracellular electrolyte mustbe equalized throughout all body fluids. Sincethis adjustment apparently takes place chiefly byshift of water from extracellular to intracellularcompartments, the magnitude of this transfer ofwater will be dependent upon the relation of thevolume of extracellular water to total body water.It is, therefore, apparent that a value for the pro-portion of body fluid in extracellular spaces is anecessary factor in predicting alterations in thedistribution of body water under varying condi-tions.The observations in the " saline " experiments

likewise fit in with the concepts expressed in thediagram (Figure 1) showing the changes pro-duced by increase in the amount of extracellularelectrolyte without alteration in total body water.In this case, since the increase in extracellularelectrolyte augments the osmotic pressure of thisfluid, water is attracted from the cells to the ex-tracellular spaces.

In the " saline " experiments, the effective in-crease in sodium and chloride in the extracellularfluid is uncertain, especially when diuresis oc-curred. However, in general, the changes in con-centration of chloride and sodium are of an order

2 This relationship for constant total body water andwhen the only loss of base is loss of Na from extra-cellular water, may be expressed by the following for-mula:

[NalV- (Na) p [Na]aV,

where [Na]1 is the original concentration of sodium inserum water; [Na]2 is the second concentration of so-dium in serum water; (Na)p is the change in body so-dium and V is the volume of body water in liters. Theapplication of this formula to the data in the "glucose"experiments yields values for V (total body water)which fit in with the probable value for total body wa-ter, namely, about 70 per cent of total body weight.

273


of magnitude that indicate that extracellular fluidmust have been diluted with water obtained fromthe cells of the body. The changes in concentra-tion of the proteins in erythrocytes indicate thatthese cells lost water as is also attested by thedecreases in the water of the red cells. Increasein extracellular fluid is difficult to demonstrate be-cause fairly large accumulations of interstitialfluid often give no signs. However, increases inplasma volume are indicated by the decreases inconcentration of proteins in serum and of redcells in blood. In other words, the chief findingin the " saline " experiments fit in with the con-cepts of the diagram and indicate that increase inextracellular electrolyte with little change in bodywater produces hydration of extracellular fluidsand dehydration of intracellular fluids.

It is interesting to note that no urine was ex-creted during the " glucose " experiments in spiteof the reductions in concentration of electrolyteand the probable hydration of the cells. In the" saline " experiments, part of the excess of so-dium and chloride in some instances was excretedso as to diminish the disturbances but in two ofthe experiments on dogs and all of those on rab-bits and monkeys, little urine was formed duringthe period of observation. We have no satisfac-tory explanation of the reason why the kidneysfailed to adjust electrolyte concentration.Whatever facts about renal adjustment of wa-

ter volume or electrolyte concentration are dis-covered, or whatever knowledge concerning per-meability of cellular membranes and the actualvolumes of the various types of body fluids isdeveloped, the present experiments demonstratethat disturbances in the distribution of body watercan occur and induce grave symptoms even whenbody water is little changed. In acute adrenalinsufficiency in dogs (15, 16, 17), a striking lossof sodium unaccompanied by a correspondingdiminution of body water has been demonstrated.From a chemical point of view the changes inacute adrenal insufficiency and those produced byloss of extracellular electrolyte in the "glucose"experiments are quite similar. The explanationof the symptoms and chemical evidences of de-hydration in adrenal insufficiency is probably alsosimilar to that presented in this paper. After thepresent experiments were practically completedand the interpretation developed, Gilman (18) re-

peated the essential features of our experimentsand showed that a decrease in blood pressure andincrease in susceptibility to the effects of hemor-rhage occur with loss of extracellular electrolyteand little change in body water. Furthermore dis-turbances in the distribution as well as theamounts of body water probably occur as the re-sult of disproportionate losses of water and elec-trolyte in diabetic coma, persistent vomiting, pro-tracted diarrhea, heat stroke, etc. It is also worthnoting that the temporary immobilization of ex-tracellular electrolyte following therapeutic injec-tion of solutions of glucose into the peritonealcavity and subcutaneous tissues will have the sameeffect as that recorded in the " glucose " experi-ments.

Gamble, Ross and Tisdall (1) have pointed outthat when the loss or gain of base is accompaniedby proportionate changes in body water, thechanges in the volumes of intracellular and extra-cellular fluids may be estimated from the con-centrations of intracellular potassium and extra-cellular sodium. However, when the loss or gainof base is not accompanied by a proportionatechange in body water such as occurs in pathologi-cal disorders accompanied by marked changes inthe concentration of sodium in the serum, the esti-mation of the probable changes in the volumes ofintracellular and extracellular fluid cannot bemade without a knowledge of the ratio of intra-cellular potassium to extracellular sodium in thebody.Few reports give data which enable one to cal-

culate the ratio of body potassium to body sodium.Katz (9) found the ratio in adult human muscleto be 2.37; Klose (10) found the ratio in thewhole body of an infant to be 0.45 and Iob andSwanson (11), 0.52. In this laboratory (19) theratio for a dog was 0.84; for a monkey, 1.22 andfor two rabbits, 1.41 and 1.44. (The ratios arebased on molecular concentrations.) In order toapply ratios derived from analyses of whole bod-ies, it is necessary to establish how nearly sodiumis exclusively extracellular. Furthermore, theprobable volume of extracellular fluid must bedetermined. In any case, it is misleading to speakof intracellular and extracellular water withoutbearing in mind that the water of the body maybecome either intracellular or extracellular, de-pending on the factors governing its distribution.

