Significant Differences In Na Research Articles

Diagnosis of drowning: Electrolytes and total protein in sphenoid sinus liquid

In this study, electrolyte (sodium (Na), chlorine (Cl), and magnesium (Mg)) and total protein (TP) concentrations and volume of liquid in the sphenoid sinus were examined to determine their usefulness to elucidate whether drowning occurred in freshwater or seawater. We examined 68 cases (seawater drowning group: 27 cases, freshwater drowning group: 21 cases, non-drowning group: 20 cases). There was a significant difference in Na, Cl, Mg, and TP concentrations of liquid in the sphenoid sinus among the three groups (seawater drowning, freshwater drowning, and non-drowning groups). To distinguish freshwater drowning from seawater drowning, Na, Cl, and Mg concentrations of liquid in the sphenoid sinus might serve as useful indicators.

NaCl-Induced Changes of Ion Fluxes in Roots of Transgenic Bacillus thuringiensis (Bt) Cotton (Gossypium hirsutum L.)

Bacillus thuringiensis (Bt) cotton is grown worldwide, including in saline soils, but the effect of salinity on ion fluxes of Bt cotton remains unknown. Responses of two transgenic Bt cotton genotypes (SGK321 and 29317) and their corresponding receptors, Shiyuan 321 (SY321) and Jihe 321 (J321), to 150 mmol L−1 NaCl stress were studied in a growth chamber. The root dry weight of SGK321 and 29317 under NaCl treatment was decreased by 30 and 31%, respectively. However, their corresponding receptor cultivars SY321 and J321 were less affected (19 and 24%, respectively). The root length and surface area of the Bt cultivars were significantly decreased relative to their receptors under salt stress. NaCl treatment significantly increased Cry1Ac mRNA transcript levels in SGK321 and 29317 but did not affect Bt protein content in leaves or roots of either cultivar at 1 and 7 d after NaCl treatment. Fluxes of Na+, K+, and H+ in roots were investigated using the scanning ion-selective electrode technique. Both mean K+ efflux rate and transient K+ efflux of the Bt cultivars increased four-fold compared to their corresponding receptors when exposed to salinity stress. There were no significant differences in Na+ efflux between Bt and non-Bt cottons. Furthermore, the Na+ contents in roots and leaves of all genotypes dramatically increased under salt stress, whereas K+ contents decreased. Our results suggested that Bt cotton cultivars are more sensitive to salt stress than their receptor genotypes.

Comparative Study of Hemodynamics Electrolyte and Metabolic Changes During Prone and Complete Supine Percutaneous Nephrolithotomy

BackgroundNowadays Percutaneous Nephrolithotomy (PCNL) is performed in prone and supine positions. Physiologic solutions should be used to irrigate during PCNL. Irrigation can cause hemodynamic, electrolyte and acid-base changes during PCNL.ObjectivesThe current study aimed to compare the electrolyte, hemodynamic and metabolic changes of prone and complete supine PCNL.Patients and MethodsIt was a randomized clinical trial study on 40 ASA class I and II patients. Twenty of patients underwent prone PCNL (Group A) and the other twenty underwent complete supine PCNL (Group B). The two groups received the same premedication and induction of anesthesia. Blood pressure (systolic, diastolic and mean) and pulse rate were recorded before, during and after anesthesia and Hb, Hct, BUN, Cr, Na, and K were also measured before and after operation in the two groups. The volume of irrigation fluid, total effluent fluid (the fluid in the bucket and the gazes) and volume of absorbed fluid were measured.ResultsThere were no significant differences in Na, K, BUN, Cr, Hb and Hct between the two groups. Absorption volume was significantly different between the two groups (335 ± 121.28 mL in group A and 159.45 ± 73.81 mL in group B, respectively) (P = 0.0001). The mean anesthesia time was significantly different between the two groups (P = 0.012). There was a significant difference in bleeding volume between supine and prone PCNL (270.4 ± 229.14 in group A and 594.2 ± 290 in group B, respectively) (P = 0.0001). Mean systolic blood pressure during operation and recovery was 120.2 ± 10.9 and 140.7 ± 25.1 in group B, and 113.4 ± 6.4 and 126.2 ± 12.7 in group A, respectively. Systolic blood pressure between the two groups during operation and recovery was significantly different (P = 0.027 and P = 0.022, respectively). Mean diastolic blood pressure in supine group during operation and recovery was 80.53 ± 7.57 and 95.75 ± 17.48, and 73.95 ± 3.94 and 83.4 ± 12.54 in prone group, respectively. Diastolic blood pressure was significantly different between the two groups. It was 80.55 ± 7.57 and 95.75 ± 17.48, respectively during operation and recoveryin the supine group and 73.95 ± 3.94 and 83.4 ± 12.54 in the prone group, respectively (P = 0.001 and P = 0.014, respectively), but there was no significant difference between the pulse rate mean value of the two groups.ConclusionsThe electrolyte and metabolic changes were not significantly different between the two groups, and although fluid absorption in prone group was more than that of the complete supine group, there was no significant difference between the two groups. Considering advantages of complete supine PCNL such as less hemodynamic changes (less hypotension, less fluid absorption and less duration of operation) this kind of PCNL was recommended.

