A quantitative electrochemical theory of the electrolyte permeability of mosaic membranes composed of selectively anion-permeable and selectively cation-permeable parts, and its experimental verification. II. A quantitative test of the theory in model systems which do not involve the use of auxiliary electrodes

The theory of the electrolyte permeability of mosaic membranes composed of ideally anion-selective and ideally cation-selective parts in juxtaposition is tested in a model which consists of an all-electrolytic cyclic arrangement of four component parts: dilute solution/anion-selective membrane/concentrated solution/cation-selective membrane/dilute solution. In this system cations move from the concentrated to the dilute solution across the cation-selective membrane and an equivalent number of anions move through the anion-selective membrane. This movement of ions corresponds to a flow of current in the system. According to the theory, the number of equivalents of electrolyte which penetrate in any given time across the membranes must be identical with the number of faradays of electricity which flow during the same period. The system is essentially a combination of two menbrane-concentration cells arranged in series in a short-circuited state without the presence of electrodes. Experimentally the magnitude of the current was determined by measuring with probe electrodes the potential across an element of the circuit whose resistance was known and constant. The number of faradays of electricity (determined from time-current data) flowing in the system during a measured time was compared with the analytically determined number of equivalents of electrolyte which moved across the membranes during the same period. In a variety of experimental systems the two values show a 1:1 ratio with a mean deviation of ± 1.8 per cent.

Electrolyte studies in heart failure. II. Extracellular factors in the pathogenesis of congestive edema

Indirect metabolic studies and direct muscle biopsy studies have indicated diminution of intracellular electrolyte concentration during congestive heart failure explainable by extrusion of these electrolytes due to increase in osmolarity within the cells. Acute and chronic physical and circulatory stress in cardiac patients produced an elevation of plasma sodium concentration indicative of a concomittant increase in osmolarity of the extracellular fluid.

Varying role of extracellular electrolytes in metabolic acidosis and alkalosis

The responses of plasma and extracellular space to different types of acids and alkalis were studied in nephrectomized cats. Compensation for mineral acids can largely be accounted for by changes which are detectable in extracellular constituents. These changes are movement of Na+ and K+ into the extracellular space (ECS) and loss of HCO3– from the ECS. Organic acids which penetrate cells rapidly and may be expected to cause an intracellular and extracellular acidosis, produce negligible changes in extracellular content of Na and K. Alkalosis produced by NaOH or NaHCO3 was compensated for mainly by extracellular gain of bicarbonate and loss of Na. The response to NH4OH was unusual in that this alkaline solution caused an acidosis with movement of K into the ECS. The site of compensation for the various acids and alkalis was indicated by a comparison of the volume of agent infused with the change in volume of the ECS. The distribution of Na in these animals was not related as much to the concentration of Na in the ECS as it was to the pH produced by the solution infused. The response of the living organism to different types of acids and alkalis is variable and seems mainly related to the distribution of the material in the body.

Effect of temperature on electrolyte metabolism of isolated frog skin

A study is presented on the effect of temperature on unidirectional active ion transport, resting electrolyte equilibrium (electrolyte composition), and oxygen consumption in isolated frog skin. The aims were twofold: first, to find out whether the rate of active transport can be changed without affecting the Na⁺ and K⁺ balance of skin itself; second, to arrive at minimal ΔNa/ΔO₂ values by correlating quantitatively inhibition of active ion transport with inhibition of O₂ consumption. NaCl transport was maximal at 20°C. At 28° and at temperatures below 20°, rate of NaCl transport was diminished. In many instances NaCl transport was diminished in skins which maintained their normal Na⁺ and K⁺ content. In several cases, however, neither rate of transport nor resting electrolyte equilibrium was affected; in other cases, both were. O₂ consumption decreased when lowering the temperature over the range from 28 to 10°C. From a plot of log Q_OO2 against 1/T an activation energy of µ 13,700 cal. was calculated, valid for the range from 10 to 20°C. It appeared that µ was smaller for temperatures above 20°C. Working between 10 and 20°, it was found that, on the average, 4 to 5 equivalents of Na⁺ were transported for one mole of O₂ consumed in skins with undisturbed resting electrolyte equilibrium.

Acetylcholine and electrolyte metabolism in the various chambers of the frog and turtle heart

Evidence has accumulated suggesting acetylcholine may he involved in initiation of the heart heat. Acetylcholine and electrolyte metabolism in the various chambers of the heart have been studied. The area of highest intrinsic rhythm (sinus) contained greater amounts of acetylcholine equivalents, true cholinesterase, choline acetylase and sodium; all of these decreasing in amount in areas of lower intrinsie rhythm. It is concluded that intrinsic rhythm may he directly correlated with overall acetylcholine metabolism and sodium content and inversely related to overall energy metabolism and potassium concentration.

