Liver cell membrane alterations during hemorrhagic shock in the rat

JOURNAL

OF SURGICAL

31,506-5 15 ( 1981)

RESEARCH

Liver Cell Membrane

Alterations

during Hemorrhagic

Shock in the Rat’

RONALD L. HOLLIDAY, M.D.,* HANA P. ILLNER, M.D.tp2 AND G. TOM SHIRES, M.D.? *Department of Surgery, University of Western Ontario, London, Ontario, Canada, and TDepartment of Surgery, The New York Hospital-Cornell Medical Center, 525 East 68th Street, New York, New York 10021 Submitted for publication December 23, 1980 Previous studies using the Ling-Gerard microelectrode to measure membrane potential and a muscle biopsy technique to determine water and electrolyte content have established a skeletal muscle cell membrane defect in hemorrhagic shock. The present study was undertaken to compare and contrast changes occurring on a cellular level in the liver and skeletal muscle of the rat during sustained hemorrhagic shock. The liver has been suggested as a possible primary site of organ failure during prolonged shock with a loss of normal liver processesand important hepatic metabolic functions. Thirty-four experiments were performed in rats with 11 experiments in the control group. Skeletal muscle membrane potential as well as liver ccl1 membrane potential was measured after opening the abdomen through a midline incision. The ventral lobe of the liver was exposed and placed on a suspension apparatus to decrease respiratory interference and the liver was impaled with a Ling-Gerard microelectrode. Muscle cell resting membrane potentials were measured in exposed skeletal muscle in the leg of the animals. Biopsy samples were obtained at intervals in both the liver and skeletal muscle. Twenty-three experiments were conducted by producing hemorrhage with the withdrawal of blood over a 5- to 15-min period of time and maintaining a systolic blood pressure of 60 mm Hg for 115 + 40 min. The distribution of water and electrolytes in intra- and extracellular space in the muscle biopsies as well as in the liver on the basis of chloride distribution was considered to be a passive phenomenon related to the resting cell membrane potential as predicted by the Nernst equation. Correction of the measured water and electrolyte content of the biopsies for residual blood was carried out with the use of chromium-51-tagged red blood cells. The control group of rats did not demonstrate any significant change in membrane potential of either muscle or liver cells during the experiment. The membrane potentials were maintained at normal levels in the muscle -91.4 f 2.2 mV, and in the liver at a mean of -40.3 + 3.3 mV. The hemorrhagic shock group of animals demonstrated significant changes. Muscle membrane potential decreased to -80.99 + 6.3 mV (P K 0.01) while at the same time period the liver membrane potential decreased to -24.1 + 4.6 mV (P < 0.001). The results of these experiments give further evidence of a cellular membrane defect in hemorrhagic shock. The liver cell membrane potential changes and accompanying water and electrolyte shifts occurred before any significant changes in the muscle tissue. The data indicate the existence of a major alteration in rat liver cell membrane function early in the shock state.

INTRODUCTION

Previous studies [2, 19, 24, 261 using the Ling-Gerard microelectrode to measure membrane potential (PD) and a muscle biopsy technique to determine water and electrolyte content have established a skeletal muscle cell membrane defect in hemorrhagic shock. The membrane depolarization, with a decreaseof extracellular water volume and an increase of intracellular water volume in ’ Supported in part by NIH Grant GM-23000. * To whom reprint requests should be addressed. 0022-4804/8 1/ 120506-lOSO .00/O Copyright Q 1981 by Academic Press, Inc. AU rights of reproduction in any form reserved.

skeletal muscle were concomitant with an elevation of intracellular sodium and chloride concentrations. The total water and electrolyte content of skeletal muscle in hemorrhagic shock did not significantly change from control values. The present study was undertaken to compare and contrast changes occurring on cellular level in the liver and skeletal muscle of the rat during sustained hemorrhagic shock. The liver has been suggested as a possible primary site of organ failure during prolonged shock [25] with a loss of normal

506

HOLLIDAY,

ILLNER, AND SHIRES: CELL MEMBRANE

FIG. 1. In viva transmembrane potential measurements in rat liver and skeletal muscle.

detoxification processes and/or more probably with a loss of the important hepatic metabolic production [ 31. METHODS AND MATERIALS

