POTASSIUM STIMULATION OF OXIDATION AND PHOSPHORYLATION IN PIGEON-MUSCLE MITOCHONDRIA

1966 ◽  
Vol 44 (8) ◽  
pp. 1127-1132 ◽  
Author(s):  
G. J. Marcus ◽  
J. F. Manery
Keyword(s):  
Potassium Concentration ◽  
Sodium Concentration ◽  
Oxygen Electrode ◽  
High Potassium ◽  
Muscle Mitochondria ◽  
High Sodium ◽  
Glucose Phosphate ◽  
Minute Period ◽  
The Mean ◽  
Stimulation Of

With alpha-ketoglutarate as substrate and a hexokinase – glucose phosphate acceptor system, the rates of oxidation and phosphorylation of pigeon-muscle mitochondria were measured in media in which the proportion of potassium to sodium was varied. As the potassium concentration was elevated from 0 to about 70 mmoles/liter, the sodium concentration was correspondingly decreased. With both the Warburg apparatus and the polarograph, the rate of respiration was shown to rise as the proportion of potassium in the medium was increased. The mean rate in the high-potassium media was 130% of that in the high-sodium media over the five-minute period measured with the oxygen electrode, and 135% over the thirty-minute period measured by Warburg manometry. The rate of phosphorylation was stimulated to an even greater extent than the rate of oxidation as sodium was replaced by potassium. In every preparation tested, the rates of phosphorylation and the P/O ratios were higher in the high-potassium media than in the high-sodium media.

Aorta Electrolytes of Hypotensive Potassium-Deficient Rats

1958 ◽  
Vol 195 (2) ◽  
pp. 445-447 ◽  
Author(s):  
S. Charles Freed ◽  
Shirley St. George ◽  
Ray H. Rosenman
Keyword(s):  
Blood Pressure ◽  
Potassium Concentration ◽  
Pressure Rise ◽  
Sodium Concentration ◽  
Sodium Content ◽  
Potassium Deficiency ◽  
Sodium Potassium ◽  
High Sodium ◽  
Blood Pressure Rise ◽  
Arterial Tone

The hypotension of potassium-deficiency is associated with a decrease in aorta potassium concentration, the sodium content remaining unchanged, resulting in a high sodium/potassium ratio. Loss of arterial tone may result and thus contribute to the lowering of blood pressure. Cortisone administration to such rats does not alter the low aorta potassium content but appreciably reduces the sodium concentration. The return to a more normal sodium/potassium ratio in the aorta following cortisone may restore the arterial tone and thus explain the blood pressure rise to normal levels.

A survey of the potassium concentration in the red blood cells of British breeds of sheep

1957 ◽  
Vol 48 (4) ◽  
pp. 433-437 ◽  
Author(s):  
John V. Evans ◽  
M. S. Mounib
Keyword(s):  
Red Blood Cells ◽  
Whole Blood ◽  
Blood Cells ◽  
Potassium Concentration ◽  
High Potassium ◽  
The Mean ◽  
High Level ◽  
Mean Concentration ◽  
Representative Samples

The concentrations of potassium in the whole blood of representative samples of sixteen British breeds of sheep have been studied.The proportion of sheep with a high level of potassium in the whole blood (high potassium or HK type) was found to differ significantly between breeds. It ranged from 0% in the English Leicester to 73% in the Rough Fell.There were significant differences between breeds in the mean concentration of potassium in the whole blood of both the LK and HK sheep.

scholarly journals Performance Qualification of Two Processor-controlled Dosing Pumps for the Production of Mixed Infusion Solutions in a Closed System

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Terry Hennache ◽  
Gwénaëlle Clabaut ◽  
Lina Mustapha ◽  
Jean-Marc Dubaele ◽  
Frédéric Marçon
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Closed System ◽  
Potassium Concentration ◽  
Sodium Concentration ◽  
Relative Bias ◽  
Relative Standard ◽  
Performance Qualification ◽  
The Mean

