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  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 15 (1968), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract— —A study has been made of the contribution of noradrenaline transport along sympathetic nerves to their terminal stores of transmitter by ligating the splenic nerves of the cat, and measuring both the noradrenaline that accumulates above the constriction, and the noradrenaline content of the spleen. The biochemical estimations were supplemented by fluorescence histochemistry. The effect of abolishing efferent impulses in the splenic nerves was examined by cutting their preganglionic nerve supply.The proximo-distal flow rate for noradrenaline was calculated as 1.4-3.3 mm/hr assuming that all the noradrenaline that accumulates is derived from the cell bodies in the ganglion without net addition or loss in the axons. The process was not dependent on impulse traffic in the nerves, since decentralization did not significantly effect the accumulation. The amount of noradrenaline arrested by the constriction in 24 hr was only 1 per cent of the stores in the terminals of those nerves, and consequently no change was detected in the spleen's noradrenaline content as a result of constricting its nerve supply.In the presence of an intact reflex pathway to the spleen, the stress of the operative procedure produced a marked constriction of the spleen, and depletion of its noradrenaline content. These changes could be prevented either by section of the preganglionic splanchnic nerves, or by ligation of the splenic nerves, thereby blocking the conduction of efferent nerve impulses.The evidence favours a proximo-distal flow of noradrenaline in sympathetic nerves, independent of nerve impulses, which makes, however, a negligible quantitative contribution to the terminal stores of transmitter.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 28 (1977), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The dopamine β-hydroxylase (DβH) content and activity of large dense-core noradrenergic vesicles purified from bovine splenic nerve were determined using two assay procedures : enzymic activity expressed in Units per mg protein and homospecific activity based on radioimmunoassay expressed in Units per mg DβH antigen. Approximately two-thirds of the total enzyme activity is latent in these vesicles, even after various treatments designed to compromise vesicle integrity. DβH can be completely unmasked by brief treatment with 0.01-0.05% Triton X-100 and activity increases from 0.20 to 0.64 Units per mg vesicle protein. Calculations based on both assay methods suggested that an average of 7% (range 3-15%) of the total vesicle protein was DβH and that the average vesicle contained about 4 molecules of enzyme (range 2-9 molecules). The estimated homospecific activities indicated an average of 25 and 50% (range 18-72%) of the vesicle enzyme was inactive in the various samples using the two antibodies. The vesicle can synthesize up to 30 molecules of noradrenaline/s per molecule of DβH at near optimal substrate concentration, and 60-270 molecules of norepinephrine/s per vesicle. The assumptions used in the various calculations were critically analyzed and, based on the methods employed, it is tentatively considered to be unlikely that there could be more than 5-12 molecules of DβH per vesicle. The possibility that circulating DβH originates primarily, if not exclusively, from the large dense-core vesicle type is considered and the functional implications of the data support the concept of vesicle reuse during several cycles of exocytosis involving a quantal size equal to a fraction of the vesicle transmitter content.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 16 (1969), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The experiments were designed to detect somatopetal transport of [14C]noradrenaline in the postganglionic sympathetic nerves supplying the cat spleen and sheep eye. The animals were treated with nialamide to protect the radioactive noradrenaline, after uptake into the nerve terminals, from monoamine oxidase.In the spleen, the transmitter stores were labelled by infusion of [14C]noradrenaline into a branch of the splenic artery. The branches of the nerves to the infused and non-infused sides of the spleen were ligated in an attempt to arrest, distal to the constriction, any noradrenaline transported somatopetally in the axons from their terminals. After 24 hr, however, there was less radioactivity in the nerves distal compared to proximal to the constriction, despite heavier labelling of the terminal transmitter stores in the infused portion of the spleen. The proximal accumulation of radioactivity could be attributed to a somatofugal transport of [14C]noradrenaline.Experiments were also done on the intact sympathetic nerve supply of the sheep eye. The sympathetic nerve terminals in the smooth muscle of the left eye were heavily labelled 5 days after the injection of [14C]noradrenaline into the left vitreous humour. However, both superior cervical ganglia were only lightly labelled, and there was no significant difference in the radioactivity present in the two ganglia.The results provide no support for a bidirectional transport of noradrenaline in sympathetic nerves but are consistent with a somatofugal transport of the amine storage vesicles from their site of synthesis in the soma to the axon terminals.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 43 (1984), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The presence of the catecholamine synthetic enzyme, phenylethanolamine N-methyl transferase (PNMT), has been detected in the expansor secundariorum, a smooth muscle of the avian wing. The concentration of the enzyme was estimated over a 10-week time course from 17 days incubation to 9 weeks posthatch and found to increase rapidly up until hatch in parallel with dopamine β-hydroxylase activity, but then to fall precipitously to very low levels. The time course of the initial increase in activity corresponds to the presence of ingrowing sympathetic nerve fibres, and denervation of the expansor results in loss of 〉80% of the PNMT activity.It is concluded that during the period of innervation the growing nerves contain the enzyme PNMT and therefore have the capacity to synthesize adrenaline, but that shortly after innervation is complete the capacity to synthesize adrenaline is lost. Several alternate mechanisms are proposed to explain the observations.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 296 (1982), S. 569-570 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Muscles from 1-day old birds bound 0.165±0.024fmol of 3H-QNB per mg wet weight. In 3-week old chicks that were unilaterally denervated at 1 day old, no significant loss of binding sites occurred (0.140±0.018 fmol per mg wet weight, P〉0.1), whereas binding in the contralateral, ...
