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
    Evidence for mediated transport of chloride in cat cerebral cortex in vitro (1969)
    Springer
    Experimental brain research 8 (1969), S. 219-231 
    Details
    ISSN: 1432-1106
    Keywords: Cerebral cortex in vitro ; Chloride transport ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The kinetics of the uptake of chloride by slices of cat cerebral cortex incubated in vitro have been studied for a wide range of concentrations of chloride and potassium in the incubation media. 1. In studies with 36Cl at a constant concentration of external K+, the rate of entry of chloride into slices of cat cerebral cortex (after equilibration with the fluid of the extracellular space) followed Michaelis-Menten kinetics with Vmax=7.7 μmoles/g/min and Km=245 mM. The kinetic data so described differ significantly from a curve describing simple diffusion (P 〈 0.02). 2. A clear dependence on concentration of K+ in the incubation medium was demonstrated. When external chloride was held constant at 6.8 mM and concentrations of potassium were varied over a range of 27–100 mM, the apparent rate of entry of chloride followed Michaelis-Menten kinetics with Vmax=0.191 μmoles/ g/min and Km=30.3 mM. 3. Under similar equilibrium conditions, the rate of influx of chloride was not statistically different from the rate of efflux, and the value for extracellular space (355 μl/g) derived by extrapolation from efflux data was of an identical order of magnitude to the value (352 μl/g) obtained from influx data. These values are essentially identical to those previously determined for chloride space of cat cerebral cortex in vivo (Bourke, Greenberg and Tower 1965). 4. The total, membrane-delimited content of chloride in cerebral cortex, as defined in these studies in vitro, was a function of the concentration of K+ in the incubation medium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234250
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Studies of the development and subsequent reduction of swelling of mammalian cerebral cortex under isosmotic conditions in vitro (1969)
    Springer
    Experimental brain research 8 (1969), S. 232-248 
    Details
    ISSN: 1432-1106
    Keywords: Cerebral cortex in vitro ; Edema ; Fluid compartmentation ; Chloride transport ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ionic parameters of incubation media which foster both the development and subsequent reduction of swelling of slices of cerebral cortex under isosmotic conditions of incubation in vitro are described. A linear relationship between increasing chloride concentrations in incubation media and progressive swelling of tissue slices (under conditions of constant temperature and K+ concentrations and isotonicity of incubation media) is demonstrated. Subsequent reduction of chloride concentration in incubation media together with reciprocal replacement by isethionate is associated with significant and characteristic reduction in the volume of tissue swelling when all other conditions of incubation, including isotonicity of the media, are kept constant. The ionic composition of the fluid of swelling under different conditions of incubation is derived together with the ionic composition and expected transmembrane potentials of the neuronal compartment of cerebral cortex in vitro. Mechanisms involved in the development and subsequent reduction of swelling of cerebral cortex in vitro are discussed, and proposals for possible clinical applications are suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234251
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Mediated transport of chloride from blood into cerebrospinal fluid (1970)
    Springer
    Experimental brain research 10 (1970), S. 17-38 
    Details
    ISSN: 1432-1106
    Keywords: Chloride transport in vivo ; CSF ; Hydrocephalus ; Extracor poreal hemodialysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The kinetics of transport of chloride from blood into CSF have been studied in the adult cat in vivo for a wide range of concentrations of chloride in arterial plasma: 1. In studies employing isosmotic replacement of body chloride with isethionate by means of extracorporeal hemodialysis, the chloride content in cerebral cortex and corpus callosum and concentration in CSF were relatively resistant to change despite the fact that plasma chloride was varied over the range 120.5 to 8.1 mM. 2. During hemodialysis the ratio of the concentration of chloride in CSF (or content in cerebral cortex) versus the concentration of chloride in arterial plasma was maintained for at least 1 or 2 h at as much as 10 times the ratios present in normal animals. 