Abstract: The aim of this study is to carry out performance qualifications of 2 processor-controlled dosing pumps for the production of mixed infusion solutions in a closed system.: Two dosing pumps have been qualified regarding their use: a processor-controlled dosing pump MediMix: The mean relative biases found with different products used for the qualifications of the two controllers were below the manufacturer’s specifications. When pumping operations were performed outside the manufacturer’s recommended ranges of volumes, relative bias remained below 10 %. Low relative bias (<3 %) and relative standard deviation (<1 %) were also found with routine controls (weight, osmolality, sodium concentration, potassium concentration) performed on test batches produced with the 12-pumps automated compounding device (ACD).: The single pump controller MediMix

Sodium and potassium in erythrocytes of adult and fetal goats

1960 ◽  
Vol 199 (6) ◽  
pp. 1174-1176 ◽  
Author(s):  
Jack N. Blechner
Keyword(s):  
Blood Cells ◽  
Potassium Concentration ◽  
Sodium Concentration ◽  
Maternal Blood ◽  
Red Cell ◽  
Fetal Blood ◽  
Oxygen Dissociation ◽  
The Mean ◽  
Dissociation Curves ◽  
Sodium And Potassium

Sodium and potassium concentrations in the erythrocytes of adult and fetal goats were estimated by flame photometry. In the fetus there is a higher potassium and a lower sodium concentration than in the adult. The mean fetal potassium concentration is 104.8 mEq/l. of red cells and the sodium 15.8; the maternal values are 68.4 and 35.4, respectively. Pregnancy does not appear to alter the sodium and potassium concentrations in adult goat erythrocytes. Moreover, the fetal levels show no change with advancing gestation, from the 52nd to the 142nd day. The sodium and potassium gradients between the red blood cells and the plasma in fetal blood are higher than in maternal blood and suggest the possibility of an increased energy expenditure by fetal erythrocytes. The findings lend support to the hypothesis that the ionic environment within the red cell is one of the factors contributing to the differences between the oxygen dissociation curves of fetal and maternal whole blood.

scholarly journals Untersuchungen über den Kaliumtransport bei Escherichia coli B / Potassium Transport in Escherichia coli B

1972 ◽  
Vol 27 (1) ◽  
pp. 62-67 ◽  
Author(s):  
G. Pilwat ◽  
U. Zimmermann
Keyword(s):  
Escherichia Coli ◽  
Potassium Concentration ◽  
Sodium Concentration ◽  
Extracellular Potassium ◽  
High Sodium ◽  
Extracellular Potassium Concentration ◽  
Intracellular Potassium ◽  
Extracellular Sodium ◽  
Escherichia Coli B ◽  
Intracellular Potassium Concentration

The stationary intracellular potassium concentration in E. coli B 525 has been studied as a function of the extracellular potassium and sodium concentrations.The ratio of extracellular to intracellular potassium concentration is shown to be a linear function of the extracellular potassium concentration if the extracellular sodium concentration is low (20 mmoles/l). In the case of high sodium concentration (100 mmoles/l) the ratio is independent of the extracellular potassium concentration if the potassium concentration is below 1,2 mmoles/l.In order to describe the distribution of potassium uniformly over the whole range of the extracellular potassium and sodium concentrations a carrier system with two sites has to be supposed.