Thirty-four experiments were performed on young female rats weighing from 180 to 220 g (Sprague-Dawley and Simonsen Laboratories). The animals were anesthetized with intraperitoneal pentobarbital (30 mg/ kg) and placed on a warming board to maintain a constant body temperature of 37°C. The carotid artery was cannulated, and the catheter was connected to a Statham Transducer to monitor blood pressure. Tracheostomy was performed and the animals were allowed to breathe room air. Blood gas and pH determinations were done at the beginning and at the termination of each experiment. The animals were divided randomly into control and shock groups. Control Group

Eleven animals were included in this group. Skeletal muscle membrane potential was measured as previously described [2, 7, 24, 261. Liver cell membrane potential was measured after opening the abdomen through a midline incision. The ventral lobe of the liver was then exposed and gently placed on a suspension apparatus to decrease respiratory interference. The liver was impaled as demonstrated in Fig. 1. Care was taken not to produce venous congestion of the liver.

ALTERATIONS

IN SHOCK

507

The control experiments lasted 101 -I- 23 min. Muscle cells resting membrane potentials were measured every 15-30 min. The measurements of liver cell potential were made 1 hr after the beginning of the experiment and continued at 15- to 30-min intervals through the experiment. The liver was placed back in the abdominal cavity between study periods. Nine animals had the liver removed, the ventral lobe discarded and biopsy samples weighing OS-l.0 g taken as described previously for muscle [ 24,261. The muscle samples (rectus abdominis) were obtained from these same animals and analyzed in similar fashion using 2 ml of 10% acetic acid for electrolyte extraction. The residual red blood cell (RBC) mass of the biopsies was estimated by tagging RBCs with chromate-5 1: Approximately 0.5 ml of whole blood was withdrawn from another rat and incubated at 37°C with 25 &i of sodium chromate for 15 min. Tagging was stopped with ascorbic acid and the cells were gently washed with saline to decrease the acid load to the animal. After the centrifugation, the supernatant was discarded and sterile saline added to tagged RBC until the final volume of suspension was 0.5 ml. Following the removal of an equal volume of blood from the experimental animal, the radioactive cells were injected and allowed to equilibrate for at least 30 min before the biopsies were obtained. The “Cr activity of the biopsies was determined in a NuclearChicago well gamma counter. To terminate the experiment, the animals were exsanguinated from the aorta. Blood samples were obtained for plasma electrolytes, hematocrit, blood gases, and “Cr activity determinations. ZZ. Hemorrhagic

Shock Group

Twenty-three rats were hemorrhaged by withdrawal of blood over a 5- to 15-min period. They were maintained at a systolic blood pressure of 60 mm Hg by withdrawals or infusions of small aliquots of blood. This

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JOURNAL OF SURGICAL RESEARCH: VOL. 31, NO. 6, DECEMBER 1981

level of hypotension was sustained 115 f 40 min. Blood samples were drawn and biopsies were obtained when the animal appeared to enter a decompensated state. Muscle and liver membrane potentials were measured in a manner previously described in all the animals; the biopsies were taken from 11 animals in this group. The distribution of water and electrolytes in intra- and extracellular space in the muscle biopsies was calculated on the basis of the chloride distribution, which is considered to be a passive phenomenon related to the resting cell membrane potential (as predicted by the Nernst equation) [ 14, 301. While this hypothesis is well documented for the muscle cells, there is controversy with regard to the liver [32-341. In assuming the same mechanism of chloride distribution in the liver as in the skeletal muscle, the partition of water and electrolytes into extraand intracellular spaces was calculated as described below. It was realized that the data obtained on the basis of this method may disprove the above assumption but still elucidate the mechanism of ionic transport in the liver cells. The intracellular chloride concentration in both the liver and muscle cells was cal-

culated using the Nernst equation: PD =-61.51ogf, [Cl,-] =

(1)

1

[CL-I antilog (PD/-61.5)

’

(la)

where PD = measured membrane potential, [Cl,-] = extracellular chloride concentration, [Cl;]

= intracellular chloride concentration.

