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  • 35.10.Bg  (2)
  • Na+/H+ antiport  (2)
  • Springer  (4)
  • Jena
  • 1990-1994  (4)
Document type
Publisher
  • Springer  (4)
  • Jena
Years
  • 1990-1994  (4)
Year
  • 1
    ISSN: 1432-1440
    Keywords: Na+/H+ antiport ; Hypertension ; Diabetic nephropathy ; Hereditary factors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The incidence of diabetic nephropathy in patients with insulin-dependent diabetes mellitus (IDDM) may depend on factors other than the quality of diabetes control. Hypertension is an additional factor associated with a high degree of renal involvement in IDDM. One abnormality consistantly observed in various tissues of patients with essential hypertension is enhanced activity of the Na+/H+ antiport. In the present study we have therefore studied platelet antiport activity in 41 healthy subjects (control), in 22 patients with untreated essential hypertension (EH), and in 35 normotensive IDDM patients (type 1). Of these patients 17 exhibited signs of diabetic nephropathy (group 1) while 18 had no evidence for renal involvement of IDDM in spite of a duration of IDDM of at least 10 years (group 2). The two IDDM patient groups were undistinguishable with respect to age, body mass index, and arterial blood pressure (group 1, 117.9±2.4/78.4±1.5 mmHg; group 2, 113.9±3.6/76.1±1.8 mmHg). Antiporter activity was determined from the rate of cell volume changes induced by propionic acid. Platelet Na+/H+ exchange activity averaged 23.43±0.43 10−3·s−1 in control subjects and was markedly elevated in EH (28.38±0.62 10−3·s−1 P〈0.01). Antiport activity in group 2 patients without nephropathy averaged 24.54±0.57 10−3·s−1 and was undistinguishable from the control group. However, platelet Na+/H+ antiport activity was significantly stimulated in group 1 patients with nephropathy as compared to group 2(26.95±0.73 10−3. s−1 ; P〈0.025). Our results show that renal involvement in IDDM is associated with enhanced activity of the platelet Na+/H+ antiport.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-1440
    Keywords: Cell volume regulation ; Hypertonicity ; Lymphocytes ; Na+/H+ antiport ; Saline infusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The Na+/H+ antiport is a membrane transport protein that extrudes intracellular protons in exchange for extracellular sodium. Some details of its physiological and pathophysiological role remain poorly defined. Experimental evidence suggests that the antiporter is involved in the regulation of cell volume. In the present study, we therefore investigated the activity of the lymphocyte Na+/H+ antiport in nine healthy volunteers following acute hypertonic (2.5%) saline infusion (4 mmol NaCl/kg over 120 min). Antiport activity was measured after acidifying the cells with Na+ propionate (5–40 mM) using the fluorescent dye bis-carboxyethyl carboxyfluorescein. Hypertonic saline induced significant increases in plasma osmolality (308.4±2.3 vs. 293.5±2.7 mOsm/kg; P〈0.01), serum Na+ (150.8±3.7 vs. 138.9±0.5 mmol/kg; P〈0.01), and Cl− concentrations (118.0±3.9 vs. 101.1±1.0 mmol/kg; P〈0.01). Extracellular hypertonicity was followed by a stimulated activity of the lymphocyte Na+/H+ antiport with an increase in the apparent V max values from 2.44±0.16 to 3.27±0.34 10−3 s−1 (P〈0.01) and a slight rise in pK from 6.81±0.03 to 6.87±0.03 (P〈0.05) after hypertonic saline. In addition to antiport activation, cytosolic alkalinization was observed with cytosolic pH values averaging 6.90±0.02 before and 6.99±0.02 (P〈0.01) after hypertonic saline. Our results show for the first time that acute extracellular hypertonicity in man due to hypertonic NaCl loading is associated with a stimulated lymphocyte Na+/H+ antiport activity and cytosolic alkalinization.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 24 (1992), S. 161-164 
    ISSN: 1434-6079
    Keywords: 32.70.Jz ; 31.30.Gs ; 35.10.Bg
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The use of an effusive beam of titanium atoms crossed with a CW single-mode tunable dye laser has allowed the high-resolution, Doppler-free study of the isotope shifts between50Ti,48Ti and46Ti, for seven 3d 2 4s 2 a3 F J → 3d 2 4s 4p z 5 D J , visible transitions of Ti I. The measurements show without ambiguity the existence of a non-negligible field shift. Using the values of the nuclear radii of titanium (coming from muonic X-ray measurements), it is possible to determine the respective values of the field and mass shifts.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 31 (1994), S. 145-148 
    ISSN: 1434-6079
    Keywords: 32.70.Jz ; 31.30.Gs ; 35.10.Bg
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract High accuracy measurements of hyperfine structure due to47Ti and49Ti in the 3d 2 4s 2 a 3 F 2−3d 2 4s4p z 5 D 1 absorption line at σ=18482.772 cm−1 have been performed by use of a Doppler-free experiment, where a beam of titanium atoms is crossed by a CW single mode tunable dye laser. They have allowed for the determination of isotope shifts between46Ti,47Ti,48Ti,49Ti and50Ti. By use of accurate values of mean square nuclear charge radii for the even isotopes, it has been possible to separate mass shifts from field shifts and to determine accurate values for the mean square nuclear charge radii of47Ti and49Ti. The field shift presents a marked odd-even staggering.
    Type of Medium: Electronic Resource
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