Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Sustained oscillations of acetylcholine during nerve stimulation (1974)
    [s.l.] : Nature Publishing Group
    Nature 252 (1974), S. 485-486 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Torpedo marmorata fishes were received alive from the Station de Biologic Marine, Arcachon, France. Most experiments were done on isolated prisms, which are columns of electroplaques representing the functional unit of the organ3. After careful dissection, the prisms were allowed to recover for 1?2 ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/252485a0
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Changes of Specific Conductivity of Blood Serum in vivo after X-irradiation (1965)
    [s.l.] : Nature Publishing Group
    Nature 206 (1965), S. 1057-1058 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Fig. 1. Changes in specific conductivity of blood serum in vivo after X-irradiation The resistance data were calculated into the conductivity values (ohm?1, cm?1, 104) and statistically elaborated, and the comparison of both data was performed by the Welcoxon test. The reproducibility of our ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/2061057a0
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Axonal and glial currents activated during the post-tetanic hyperpolarization in non-myelinated nerve (1998)
    Springer
    Pflügers Archiv 436 (1998), S. 529-537 
    Details
    ISSN: 1432-2013
    Keywords: Key words Axons ; Glial cells ; Hyperpolarization- activated currents ; Inward rectification ; Non-myelinated nerve fibres ; Post-tetanic hyperpolarization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Changes in membrane potential and potassium concentration in the extracellular space ([K+]e) of rabbit vagus nerve were measured simultaneously during electrical activity and during the period of recovery using a modified sucrose-gap method and potassium-sensitive microelectrodes. After stimulation for 15 s at 15 Hz the main activity-induced increase in [K+]e reached 16.9 mM. This increase in [K+]e was paralleled by a depolarization of the preparation. The period of activity was followed by a post-tetanic hyperpolarization (PTH) lasting tens of seconds, generated by the axonal electrogenic Na+-K+ pump and to a lesser extent by the pump of the surrounding Schwann cells. The amplitude of the PTH dramatically increased in experiments in which inward currents were blocked by removal of Cl– or after application of Cs+ or Ba2+, indicating that under normal conditions the current generated by the Na+-K+ pump is strongly short-circuited. A pharmacological and kinetic study showed that these currents are: (1) the hyperpolarization-activated current I h, and (2) the inwardly rectifying I KIR current. The results show that the latter originates from Schwann cells. Our data indicate that in non-myelinated nerves there is a subtle association of inward ionic channels which (1) helps the cell to maintain an optimal membrane potential after a period of activity, and (2) contributes to the removal of excess K+ from the extracellular space.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004240050668
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Ca2+-activated K+ current generating the after-hyperpolarization in mammalian nonmyelinated nerve fibres (1989)
    Springer
    Pflügers Archiv 414 (1989), S. S135 
    Details
    ISSN: 1432-2013
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00582268
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Involvement of intracellular calcium in the phosphate efflux from mammalian nonmyelinated nerve fibers (1984)
    Springer
    The journal of membrane biology 79 (1984), S. 87-95 
    Details
    ISSN: 1432-1424
    Keywords: nerve fibers ; membrane ; transport ; phosphate ; calcium ; Ca ionophore ; Na/Ca exchange
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Phosphate efflux was measured as the fractional rate of loss of radioactivity from desheathed rabbit vagus nerves after loading with radiophosphate. The effects of strategies designed to increase intracellular calcium were investigated. At the same time, the exchangeable calcium content was measured using45Ca. Application of calcium ionophore A23187 increased phosphate efflux in the presence of external calcium in parallel with an increase in calcium content. In the absence of external calcium, there was only a late, small increase in phosphate efflux. For nerves already treated with the calcium ionophore, the phosphate efflux was sensitive to small changes in external calcium, in the range 0.2 to 2mm calcium, whereas similar increases in calcium in absence of ionophore gave much smaller increases in phosphate efflux. Removal of external sodium (choline substitution) produced an initial increase in phosphate efflux followed by a fall. The initial increase in phosphate efflux was much larger in the presence of calcium, than in its absence. The difference was again paralleled by an increase in calcium content of the preparation, thought to be due to inhibition of Na/Ca exchange by removal of external sodium. Measurements of ATP content and ATP, ADP, phosphate and creatine phosphate ratios did not indicate significant metabolic changes when the calcium content was increased. Stimulation of phosphate efflux by an increase in intracellular calcium may be due to stimulation of phospholipid metabolism. Alternatively, it is suggested that stimulation of phosphate efflux is associated with the stimulation of calcium efflux, possibly by cotransport of calcium and phosphate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01868529
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Effects of calcium and lanthanum on phosphate efflux from nonmyelinated nerve fibers (1982)
    Springer
    The journal of membrane biology 65 (1982), S. 125-130 
    Details
    ISSN: 1432-1424