The correction of the measured water and electrolyte content of the biopsies for residual RBC was carried out as follows. The blood volume of samples was determined by dividing the Vr counts in tissue by the counts of whole blood (0.1 ml). Using the hematocrit, the RBC residual volume and its Na+, K+, Cl-, and water content were calculated and subtracted from the total water and electrolytes values measured in the biopsies. These corrected values were then used to calculate the intra- extracellular partition of water and electrolytes,

Total sample chloride = extracellular water (ECW) chloride + intracellular water (ICW) chloride

(2)

= ECW [CL-] + ICW [Cl,-]

@a)

= ECW [Cl,-] + (total sample water - ECW) [Cl,-].

(2b)

Intracellular [ Na+] = intracellular [K+] =

total sample Na+ - ECW [Na,+] , ICW

(3)

total sample K+ - ECW [Ed+] , ICW

The concentration of Na+, K+, and Cl- in ECW were calculated from plasma concentrations corrected for plasma water of 0.94 and the following Donnan factors: Na+, 0.99; K+, 0.99; Cl-, 1.01. (27). The relative Na permeability (PNa) of the

(3a)

rat liver cell was calculated by the modified Goldman equation:

[&+I PNa+ =

antilog(PD/61.5)

P&+1

- K+l .

HOLLIDAY,

ILLNER, AND SHIRES: CELL MEMBRANE

ALTERATIONS

IN SHOCK

509

The partition of water and electrolytes into intra- and extracellular compartments 120 in skeletal muscle in control and shock states 100 is summarized in Table 1. Table 2 demon00 strates the total content of electrolytes in skeletal muscle, expressed in milliequiva60 lents per 100 g of fat-free dry weight (FFDW), with no significant change between the control and shock groups of animals. The corresponding data obtained from liver biopsies in control and shock states are Systolic BP Muscle PD Liver PD summarized in Tables 3 and 4. Both the in(mV) (mV) (mmHg) tracellular water volume and the total water FIG. 2. Changes in liver and skeletal muscle memcontent were significantly increased in the brane potentials and blood pressure in responseto hemanimals of the shock group. Intracellular orrhagic shock. Na+ and Cl- concentrations have increased with a significant decrease in intracellular RESULTS K+ concentrations. The changes in total elecThe control group of rats did not dem- trolyte content of liver samples were also onstrate any significant change in membrane significant; a large increase in Na+ and Clpotential of either muscle or liver cells dur- with a decrease in total K+. ing the experiment. The membrane potenPlasma Na+ and Cl- concentration were tials were maintained at normal levels, in not significantly different in both groups; muscle at the mean of -91.4 ? 2.2 mV; in plasma K+ concentration was 7.5 meq/liter liver at the mean of -40.3 f 2.33 mV. in shock group as compared with 4.5 meq/ The hemorrhagic shock group of animals liter in controls. The mean residual RBC demonstrated significant changes. Muscle volume in the liver, as measured with “Crmembrane potential decreased to -80.99 tagged cells (8.70 f 3.50 ml/100 g FFDW + 6.3 mV (11.4%, P < 0.01) while at the in controls, 8.28 f 3.40 in shock animals) same time period, the liver membrane po- was approximately the same in both groups. tential decreasedto -24.1 f 4.6 mV (37.8%, In the muscle, the residual RBC volume of P < 0.001). This response is illustrated in the shock group (0.65 ZL 0.20 ml/100 g Fig. 2. FFDW) was significantly lower when com140

TABLE 1 THEDISTRIBUTIONOFWATERANDTHEINTRACELLULARELECTROL~ECONCENTRATIONSINSKELETAL MUSCLEINTHECONTROLANDSHOCKGROIJPS ECW” Control N=9 0.066 + 0.017 Shock N = 11 0.057’ + 0.008

ICW”

Percentage ECW

Na+Icwb

K+IEW b

Clbvb

0.249 f 0.017

21.63 f 2.97

4.19 + 2.71

185.66 + 27.86

3.98 + 0.29

0.277’ * 0.011

20.29 f 4.67

7.69 + 3.48

178.76 k 19.34

5.78 + 1.63

Note. All data expressed as mean + SD. a In l/l00 g fat free dry wt. b In meq/l. ‘N = 7 (see Discussion).

