THE EFFECTS OF OESTROGEN AND PROGESTERONE ON THE SODIUM AND POTASSIUM CONCENTRATIONS OF RAT UTERINE FLUID

1970 ◽  
Vol 47 (3) ◽  
pp. 309-319 ◽  
Author(s):  
C. A. B. CLEMETSON ◽  
V. R. MALLIKARJUNESWARA ◽  
M. M. MOSHFEGHI ◽  
J. J. CARR ◽  
J. H. WILDS
Keyword(s):  
Membrane Potential ◽  
Potassium Concentration ◽  
Ovarian Hormones ◽  
Pronounced Change ◽  
Sodium Potassium ◽  
Delayed Implantation ◽  
Uterine Fluid ◽  
Sodium And Potassium

SUMMARY Studies of the electrolyte concentrations of uterine fluid samples from spayed rats, after injection of ovarian hormones, showed a much higher potassium concentration after treatment with oestrogen (42·3 m-equiv./1.) than with progesterone (20·8 m-equiv./1.). There was an even more pronounced change in the sodium: potassium ratio, which fell from 7·3 to 1 with progesterone to 2·5 to 1 with oestrogen. These findings are supported by recalculation of the results of Heap & Lamming (1962). It is suggested that these changes in the Na+ and K+ concentrations of uterine fluid produce changes in the membrane potential of the endometrium which could account for delayed implantation of the negatively charged blastocyst under progesterone dominance and implantation under oestrogen dominance.

THE ROLE OF ELECTROLYTES OF THE ENDOMETRIUM AND UTERINE FLUID DURING DELAYED IMPLANTATION IN RATS

1973 ◽  
Vol 59 (3) ◽  
pp. 461-464 ◽  
Author(s):  
B. S. SETTY ◽  
MAN MOHAN SINGH ◽  
S. R. CHOWDHURY ◽  
AMIYA B. KAR
Keyword(s):  
Electrolyte Concentration ◽  
Delayed Implantation ◽  
Uterine Fluid ◽  
Sodium And Potassium

SUMMARY Sodium and potassium levels were determined in the rat endometrium and uterine washings during normal and 'delayed' implantation. Both endometrium and uterine washings of normal rats differed from those of 'delayed' animals in their electrolyte concentrations. A dose of oestradiol dipropionate (1 μg/rat) capable of inducing implantation in 'delayed' rats (ovariectomized and maintained on progesterone) did not evoke any significant changes in electrolyte concentration of either the endometrium or uterine washings. These findings are discussed in the light of a hypothesis regarding delayed implantation in rats.

The Excretion of Sodium, Potassium and Water by the Malpighian Tubules of the Stick inSect, Dixippus Morosus (Orthoptera, Phasmidae)

1955 ◽  
Vol 32 (1) ◽  
pp. 200-216 ◽  
Author(s):  
J. A. RAMSAY
Keyword(s):  
Potassium Concentration ◽  
Physiological Activity ◽  
Liquid Paraffin ◽  
Stick Insect ◽  
Proximal Region ◽  
Malpighian Tubules ◽  
Electrochemical Gradient ◽  
Sodium Potassium ◽  
Single Tubules ◽  
Sodium And Potassium

1. The excretion of sodium, potassium and water by the Malpighian tubules of the stick insect has been further studied in preparations of single tubules isolated in droplets of medium under liquid paraffin. 2. There is some gradation of physiological activity along the length of the superior tubule. Sodium, potassium and water are secreted into the tubule at all levels, but the sodium/potassium ratio is greater in the proximal region. 3. The proximal and middle regions of the inferior tubule have not been shown to differ in any way from the corresponding regions of the superior tubule. The distal dilatation has quite different properties and does not produce urine. 4. The rate of urine flow increases markedly as the potassium concentration in the medium is increased; the corresponding effect of sodium is barely detectable. 5. Sodium, like potassium, can be actively transported against an electrochemical gradient, and does not appear to compete with potassium in the secretory mechanism. 6. The rates of secretion of sodium and potassium vary in direct proportion to the respective concentrations of these ions in the medium. The rate of secretion of potassium is more than ten times greater than that of sodium.

