Effect of selected hypotensive drugs on the rate of sodium outflow through lymphocyte cell membranes and sodium lymphocyte levels in patients with primary hypertension]

Sodium outflow rate through lymphocyte cell membranes was investigated in patients with primary hypertension with disturbed and normal sodium transport through these membranes during the treatment with hydrochlorothiazide, propranolol, clonidine or verapamil. It was found that hydrochlorothiazide increases total outflow rate of sodium ions through lymphocyte cell membranes and decreases its concentration in the lymphocytes but does not affect ouabain-dependent sodium outflow rate. It was also noted that verapamil increases total and ouabain-dependent sodium outflow rate through lymphocyte cellular membranes and decreases its lymphocyte levels.     

Sodium outflow rate through lymphocyte cell membranes, serum levels of sodium, potassium, aldosterone, total catecholamines, 6-keto- PGF2alpha and plasma renin activity in patients with primary arterial hypertension treated with captopril]

Sodium ions outflow rate through lymphocyte membranes, serum sodium, potassium, aldosterone, total catecholamines and 6-keto-PGE alpha levels, and plasma renin activity were studied in patients with mild hypertension associated with low and hugh plasma renin activity treated with captopril in a single dose of 12.3 mg and after the treatment with daily doses of 12.5 mg and 25 mg for 3 days. It was found, that captopril in hypertensive patients with high plasma renin activity decreases both systolic and diastolic blood pressure, decelerates heart rate, and decreases serum total catecholamines and plasma renin activity. Sodium ions outflow rate and serum sodium, potassium, aldosterone, and 6-keto-PGE alpha remain unchanged. Captopril in hypertensive patients with low plasma renin activity. The remaining parameters are unchanged. Moreover, it was noted that serum 6-keto-PGE alpha levels are lower in hypertensive patients with low plasma renin activity.     

Effect of normal and high sodium diet on the sodium outflow rate through lymphocyte cell membrane and lymphocyte sodium level in patients with mild primary hypertension]

An effect of normal and high sodium diet on the rate of sodium outflow rate through lymphocyte cell membranes was evaluated in patients with mild primary hypertension with normal value of Na+ outflow rate index. It was found that high sodium value does not increase the value of this index in patients with mild primary hypertension but it does increase Na+ levels in lymphocytes. However, high sodium diet increases the value of this parameter in patients with mild primary hypertension with normal value of Na+ outflow rate through lymphocyte cell membranes and does not effect sodium level in the lymphocytes. According to the authors, high sodium diet in patients with normal renal function does not affect serum sodium levels.     

Sodium outflow rate through lymphocyte cellular membranes in women with arterial hypertension caused by pregnancy and in health pregnant women]

Ouabain- and furosemide-dependent rate of sodium outflow through lymphocytes cellular membranes was measured in both healthy pregnant women and those with arterial blood hypertension caused by pregnancy. It was shown, that ouabain-dependent sodium outflow rate is decreased in healthy women in the I, II, and III trimester of pregnancy, while in women with arterial hypertension in the III trimester. No difference in sodium outflow rate both total and furosemide-dependent in healthy pregnant women during the I, II and III trimester, and in pregnant women with arterial hypertension due to pregnancy in the III trimester was noted. No difference in sodium outflow rate was noted in pregnant women with the arterial hypertension due to pregnancy with familial history of the hypertension.     

The kinetics of sodium extrusion in striated muscle as functions of the external sodium and potassium ion concentrations

After a 20 min initial washout, the rate of loss of radioactively labeled sodium ions from sodium-enriched muscle cells is sensitive to the external sodium and potassium ion concentrations. In the absence of external potassium ions, the presence of external sodium ions increases the sodium efflux. In the presence of external potassium ions, the presence of external sodium ions decreases the sodium efflux. In the absence of external potassium ions about one-third of the Na⁺ efflux that depends upon the external sodium ion concentration can be abolished by 10^-5 M glycoside. The glycoside-insensitive but external sodium-dependent Na⁺ efflux is uninfluenced by external potassium ions. In the absence of both external sodium and potassium ions the sodium efflux is relatively insensitive to the presence of 10^-5 M glycoside. The maximal external sodium-dependent sodium efflux in the absence of external potassium ions is about 20% of the magnitude of the maximal potassium-dependent sodium efflux. The magnitude of the glycoside-sensitive sodium efflux in K-free Ringer solution is less than 10% of that observed when sodium efflux is maximally activated by potassium ions. The inhibition of the potassium-activated sodium efflux by external sodium ions is of the competitive type. Reducing the external sodium ion concentration displaces the plots of sodium extrusion rate vs. [K]_o to the left and upwards.     