510

JOURNAL OF SURGICAL RESEARCH: VOL. 31, NO. 6, DECEMBER 1981 TABLE 2 TOTAL SKELETALMUSCLE BIOPSYELECTROLYTEAND WATER CONTENTIN THE CONTROL AND SHOCKGROUPS Na+b

K+b

Cl-b

0.323 + 0.018

11.6 + 1.3

47.2 f 6.8

9.1 + 1.4

0.345 * 0.020

11.1 + 1.3

49.6 f 5.7

9.9 f 1.6

H,O’ Control N=9 Shock N= 11

Note. All data expressed as mean + SD. 0 In l/l00 g fat free dry wt. b In meq/l.

pared with the controls (0.93 f 0.35 ml/ 100 g FFDW). The relative Na+ permeability of 0.196 f 0.020 was calculated for the liver cell membrane in control state. The change to 0.220 + 0.040, calculated for the shock group, was insignificant. DISCUSSION

The results of these experiments give further evidence of a cellular membrane defect in hemorrhagic shock. The liver cell membrane potential changes and accompanying water and electrolyte shifts has occurred before any significant changes in the muscle tissue. The data indicate the existence of a major alteration in rat liver cell membrane function early in the shock state. First measurements of liver cell membrane potentials were made in 1957 by Li

and McIlwain [ 181 on isolated guinea pig liver slices. Other studies have been made on rat liver in situ [20, 23, 301, and isolated perfused dog liver [ 161. Elshove and Van Rossum have studied rat liver slices in vitro [ lo]. Most authors have established the resting membrane potential in liver to be between -35 and -45 mV. This is consistent with the value of -40.25 + 2.3 measured in control group of animals in the present studies. The intracellular electrolyte concentrations of liver tissue reported by other authors are also in close approximation to the control values in these experiments: Williams and Woodbury [ 3 1] estimated values of [Na+] 22, [K+] 165, and [Cl,-] 22 meq/liter cell water: Claret and Mazet reported values of [Na+] 16.4, [K+] 113, and [Cl-] 25.5 meq/ liter [5]. Variations from the results of the

TABLE 3 THE DISTRIBUTIONOF WATER AND THE INTRACELLULARELECTROLYTECONCENTRATIONSIN LIVER IN THE CONTROLAND SHUCK GROUTS ECW”

ICW”

Percentage ECW

NatlCW b

K?SW b

Cl&b

Control N = 9 0.018 + 0.009 0.219 + 0.014 7.71 + 3.83 27.23 + 3.92 155.31 k 19.01 25.76 + 2.23 Shock 0.023 + 0.013’ 0.275 k 0.028’ 7.79 + 5.29’ 66.74 k 14.13 106.71 k 22.00 49.93 + 10.21 N= 11 P < 0.001 P < 0.001 P < 0.001 P < 0.001 Note. All data expressed as mean -t SD. ’ In l/l00 g fat free dry wt. b In meq/l. ‘N = 7 (see Discussion).

HOLLIDAY,

ILLNER,

AND

SHIRES:

CELL

MEMBRANE

TABLE

TOTALLIVER BIOPSYELECTROLYTEANDWATER

ALTERATIONS

IN SHOCK

5 11

4

CONTENTINTHECONTROLANDSHOCKGROUPS

H,O”

Na+b

K+b

Cl-b

0.237 + 0.012 0.299 iz 0.021 P < 0.001

8.77 + 0.93 22.11 + 5.74 P < 0.001

33.91 k 3.82 28.68 k 4.29 P < 0.001

7.76 f 0.71 16.12 + 3.06 P < 0.001

Control N=9 Shock N= 11

Note. All data expressed as mean k SD. ’ In l/100 g fat free dry wt. b In meq/l.

present study [Na+] 27.2, [K+] 155.3, and [Cl-] 25.8 are likely due to the methods used to calculate extracellular and intracellular water distribution, that is, inulin space versus chloride space as calculated from the Nernst equation. Transmembrane potential is assumed to be the result of either an electrogenic sodium pump (with active outward transport of sodium by a redox system) or an electroneutral coupled sodium-potassium exchange pump with diffusion of sodium and potassium down their respective chemical gradients [ 6, 12, 141. The resting membrane potential is then generated due to the different permeabilities of cell membrane to these two ions. Previous studies [2, 24, 261 have demonstrated and interpreted the changes concomitant with decreased PD in hemorrhagic shock in muscle tissue in rats, dogs, and primates. The changes included a decrease in ECW volume, increase in ICW volume, elevation of intracellular Na+ and Cl- concentrations with a decrease in intracellular K+ concentration. Similar, but quantitatively smaller, changes occurred in present experiments in the rat skeletal muscle. It was suggested that these changes occur because of a decrease in the active transport system and/or change in relative sodium permeability (P&. Liver is a nonexcitable cellular tissue and some of the membrane properties of the cells are in all likelihood different from excitable skeletal muscle. Nevertheless, most authors consider the liver membrane potential to be