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 312 (1984), S. 364-367 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Irides from adult albino rats (250-300 g body weight) of both sexes were used. After culture for four or six days in Eagles basal medium supplemented with 10% fetal calf serum, irides were removed, freeze-thawed and stretch-mounted on glass slides. Specific stain was clearly visible in all regions ...
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Female Porton rats (200-250 g) were anaesthetised with intraperitoneal sodium pentobarbital (42 mg per kg body weight) and placed in a Kopf stereotaxic apparatus. A 21 or 23 gauge steel needle connected to a Harvard infusion pump was inserted stereotaxically in either a lateral or the third ...
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1573-6865
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A method has been developed to raise an antiserum against ovalbumin that can detect this antigen immunohistochemically in chicken sensory ganglia. Ovalbumin-like immunoreactivity has been identified in a subpopulation of chicken dorsal root ganglion neurons by the generation of antibodies to aldehyde-conjugated ovalbumin but not by the antibodies to native ovalbumin, although both antibodies recognize the much higher concentrations of ovalbumin in sections of the oviduct. Biochemical analysis demonstrated that the antigen is more readily detectable in fixed tissue extracts than in fresh tissue extracts. Sensitive immunoblot analysis combined with affinity purification of the antigen, has confirmed that the antigen is of the same molecular weight as ovalbumin. Furthermore, the immunoreactive material elutes at a position identical to native ovalbumin on a molecular sieve column. These findings argue that molecules sensitive to aldehyde fixation may be more readily detected by the use of antisera prepared against aldehyde-modified antigens. The function of the ovalbumin-like antigen in these neurons is unknown.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1573-6865
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A method has been developed to raise an antiserum against ovalbumin that can detect this antigen immunohistochemically in chicken sensory ganglia. Ovalbumin-like immunoreactivity has been identified in a subpopulation of chicken dorsal root ganglion neurons by the generation of antibodies to aldehyde-conjugated ovalbumin but not by the antibodies to native ovalbumin, although both antibodies recognize the much higher concentrations of ovalbumin in sections of the oviduct. Biochemical analysis demonstrated that the antigen is more readily detectable in fixed tissue extracts than in fresh tissue extracts. Sensitive immunoblot analysis combined with affinity purification of the antigen, has confirmed that the antigen is of the same molecular weight as ovalbumin. Furthermore, the immunoreactive material elutes at a position identical to native ovalbumin on a molecular sieve column. These findings argue that molecules sensitive to aldehyde fixation may be more readily detected by the use of antisera prepared against aldehyde-modified antigens. The function of the ovalbumin-like antigen in these neurons is unknown.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Noradrenergic axons in the enteric plexuses of the guinea-pig ileum have been identified at the ultrastructural level using three techniques: the chromaffin reaction, localization of dopamine-β-hydroxylase (DBH) with horseradish peroxidase-conjugated antibody, andin vivo andin vitro loading with 5-hydroxydopamine (5-OHDA). In the myenteric (Auerbach's) plexus from normal ileum all of these methods produced electron-dense deposits in a distinctive population of axonal varicosities that contained many flattened vesicles (usually more than 30% of the total number of vesicles), as well as oval or irregularly shaped vesicles. When noradrenergic axons to the small intestine had degenerated after surgical denervation, no profiles containing vesicles with electron-dense deposits were observed with the chromaffin reaction, DBH localization or loading with 5-OHDA. Pretreatment with 6-hydroxydopamine (6-OHDA) substantially reduced the number of noradrenergic axons identified by these three techniques. Axons with many flattened vesicles of similar dimensions but without dense cores were found in myenteric plexus from conventionally fixed intestine. These axons had the same distribution within the ganglia as cytochemically labelled noradrenergic terminals and disappeared after extrinsic denervation. In the normal submucous (Meissner's) plexus, both 5-OHDA loading and the chromaffin reaction produced electron-dense granules in small and large vesicles in some axon terminals. In ganglia labelled by these techniques, reactive terminals contained many small round vesicles and few flattened and large round vesicles as did a population of nonreactive terminals. In axon terminals of submucous plexus labelled with anti-DBH, flattened vesicles were found to be more numerous than with the other treatments. As in the myenteric plexus, all reactive axons disappeared from the submucous plexus after extrinsic denervation. In conventionally processed submucous ganglia, noradrenergic axon profiles could not be distinguished from some non-noradrenergic profiles on the basis of types and proportions of vesicles. In the myenteric plexus noradrenergic axon terminals were seen most often near the edges of ganglia. Noradrenergic varicosities also occurred near nerve cell bodies but were rarely found in internodal strands. In the submucous plexus noradrenergic terminals appeared to be randomly distributed throughout submucous ganglia. No axosomatic synapses formed by noradrenergic axons were found in either plexus, but synapses on nerve processes were occasionally encountered in submucous ganglia.
    Type of Medium: Electronic Resource
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