Sodium dependence of the thyrotrophin-induced depolarization in cultured porcine thyroid cells

1986 ◽  
Vol 108 (2) ◽  
pp. 225-230 ◽  
Author(s):  
T. A. Hambleton ◽  
J. R. Bourke ◽  
G. J. Huxham ◽  
S. W. Manley
Keyword(s):  
Membrane Potential ◽  
Action Potentials ◽  
Potassium Concentration ◽  
Sodium Current ◽  
Resting Membrane Potential ◽  
Thyroid Cell ◽  
Free Medium ◽  
Thyroid Cells ◽  
Voltage Dependent ◽  
Sodium And Potassium

ABSTRACT Cultured porcine thyroid cells exhibit a resting membrane potential of about − 73 mV and depolarize to about − 54 mV on exposure to TSH. The depolarizing response to TSH was preserved in a medium consisting only of inorganic salts and buffers, but was abolished in sodium-free medium, demonstrating dependence on an inward sodium current. Increasing the potassium concentration of the medium resulted in a reduction in the resting membrane potential of 60 mV per tenfold change in potassium concentration, and a diminished TSH response. A hyperpolarizing TSH response was observed in a sodium- and bicarbonate-free medium, indicating that a hyperpolarizing ion current (probably carried by potassium) was also enhanced in the presence of TSH. Tetrodotoxin blocked the TSH response. We conclude that the response of the thyroid cell membrane to TSH involves increases in permeability to sodium and potassium, and that the thyroid membrane ion channels bear some similarity to the voltage-dependent sodium channels of excitable tissues, despite the absence of action potentials in the thyroid. J. Endocr. (1986) 108, 225–230

THE INFLUENCE OF OVARIAN HORMONES ON SOME CHEMICAL CONSTITUENTS OF THE UTERINE WASHING OF THE RAT AND RABBIT

1962 ◽  
Vol 25 (1) ◽  
pp. 57-68 ◽  
Author(s):  
R. B. HEAP ◽  
G. E. LAMMING
Keyword(s):  
Replacement Therapy ◽  
Reproductive Cycle ◽  
Luteal Phase ◽  
Chemical Constituents ◽  
Ovarian Hormones ◽  
Sodium Potassium ◽  
Uterine Fluid ◽  
Intact Rats

SUMMARY Uterine washings were recovered from intact rats and rabbits at different stages of the reproductive cycle and from spayed animals, some of which were treated with ovarian hormones. The washings were analysed for several chemical constituents. In the rat at oestrus there was a marked increase in both the amount of uterine fluid and in several chemical constituents of the uterine washing (sodium, potassium, nitrogen, carbohydrate). Similar significant increases were shown in spayed rats treated with oestradiol. The uterine washing from the rabbit contained significantly greater amounts of potassium, phosphorus, nitrogen and carbohydrate during the luteal phase (pseudopregnancy) than at oestrus. These increases were confirmed in spayed groups treated with progesterone alone or with oestradiol + progesterone and also with oestradiol replacement therapy which was probably caused by excessive dosage. These findings showed that ovarian hormones affected the composition of uterine washings and their significance is discussed.

The Composition of Haemolymth in Aquatic Insects

1962 ◽  
Vol 39 (3) ◽  
pp. 325-344 ◽  
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Amino Acids ◽  
Aquatic Insects ◽  
Free Amino Acids ◽  
Free Amino ◽  
Inorganic Phosphate ◽  
Potassium Concentration ◽  
Chloride Concentration ◽  
Sodium Concentration ◽  
Sodium Potassium ◽  
Sodium And Potassium

1. Analyses were made of haemolymph obtained from aquatic representatives of nine major orders in the Insecta. 2. In the Odonata, Plecoptera, Ephemeroptera and Hemiptera-Heteroptera, the sodium concentration is relatively high and the potassium concentration is low. The chloride concentration is relatively high, but it never exceeds the sodium concentration. 3. In the Neuroptera, Coleoptera, Trichoptera and Diptera the sodium concentration is relatively high and the potassium concentration is low. In Nymphula nymphaeta (Lepidoptera) both the sodium and potassium concentrations are low. In all of these endopterygotes the chloride concentration is relatively low. 4. There is no correlation between diet and the sodium/potassium ratio in haemolymph of aquatic insects. 5. The problem of cation-anion balance is discussed. It is suggested that free amino acids contribute little to the anion pool. Bicarbonate and phosphate, largely as inorganic phosphate, contribute a small amount to the anion pool in exopterygotes. Phosphate contributes considerably more to the anion pool in some endopterygotes. Nevertheless, in all of the insects investigated, there is a deficit of anions. This deficit is usually greater in the endopterygotes. 6. The calculated osmotic activities of the known ions and free amino acids are less than the observed osmotic activities of haemolymph. It is inferred that non-amino organic acids must be present. Preliminary investigations indicate that non-amino acids are present in the concentrations required to account for both the osmotic and the anion deficits.