under control, at least partially, of a Na+K+ pump. Claret et al. [4] and Claret and Mazet [5] on the basis of their experiments assumed the existence of a Na+-K+ electrogenie pump exchanging three Na+ ions for two K+ ions, (former transported out of the cell, latter into the cell). Cardiac glycosides, known as specific inhibitors of active ion transport, have been shown to decrease ion transport in liver slices. Lambotte and coworkers [ 16, 171 also have given experimental evidence of a Na+-K+ exchange between liver cells and plasma which can be blocked by cardiac glycoside ouabain. Williams et al. [32-341 produced conflicting results in an elaborate in vivo study; unable to explain the resting liver potential as a simple diffusion potential, they concluded their discussion in favor of an electrogenic component. The relative sodium permeability of cell membrane in liver is also considered to be different from the values reported for muscle cells(PN,/Pk = 0.01). Claret and Mazet [5] suggested PNa;/PK of 0.52; Williams et al. [32] reported value of 0.2; in the present study the value of 0.196 in control animals increased slightly to 0,216 in the shock animals. Previous data [23] have indicated more rapid cell membrane depolarization in rat liver than in rat muscle after the death of the animal. While the potential of the liver cells decreased more than 50% in 20 min, the muscle cell potential remained virtually constant over the time period of the exper-

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JOURNAL OF SURGICAL RESEARCH: VOL. 31, NO. 6, DECEMBER 1981

iment (40 min). Monsaigeon and Schirar [20] investigated the liver cell membrane response to hemorrhagic shock in vivo and reported a decreased membrane potential with hemorrhage. In the present experiments, the membrane PD has decreased 31% in liver as compared to 11% decrease in skeletal muscle during the same time period of hemorrhagic shock. The changes in water and electrolyte distribution during hemorrhagic shock invite further discussion. The increasing electrolyte and water shifts in the time course of the low flow state are not parallel in liver and muscle tissues. The trend in muscle tissue with decreasing PD is as previously reported, decreasing ECW and increasing ICW volume associated with elevated intracellular Na+ and Cl- concentrations and decreased Kf concentration. The changes in the above parameters are similar, but again earlier and greater in the liver tissue. The liver intracellular water volume in shock has increased by 26%, intracellular Na+ concentration by 150% and intracellular Cl- concentration by 100%. The large shift of water, sodium and chloride into the cells is also reflected in an increase of their total content in liver in hemorrhagic shock. The total liver water increased from 0.237 liter/100 g FFDW in control group to 0.299 liter/100 g FFDW in shock group (+26.1%) Na+ content increased from 8.8 to 22.1 meq/lOO g FFDW (+152%) and Cl- from 7.8 to 16.1 meq/lOO g FFDW (+107%). On the contrary, the previously reported substantial movements of sodium, chloride, and water intracellularly in skeletal muscle during hemorrhagic shock were not associated with a significant change in their total content. Furthermore, when the same animals were used for control and shock study, the amount of fluid lost from muscle ECW in shock appeared as an increase in muscle ICW. In other words, the electrolytes and water changes due to the low flow state in skeletal muscle were predominantly taking place between extra- and intracellular compartments of muscle tissue,

