ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    Digitale Medien
    Digitale Medien
    [s.l.] : Nature Publishing Group
    Nature 304 (1983), S. 638-640 
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] The molluscan neuropeptide FMRFamide, isolated from the clam Macrocallista nimbosa5, has potent effects on smooth muscle6, cardiac muscle7 and neurones (ref. 8 and G.A.C. and N. Davies, unpublished). Immunocytochemical studies in the snails Lymnaea stagnalis9 and Helix aspersa10 provide clear ...
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    ISSN: 1432-119X
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the central nervous system of the pond snail Lymnaea stagnalis a large number of elements (cells and fibers) can be identified with antisera (a-FM) to the molluscan cardioactive tetrapeptide FMRFamide (Phe-Met-Arg-Phe-NH2). Of these elements some are also reactive to antivasotocin (a-VT) and/or anti-gastrin (a-Gas). These observations suggest that the a-FM positive elements belong to more than one type. Previous results had already indicated that the immunoreactivity of many a-FM positive cells is influenced by the type of fixation. Taking into account the effects of three fixatives on the reactivity of the cells, and their staining characteristics with the two other antisera used, 8 a-FM positive types could be distinguished. Homologous and heterologous adsorptions were carried out to test the specificity of a-FM, a-VT and a-Gas. After homologous adsorptions no staining was obtained. After heterologous adsorptions only part of the multiple staining cells were identified. This indicates that in a-FM, a-VT and a-Gas in addition to (more) selective IgG molecules, less specific IgG molecules occur that can bind to other peptides than those used to raise the antisera (cross-reaction). The (more) selective IgG molecules in a-FM bind to 6 of the a-FM positive types, suggesting that in L. stagnalis a family of FMRFamide-like substances occurs. This conclusion is sustained by results obtained with a-FM adsorbed with fragments of FMRFamide. It appeared that the less selective IgG molecules in a-FM, a-VT and a-Gas cause the multiple stainings of those cells that remain unstained with an antiserum adsorbed with a heterologous antigen. Multiple staining, which can not be abolished by heterologous adsorption, probably is due to the binding of (more) selective IgG molecules to different antigenic determinants present in the cells. The results show that unexpected cross-reactions may occur in immunocytochemical staining procedures. It thus seems precarious to draw conclusions about the chemical structure of a peptide solely on the basis of immunocytochemical studies.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Histochemistry and cell biology 73 (1982), S. 499-508 
    ISSN: 1432-119X
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary FMRFamide-like immunoreactivity has been localized in different parts of the hydra nervous system. Immunoreactivity occurs in nerve perikarya and processes in the ectoderm of the lower peduncle region near the basal disk, in the ectoderm of the hypostome and in the ectoderm of the tentacles. The immunoreactive nerve perikarya in the lower peduncle region form ganglion-like structures. Radioimmunoassays of extracts of hydra gave displacement curves parallel to standard FMRFamide and values of at least 8 pmol/gram wet weight of FMRFamide-like immunoreactivity. The immunoreactive material eluted from Sephadex G-50 in several components emerging shortly before or after position of authentic FMRFamide. The presence of FMRFamide-like material in coelenterates shows that this family of peptides is of great antiquity.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    ISSN: 1432-0878
    Schlagwort(e): Immunocytochemistry ; Biologically active peptides ; Lymnaea stagnalis ; Neurohormone ; Neurotransmitter
