Bibliothek

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    ISSN: 1471-4159
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Abstract: Recent studies have shown marked increases in brain content of neuropeptide Y (NPY) after seizures induced by intraperitoneal injection of kainic acid and after pentylenetetrazole kindling in the rat. We have now investigated possible changes in the rate of biosynthesis of NPY after kainic acid treatment, by using pulse-labeling of the peptide and by determining prepro-NPY mRNA concentrations. For pulse labeling experiments, [3H]tyrosine was injected into the frontal cortex, and the incorporation of the amino acid into NPY was determined after purifying the peptide by gel filtration chromatography, antibody affinity chromatography, and reversed-phase HPLC. At 2 and 30 days after kainic acid treatment, the rate of tyrosine incorporation was enhanced by ∼380% in the cortex. In addition, concentrations of prepro-NPY mRNA were determined in four different brain areas by hybridization of Northern blots with a complementary 32P-labeled RNA probe 2, 10, 30, and 60 days after kainic acid treatment. Marked increases were observed in the frontal cortex (by up to 350% of controls), in the dorsal hippocampus (by 750%), and in the amygdala/pyriform cortex (by 280%) at all intervals investigated. In the striatum only a small, transient increase was observed. The data demonstrate increased expression of prepro-NPY mRNA and an enhanced rate of in vivo synthesis of NPY as a result of seizures induced by the neurotoxin kainic acid.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    ISSN: 1471-4159
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Phencyclidine (PCP) is a non-competitive NMDA glutamate receptor antagonist that induces psychotomimetic effects in humans and experimental animals. Chronic PCP exposure elicits signs of persistently altered frontal brain activity and related behaviors which are also seen in patients with schizophrenia. Secretogranin II (sg II) belongs to the chromogranin family of proteins that exist in large dense core vesicles in nervous tissue. In the brain, 90% of sg II is processed to the small peptide secretoneurin. We previously detected differential effects of single-dose and subchronic PCP administration on sg II expression in the rat prefrontal cortex (PFC). In the present study, we applied PCP to organotypic PFC slices. PCP application for 28 h induced decreased tissue and culture medium secretoneurin content. In contrast, incubation with the adenylate cyclase activator forskolin caused significantly increased secretoneurin levels after 8 h. PCP for 4 h followed by 24 h without PCP resulted in increased culture medium secretoneurin content but no change in tissue levels. sg II mRNA expression was decreased after 28 h PCP application in cortical neurons. Immunohistochemical and TUNEL staining profiles indicated that the alterations were not due to neurodegeneration. PCP for 5 days changed neither the secretoneurin tissue or culture medium levels, nor the sg II mRNA expression. These results demonstrate that PCP modulates sg II expression in PFC tissue in the absence of afferent inputs and that the nature of these changes is dependent upon the duration of exposure to and/or withdrawal from PCP.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    European journal of neuroscience 2 (1990), S. 0 
    ISSN: 1460-9568
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Levels of several neuropeptides were measured in the frontal cortex, dorsal hippocampus, striatum, and amygdala/pyriform cortex in rats kindled for 5 weeks by daily injection of pentylenetetrazol (30 mg/kg, i.p.). Significantly increased concentrations (by 30–140%) were found in all examined brain areas for neuropeptide Y, somatostatin (except hippocampus) and neurokinin-like immunoreactivity 10 days after the last kindling session. Similar but less pronounced changes were also found 24 h after the last seizure. The increase in total neurokinin-like immunoreactivity was due to a marked increase in neurokinin B as revealed by HPLC analysis. Increases in peptide levels, however, were restricted to fully kindled animals. At the same time no changes in levels of substance P, vasoactive intestinal polypeptide and calcitonin gene-regulated peptide were observed. Cholecystokinin octapeptide was enhanced only in the hippocampus (by 46%). The increases in neuropeptide Y, somatostatin, and neurokinin-like immunoreactivity subsided after 3 months. A markedly decreased seizure threshold was observed 10 days and 2 months after the final kindling session.No nerve cell degeneration was observed in kindled rats 24 h or 10 days after the last pentylenetetrazol injection. Some animals (2 of 4), however, exhibited signs of blood-brain barrier damage when examined 24 h after the last kindling session which may reflect the preceding convulsions. No such changes were detected after 10 days.The increases in peptide levels may suggest increased activity of respective neurons which, at least to some degree, may be associated with γ-aminobutyric acid. The changes in peptide levels may be more closely related to the kindling procedure itself than to the decreased seizure threshold of the animals.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    ISSN: 1460-9568