Physiological characteristics of salt tolerance in centipedegrass (Eremochloa ophiuroides (Munro) Hack. cv. TifBlair)

Physiological characteristics of salt tolerance in centipedegrass (Eremochloa ophiuroides (Munro) Hack.) were investigated by comparing ion uptake, osmotic regulation, osmolytes, oxidative stress and antioxidant enzymes of salt-tolerant cultivar ‘TifBlair’ and salt-sensitive ‘Common’. Treatments at 0–150 mmol L−1 NaCl were conducted for 10 days. Growth was higher in ‘TifBlair’ than in ‘Common’ at 25 and 50 mmol L−1 NaCl, and was depressed in both cultivars at above 75 mmol L−1 NaCl. No significant difference in Na and Cl concentrations in the shoot and roots was observed between the cultivars, although ‘TifBlair’ was more tolerant to Na and Cl than ‘Common’. Osmotic pressure, glycinebetaine and free proline concentrations in the shoot increased in both cultivars with an increase in NaCl concentration; the increase was higher in ‘TifBlair’. Malondialdehyde concentration, an index of oxidative damage, in the shoot increased in both cultivars with an increase in NaCl concentration; the increase was not significantly different between the cultivars. On the contrary, hydrogen peroxide concentration was higher in ‘TifBlair’ than in ‘Common’. ATPase activity of the shoot plasmalemma increased in ‘TifBlair’ with an increase in NaCl concentration, while decreased in ‘Common’ at 50 mmol L−1 NaCl. The activity of antioxidant enzymes (superoxide dismutase, peroxidase, catalase and ascorbate peroxidase) tended to be higher in ‘TifBlair’ than in ‘Common’. The results suggest that adjustment of osmotic pressure by accumulation of compatible solutes and exclusion of Na and Cl, and elimination of activated oxygen by induction of antioxidant enzymes are responsible for the salt tolerance of centipedegrass ‘TifBlair’.

Protective role of proline against salt stress is partially related to the improvement of water status and peroxidase enzyme activity in cucumber

A salt-sensitive cucumber cultivar “Jinchun No. 2” (Cucumis sativus L.) was used to investigate the role of proline in alleviating salt stress in cucumber. Proline was applied twice (day 0 and day 4 after salt treatment) as a foliar spray, with a volume of 25 mL per plant at each time. Plant dry weight, leaf relative water content, proline, malondialdehyde (MDA), Na+, K+ and Cl− contents, as well as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) activities in the plants were determined at day 8 after salt treatment. The results showed that 100 mmol L–1 NaCl stress significantly decreased plant dry weight, leaf relative water and K+ contents, and increased leaf MDA, Na+ and Cl− contents and SOD, POD, CAT and APX activities. However, leaf proline accumulation was not affected by salinity. The exogenous application of proline significantly alleviated the growth inhibition of plants induced by NaCl, and was accompanied by higher leaf relative water content and POD activity, higher proline and Cl− contents, and lower MDA content and SOD activity. However, there was no significant difference in Na+ and K+ contents or in CAT and APX activities between proline-treated and untreated plants under salt stress. Taken together, these results suggested that the foliar application of proline was an effective way to improve the salt tolerance of cucumber. The enhanced salt tolerance could be partially attributed to the improved water status and peroxidase enzyme activity in the leaf.