Effect of Na+ and K+ Ions on the Initial Crystallization Process of Lysozyme in the Presence of D2O and H2O

In the initial stage of the crystallization of egg-white lysozyme, monomeric lysozyme aggregated rapidly to form a nucleus in the presence of high salt concentrations. In the present studies, we examined the initial aggregation process of lysozyme (initial crystallization process of lysozyme) in D₂O/H₂O with sodium ions or potassium ions, and investigated the relationship between the surface hydrophobicity and the aggregation rate of lysozyme. The effect of sodium ions or potassium ions on the initial aggregation process of lysozyme in D₂O was clearly different from H₂O. The initial aggregation rate of lysozyme in H₂O was slower than in D₂O. In the case of H₂O, the initial aggregation rate was about the same in both ions. But in the case of D₂O, the initial aggregation rate was affected by the ion species and the value was lower in potassium ions than in sodium ions. These results suggest that the interaction between lysozyme molecules is stronger in D₂O than in H₂O. Furthermore, sodium ions have a stronger effect on the interaction than potassium ions in the case of D₂O. There was a good correlation among the initial aggregation rate, surface hydrophobicity, and ζ-potential of lysozyme. The hydrophobic interaction may be an important active force in the initial aggregation process of lysozyme.     

Effect of Na+ and K+ Ions on the Initial Crystallization Process of Lysozyme in the Presence of D2O and H2O

In the initial stage of the crystallization of egg-white lysozyme, monomeric lysozyme aggregated rapidly to form a nucleus in the presence of high salt concentrations. In the present studies, we examined the initial aggregation process of lysozyme (initial crystallization process of lysozyme) in D₂O/H₂O with sodium ions or potassium ions, and investigated the relationship between the surface hydrophobicity and the aggregation rate of lysozyme. The effect of sodium ions or potassium ions on the initial aggregation process of lysozyme in D₂O was clearly different from H₂O. The initial aggregation rate of lysozyme in H₂O was slower than in D₂O. In the case of H₂O, the initial aggregation rate was about the same in both ions. But in the case of D₂O, the initial aggregation rate was affected by the ion species and the value was lower in potassium ions than in sodium ions. These results suggest that the interaction between lysozyme molecules is stronger in D₂O than in H₂O. Furthermore, sodium ions have a stronger effect on the interaction than potassium ions in the case of D₂O. There was a good correlation among the initial aggregation rate, surface hydrophobicity, and -potential of lysozyme. The hydrophobic interaction may be an important active force in the initial aggregation process of lysozyme.     

Diabetes-induced changes of nitric oxide influence on the cardiovascular action of secretin

The modulation by condition of the lack or the excess of nitric oxide (NO) on cardiovascular action of secretin in diabetic rats was investigated. In vitro the isolated heart function and in vivo, the systolic (SBP), diastolic (DSP) blood pressure and heart rate (HR) were measured. Secretin evoked inotropic positive effect and increased coronary outflow (CO), in vivo did not increase systemic pressure and the highest dose of the peptide increased the heart rate. NO synthase inhibitor, N(G) nitro-L-arginine methyl ester (L-NAME) deeply increased the systemic pressure and in vitro decreased coronary outflow. L-arginine and sodium nitroprusside (SNP) did not influence the isolated heart function and in vivo decreased the systemic pressure. L-NAME preserved the inotropic positive effect of secretin and the increase of the coronary outflow. In vivo co-administration of L-NAME+secretin evoked hypotensive effect and abolished the increase of the heart rate after the highest dose of the peptide. L-arginine abolished inotropic positive effect of the peptide and the increase of coronary outflow. In vivo co-administration of these substances caused hypotension and attenuated the increase of the heart rate after the highest dose of secretin. Co-injection of SNP and secretin preserved the inotropic effect of secretin and abolished the increase of the coronary outflow. In vivo infusion of SNP+secretin evoked hypotension and similarly to L-arginine, SNP abolished tachycardia induced by the highest dose of secretin. Both the lack and the excess of nitric oxide changed the cardiovascular action of secretin in diabetic rats.     