3. In studies with 36Cl, the rate of entry of chloride from blood into CSF followed Michaelis-Menten kinetics with the Vmax=0.55 μmole/ ml/min and with the Km 〈 60 mM and possibly 〈 8.1 mM. On the other hand the rate of entry of chloride from blood into cerebral cortex and corpus callosum was much slower and followed simple diffusion kinetics. 4. Evidence is presented indicating that chloride is transported from blood to CSP at the choroid plexus as well as at other sites. 5. On the basis of the rate of entry of chloride into CSF, the rate of bulk production of CSF in the adult cat was calculated to be 17.1 μl/min at normal plasma concentrations of chloride, a value in close agreement with previous estimates of the rate of production of CSF in the adult cat. 6. The relationships of the content of chloride in skeletal muscle and in liver to the concentration of chloride in plasma are presented, when the latter is varied over the range 120.5 to 8.1 mM.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00340517
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    FLUID COMPARTMENTATION AND ELECTROLYTES OF CAT CEREBRAL CORTEX IN VITRO–I SWELLING AND SOLUTE DISTRIBUTION IN MATURE CEREBRAL CORTEX (1966)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 13 (1966), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The distribution of indicator solutes (inulin, sucrose, raffinose, thiocyanate, chloride, and isethionate) and the swelling in slices of adult cat cerebral cortex incubated in vitro have been investigated for a variety of incubation media and conditions. Where appropriate, these data have been compared with analogous data obtained on cat cerebral cortex in vivo (Bourkeet al., 1965) and with data previously reported for slices of rat cerebral cortex (Pappius and Elliott, 1956; Pappiuset al., 1962) and guinea pig cerebral cortex (Varon and McIlwain, 1961; Keeseyet al., 1965) incubated in vitro under comparable conditions.In addition to substantial agreement of present data with previously reported in vitro data, a number of new findings have been added by the present study: (a) a component of slice swelling which is K+-dependent; (b) the association of slice swelling with presence of a diffusible, external anion (Cl−) and its prevention by replacement with a relatively non-diffusible anion (isethionate−); (c) variation of the size of slice chloride spaces as a direct function of slice swelling; (d) dependence of the size of slice fluid spaces accessible to inulin and sucrose upon time, during incubation, of solute addition and upon K+ concentration of the incubation medium; (e) indications of the dynamic and presumably metabolically-dependent nature of indicator solute distribution; and (f) the mobility of a portion of the fluid of swelling associated with changing the K+ concentration but not the tonicity of the medium during incubation.At least five operationally-defined fluid compartments may be inferred from the present data : (1) interstitial or extracellular space(s) readily accessible to all solutes and of a size which can be minimally estimated from direct determinations in viuo; (2) additional fluid space(s) accessible to most solutes, including inulin and sucrose, under apparently suboptimal conditions of slice metabolism in vitro; (3) fluid space(s) prone to swell under in vitro conditions and readily accessible in vitro to chloride and thiocyanate but not to inulin or sucrose; (4) fluid space(s) which swell reversibly in the presence of added external K+ (or Rb+) and are inaccessible to all usual indicator solutes; and (5) after exclusion of the foregoing, the remaining fluid presumably comprising most of the intracellular space(s).The data have been discussed in terms of the morphological complexity of cerebral cortex, in terms of applicability to studies of cortical electrolyte distribution, and in terms of the general problem of delineating cerebral interstitial spaces.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-4159.1966.tb04267.