Application of wave intensity technique on assessing hemodynamic changes in hyperthyroidism

Objective To investigate the value of wave intensity (WI) technique in assessing hcmodynamic alteration of hyperthyroid patients.Methods Thirty five hyperthyroid patients and 32 healthy people were examined with high frequency ultrasonography. Right common carotid artery (RCCA) was targeted for ultrasonic imaging to obtain WI parameters which were automatically calculated by WI software. WI parameters include amplitude of the peak during early systole (W1), amplitude of the peak during late systole (W2),area of the negative wave during mid-systole (NA),interval between R wave of electrocardiogram and W1 (R-1st), interval between W1 and W2 ( 1st -2nd), arterial stiffness (β), arterial compliance(AC) and pulse wave velocity including PWVβ and PWVw1. Results ①Both W1 and W2 of hyperthyroid group were significantly higher than those of the control group [W1 : (24. 94 ± 15.45) × 103 mm Hg · m-1 · s-3 vs (9.70±4.88)×103mm Hg·m-1·s-3, P<0.001,1 mm Hg =0.133 kPa; W2: (3. 33 ± 1. 82)×103mm Hg·m-1·s-3 vs (2.10 ± 1. 24) × 103mm Hg·m-1·s-3, P = 0. 003]. ②Both R-1st and 1st -2nd of hyperthyroid group were lower compared with the control group and both comparisons had statistically significant differences [R-1st: (79.49 ± 14. 64)ms vs ( 104.47 ± 11.52)ms, P<0. 001; 1st - 2nd: (226. 37 ± 26. 33) ms vs (266.69 ± 18.38) ms, P <0. 001]. ③There was no significant difference in NA,β, AC, PWVβ and PWVw1 between two groups. ⑤Of 35 hyperthyroid patients, 11 presented several abnormal waves on WI curves during mid-systole. Conclusions WI parameters reflect both cardiac and vascular changes of hyperthyroid patients. Mid-systolic hemodynamic turbulence appears in a portion of hyperthyroid patients. Key words: Ultrasonography; Hyperthyroidism; Hemodynamic phenomena; Wave intensity

Mechanisms of Salt Tolerance in Transgenic Arabidopsis thaliana Carrying a Peroxisomal Ascorbate Peroxidase Gene from Barley

Ascorbate peroxidases (APX), localized in the cytosol, peroxisome, mitochondria, and chloroplasts of plant cells, catalyze the reduction of H 2O 2 to water by using ascorbic acid as the specific electron donor. To determine the role of peroxisomal type ascorbate peroxidase (pAPX), an antioxidant enzyme, in protection against salt-induced oxidative stress, transgenic Arabidopsis thaliana plant carrying a pAPX gene (HvAPX1) from barley (Hordeum vulgare L.) was analyzed. The transgenic line pAPX3 was found to be more tolerant to salt stress than the wild type. Irrespective of salt stress, there were no significant differences in Na+, K+, Ca 2+, and Mg 2+ contents and the ratio of K+ to Na+ between pAPX3 and the wild type. Clearly, the salt tolerance in pAPX3 was not due to the maintenance and reestablishment of cellular ion homeostasis. However, the degree of H 2O 2 and lipid peroxidation (measured as the levels of malondialdehyde) accumulation under salt stress was higher in the wild type than in pAPX3. The mechanism of salt tolerance in transgenic pAPX3 can thus be explained by reduction of oxidative stress injury. Under all conditions tested, activities of superoxide, glutathione reductase, and catalase were not significantly different between pAPX3 and the wild type. In contrast, the activity of APX was significantly higher in the transgenic plant than in wild type under salt stress. These results suggested that in higher plants, HvAPX1 played an important role in salt tolerance and was a candidate gene for developing salt-tolerant crop plants.