with total electrolyte and water content of this tissue unchanged. In explaining the different situation in liver, it is necessary to consider the marked swelling of liver cells early in shock, requiring a large amount of fluid. Extracellular fluid volume in liver is physiologically small (in present results 7.7% of total liver fluid in control group) and has to be repleted from intravascular space to meet the intracellular demand. This replenishment is probably facilitated due to the preferential blood supply to the liver in shock. The fact that the residual RBC volume in liver did not change in shock, while in skeletal muscle decreased from control values by 29%, supports this possibility. With fluid repletion from plasma, the liver becomesa major fluid sequestration site of the animal, the volume of ECW lost in liver cells being much higher than physiological liver ECW space. The reported changes in liver ECW induced by shock state (Table 3) appear equivocal, with a slight increase in the mean ECW volume. However, this value represents only seven of the eleven animals in the shock group. In the rest of the animals the application of Eqs. (1) and (2) produced physiologically impossible negative values for ECW volume. The calculated negative ECW may be a result of: (a) spuriously low PD applied to Eq. ( 1), resulting in falsely high [Cl,-], (b) inadequate leaching of Cl- from the biopsy, or (c) overestimation of total biopsy water content. (a) The membrane potential measurements display a small variability (+ 3 mV) of the mean in normal tissue, due to slight changes in electrical characteristics of the microelectrode and the circuit. During the shock period, the variation even increases in association with individual response of cells to the insult. On a high PD level, a small voltage drop will not change the calculated [Cl,-] (Eq. (la)) significantly; on a low PD level (-25 mV in shock in present experiments) the same change will result in a marked increase of calculated [Cli-1.

HOLLIDAY,

ILLNER,

AND

SHIRES:

CELL

It is estimated that the extracellular space of normal liver is in the range of 4-9s of total water [ 21, 291; the value obtained in the present experiments was 7.7 + 3.8%. The combination of small ECW volume in liver (even in control state) with a large overestimation of [Cl,-] due to a small variation of PD, is likely to produce the calculated negative ECW in shock. In order to illustrate the above discussion, the standard deviation of the mean PD in shock group (5 mV) was added to the measured PD, the [Ch-] and ECW values were recalculated and in all four experiments a very small, but positive value of ECW was obtained. On the contrary, the slight increase of PD measurement due to the random variation will result in spurious results in the opposite direction, i.e., lower [Cli-] and overestimated ECW volume. It is conceivable that some of the seven animals in shock with calculated positive ECW (X = 7.79%) were subjected to this experimental error. In conclusion, from results in these experiments, it is not possible, due to the inherent experimental error, to determine exactly the ECW value in liver in the shock group. The limitations of the “true” ECW volume are nevertheless certain, (0 < ECW < 7.79% of the total liver water) and the value is in all likelihood near to the mean ECW of the whole group (2.5% N = 11). Possible error in (b) and (c) would decrease the total Cl- concentration (Cl,-/ HzO) resulting in C&-/H,0 < [Cl,-] and thus calculated negative ECW; nevertheless, these two possibilities of technical error were disregarded on the basis of previous careful examinations of employed methods. An alternate theoretical explanation for negative ECW consequent to the extremely low liver PD in shock would be a possibility of local traumatization of ventral lobe due to the necessary manipulation during measurements. In other words, it seems possible that the ventral lobe PD change would slightly precede the other lobes, used for the biopsy, the local trauma being superimposed

MEMBRANE

ALTERATIONS

IN SHOCK

513

on the shock insult. To eliminate this possibility, small group of animals was used for comparative measurements made in the ventral lobe in series and later during the experiment singularly in the other lobes. No significant difference between the “traumatized” and “untraumatized” area measurements was found. In conclusion, it is assumed that the liver ECW volume, low in normal condition, decreases to an extremely low value after the hemorrhage. In view of tremendous intracellular swelling, associated with excessive increase of total Na+, Cl-, and water content in liver biopsies of all animals of the shock group, the determination of exact ECW volume in these experiments is nonpertinent, being a result of combined successive fluid depletion into cells and repletion from vascular bed. Histologically, there is also evidence for liver intracellular swelling and a decreased ECW volume in shock [ 11, 221. DePalma et al. [9] reported marked intracellular edema with widening and distortion of the endoplasmic reticulum in liver of rats in hemorrhagic shock. The evidence for reversibility of this cellular defect with treatment was also presented. Similarly, changes in rat liver mitochondria in shock, including swelling and distortion of mitochondrial membranes were documented by White et al. [29]. The marked cellular alteration associated with membrane depolarization in liver during hemorrhagic shock could be a result of an active transport inhibition and/or a change in the cell permeability of ions. Baue et al. [ 1, 351 provides some evidence for decreased activity of the Na+-K+ pump. The Na+-K+ ATPase which is considered to be an important part of the Na+-K+ transport mechanism at the cell membrane level was increased in early and late shock. According to the authors, the increased activity of this enzyme may be due to increased intracellular Na+ as shown in present experiments. Chaudry and Baue (3) have documented a decrease in energy substrates available in