Relation of Intracellular K+ and Steroidogenesis in Isolated Adrenal Zona Glomerulosa and Fasciculata Cells

1975 ◽  
Vol 49 (1) ◽  
pp. 13-26
Author(s):  
F. A. Mendelsohn ◽  
C. Mackie
Keyword(s):  
Potassium Concentration ◽  
Zona Glomerulosa ◽  
Zona Fasciculata ◽  
High Potassium ◽  
External Potassium ◽  
Glomerulosa Cells ◽  
Unit Gravity Sedimentation ◽  
Zona Glomerulosa Cells ◽  
Stimulation Of

1. Intracellular K+ content, water spaces and corticosterone output were measured in isolated zona glomerulosa and zona fasciculata-reticularis cell suspensions of rat adrenal cortex, after incubations in vitro under conditions designed to alter steroidogenesis. 2. Intracellular K+ of unpurified zona glomerulosa cells was not altered after stimulation of corticosterone output with serotonin. Similarly, with zona glomerulosa cells purified by unit gravity sedimentation, no change in intracellular K+ was detected after stimulation of steroidogenesis with serotonin or angiotensin II. 3. In high-potassium medium (final concentration 84 mmol/l), parallel increases in intracellular K+ and corticosterone output were observed with both unpurified and purified zona glomerulosa cells. However, a similar increase in intracellular K+ also occurred in high-potassium medium with zona fasciculata cells, whose steroid output is unresponsive to external potassium concentration ([K+]). 4. Ouabain at 10−5 mol/l depressed the intracellular [K+] of glomerulosa cells but did not alter basal or stimulated corticosterone output. Similar results were obtained with fasciculata cells. 5. Ouabain at 5×10−4 mol/l further depressed intracellular [K+] of glomerulosa cells and inhibited basal and stimulated corticosterone output. However, this concentration of ouabain also inhibited steroidogenesis in fasciculata cells. 6. These results demonstrate a variety of situations where changes in intracellular [K+] are dissociated from those in corticosterone output and indicate that intracellular [K+] cannot be the sole mechanism regulating steroidogenesis under these conditions.

DC Potentials of the Membranous Labyrinth

1958 ◽  
Vol 193 (1) ◽  
pp. 203-206 ◽  
Author(s):  
Catherine A. Smith ◽  
Hallowell Davis ◽  
Bruce H. Deatherage ◽  
Carl F. Gessert
Keyword(s):  
Guinea Pig ◽  
Potassium Concentration ◽  
Sodium Concentration ◽  
Resting Potential ◽  
High Potassium ◽  
Membranous Labyrinth ◽  
Cochlear Duct ◽  
Low Sodium ◽  
Dc Potential ◽  
Dc Potentials

The endolymphatic DC potentials were measured in the utricle, saccule and cochlear duct of the membranous labyrinth of the guinea pig and compared with potassium analyses of the endolymph. The average utricular potential was found to be +4 mv, the saccular potential +1 mv, and the cochlear potential +65 mv. The average potassium concentration of utricular endolymph was 139 mEq/l.; that from the cochlea was similar. The cochlear DC potential is approximately 70 mv higher than that of the vestibule (utricle and saccule), whereas the high potassium and low sodium concentration of endolymph is similar throughout. It is concluded that the endolymphatic resting potential of the internal ear is not correlated with the potassium or the sodium concentration of the endolymph.

Generation of transepithelial potentials by isolated perfused reptilian distal tubules

1978 ◽  
Vol 234 (3) ◽  
pp. F238-F246 ◽  
Author(s):  
K. W. Beyenbach ◽  
W. H. Dantzler
Keyword(s):  
Sodium Transport ◽  
Ethacrynic Acid ◽  
Potassium Concentration ◽  
Sodium Concentration ◽  
Garter Snake ◽  
High Sodium ◽  
Distal Tubules

Transepithelial potentials were measured in the most distal segments of garter snake (Thamnophis spp.) distal tubles perfused in vitro. The segments generated high lumen-negative potentials when sodium was in the lumen. The size of the potentials was a saturable function of luminal sodium concentrations between 0 and 32 mM. The potentials were stable with time only when sodium concentrations in the lumen were less than 30 mM. Perfusion with high sodium concentrations resulted in transient potentials. Stable potentials changed markedly when the lumen sodium concentration or the bath potassium concentration was altered suddenly, but they were independent of lumen potassium concentrations and bath sodium concentrations. Amiloride stimulated or inhibited the potentials, ouabain partially depressed them, and ethacrynic acid and cyanide inhibited them slowly and often irreversibly. We conclude that distal transepithelial potentials reflect sodium transport from lumen to bath across a tight asymmetric epithelium which differs from other sodium-transporting epithelia in that stable transepithelial potentials are maintained only with luminal sodium concentrations less than 30 mM.