THE SODIUM AND POTASSIUM CONCENTRATIONS IN THE UTERINE FLUID OF THE RAT AT THE TIME OF IMPLANTATION

1972 ◽  
Vol 54 (3) ◽  
pp. 417-423 ◽  
Author(s):  
C. A. B. CLEMETSON ◽  
J. K. KIM ◽  
V. R. MALLIKARJUNESWARA ◽  
J. H. WILDS
Keyword(s):  
Blood Serum ◽  
Marked Reduction ◽  
Potassium Concentration ◽  
Normal Pregnancy ◽  
Uterine Horn ◽  
Fluid Volume ◽  
Low Doses ◽  
Uterine Fluid ◽  
The Mean ◽  
Sodium And Potassium

SUMMARY Rat uterine fluid Na+ and K+ concentrations were calculated from the ratio of the Na+ and K+ concentrations in uterine washings, on the assumption that the sum of Na+ and K+ (mequiv./l) is the same in blood serum and in uterine fluid. Uterine fluid volumes were likewise calculated from the total quantity of Na+ and K+ washed out of the uterine horn. The mean uterine fluid volume was 7·6 μl per horn and the mean potassium concentration was 45·8 mequiv./l on day 6 of normal pregnancy. Both oophorectomy alone on day 2 and oophorectomy followed by daily injections of progesterone, cause a marked reduction of the uterine fluid volume on day 6 of pregnancy. Oophorectomy on day 2 caused a significant reduction in the uterine fluid K+ concentration. Administration of high and low doses of progesterone after oophorectomy on day 2 of pregnancy resulted in uterine fluid potassium concentrations higher and lower, respectively, than the normal day 6 fluid. It is postulated that a high uterine fluid K+ concentration is essential for blastocyst-endometrial contact preceding implantation and that this may be significant with regard to certain types of delayed implantation.

scholarly journals Influence of Erythrocytes on Direct Potentiometric Determination of Sodium and Potassium

1983 ◽  
Vol 20 (2) ◽  
pp. 116-120 ◽  
Author(s):  
P Bijster ◽  
H L Vader ◽  
C L J Vink
Keyword(s):  
Whole Blood ◽  
Potassium Concentration ◽  
Reference Electrode ◽  
Sodium Concentration ◽  
General Phenomenon ◽  
Liquid Junction ◽  
Direct Potentiometry ◽  
The Difference ◽  
Sodium And Potassium

We have shown that the sodium concentration in whole blood measured by direct potentiometry is higher than in plasma. The ‘erythrocyte-effect’, already described by Siggaard Andersen, is most pronounced for instruments equipped with a reference electrode with an open static liquid junction and is thus a general phenomenon. Instruments with a modified liquid junction show less interference. The same phenomenon appears for the determination of the potassium concentration, although the difference between whole blood and plasma, when measured with instruments equipped with a modified liquid junction, can be neglected in practice.

scholarly journals Changes in the Membrane Permeability of Frog's Sartorius Muscle Fibers in Ca-Free EDTA Solution

1963 ◽  
Vol 47 (2) ◽  
pp. 379-392 ◽  
Author(s):  
H. Kimizuka ◽  
K. Koketsu
Keyword(s):  
Membrane Permeability ◽  
Chloride Content ◽  
Chloride Ions ◽  
Sartorius Muscle ◽  
Constant Field ◽  
Sodium Influx ◽  
Sodium Potassium ◽  
Edta Solution ◽  
Frog Sartorius ◽  
Sodium And Potassium

The changes in the membrane permeability to sodium, potassium, and chloride ions as well as the changes in the intracellular concentration of these ions were studied on frog sartorius muscles in Ca-free EDTA solution. It was found that the rate constants for potassium and chloride efflux became almost constant within 10 minutes in the absence of external calcium ions, that for potassium increasing to 1.5 to 2 times normal and that for chloride decreasing about one-half. The sodium influx in Ca-free EDTA solution, between 30 and 40 minutes, was about 4 times that in Ringer's solution. The intracellular sodium and potassium contents did not change appreciably but the intracellular chloride content had increased to about 4 times normal after 40 minutes. By applying the constant field theory to these results, it was concluded that (a) PCl did not change appreciably whereas PK decreased to a level that, in the interval between 10 and 40 minutes, was about one-half normal, (b) PNa increased until between 30 and 40 minutes it was about 8 times normal. The low value of the membrane potential between 30 and 40 minutes was explained in terms of the changes in the membrane permeability and the intracellular ion concentrations. The mechanism for membrane depolarization in this solution was briefly discussed.

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