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JOURNAL OF SURGICAL RESEARCH: VOL. 31, NO. 6, DECEMBER 1981

meabilities of cell membranes in rat liver. J. Physshock in both liver and kidney cells, which iol. 223: 279, 1972. could also account for decreased activity of 6. Conway, E. J. Nature and significance of concenthe energy dependent Na+-K+ pump. tration relations of potassium and sodium ions in Cunningham er al. [ 7,8] in clinical studies skeletal muscle. Physiol. Rev. 37: 84, 1957. reported red blood cell alterations in patients 7. Cunningham, J. N., Jr., Shires, G. T., and Wagner, I. Y. Cellular transport defects in hemorrhagic during long severe hemorrhagic shock. An shock. Surgery 70: 215, 1971. increased intracellular Na+ and decreased 8. Cunningham, J. N., Jr., Shires, G. T., and Wagner, K+ concentrations were demonstrated. Early I. Y. Changes in intracellular sodium and potassium studies [ 151on the mechanism involved have content of red blood cells in trauma and shock. Amer. J. Surg. 122: 650, 1971. indicated a decrease in active transport 9. De Palma, R. G., Holden, W. D., and Robinson, across the red cell membrane as the etiology A. V. Fluid therapy in experimental hemorrhagic of the elevated Na+ content in deep hemshock: Ultrastructural effects in liver and muscle. orrhagic shock. Ann. Surg. 175: 539, 1972. In conclusion, the liver is another area of 10. Elshove, A., and Van Rossum, G. D. U. Net movements of sodium and potassium and their relation disturbed cellular function in hemorrhagic to respiration in slices of rat liver incubated in vitro. shock. The marked increase of Na+ concenPhysiol. 168: 531, 1963. tration and water volume in liver cells lead- 11. J. George, B. C., Ryan, N. T., Ullrick, W. C., and ing to a large sequestration ‘of functionally Egdahl, R. H. Persisting structural abnormalities unavailable extracellular fluid was similar in liver, kidney, and muscle tissues following hemorrhagic shock. Arch. Surg. 113(3): P289-93, 1978. to that described previously in muscle and 12. Goldman, D. E. Potential, impedance and rectifibrain tissues [ 13, 241.

SUMMARY

Hemorrhagic shock was induced in rats. Resting membrane potential differences, electrolyte concentrations and water distribution were studied in liver and skeletal muscle cells. The depression of membrane potential concomitant with cellular swelling and Na+ uptake were noted earlier in the liver than in the muscle. The present data are consistent with the concept of impaired membrane transport in low flow states. REFERENCES 1. Baue, A. E., Wurth, M. A., and Sayeed, M. Alterations in hepatic cell function during hemorrhagic shock. Bull. Sot. Int. Chir. 5: 381, 1972. 2. Campion, D. S., Lunch, L. S., Rector, F. C., Jr., Carter, N. W., and Shires, G. T. The effect of hemorrhagic shock on transmembrane potential. Surgery 66: 1051, 1969. 3. Chaudry, I. H., and Baue, A. E. Depletion of replenishment of cellular cyclic adenosine monophosphate in hemorrhagic shock. Surg. Gynecol. Obstet. 145(6): P877-81,

1977.

4. Claret, M., Coraboeuf, E., and Gravier, M. Effect of ionic concentration changes in membrane potential of perfused rat liver. Arch. Int. Physiol. B&hem. 78: 531, 1970. 5. Claret, M., and Mazet, J. L. Ionic fluxes and per-