Water extrusion in the trap bladders ofUtricularia vulgaris

In the trap bladder ofUtricularia vulgaris, a sudden expansion (convex bladder) by opening of the entrance door upon stimulus was followed by slow decreases in bladder width and internal hydrostatic pressure. The decreases were caused by continuous water outflow from bladder lumen. The bladder reached initial resetting state (concave bladder) in about 30 min. The internal pressure reduced to 0.86 bar. This reduction was inhibited by application of sodium azide in the bladder lumen. The total water outflow for 30 min from a bladder, measured using a glass capillary inserted in the bladder, was 630 nl: the rate was 21 nl/min. This rate was also inhibited by sodium azide. In bladder resetting under paraffin oil, it was observed that water emerges from near the free edge of the trap door. From light and electron microscopic observations of the entrance region, it is concluded that the inlet of water outflow is the bifid trichomes which stand on the inner surface of the bladder near the entrance, and the outlet is the outer and middle zones of the pavement epithelium, or threshold, against which the free edge of the door rests.     

Quantitative assessment of the blood supply to the focus of myocardial ischemia in dogs in pharmacological research

The method of quantitative evaluation of blood supply of ischemic myocardial focus was suggested, it consists in measuring the venous blood outflow from the ischemic area with the help of ultrasonic technique. In experiments on anaesthetized dogs with coronary artery occlusion the rate of blood flow and dynamics of its changes in the ischemic focus were determined. It was shown that sodium oxybutyrate improves the blood supply of myocardial ischemic area.     

Resolution of Pump and Leak Components of Sodium and Potassium Ion Transport in Human Erythrocytes

Further support for the pump-leak concept was obtained. Net transport was resolved into pump and leak components with the cardiac glycoside, ouabain. The specificity of ouabain as a pump inhibitor was demonstrated by its ineffectiveness when the pump was already inhibited by lack of one of the three pump substrates, sodium ion, potassium ion, or adenosine triphosphate. In the presence of ouabain the rates of passive transport of sodium and potassium ions changed almost in proportion to changes in their extracellular concentrations when one ion was exchanged for the other. In the presence of ouabain and at the extracellular concentrations which produced zero net transport, the ratio of potassium ions to sodium ions was 1.2-fold higher inside the cells than outside. This finding was attributed to a residual pump activity of less than 2% of capacity. The permeability to potassium ions was 10% greater than the permeability to sodium ions. A test was made of the independence of pump and leak. Conditions were chosen to change the rate through each pathway separately or in combination. When both pathways were active, net transport was the sum of the rates observed when each acted separately. A ratio of three sodium ions pumped outward per two potassium ions pumped inward was confirmed.     

D2O as a modifier of ionic specificity of Na, K-ATPase

Effect of heavy water D2O on the rate of hydrolysis of ATP and pNPP by Na,K-ATPase was studied. Heavy water of high concentration inhibits the rate of ATPase reaction in all the studied ratios of the ions Na/K at constant ionic strength 150 mM. Activation of the enzyme was observed in the solution with low concentration of heavy water (less than 5%). The value of isotope effects depended on the ratio between sodium and potassium ion concentrations in the medium. At low temperature no activation of the enzyme with heavy water in low concentration was observed. Substitution of usual water for the heavy one was accompanied by a decrease of apparent constants of enzyme activation with sodium and potassium ions. During pNPP hydrolysis with Na,K-ATPase an increase of reaction rate in the medium with heavy water was observed. Substitution of potassium ions by cesium resulted in an increase of isotope effects during ATP and pNPP hydrolysis. Analysis of isotope effects in terms of the molecular model of sodium pump proposed permits a conclusion that the isotope effects of heavy water are explained by its influence as a solvent, the binding centres of potassium and sodium ions are localized in different regions of the enzyme differing in physico-chemical properties. The structure of sodium centres is controlled by hydrogen bonds, and of potassium ones--by hydrophobic interactions; the transport of ions by the enzyme is accompanied by dehydration of ions.     