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Secretoneurin is a recently discovered neuropeptide derived from secretogranin II (SgII). Since this peptide could be detected in the dorsal horn of the spinal cord we studied whether it is localized in and released from primary afferent neurons. Secretoneurin was investigated with immunocytochemistry and radioimmunoassay in spinal cord, dorsal root ganglia and peripheral organs. SgII mRNA was determined in dorsal root ganglia. Normal rats and rats pre-treated neonatally with capsaicin to destroy selectively polymodal nociceptive (C-) fibres were used. Slices of dorsal spinal cord were perfused in vitro for release experiments. Immunocytochemistry showed a distinct distribution of secretoneurin-immunoreactivity (IR) in the spinal cord and lower brainstem. A particularly high density of fibres was found in lamina I and outer lamina II of the caudal trigeminal nucleus and of the spinal cord. This distribution was qualitatively identical in rat and human post-mortem tissue. Numerous small diameter and some large dorsal root ganglia neurons were found to contain SgII mRNA. Capsaicin treatment led to a marked depletion of secretoneurin-IR in the substantia gelatinosa, but not in other immunopositive areas of the spinal cord and to a substantial loss of small (〈25 μm) SgII-mRNA-containing dorsal root ganglia neurons. Radioimmunoassay revealed a significant decrease of secretoneurin-IR in the dorsal spinal cord, the trachea, heart and urinary bladder of capsaicin-treated rats. Perfusion of spinal cord slices with capsaicin as well as with 60 mM potassium led to a release of secretoneurin-IR. In conclusion, secretoneurin is a neuropeptide which is stored in and released from capsaicin-sensitive, primary afferent (C-fibre) neurons. It may, therefore, be a novel peptidergic modulator of pain transmission or of C-fibre mediated non-nociceptive information.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 339 (1989), S. 173-177 
    ISSN: 1432-1912
    Schlagwort(e): Epilepsy ; Kainic acid ; Neuropeptide Y ; Somatostatin ; Vasoactive intestinal polypeptide
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Changes in immunoreactivities of neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) were investigated in the brain of rats after severe kainic acid (KA, 10 mg/kg, i.p.) induced limbic seizures. Decreased levels of both neuropeptides were observed in the frontal cortex, striatum, dorsal hippocampus and amygdala/pyriform cortex subsequently to the period of acute seizures (3 h after injection of the toxin). Then NPY increased consistently in the frontal cortex, hippocampus and amygdala/pyriform cortex. Highest levels (290% of controls) were found in the frontal cortex after two months. Anticonvulsant therapy with phenobarbital (20 mg/kg, i.p., twice daily for three weeks) partially suppressed the rise in NPY levels. Immunoreactivity of VIP increased (to 150%) in the frontal cortex only transiently 3 days after injection of kainic acid. At the subsequently examined time intervals (10–60 days after kainic acid) it declined to control values. Levels decreasing subsequently to acute seizures reflect increased release and degradation of the respective peptide. Increased NPY levels suggest “upregulation” of NPY/ somatostatin/GABA neurons due to the decreased seizure threshold of the animals. The early, reversible rise of VIP in the cortex points to a short-lasting activation of this peptide system contained in local cholinergic neurons. This may be a consequence either of the acute seizures or subsequent neuropathological changes.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    ISSN: 1573-2568
    Schlagwort(e): OBSTRUCTIVE ILEUS ; NEUROPEPTIDES ; TISSUE LEVELS
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The neuropeptides substance P, vasoactiveintestinal polypeptide, and the recently discoveredpeptide secretoneurin are neurotransmitters of theintrinsic nervous system of the gut and effect gutmotility. The aim of this study was to investigatewhether these neuropeptides are involved in thepathophysiology of large bowel ileus. Five patientsunderwent colonic resections for obstructive cancer ofthe colon. Full-thickness specimens of the resected colonwere taken 10 cm proximal and 10 cm distal to the siteof tumor obstruction. Substance P-, vasoactiveintestinal polypeptide-, and secretoneurin-likeimmunoreactivities were measured in the specimens byradioimmunoassay. In addition immunocytochemistry wasperformed. Tissue levels of substance P, vasoactiveintestinal polypeptide, and secretoneurin were lower inthe prestenotic than in the poststenotic bowel segment. Inaccordance, immunocytochemistry revealed a denserstaining of ganglion cells and fibers for all threeneuropeptides in the poststenotic bowel. The decreasedtissue levels of substance P, vasoactive intestinalpolypeptide, and secretoneurin in the prestenotic bowelsegment may contribute to the final decompensation ofobstructive ileus.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...