cation in membrane. J. Physiof. 27: 37, 1943. 13. Grossman, R. Intracellular potentials of motor cortex neurons in cerebral ischemia. Electroenceph. Clin. Neurophysiol. 24: 291, 1968. 14. Hodgkin, A. L., and Katz, B. The effect of sodium ions on the electrical activity of the giant axon of the squid. J. Physiol. 108~ 37, 1949. 15. lllner, H., Cunningham, J. N., and Shires, G. T. The red blood cell sodium content and permeability changes in hemorrhagic shock. Amer. J. Surg., in press. 16. Lambotte, L. Influence of temperature on sodiumpotassium exchange produced by ouabain in the perfused dog liver. Arch. Int. Physiol. Biochem. 77: 331, 1969. 17. Lambotte, L., Kestens, P. J., and Haxhe, J. J. Sodium gain and potassium loss produced in the liver by adrenaline. Arch. Int. Physiol. Biochem. 77: 345, 1969. 18 Li, C. L., and Mcllwain, H. Maintenance of resting membrane potentials in slices of mammalian cerebral cortex and other tissues in vitro. J. Physiol. 139: 178, 1957.

19. Ling, G., and Gerard, R. W. The normal membrane potential of frog sartorius fibers. J. Cell Camp. Physiol. 34: 383, 1949. 20. Monsaingeon, A., and Schirar, M. Changes in electrical potential within the liver and the kidneys during acute surgical conditions. Eur. Surg. Res. 1: 299, 1969. 21. Rothschild, M. A., Bauman, A., Yalow, R. S., and Berson, S. A. Tissue distribution of I”‘-labeled human serum albumin following intravenous administration. J. Clin. Invest. Vol. 34, 1354, 1955.

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22. Russo, M. A., and Conforti, A. Subcellular reactions to injury. Ultrastructural and biochemical investigations on the hepatic cellular damage produced by hemorrhagic shock in dogs. J. Puthol. 121(2): P107-13, 1977. 23. Schanne, O., and Corabeuf, E. Potential and resistance measurements of rat liver cells in situ. Nature (London) 210: 1390, 1966. 24. Shires, G. T., Cunningham, J. N., Baker, C. R. F., Reeder, S. F., Illner, H., Wagner, I. Y., and Maher; J. Alterations in cell membrane function during hemorrhagic shock in orimates. Ann. Sure. 176: 288, 1972: 25. Shoemaker, W. C., Szanto, P. B., Fitch, L. B., and Brill, N. R. Hepatic physiologic and morphologic alterations in hemorrhagic shock. Surg. Gynecol. Obstet. 118: 828, 1964. 26. Trunkey, D. D., Illner, H., and Shires, G. T. The effect of hemorrhagic shock on intracellular muscle action potential in the primate. Surgery 74: 241, 1973. 27. Van Leeuwen, A. M. Net cation equivalency (base binding power) of the plasma proteins. Acra Med. Stand. 176, Suppl. 442, 1964. 28. Whittam, R. Active cation transport as a pacemaker of respiration. Nature (London) 191: 603, 1961.

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ALTERATIONS

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29. White, R. R., Mela, L., Becalxo, L. V., Jr., Olofsson, K., and Miller, L. D. Hepatic ultrastructure in endotoxemia, hemorrhage, and hypoxia: Emphasis on mitochondrial changes. Surgery 73: 525, 1973. 30. Wilde, W. S. The chloride equilibrium in muscle. Amer. J. Physiol. 143: 666, 1945. 31. Williams, J. A., and Woodbury, D. M. Determination of extracellular space and intracellular electrolytes in rat liver in vivo. J. Physiol. 212: 85.1971. 32. Williams, J. A., Withrow, C. D., and Woodbury, D. M. Effects of ouabain and diphenylhydantoin on transmembrane potentials, intracellular electrolytes and cell pH of rat muscle and liver in vivo. J. Physiof. 212: 101, 1971. 33. Williams, J. A., Withrow, C. D., and Woodbury, D. M. Effects of nephrectomy and KC1 on transmembrane potentials, intracellular electrolytes and cell pH of rat muscle and liver in vivo. J. Physiol. 212: 117, 1971. 34. Williams, J. A., Withrow, C. D., and Woodbury, D. M. Effects of CO2 on transmembrane potentials of rat liver and muscle in vivo. J. Physiol. 215: 539, 1971. 35. Wurth, M. A., Sayeed, M. M., and Baue, A. E. (Na’ + K+) ATPase activity in the liver with hemorrhagic shock. Proc. Sot. Exp. Biol. Med. 139: 1238, 1972.