Sodium periodate stimulation of human lymphocytes : A comparison between normal and chronic lymphocytic leukemia lymphocytes

Lymphocytes from healthy donors and from patients with chronic lymphocytic leukemia (CLL) were stimulated to divide with sodium periodate. The time of maximal response of normal lymphocytes to sodium periodate (NaIO₄) was earlier than that observed to phytohemagglutinin (PHA), but the magnitude was lower. In comparison, CLL lymphocytes responded to NaIO₄ more extensively and earlier than to PHA.     

The Effect of Deleterious Concentrations of Mercury on the Photosynthesis and Growth of Chlorella pyrenoidosa

The effect of mercury ions on the photosynthesis and growth of Chlorella pyrenoidosa in a balanced medium has been studied and compared with the effect of copper. In many ways Hg treated algae behave like algae treated with Cu in concentrations of the same molarity, but important deviations occur. Hg acts at a lower and in a more narrow range of concentrations than does Cu due to a more specific binding. The depressing effect of Hg is not counteracted by other cations such as potassium and sodium, and iron has only a slight effect. Cell division is stopped after Hg addition and there is no accumulation of assimilation products. On the contrary the cells become pale yellow. Preliminary studies indicate a light-independent leakage in the cytoplasmatic membrane leading to an outflow of potassium ions. This is the primary action of both Hg and Cu poisoning, but the leakage does not seem to be correlated with the decrease of photosynthesis. After a lapse of time — dependent on the mercury/cell concentration ratio — a detoxication takes place probably due to the binding of Hg to “insensitive sites” in the cells. Probable mechanisms for the action of Hg on photosynthesis and growth are discussed.     

Factors regulating the functioning of the in vitro perfused aglomerular kidney of the anglerfish,Lophius piscatorius L.

• 1.1. Kidneys of Lophius were perfused from the renal portal vein with a Ringer's solution.
• 2.2. Mammalian and piscine neurohypophysial hormones (in doses of 20–500 ng/kg body wt) did not affect the rate of urine production or the urinary concentration of inorganic ions.
• 3.3. The rate of urine production and the urinary concentration of magnesium and sodium ions varied with the concentration of magnesium in the perfusate.
• 4.4. The rate of urine production was positively correlated with urine magnesium concentration (r = 0.83 ± 0.04) and negatively correlated with that of sodium (r = −0.40).
• 5.5. The urinary concentration of sodium ions varied inversely with that of magnesium ions (r = −0.89).
• 6.6. Ouabain treatment (0.1–0.8 mM/l) reduced the rate of urine production by over 60% and altered, to varying extents, the pattern of electrolyte excretion. A simple model for the mode of formation of urine by the aglomerular kidney, based on the present results and other observations is suggested.

     

On the effect of ammonium and lithium ions upon frog nerve deprived of sodium

An analysis has been made of the effect of ammonium and of lithium ions upon frog nerve deprived of sodium. Ammonium ions cannot substitute for sodium ions and restore the excitability of the nerve fibers; nor can they increase the L fraction of the membrane potential and the efficiency of the nerve reaction. Certain observations, however, indicate that the presence of ammonium ions outside the nerve fibers may delay the development of inexcitability in a sodium-free medium of nerve fibers restored by a moderate amount of sodium ions. Lithium ions can substitute for sodium and restore to nerve fibers of the A and C groups the ability to conduct impulses; the effect upon B fibers has not been investigated. Lithium cannot substitute for sodium in the role that sodium plays in the creation of the L fraction and in the establishment of the nerve reaction. In this respect lithium and sodium have opposite effects. This fact establishes an important difference between the two physiological responses that the nerve fibers can produce, the nerve impulse and the nerve reaction. With untreated nerve the depolarization of nerve by lithium ions at high concentrations is preceded by a phase of hyperpolarization; with nerve deprived of sodium the depolarization begins without delay.     