Changes in physiological indicators associated with salt tolerance in two contrasting cashew rootstocks

In order to identify salt tolerance indicators, several physiological variables were evaluated in two contrasting cashew (Anacardium occidentale L.) rootstocks in response to salt stress. The tolerant CCP 09 genotype showed better growth performance after two weeks under a large range of NaCl salinity (50, 100, 150 and 200 mM). The NaCl treatments induced a significant drop in transpiration as a consequence of an increased stomatal resistance in both genotypes. No significant differences in Na+, Cl, and K+ concentrations were found in both roots and leaves regardless of rootstocks. The tolerant genotype exhibited lower relative water content and less negative leaf osmotic potential as compared with the sensitive genotype and, therefore, these variables could not be related to salt tolerance. Salt stress caused more significant changes in protein and amino acid concentrations in roots than in leaves. Among the physiological indicators, leaf membrane damage was closely associated with the differences in salt tolerance between the two cashew genotypes. Furthermore, under NaCl salinity the tolerant rootstock showed greater ability to accumulate compatible organic solutes (amino acids, proline and soluble sugars) in leaves in addition to maintaining the soluble sugar concentration in roots as compared with the sensitive rootstock.

Responses of ectomycorrhizal Populus tremuloides and Betula papyrifera seedlings to salinity

Roots of trembling aspen ( Populus tremuloides Michx.) and paper birch ( Betula papyrifera Marsh.) seedlings were inoculated with Hebeloma crustuliniforme or Laccaria bicolor and treated with 25 mM NaCl for 6 weeks. Both tree species appeared to be relatively tolerant of the applied NaCl treatment and did not develop visible leaf symptoms that are characteristic of salt injury. Salt treatment reduced total dry weights in aspen and birch, but did not significantly affect transpiration rates and root hydraulic conductance. Salt-treated ectomycorrhizal aspen maintained higher root hydraulic conductance compared with non-mycorrhizal plants. Na and Cl concentrations increased in shoots and roots of mycorrhizal and non-mycorrhizal aspen and birch in response to NaCl treatment. Roots of NaCl-treated aspen inoculated with H. crustuliniforme had over twofold higher concentrations of Na compared with non-mycorrhizal NaCl-treated plants. Similarly to aspen, Na and Cl concentrations increased in roots and shoots of NaCl-treated birch seedlings. However, in birch, there were no significant differences in Na and Cl concentrations between mycorrhizal and non-mycorrhizal plants. The results suggest that salt exclusion by the ectomycorrhizal associations is host-specific or/and that the processes leading to salt exclusion are activated in ectomycorrhizal plants by a threshold salt level which may vary between plant species.

Presence of a functional TSH receptor on human erythrocytes

The presence of thyrotropin receptors (TSHR) has been reported in some extrathyroidal tissues but its physio-pathological role still remains unclear. TSH (seems to) affects the human erythrocytes Na +/K +-ATPase in vitro, however receptors on erythrocytes have not yet been described. In this work the effect of recombinant human TSH (rhTSH) on sites number and activity of erythrocyte Na +/K +-ATPase was investigated in a group of thyroidectomized patient enrolled for rhTSH test. As detected by 3H-ouabain binding, rhTSH administration induced a significant increase in the number of sites ( p = 0.005) and in the Kd ( p = 0.006) of Na +/K +-ATPase. rhTSH did not induce significant difference in Na +/K +-ATPase activity measured by 86Rb uptake. 125I-TSH binding studies and Western blotting data showed the existence of TSHR in the erythrocytes of healthy donors. In conclusion The TSH action on Na +/K +-ATPase of human erythrocytes can be explained by the presence of TSHR

Hypoxia upregulates amino acid transport in a human neuroblastoma cell line

Background/Purpose Some tumor cells survive and even grow in hypoxic conditions. We examined the effect of hypoxia on amino acid transport in a human neuroblastoma cell line SK-N-SH. Methods Cells were incubated under hypoxic conditions (1% O 2–5% CO 2–94% N 2). After 0, 8, 16, and 24 hours, the transport of 3H-glutamine, 3H-glutamate, and 3H-leucine was assayed. 3H-Thymidine and 3H-leucine incorporation was measured for the determination of DNA and protein synthesis, respectively. Results Hypoxia increased Na +-dependent glutamine and Na +-independent leucine transport significantly at 16 and 24 hours compared with control ( P < .01) by a mechanism that increased V max without affecting K m. These increases were completely blocked by actinomycin D and cycloheximide. There was no significant difference in Na +-dependent glutamate transport between control and hypoxic groups. DNA and protein synthesis significantly decreased in the hypoxic condition compared with control ( P < .01). Conclusions This study demonstrated that hypoxia upregulates amino acid transport in a human neuroblastoma cell line. This mechanism may allow cells to survive and even grow under hypoxic conditions.