274


SUMMARY

Experiments on dogs, rabbits and monkeys are

described which induced (1) loss of extracellularelectrolyte with little change in total body waterand (2) increase in extracellular electrolyte withlittle change in total body water.The loss of extracellular electrolyte with little

change in body water induted symptoms and signsof dehydration. The concentrations of chlorideand sodium in serum were reduced; the concen-

trations of proteins in serum and the proportionsof red cells in blood increased; the concentrationsof proteins in erythrocytes were reduced by in-creases in cellular water. These phenomena are

probably referable to shift of extracellular waterinto body cells producing dehydration of extra-cellular fluids and hydration of intracellular fluids.

Increase in extracellular electrolyte with littlechange in total body water induced few symptomsexcept thirst. The concentrations of chloride andsodium in serum increased; the concentrations ofproteins in serum and the proportion of red cellsin blood decreased; the concentrations of proteinsin erythrocytes increased owing to losses of cellu-lar water. The probable explanation of thesefindings is shift of water from body cells intoextracellular spaces producing dehydration of thecells and hydration of extracellular fluids.The factors governing the distribution of body

water are discussed.

BIBLIOGRAPHY

1. Gamble, J. L., Ross, G. S., Tisdall, F. F., The metab-olism of fixed base during fasting. J. Biol..Chem.,1923, 57, 633.

2. Gamble, J. L., Blackfan, K. D., and Hamilton, B., Astudy of the diuretic action of acid-producing salts.J. Clin. Invest., 1925, 1, 359.

3. Atchley, D. W., Loeb, R. F., Richards, D. W., Jr.,Benedict, E. M., and Driscoll, M. E., On diabeticacidosis. A detailed study of electrolyte balancesfollowing the withdrawal and reestablishment ofinsulin therapy. J. Clin. Invest., 1932, 12, 297.

4. Butler, A. M., McKhann, C. F., and Gamble, J. L.,Intracellular fluid loss in diarrheal disease. J.Pediat., 1933, 3, 84.

5. Schechter, A. J., Cary, M. K., Carpentieri, A. L., andDarrow, D. C., Changes in composition of fluidsinjected into the peritoneal cavity. Am. J. Dis.Child., 1933, 46, 1015.

6. Peters, J. P., and Van Slyke, D. D., QuantitativeClinical Chemistry. Volume II. Methods. Wil-liams & Wilkins Co., Baltimore, 1932, p. 691.

7. Ibid., p. 736.8. Ibid., p. 738.9. Katz, J., Die mineralishen Bestandtheile des Muskel-

fleisches. Arch. f. d. ges. Physiol., 1896, 63, 1.10. Klose, E., Zur Kenntniss der K6rperzusammensetzung

bei Erniihrungsst6rungen. Jahrb. f. Kinderh.,1914, 80, 154.

11. Iob, V., and Swanson, W. W., Mineral growth of thehuman fetus. Am. J. Dis. Child., 1934, 47, 302.

12. Kerr, S., Studies on the inorganic composition ofblood. II. Changes in the potassium content oferythrocytes under certain experimental conditions.J. Biol. Chem., 1926, 67, 721.

13. Wakeman, A. M., Eisenman, A. J., and Peters, J. P.,A study of human red blood cell permeability. J.Biol. Chem., 1927, 73, 567.

14. Yannet, H., and Darrow, D. C., The chemical changesin red cells accompanying changes in the concen-tration of plasma. (To be published.)

15. Loeb, R. F., Atchley, D. W., Benedict, E. M., andLeland, J., Electrolyte balance studies in adrenalec-tomized dogs with particular reference to the ex-cretion of sodium. J. Exper. Med., 1933, 57, 775.

16. Harrop, G. A., Weinstein, A., Soffer, L. J., andTrescher, J. H., Studies on the suprarenal cortex.II. Metabolism, circulation and blood concentra-tion during suprarenal insufficiency in the dog. J.Exper. Med., 1933, 58, 1.

17. Harrop, G. A., Soffer, L. J., Ellsworth, R., andTrescher, J. H., Studies on the suprarenal cortex.III. Plasma electrolytes and electrolyte excretionduring suprarenal insufficiency in the dog. J. Ex-per. Med., 1933, 58, 17.

18. Gilman, A., Experimental sodium loss analogous toadrenal insufficiency: The resulting water shiftand sensitivity to hemorrhage. Am. J. Physiol.,1934, 108, 662.

19. Unpublished data.

275

a parallel loss of water and electrolyte, they do

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