The transport of Na+ and K+ ions through phospholipid bilayers mediated by the antibiotics salinomycin and narasin studied by 23Na- and 39K-NMR spectroscopy

Addition of the ionophoric antibiotics salinomycin or narasin to preparations of large unilamellar vesicles made from egg yolk phosphatidylcholine in sodium or potassium chloride solutions gives rise to dynamic effects in the 23Na- and 39K-NMR spectra. The dynamic spectra arise from the ionophore-mediated transport of the metal ions through the membrane. The kinetics of the transport are followed as a function of the concentrations of ionophore and the metal ion and are compatible in all cases with a model in which one ionophore molecule transports one metal ion. For both ionophores the transport of potassium ions is appreciably faster than that of sodium and in both cases the rate-limiting step for sodium transport is dissociation of the ionophore-metal complex. Assuming dissociation to be rate limiting in all four cases it is shown that the transport rate differences between the pairs of complexes of each metal arise solely from differences in the rates of formation. The stability constants for ionophore-metal complex formation in the membrane/water interface are evaluated.     

Sclerotherapy of craniofacial venous malformations: complications and results

Of all vascular anomalies, venous malformations are the most common, and they have a propensity for the head and neck. The authors retrospectively analyzed 40 patients with craniofacial venous malformations who underwent sclerotherapy between October of 1994 and June of 1996 to determine (1) the results of sclerotherapy with ethanol and/or sodium tetradecyl sulfate, (2) the types and rate of complications, and (3) whether outcome correlated with age, sex, location, size, tissues involved, morphology (lobular or varicose), venous outflow, or number of sclerotherapy sessions. The authors also reviewed the results after sclerotherapy and contour resection (n = 18). Comparisons between the results with ethanol and sodium tetradecyl sulfate and between sclerotherapy alone and sclerotherapy and resection combined were not done. The study was composed of three parts. They were (1) a review of records and imaging studies, (2) a panel evaluation of pretreatment and posttreatment photographs, and (3) a questionnaire that determined the patient's (or parent of the patient's) impression of therapy. Interrater and intrarater agreement were analyzed. Sclerotherapy was performed in an angiographic suite, under general anesthesia, using absolute ethanol and/or sodium tetradecyl sulfate. Complications of the treatment included acute blistering (50 percent), hemoglobinuria (28 percent), deep ulceration (13 percent), and nerve injury (7.5 percent). Two patients suffered transient facial paresis, and one had permanent unilateral vocal cord paralysis. Thirty patients (75 percent) were rated as having marked improvement or as being cured by all three members of the panel; 10 patients (25 percent) were rated as having no change or only slight improvement by one or more members of the panel. Interrater reliability was moderately positive, and intrarater reliability was highly positive. Thirty-seven patients or parents of patients (93 percent) responded to the questionnaire. The outcome was considered to be marked improvement or cured in 28 patients (76 percent), and nine respondents (24 percent) described only minor improvement or no change. Logistic regression analysis revealed that only male sex and number of sclerotherapeutic procedures were significant multivariate predictors of outcome. Size, location, tissues involved, morphology, or venous outflow were not determinant. In conclusion, sclerotherapy with ethanol or sodium tetradecyl sulfate is an effective and safe treatment for craniofacial venous malformations. Often, sclerotherapy has to be repeated. For extensive perioral malformations, combined sclerotherapy and resection give the best result.     

The influence of potassium- and sodium-free solutions on sodium efflux from squid giant axons

The sensitivity of sodium efflux to the removal of potassium ions from the external solution and the change in sodium efflux occurring when sodium ions are also removed were observed to be related. When Tris was used to replace external sodium ions, increases in sodium efflux were always observed whether the sensitivity of sodium efflux to external potassium ions was weak or strong. Greater percentage increases in sodium efflux occurred, however, the greater the sensitivity of sodium efflux to external potassium ions. When lithium ions were used to replace external sodium ions, increases in sodium efflux occurred if the sensitivity of efflux to external potassium ions was strong whereas decreases in sodium efflux took place if the sensitivity of efflux to external potassium ions was weak. Intermediate sensitivities of efflux to external potassium resulted in no change in efflux upon substitution of lithium ions for external sodium ions. In the presence of 10^-5 M ouabain, substitution of Tris for external sodium ions always resulted in a small decrease in sodium efflux. The data can be described in terms of a model which assumes the presence of efflux stimulation sites that are about 98% selective to potassium ions and about 2% selective to sodium or lithium ions.