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  • Coleoptera  (2)
  • Na+/H+ antiport  (2)
  • sap beetle  (2)
  • Springer  (4)
  • 1990-1994  (4)
Document type
Publisher
  • Springer  (4)
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.
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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.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 20 (1994), S. 1483-1493 
    ISSN: 1573-1561
    Keywords: Carpophilus obsoletus ; sap beetle ; Coleoptera ; Nitidulidae ; aggregation pheromone ; hydrocarbon ; tetraene ; date
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Males ofCarpophilus obsoletus Erichson produce an aggregation pheromone to which both sexes respond. The pheromone was identified by GC-MS as (2E,4E,6E,8E)-3,5,7-trimethyl-2,4,6,8-undecatetraene (1), which is also a minor constituent of the pheromone blends ofC. hemipterus (L.),C. freemani Dobson, andC. lugubris Murray. The pheromone was synergized in wind-tunnel bioassays by propyl acetate, a “host-type” coattractant. In a dose-response study, 50 pg of1, plus propyl acetate, was significantly more attractive than just propyl acetate. Pheromone emission from groups of 65 males, feeding on artificial diet, averaged 2.2 ng/male/day. Emissions from individual males were larger, averaging 72 ng/day and ranging as high as 388 ng/day. Synthetic1 was tested in a date garden in southern California (500 µg/rubber septum), using fermenting whole-wheat bread dough as the coattractant. The pheromone plus dough attracted significantly more beetles than dough alone (means were 4.2 and 0.0 beetles per week per trap). Captured beetles were 54% females. Field trap catches were highest during the months of July and August.
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  • 4
    ISSN: 1573-1561
    Keywords: Carpophilus mutilatus ; sap beetle ; Coleoptera ; Nitidulidae ; aggregation pheromone ; hydrocarbon ; triene ; date ; host volatiles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Males ofCarpophilus mutilatus Erichson produce an aggregation pheromone to which both sexes respond. The pheromone includes two hydrocarbon components, (3E,5E,7E)-5-ethyl-7-methyl-3,5,7-undecatriene (1) and (3E,5E,7E)-6-ethyl-4-methyl-3,5,7-decatriene (2). These were emitted in a 10∶1 ratio and in a total amount of ca. 5 ng per feeding male per day. All tested doses of1 and2, from 0.03 to 30 ng, were more attractive than controls in wind-tunnel tests, but there was no evidence of synergism between these trienes. Dramatic synergism between the pheromone and a food-type coattractant occurred in the field, however. In a date garden in southern California, traps with a combination of synthetic1 and fermenting whole-wheat bread dough attracted 22 times more beetles than dough by itself and 295 times more than1 by itself. Volatile collections from males also contained three oxygenated compounds that were absent from females. One of these was tetradecanal (ca. 5 ng per male per day), but the structures of the other two are presently undetermined (0.8 and 1.1 ng per male per day). No function for these was demonstrated. One compound originating in the artificial diet, 2-phenylethanol, was particularly attractive in the wind-tunnel bioassay, as was the chromatographic solvent, methanol.
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