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Perikarya and nerve fibers were immunocytochemically identified in the central nervous system of the pond snail Lymnaea stagnalis by means of the unlabelled antibody enzyme method with antisera to 15 biologically active peptides of vertebrates: vasopressin, vasotocin, oxytocin, α-melanocyte stimulating hormone (α-MSH), met-enkephalin, somatostatin, glucagon, insulin, glucose-dependent insulinotropic peptide (GIP), vaso-active intestinal polypeptide (VIP), gastrin, secretin, pancreatic polypeptide (PP), Substance P, calcitonin. No immunostaining was obtained with antisera to β-endorphin, cholecystokinin (CCK), neurophysin I and II. Particular neurons could be identified with two antisera (anti-vasopressin/vasotocin, anti-α-MSH/metenkephalin, anti-substance P/PP, anti-PP/gastrin). Apparently this indicates that populations of cells identified with a given antiserum may consist of more than one cell type. Only a few of the new peptidergic cells appeared to be identical with classical neurosecretory cells. Thus the growth hormone producing Light Green Cells stained with anti-somatostatin and the axon terminals of the ovulation hormone producing Caudo-Dorsal Cells with anti-met-enkephalin. Whether this indicates structural identity of the growth hormone with somatostatin and of the ovulation hormone with met-enkephalin remains to be investigated. Just like the classical neurosecretory cells a number of the new peptidergic cells (anti-glucagon, -insulin, -met-enkephalin, -somatostatin, and -PP positive cells) send their axons to the peripheries of commissures, connectives or nerves. Thus these cells can be considered as probably neuroendocrine. The classical neurosecretory cells release their products into the haemolymph from these sites. Other new peptidergic cells (e.g., anti-vasopressin, -vasotocin, -oxytocin and -GIP positive cells) have axons that terminate, probably synaptically, on other neurons, indicating that they are “more conventional” neurons, their products being neurotransmitters/neuromodulators. It can also not be excluded that some cells of a population containing a given peptide are neuroendocrine and others make contact with other neurons.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    ISSN: 1432-0878
    Schlagwort(e): Immunocytochemistry ; Cardioactive peptide ; Lymnaea stagnalis ; Neurohormone ; Neurotransmitter
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary With an antiserum to the molluscan cardioactive tetrapeptide FMRF-amide immunoreactive perikarya and nerve fibers were identified in the central and peripheral nervous system of the pond snail Lymnaea stagnalis. Their localization is described. The same antiserum yielded reactive product in particular cells of the epithelium of the alimentary tract. The use of two different fixatives, glutaraldehyde, and a mixture of glutaraldehyde, picric acid, and acetic acid (GPA) showed that certain nerve cells can be identified only in material fixed with either the one or the other of these two fixatives, a result which indicates that in Lymnaea more than one FMRF-amide-like substance may occur. “Positive” axon endings were found in the periphery of various nerves, i.e., in places where neurohormones are released into the blood. Other fibers were found to end, probably synaptically, on other neurons, on epithelial cells in the stomach, and between muscle cells in various parts of the body, e.g., in the heart. In these cases the FMRF-amide-like substance may function as a neurotransmitter or a neuromodulator.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    ISSN: 1432-0878
    Schlagwort(e): Peptidergic neurotransmission ; Lymnaea stagnalis ; Immunocytochemistry ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Three neuronal systems of the pond snail Lymnaea stagnalis were immunocytochemically investigated at the ultrastructural level with the unlabeled peroxidase-antiperoxidase technique. Preliminary electrophysiological and cell-filling investigations have shown that a cluster of neurons which reacts positively with an antiserum against the molluscan cardio-active peptide FMRFamide, sends axons to the penis retractor muscle. In this muscle anti-FMRF-amide (aFM) positive axons form neuro-muscular synapses with (smooth) muscle fibers. The morphological observations suggest the aFM immunoreactive system to be involved in peptidergic neurotransmission. In the right parietal ganglion a large neuron (LYAC) is penetrated by aFM positive axons which form synapse-like structures (SLS) with the LYAC. The assumption that the SLS represent the morphological basis for peptidergic transmission is sustained by the observation that iontophoretical application of synthetic FMRFamide depolarizes the LYAC. The axons of a group of pedal anti-vasopressin (aVP) positive cells run in close vicinity to the cerebral ovulation (neuro-)-hormone producing cell system (CDC system) Synapses or SLS between the two systems were not observed. The fact that (bath) application of arg-vasopressin induces bursting in the CDC, may indicate that the vasopressin-like substance of the aVP cells is released non-synaptically.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    ISSN: 1432-0878