Involvement of PI 3-kinase in IGF-I stimulation of jejunal Na+-K+-ATPase activity and nutrient absorption.

Mechanisms responsible for increased jejunal transport rates observed in tissues treated with orally administered insulin-like growth factor-I (IGF-I) were studied in 5-day-old colostrum-deprived piglets. Human recombinant IGF-I (3.5 mg. kg(-1). day(-1)) or control vehicle was given orogastrically for 4 days. Disaccharidase activity, fructose uptake, and Na+-glucose cotransporter SGLT-1 protein abundance were similar between groups. Oral IGF-I produced greater rates of enterocyte Na+-K+-ATPase activity with no significant differences in Na+-K+-ATPase abundance. Cellular mechanisms responsible for transport changes were studied in Ussing chambers. In control tissues, the presence of IGF-I in mucosal solutions increased basal short-circuit current (I(sc)), potential difference, D-glucose-stimulated I(sc), and Na+-K+-ATPase activity; these changes were abolished by preincubation of tissues with wortmannin, a phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor. The results suggest that the effect of IGF-I on jejunal ion and nutrient transport involves activation of PI 3-kinase and stimulation of Na+-K+-ATPase activity in enterocytes.

The development of excitatory capability in Aplysia californica bag cells observed in cohorts

The bag cells of Aplysia release egg laying hormone in sexually mature animals. Bag cells cannot sustain the long-lasting excitatory afterdischarge (AD) required for hormone release prior to sexual maturity (T.A. Nick, L.K. Kaczmarek, T.J. Carew, Ionic currents underlying developmental regulation of repetitive firing in Aplysia bag cell neurons, J. Neurosci. 1996;16:7583–7598; L.A. Fieber, Characterization of Na + and Ca 2+ currents in bag cells of sexually immature Aplysia californica, J. Exp. Biol. 1998;201:745–754). To investigate the development of bag cell excitability, whole-cell voltage-clamp experiments were executed in dissociated bag cells from four cohorts (batches) of hatchery-reared A. californica maintained at 13–15°C. K + current densities, representing the sum of at least four different outward K + currents (Nick et al., 1996), declined significantly as a function of age, beginning at least 2–3 months before sexual maturity. The K + current decreases coincided with the first appearance of Na + and Ca 2+ currents in bag cells, which occurred at ages 6–7 months. Whole cell K + currents were not decreased significantly by a cAMP analog earlier than 1 month prior to the onset of reproductive activity. The frequency of observing Na + currents in whole cell recordings was low for developmental times earlier than sexual maturity. In one winter batch, both control and PMA-treated Na + currents increased significantly with age, and PMA-treated current densities were significantly greater than controls, but the other two batches studied had significant differences in Na + current frequency only at sexual maturity. Ca 2+ currents were reliably measured in more cells than were Na + currents. The Ca 2+ current frequency increased significantly with maturity in one winter batch. Ca 2+ currents were significantly increased by phorbol ester treatment beginning 6–8 weeks before reproductive activity in the two winter batches. These observations support the hypothesis that bag cell excitability is not fully developed until shortly before sexual maturity.

Increased functional Na(+)-K+ pump activity in the vasculature of fructose-fed hyperinsulinemic and hypertensive rats.

