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  • 1
    Electronic Resource
    Electronic Resource
    High-Affinity Uptake of Spermine by Slices of Rat Cerebral Cortex (1981)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 36 (1981), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: The accumulation of the polyamine spermine into 0.1-mm prisms of rat cerebral cortex has been investigated at both 37°C and at 4°C. Kinetic analysis of the temperature-sensitive portion of uptake indicates two high-aftinity saturable components together with an unsaturable component at high concentrations. The ‘very high’– affinity saturable system (Km= 3.8 nM) was temperature- and sodium-dependent, and significantly reduced by metabolic inhibitors, findings that are consistent with an active transport system for spermine into brain tissue. The ‘high’– affinity saturable component (Km= 0.44 μM) was sodium-dependent and inhibited by ouabain, but only partially susceptible to inhibition by 2,4-dinitrophenol and sodium cyanide. The significance of these results with respect to the function of spermine in the central nervous system is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-4159.1981.tb00409.x
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    CLEARANCE OF THE POLYAMINES FROM THE PERFUSED CEREBROVENTRICULAR SYSTEM OF THE RABBIT (1978)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 30 (1978), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract— The clearance of the polyamines spermidine and spermine from cerebrospinal fluid was investigated in the rabbit by ventriculocisternal perfusion. Clearance involved both saturable and nonsaturable uptake processes. The saturable component was a high affinity system with an affinity constant of 21 μm for spermidine and 24 μm for spermine. The clearance of spermidine was reduced by the presence of spermine and vice-versa. Other polyamine congeners also reduced spermidine and spermine clearance and it is suggested that the two polyamines share the same carrier. Evidence for concentrative uptake of polyamines into choroid plexus is presented and it is suggested that an active system may also transport polyamines into brain tissue. At high perfusion concentrations simple diffusion may also take place.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-4159.1978.tb10788.x
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    THE UPTAKE OF SPERMIDINE AND SPERMINE BY SLICES OF MOUSE CEREBRAL HEMISPHERES (1975)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 25 (1975), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract— Spermidine and spermine are taken up into mouse cerebral hemisphere slices by active transport and can be accumulated well above the medium concentration. The uptake process shows saturation kinetics and resembles that for amino acid uptake in that it is sensitive to temperature and inhibited by cyanide, 2,4-dinitrophenol or by the absence of glucose from the medium. However, at low initial medium concentrations spermine is taken up by a process which is insensitive to metabolic inhibitors or to temperature. It is suggested that either physical binding to a cellular constituent or exchange transport may account for this uptake. Ouabain does not inhibit polyamine uptake. Spermidine or spermine uptake is inhibited by cadaverine and putrescine. Spermine is the most potent inhibitor of spermidine uptake and vice-versa. Polyamine uptake differs from that of amino acids in that it is increased by a reduction in medium sodium or calcium content and decreased by an increase in medium potassium content. Recently taken up spermine undergoes heteroexchange with spermidine and homoexchange with recently entered spermine. Spermidine undergoes neither heteroexchange with spermine nor homoexchange.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-4159.1975.tb06977.x
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    THE DISTRIBUTION AND METABOLISM OF PUTRESCINE, SPERMIDINE AND SPERMINE INJECTED INTO THE CEREBRAL VENTRICLES OF RABBITS (1976)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 26 (1976), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Following the intracerebroventricular injection into rabbits of spermidine or spermine the highest concentrations were initially found in the caudate nucleus, hypothalamus and medulla. Subsequently there was a rapid decline in the amounts present in the caudate nucleus and hypothalamus and, particularly in the case of spermidine, an increase in the conccntration in the lower brain stem and cervical cord. This pattern of changes is consistent with the amines being redistributed by passage in CSF. Intraventricularly injected putrescine followed the same initial distribution pattern but within 2 days it had been largely converted to spermidine and spermine. Synthesized polyamines accumulated in all the regions examined. The time course of synthesis indicated that spermidine was the precursor of spermine. Spermine was also formed from injected spermidine and vice-versa. These findings concur with the pharmacological and neurotoxic actions of putrescine, spermidine and spermine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-4159.1976.tb07007.x
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    Paper (German National Licenses)
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  • 5
    Electronic Resource
    Electronic Resource
    THE REGIONAL DISTRIBUTION OF THE POLYAMINES SPERMIDINE AND SPERMINE IN BRAIN (1973)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 20 (1973), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract— The distribution in brain of the polyamines spermidine and spermine is described in the rat, dog, sheep, rabbit and in man. The distribution pattern was about the same in all the species, spermidine concentration being highest in areas rich in white matter. The concentration of spermine was lower than that of spermidine and showed less variation from area to area. Rat brain polyamine content was the same in rats killed by decapitation as in those killed by rapid freezing in liquid nitrogen and was also unchanged up to 48 h after the death of the animal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-4159.1973.tb00091.x
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    Paper (German National Licenses)
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  • 6
    Electronic Resource
    Electronic Resource
    Responses of quail, pheasants, and sparrows to one oral dose of dimethoate and to consumption of dimethoate treated bran baits (1986)
    Springer
    Bulletin of environmental contamination and toxicology 36 (1986), S. 616-621 
    Details
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01623559
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    Paper (German National Licenses)
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  • 7
    Electronic Resource
    Electronic Resource
    The synthesis and turnover of spermidine and spermine in mouse brain (1979)
    Springer
    Neurochemical research 4 (1979), S. 269-275 
    Details
    ISSN: 1573-6903
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Following the administration to mice of radiolabeled putrescine by intraventricular injection, changes in the specific radioactivity of putrescine, spermidine, and spermine have been measured. Putrescine decline was biphasic, being more rapid over the first 12 hr(t 1/2=5 hr) than over the remainder of the 48-hr period (t 1/2=11 hr) that significant labeling was detected. Spermidine was rapidly labeled during the decline in putrescine radioactivity and maximum incòrporation of label occurred at 18 hr. Subsequently, spermidine specific activity declined with a half-life of 22 days. Spermine synthesis was slower, with maximum labeling occurring after 4 days. Spermine turnover, measured at a time when spermidine radioactivity had substantially declined, was extremely slow (t 1/2=92 days). The data supports the view that putrescine is a precursor of spermidine which in turn is required for spermine synthesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00964150
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    Paper (German National Licenses)
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