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    FLUID COMPARTMENTATION AND ELECTROLYTES OF CAT CEREBRAL CORTEX IN VITRO–III ONTOGENETIC AND COMPARATIVE ASPECTS (1966)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 13 (1966), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Studies on swelling and fluid compartmentation have been carried out in vitro on incubated slices of cerebral cortex from kittens 1.5-120 days post-natal age and on incubated sections of corpus callosum and slices of liver and kidney cortex from adult cats. The findings have been compared with analogous data for incubated slices of adult cat cerebral cortex, studied under identical conditions (Bourke and Tower, 1966a, b), in order to identify the probable morphological correlates of fluid and electrolyte distribution.Incubated cortical slices from neonatal (1.5-4-day-old) kittens exhibit none of the relevant characteristics of slices from adult cerebral cortex. By 1 month post-natal age, K+-dependent swelling of slices becomes demonstrable, and the K+ and Na+ contents of slices approximate adult levels. Both these developments coincide with the morphological and physiological maturation of cortical neurons. At 3 months post-natal age, slice swelling accessible to C1− but not to sucrose becomes observable and the dependence of sucrose space size on time, during incubation, of solute addition becomes demonstrable. Both these developments follow completion of axonal myelination in the cortex but coincide with the period of cortical glial cell proliferation.Incubated sections of corpus callosum from adult cats exhibit none of the relevant characteristics observed for cortical slices under identical conditions. Tissue swelling is minimal and uninfluenced by K+ concentrations of incubation media. Tissue fluid spaces accessible to sucrose are approximately twice the size of spaces accessible to inulin. In general, qualitatively similar results have been obtained for incubated slices of cat liver or kidney cortex or for incubated sections of rat diaphragm under the same conditions. A behaviour for glial cells (? astrocytes) in cerebral cortex under such in vitro conditions distinctly different from behaviour of subcortical glial cells is suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-4159.1966.tb04269.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    FLUID COMPARTMENTATION AND ELECTROLYTES OF CAT CEREBRAL CORTEX IN VITRO–II SODIUM, POTASSIUM AND CHLORIDE OF MATURE CEREBRAL CORTEX (1966)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 13 (1966), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The contents of K+, Na+ and Cl− in various incubation media and in slices of adult cat cerebral cortex incubated in vitro under a variety of conditions have been determined in conjunction with studies on slice swelling and fluid compartmentation reported in the preceding paper (Bourke and Tower, 1966).Cortical slices incubated in media containing 16 Or 27 mm-K+ exhibit contents of K+ and Na+ most nearly comparable to those found in viuo. Substitution of isethionate− For Cl− or omission of Ca2+ in such media have little effect on slice cation composition. Rb+ can effectively substitute for K+, but substitution of Li+ or choline+ for most of the naf in incubation media is associated with accumulation of these cations in slices at the expense of both K+ and Na+.Compared to values in vivo for net contents and/or concentrations of electrolytes in the non-sucrose spaces of cortical slices, conditions yielding most favourable data in vitro appeared to be incubation of cortical slices in 16 mm-K+ medium or in 27 mm-K+ medium with either omission of Ca2+ or replacement of Cl− by isethionate.Essentially complete inhibition of maintenance of K+ and extrusion of Na+ in slices of cat cerebral cortex occurs upon incubation with 10−5 or 10−4m-ouabain, with 50 per cent inhibition of cortical slice electrolyte metabolism occurring at about 8 × 10−7m-ouabain.Cortical slices incubated in 27 mm-K+ medium in the presence of 42K exhibited rates of exchange and turnover of slice K+ (in non-sucrose spaces) of 0·7 μequiv./min and 6.45 per cent respectively. In the presence of 10−5m-ouabain, a maximal ratio of slice specific activity/medium specific activity is attained within about 5 min after 42K addition, compared to 〉20 min for control slices. In neither case does the maximal specific activity ratio exceed about 0.85; this suggests that some 10-15 per cent of total cortical K+ comprises a “slowly exchangeable” fraction.In the presence of Ca2+ (1.3 mm) slice oxygen consumption is markedly stimulated (39 per cent) and aerobic glycolysis is markedly depressed (54 per cent) in the presence of 10−5m-ouabain; whereas on omission of Ca2+ from incubation media, both respiration and glycolysis are normally stimulated but, with 10−5m-ouabain present, both are significantly depressed (20 per cent and 37 per cent respectively). Possible relevance of these effects to mobilization of tissue Ca2+ by ouabain and to effects of intracellular Ca2+ on mitochondrial respiratory metabolism is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-4159.1966.tb04268.x
    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...