    Schlagwort(e): Immunocytochemistry ; FMRF-amide ; Central nervous system ; Neurohormone ; Neurotransmitter
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary With an antiserum to the molluscan cardio-excitatory tetrapeptide FMRF-amide neurons and/or nerve fibers were immunocytochemically identified in the central nervous systems of a snail (Lymnaea stagnalis), some insects (Leptinotarsa decemlineata, Periplaneta americana, Locusta migratoria, Pieris brassicae), a fish (Poecilia latipinna) and a mammal (mouse). The fact that immunoreactive material was observed in neurohaemal organs (corpora cardiaca of the insects) as well as in axon terminals ending on other neurons, seems to indicate that this peptide can function as a neurohormone and/or as a neurotransmitter. The results sustain the hypothesis that biologically active peptides have a wide distribution in the animal kingdom.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    ISSN: 1432-0878
    Schlagwort(e): Immunocytochemistry ; ACTH ; Lymnaea stagnalis ; Neurohormone ; Neurotransmitter
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Two giant neurons (diameter 130 μm) were identified immunocytochemically by means of the unlabeled antibody enzyme technique with anti ACTH 1–39 and 1–24 in the pond snail Lymnaea stagnalis. The cells are located in the visceral and the right parietal ganglion, respectively. They contain moderately electron dense elementary granules (diameter 150–160 nm). By means of the intracellular horseradish peroxidase injection technique it was shown that the cells send fibres into the neuropiles of various ganglia and into nerves. Synapses occur on the fine fibre branches in the neuropile. Synapse-like structures were found on the cell bodies and on the major fibres. The giant neurons are electrotonically coupled. With toluidine blue staining for small peptides it was demonstrated that in the central nervous system of the pond snail numerous peptidergic neurons occur in addition to those identified with the classical staining methods for neurosecretion.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    ISSN: 1432-0878
    Schlagwort(e): Immunocytochemistry ; Biogenic amines ; Vasotocin ; Lymnaea stagnalis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Consecutive sections of certain neurons in the central ganglia of the pond snail Lymnaea stagnalis appear to be immunoreactive to anti-dopamine and anti-serotonin. The Cerebral Giant Neurons stain in addition with antivasotocin. The observations indicate the presence of two biogenic amines within the same neuron and in addition their co-existence with a biologically active peptide.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    ISSN: 1432-0878
    Schlagwort(e): FMRF-amide ; Immunocytochemistry ; Nervous system ; Microstomum lineare (Turbellaria)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The central nervous system (CNS) and the peripheral nervous system (PNS) of the flatworm Microstomum lineare were studied by means of the peroxidase-antiperoxidase (PAP) immunocytochemical method, with the use of antisera to the molluscan cardioactive peptide FMRF-amide. FMRF-amide immunoreactive perikarya and nerve fibres are observed in the CNS and the PNS. In the CNS, immunoreactive perikarya and nerve fibres occur in the brain, in the epithelial lining and the mesenchymal surroundings of the ciliated pits, and positive fibres in the longitudinal nerve cords. In the PNS, immunoreactive fibre bundles with variocosities occur in the pharyngeal nerve ring, in symmetrical groups of perikarya on each side of the pharynx, and in the mouth area. Positive perikarya and meandering nerve fibres appear in the intestinal wall. A few immunoreactive cells and short nerve processes are observed at the male copulatory organ and on both sides of the vagina. Some immunoreactive peptidergic cells do not correspond to cells previously identified by histological techniques for neurosecretory cells. The distribution of immunoreactivity suggests that the FMRF-amide-like substance in CNS and PNS in this worm has roles similar to those of the brain-gut peptides in vertebrates. The status of FMRF-amide-like peptides as representatives of an evolutionarily old family of peptides is confirmed by the positive immunoreaction to anti-FMRF-amide in this primitive microturbellarian.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...