Effect of estrogen and progesterone on water and electrolyte content of rabbit uteri

Estrogen, either endogenous or exogenous, caused an uptake of water in the rabbit endometrium. Endometria of rabbits in estrus or of spayed rabbits treated with estrogen had an extracellular compartment which was twice as large as the intracellular phase A similar distribution of water was observed in the endometria of ovariectomized control rabbits. Progesterone caused a complete reversal in the distribution of the endometrial water. Thus, pseudopregnant or progesterone-treated rabbit endometria had an intracellular phase which was twice as large as the extracellular compartment. Changes in Na and K concentrations were associated with these shifts in water between the exterior and interior of the cells. Endometria of progesterone-treated or pseudopregnant rabbits had high K and low Na concentrations in comparison to the estrous, estrogen-treated or ovariectomized rabbit endometria. Expressed as total K/Na ratios, the endometria showed extreme differences, being 0.54 under estrogen domination and 1.38 under progesterone influence.

Muscle electrolytes in acid and alkaline solutions

Isolated frog muscles were equilibrated in solutions of varying pH and were then analyzed for potassium, sodium and sometimes chloride, phosphate, or bicarbonate. It was found that acid applied outside the muscle causes in most cases an increased loss of K. Over the physiological pH range this was also true of Na in experiments in which the complication of the extracellular space was minimized by replacing 90% of the NaCl of the solution by sucrose. In the other experiments the variations were such that it was impossible to establish any regular effect of pH on the movements of sodium. Except at a pH below 2 or above 12 the Na did not appear to exchange with K in response to injury. It is suggested that the Na pump in muscle works better when the Na is being moved into a more acid solution. It is concluded that muscle neutralizes external acid in part by loss of K, sometimes by loss of Na, and to some extent by gain of chloride. There was a slightly increased loss of phosphate and bicarbonate from muscle in the more acid solutions but no evidence of an increase in the extracellular fluid as measured by inulin.

Effect of acute fasting in the rat on water and electrolyte content of serum and muscle and on total body composition

Thirteen acutely fasted male adult rats were compared with six fed controls in respect to serum electrolyte levels (7 rats), total carcass (7 rats) and skeletal muscle composition (13 rats). Of the serum electrolyte levels only potassium was mildly depressed; there was no evidence of hypochloremic alkalosis or of hyponatremia. The loss of weight ranged between 25 and 37% of the initial value (mean = 32%). Total body fat was decreased most (mean = –97%). Lean body mass was relatively increased from 90 to 99% of the final body weight, but was absolutely decreased by 25% of the initial value; the ratio of water to fat-free solids was unchanged. In the total fat-free carcass, chloride was increased more than sodium, potassium was decreased relative to the total wet tissue, to total water and to nitrogen. In fat-free skeletal muscle, chloride and the chloride/sodium ratio only were increased. Either the extracellular fluid taken as the chloride space was expanded or chloride was sequestered or both. On the former assumption, intracellular water, sodium and potassium concentrations were unchanged.

Electrolyte and lipid composition of skeletal and cardiac muscle in mice with hereditary muscular dystrophy

Skeletal and cardiac muscle from strain 129 mice with hereditary muscular dystrophy and from their normal littermates were analyzed for sodium, potassium, total lipids and the separate lipid components. Dystrophic skeletal muscle contained 12–23% less potassium and 68–107% more sodium than the normal anatomical counterparts when referred to fat-free dry weight. Cardiac muscle from dystrophic mice did not differ from the normal in potassium content and had only 20% more total lipid. Fat content was substantially greater in dystrophic skeletal muscle than in normal muscle by the following percentages: 92% for total lipids, 168% for triglycerides, 140% for total cholesterol and 87% for nonesterified fatty acids assayed by infrared analysis. The phospholipid content of dystrophic and normal skeletal muscle, however, was approximately the same. The lack of information concerning interstitial connective tissue content of these tissues bars any precise interpretation of the electrolyte or lipid changes in this genetic myopathy.

Electrolyte content of rat heart atria and ventricles

Extracellular tissue spaces are compared using inulin, sucrose, chloride and sodium in hearts perfused with Ringer-Locke solution by Langendorff's method. Also chloride and sodium spaces are given for unperfused, fresh hearts. From the inulin spaces the intracellular chloride, sodium, potassium and water concentrations in both perfused and unperfused heart chambers have been calculated. Data showing the specificity of the atrium and ventricles of the heart are presented.

Effect of thiazide diuretics on plasma volume, body electrolytes, and excretion of aldosterone in hypertension

A study has been made at the Mayo Clinic of the results of treatment in 28 hypertensive patients receiving thiazide diuretics. The use of these agents produced a significant but very temporary reduction in plasma volume in most patients. The plasma volume reverted to or toward normal after the first week of treatment; therefore, hypovolemia could not explain the prolonged hypotensive effect of these drugs. Administration of thiazide diuretics did not deplete the body of its sodium stores, as measured by isotope studies in five patients on an unrestricted diet. Therapy with thiazides did not produce a persistent increase in urinary aldosterone excretion in the nine patients studied for this possibility.