We hypothesized that hyperinsulinemia may alter insulin's ability to stimulate vascular Na+/K(+)-ATPase pump activity and modulate changes in vascular responsiveness associated with hypertension. We measured potassium-induced relaxation as an indicator of Na+/K(+)-ATPase pump activity in isolated femoral arteries from fructose-fed (FF) hyperinsulinemic, Sprague-Dawley rats. FF rats had higher mean arterial blood pressures than did normal diet-fed (NF) rats (FF, 125 +/- 2.2, n = 20, vs. NF, 113.5 +/- 2.5 mmHg, n = 20, p < 0.05) and were hyperinsulinemic (FF, 64 +/- 4 vs. NF, 37 +/- 2, microU/ml insulin, p < 0.01). FF rats were more sensitive to KCl in the Na+/K+ pump bioassay (FF, 0.86 +/- 0.07, n = 21 vs. NF, 1.18 +/- 0.08, n = 17, p < 0.05, expressed as ED50 in mmol/l KCl). Exogenous insulin (100 mU/ml) increased Na+/K+ pump sensitivity in FF rats as compared with a boiled insulin control (insulin 45 +/- 6%, n = 11, vs. control, 11 +/- 7%, n = 13, p < 0.01, expressed as percent increase in sensitivity, i.e., ED50). There were no significant differences in Na+/K+ pump sensitivity between insulin and control responses in the NF animals (insulin 29 +/- 6%, n = 11, vs. control 46 +/- 5%, n = 10, NS). Dose-response curves were obtained in tail and femoral arteries from the same animals to norepinephrine and acetylcholine, basally and after exogenous insulin. FF vessels had reduced sensitivity to norepinephrine as compared with the NF group. Insulin increased sensitivity to acetylcholine-induced relaxations and increased AII-induced contractions in FF-rat vessels. These data suggest that in the FF rat insulin's influence on the vascular Na+/K+ pump is enhanced and may modulate the changes in vascular responsiveness seen in this model.

The effects of the cyanobacterium Microcystis aeruginosa, the cyanobacterial hepatotoxin microcystin–LR, and ammonia on growth rate and ionic regulation of brown trout

Brown trout were exposed for 63 days to five treatments: a control; the purified cyanobacterial hepatotoxin microcystin—LR (MC—LR) (41—57 μg MC—LR 1−1); lysed toxic Microcystis aeruginosa cells (41–68 μg MC—LR 1−1 and 288 μg chlorophyll a 1−1); lysed non—toxic M. aeruginosa cells (non—MC—LR containing and 288 μg chlorophyll a 1−1); ammonia (65–325 μg NH3 1−1). All treatments produced significantly reduced growth compared to controls (P&lt;0·05, Fisher test). Exposure to ammonia resulted weight loss over the first 7 days followed by weight increase, though at a significantly lower level than in the other treatments. First exposed to lysed toxic M. aeruginosa cells grew less than those exposed to lysed non—toxic cyanobacteria or purified MC—LR. Sodium influx rates after 63 days exposure to purified MC—LR, lysed toxic M. aeruginosa cells, or ammonia showed a significant increase compared to control fish or those exposed to lysed non—toxic M. aeruginosa cells. There were no significant differences in Na+ efflux or net Na+ uptake rates between treatments. Significant increases in body Na+ and Cl— were seen in fish exposed to lysed toxic M. aeruginosa cells or ammonia. Only fish exposed to ammonia showed a significant increase in body ammonia. Short—term exposure, over 4 h, to lysed toxic cells, non—toxic cells or purified MC—LR resulted in insignificant changes in Na+ flux rates compared to controls although there was a significant net Na+ loss in fish exposed to ammonia. Chronic exposure of fish to toxic cyanobacterial blooms may result in ionic imbalance and reduced growth.

Chemical and Physical Properties of Connecticut Lakes, With Emphasis on Regional Geology

ABSTRACT Chemical and physical characteristics of 60 drainage lakes in Connecticut are discussed in relation to the geology of the state. Significant differences in composition and quantities of dissolved ions were observed for lakes in different geologic zones. Waterbodies situated on the Eastern Uplands, Western Uplands, and Coastal Slope were more dilute than lakes in the Marble and Central Valleys. Although there were significant differences in Na+, Ca+2, Mg+2, Cl−, SO4 −2, and alkaline anions between different regions, none were found for K+. Unlike ionic chemistry, few differences in trophic variables were observed for lakes in the different geologic areas. On a statewide basis chlorophyll a levels were highly correlated with total phosphorus (TP), total nitrogen (TN), and Secchi disk depths. Summer TN:TP ratios suggested that chlorophyll levels in many lakes may be related to both TP and TN levels. Results are compared to previous studies in Connecticut and other areas of the northeast.

Localization of iron and other elements in the lichen Nephroma arcticum (L.) Torss.