Insulin action on membrane potential and glucose uptake: effects of high potassium

1985 ◽  
Vol 249 (1) ◽  
pp. E17-E25
Author(s):  
K. Zierler ◽  
E. M. Rogus ◽  
R. W. Scherer ◽  
F. S. Wu
Keyword(s):  
Membrane Potential ◽  
Insulin Action ◽  
Potassium Concentration ◽  
Electrical Potential ◽  
Cell Swelling ◽  
Electrical Potential Difference ◽  
High Potassium ◽  
High K ◽  
External Potassium ◽  
Stimulation Of

These experiments were designed to test the hypothesis that insulin-induced hyperpolarization is a link in the chain of events leading to stimulation of glucose transport. External potassium concentration, [K+]o, was increased by equimolar substitution of KCl for NaCl, a method known to cause cell swelling, and by substitution of [K+]o for [Na+]o with maintenance of constant [K+]o X [Cl-]o product, a method that does not cause cell swelling. When there was constant KCl product, even at 76.8 meq [K+]o insulin continued to hyperpolarize, although by only approximately 44% as much as in normal [K+]o, and insulin-stimulated 2-deoxyglucose uptake was only approximately 60% of that at normal [K+]o. With equimolar substitution of KCl for NaCl: electrical potential difference across cell membranes of surface fibers of rat caudofemoralis muscle decreased with logarithm [K+]o, in the presence or absence of insulin. Insulin-induced hyperpolarization decreased as [K+]o increased and disappeared at 36 mM [K+]o. The amount of insulin bound to its receptors in 1 h was not affected by [K+]o over the range studied. Insulin effects on membrane potential and on 2-deoxyglucose uptake, as both were altered by [K+]o, correlated well. As the probe moved in depth through the first six fibers there was stepwise decrease in depolarization in high [K+]o in the absence of insulin. Insulin hyperpolarized the deepest of these fibers, even when it did not hyperpolarize the outermost. The decrease in insulin-induced hyperpolarization as [K+]o increases is consistent with the hypothesis that insulin hyperpolarizes by decreasing the ratio PNa/PK.

CHROMATOGRAPHY OF THE 17-KETOGENIC STEROIDS IN THE DIAGNOSIS AND CONTROL OF CONGENITAL ADRENAL HYPERPLASIA

1960 ◽  
Vol XXXIII (II) ◽  
pp. 230-250 ◽  
Author(s):  
Eileen E. Hill
Keyword(s):  
Congenital Adrenal Hyperplasia ◽  
List Type ◽  
Adrenal Hyperplasia ◽  
Normal Children ◽  
Paediatric Practice ◽  
The Mean ◽  
Cortisone Therapy ◽  
And Control ◽  
Clinical Problems ◽  
Stimulation Of

ABSTRACT A method for the fractionation of the urinary 17-ketogenic steroids with no oxygen grouping at C11 and those oxygenated at C11, is applied to the clinical problems of congenital adrenal hyperplasia. In normal children the mean ratio of the non-oxygenated to oxygenated steroids is 0.24. In childrern with congenital adrenal hyperplasia the ratio is 2.3. The reason for this difference in ratio is discussed. The changes in ratio found under stimulation of the adrenal gland with exogenous or endogenous corticotrophin and the suppression with cortisone therapy are studied. This test can be applied to isolated samples of urine, a major advantage in paediatric practice, and can be carried out in routine laboratories. It is found to be reliable in the diagnosis and sensitive in the control of congenital adrenal hyperplasia.

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