    Keywords: nerve fibers ; membrane ; transport ; phosphate ; calcium ; lanthanum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Phosphate efflux was measured as the fractional rate of loss of radioactivity from rabbit vagus loaded with radiophosphate. The effects of changes in extracellular calcium and of lanthanum have been investigated. In Locke solution with normal, 0.9mm, calcium and without phosphate, the fractional rate of loss was 1.62×10−3 min−1 at 120 min after the beginning of the washing period and fell slowly (9% hr−1) during washing from 2 to 6 hr. Addition of calcium to the Locke solution produced a transient increase followed by a reversible maintained increase in phosphate efflux. The latter was 40 and 75% above efflux in normal calcium for 20 and 50mm calcium, respectively. Removal of calcium, with or without addition of EGTA, produced only a transient increase in phosphate efflux, with no subsequent maintained change. Addition of low concentrations of lanthanum produced a reversible inhibition of phosphate efflux. Half-maximal inhibition was at 3.5 μm lanthanum and appeared to be due to binding of lanthanum to more than one, probably two, sites. Measurements of inhibition by lanthanum at different calcium concentrations did not indicate any competition between calcium and lanthanum. It is suggested that at least a part of phosphate efflux depends on internal calcium and that lanthanum acts by preventing release of phosphate from the phosphate transport mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01870475
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Role of potassium in the phosphate efflux from mammalian nerve fibers (1980)
    Springer
    The journal of membrane biology 52 (1980), S. 75-82 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary The efflux of phosphate was measured in rabbit vagus nerve loaded with radiophosphate. The efflux was found to depend on the K concentration of the bathing solutions; increasing the K from 5.6 up to 150mm produced a maximal lowering of 28%; K-free solution produced a transient increase whose peak was 86% above the normal efflux. In the presence of Na, the K-free effect could be repeated; in Na-free solution, it was found only for the first application of the K-free solution. The phosphate efflux was not altered when K was replaced by Rb; replacement with Cs showed that this ion only partially mimics the effect of K. The results suggest that the transient increase in phosphate efflux is due to release of label from a K-dependent saturable binding site, which is distinct from the main intracellular pool. The binding site appears to be labeled from the inside by the Na-dependent phosphate efflux previously described. It may correspond to the phosphorylation of membrane phospholipids. A mathematical model of this system is developed and curves simulated by an analog computer are compared to the experimental results. Measurements of the membrane potential and the internal inorganic phosphate showed that the effect of K on the phosphate efflux could not be explained by changes in the membrane potential or in the internal phosphate pool.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01869008
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Continuous measurement of calcium influx in mammalian nonmyelinated nerve fibers: Effects of Na o , Ca o , and electrical activity (1986)
    Springer
    The journal of membrane biology 91 (1986), S. 157-164 
    Details
    ISSN: 1432-1424
    Keywords: mammalian nerve ; intracellular calcium ; membrane-bound calcium ; calcium buffering ; Na/Ca exchange ; electrical activity ; A23187
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary A new technique for continuous monitoring of the cellular calcium was developed and used for studying the effects of external and internal Na (Na o and Na i ), external Ca (Ca o ), Ca ionophore A23187, and electrical activity on membrane-bound and intracellular Ca in mammalian nonmyelinated nerve fibers. Increasing Ca o increased both the membrane-bound and the intracellular Ca. Lowering Na o increased the membrane-bound fraction of Ca indicating that lack of Na o enhanced the capacity of the plasma membrane to bind Ca, and produced an increase of the internal Ca pool. Increasing Na i by treatment with ouabain enhanced the Ca inflow in both, the presence and absence of Na o , presumably by stimulating the Ca o /Na i exchange. The Ca ionophore A13187 produced a large and irreversible increase in the intracellular Ca without affecting the membrane-bound fraction. On the other hand, electrical activity, which is known to produce a large increase of the total Ca in squid axon, had no measurable effect on the total calcium content in our preparation. It is concluded that in mammalian nerve fibers a Ca load by exposition to Na-free solution or to A23187 produces an accumulation of Ca into the intracellular Ca stores, whereas during electrical activity the membrane-associated extrusion mechanisms are able to maintain the intracellular Ca2+ below the threshold for intracellular sequestration. Furthermore, the results indicate that the intracellular sequestration mechanisms are dependent on the internal concentration of Na.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01925792
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Calcium efflux and intracellular exchangeable calcium in mammalian nonmyelinated nerve fibers (1988)
    Springer
    The journal of membrane biology 103 (1988), S. 121-134 
    Details
    ISSN: 1432-1424
    Keywords: mammalian nerve ; calcium efflux ; exchangeable calcium ; mitochondrial buffering ; Na−Ca exchange
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Calcium efflux was measured in desheathed rabbit vagus nerves loaded with45Ca2+. The effects of extracellular calcium, sodium, phosphate, potassium and lanthanum ions on the calcium efflux were investigated and the distribution of intracellular calcium determined by kinetic analysis of45Ca2+ efflux profiles. The45Ca2+ desaturation curve can be adequately described by three exponential terms. The rate constant of the first component (0.2 min−1) corresponds to an efflux from an extracellular compartment. The two slow components had rate constants of 0.03 and 0.08 min−1 and represent the efflux from two intracellular pools. The amounts of exchangeable calcium in these two pools, after a loading period of 150 min, were 0.170 and 0.102 mmol/kg wet weight, respectively. The total calcium efflux in physiological conditions amounted to about 24 fmol cm−2 sec−1. The magnitude of the two intracellular compartments as well as the total calcium efflux were markedly affected by extracellular phosphate, sodium and lanthanum, whereas the corresponding rate constants remained almost unchanged. Phosphate reversed the effect of sodium withdrawal on the calcium efflux: in the absence of phosphate, sodium withdrawal increased the calcium efflux to 224%, but in the presence of phosphate, sodium withdrawal decreased calcium efflux to 44%. Phosphate also affected the increase in calcium efflux produced by inhibitors of mitochondrial calcium uptake, suggesting that two different mitochondrial pools contribute to the control and regulation of intracellular calcium and of the transmembrane calcium transport.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01870943
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...