Localization of iron and other elements in the lichen Nephroma arcticum collected in Sweden (Abisko, N Lapland) was studied under acidic conditions after thalli had been soaked in a 20 mM FeCl 2 solution. Twelve elements accumulating in different parts of the thallus were detected via an SEM linked to an energy dispersive X-ray analysis unit. There were no significant differences in Na and Al amounts between the control and the FeCl 2-treated samples. The percentages of Fe in apothecial discs, ascospores, necks of apothecia and in thalli of treated samples were higher than in control samples but the percentages in the dorsal part of the dics were similar in the treated and control thalli. The percentage of Cl was higher in all five parts of the lichen samples treated with FeCl 2. Lower percentages of K, Ca and Mg were detected in those parts of the treated lichen in which high elevations of Fe and Cl were found. The ratio between “net” percentage of Cl and Fe atoms in discs and in ascospores was found to be closest to the 2.00 value, which occurs in the FeCl 2 formula. The accumulation of these two elements, coupled to the leakage of essential ions from lichen discs and ascospores, appears to be deleterious to lichen mycobiont reproductive capacity.

Effects of 17 α-Ethinyl Oestradiol in Vitro on Erythrocyte Cation Transport in Men and Women

The effects of 17 alpha-ethinyl oestradiol in vitro upon erythrocyte Na(+)-K+ cotransport were investigated in nine normal males and in eight normal females during the mid-follicular phase of the menstrual cycle. At a concentration of 10(-1) mmol/l, Na(+)-K+ cotransport was almost completely inhibited. At concentrations of 10(-12) to 10(-2) mmol/l, a minor concentration-related effect was observed in males but not females. In the same concentration range, there was a significant difference in Na(+)-K+ cotransport between sexes. Thus, erythrocyte Na+K+ cotransport is lower in females than males, probably due to chronic exposure of their erythrocytes to endogenous oestrogen.

Transfer of Na transport inhibition in proximal tubules from saline volume-expanded to nonexpanded rats

In dual micropuncture experiments the shrinking drop technique was used to measure volume flux with artificial tubular fluid (AF) alternating with harvested tubular fluid (HTF) during saline volume-expanded (VE) and nonexpanded (NE) periods. In VE rats, volume flux (Jv) (nl.mm-1.min-1) with AF was 1.78 +/- 0.08 (means +/- SE) during NE and was reduced to 1.39 +/- 0.09 (P = 0.01) during subsequent VE, whereas with randomly alternating HTF during VE it was 1.07 +/- 0.08 (P less than 0.0001 and less than 0.03, respectively). Jv with HTF from NE rats tested in the VE rats was 1.20 +/- 0.06, which is significantly higher than that measured with their own HTF (Wilcoxon rank, P = 0.05). In NE rats Jv was 1.65 +/- 0.10 and 1.69 +/- 0.10 with AF and HTF and was 1.28 +/- 0.07 (P less than 0.001 from both) with HTF obtained from VE rats. Elemental analysis of reaspirated tubular fluids showed no significant differences in Na or Cl concentrations among any of the fluids. It is concluded that during VE, a transferable Na transport inhibitor appears in proximal tubular fluid, which, together with a changed proximal tubular epithelium, possibly due to physical forces, accounts for proximal tubular Na transport inhibition during VE.

Impaired calcium metabolism associated with hypertension in Zucker obese rats

Recent data from our laboratory indicate that reduced membrane Ca-adenosine triphosphatase (ATPase) activity in non-insulin-dependent diabetics may be responsible for increases in intracellular calcium and, consequently, for elevated vascular resistance. Since obesity is frequently associated with hypertension, even before the development of overt diabetes, we evaluated blood pressure and erythrocyte cation levels and membrane Na K -ATPase and Ca-ATPase in Zucker obese rats and their lean controls (n = 10 per group). Intra-arterial blood pressure, determined via a femoral cannula, demonstrated elevated systolic and diastolic pressure in the obese rats ( P < .05). There were no significant differences in Na K -ATPase between groups, but there was a decrease in Ca-ATPase ( P < .01) in the obese rats and an increase in tissue and cellular calcium content ( P < .05). These data demonstrate a specific impairment in membrane Ca-ATPase activity in obese rats they may have caused the observed increase in cellular calcium and, consequently, increased blood pressure. These phenomena may result from impaired insulin activation of membrane Ca-ATPase in these insulin-resistant animals.