Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The innervation of the ductuli efferentes and seven zones of the guinea-pig epididymis was investigated using immunohistochemical, histochemical and electron-microscopical techniques. Nerve fibers were localized by use of antibodies against substance P (SP-IR), vasoactive intestinal polypeptide (VIP-IR) and dopamine-beta-hydroxylase (DBH-IR). In the ductuli efferentes and all zones of the epididymal duct, SP-IR is consistently observed in the interstitial tissue and perivascular areas. Histochemistry reveals a significant amount of acetylcholinesterase-containing fibers in the interstitial, perivascular and periductal smooth muscles of the ductuli efferentes and zones V, VI and VII. In contrast to the homogeneous distribution of SP-IR within all zones of the epididymis, VIP-IR is seen only in zones VI and VII. Within these zones, VIP-IR is detected in large amounts in the subepithelial and muscular layers as is a sparse number of SP-IR varicosities. DBH-IR is also seen throughout all zones in the interstitial and perivascular regions with a tendency to increase in zones VI and VII. Transmission electron microscopy (TEM) reveals evidence of a cholinergic (agranular vesicles, AGV), adrenergic (small granular vesicles, SGV) and peptidergic (large granular vesicles, LGV) innervation throughout the interstitial connective tissue of the ductuli efferentes and all epididymal zones. Furthermore AGV are localized in the subepithelial layer, and also co-stored with LGV in the muscular layer of zones VI and VII. No nerve profiles were encountered within the epithelium. A correlation of immunohistochemical findings to TEM counterparts as well as their possible functional role are discussed.
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PMID:Studies of the guinea-pig epididymis. III. Innervation of epididymal segments. 257 39

Enkephalinergic axons and terminals were identified by the PAP immunohistochemical method in lamina I (marginal zone) and lamina IIO (outer substantia gelatinosa) in the dorsal horn of the monkey spinal cord. Synaptic profiles with enkephalin-like immunoreactivity (MELI) contained clear, round, vesicles, sometimes a few large granular vesicles, and usually formed asymmetrical contacts. MELI terminals forming synaptic contacts with various sizes of dendrites and with dendritic spines were the most common type of relationship found; axosomatic contacts were few. Additionally, two types of complexes were observed in which an MELI terminal formed a specialized apposition with an unlabelled terminal. The contact often resembled a synapse and in most cases the MELI terminal was suspected to be presynaptic. One complex consisted of a MELI terminal apposing the LGV type terminal (containing large granular vesicles), which in turn was presynaptic to a dendrite. (The identity of the LGV terminal could not be determined, but it had some characteristics similar to those described for substance P terminals and for a class of primary afferents in the monkey dorsal horn). The other type of complex consisted of a MELI terminal apposing an R-type terminal (containing small, round, clear vesicles) which was in turn presynaptic to a dendrite. Often, the MELI terminal also formed a synapse onto the same dendrite. The axodendritic, axospinous and axosomatic contacts of MELI terminals in the superficial dorsal horn may produce some of the depressive postsynaptic-like effects of enkephalin iontophoresis onto dorsal horn neurons. In these cases the responses of dorsal horn neurons to both low threshold and nociceptive primary afferents is suppressed. However, the opiate receptor-dependent PAD of C-fibers observed in the dorsal horn may be mediated by the MELI complexes formed with LGV and R terminals found in lamina I.
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PMID:Ultrastructure of chemically defined neuron systems in the dorsal horn of the monkey. II. Methionine-enkephalin immunoreactivity. 635 63

The ultrastructural organization of serotoninergic axons and terminals in the superficial dorsal horn of the monkey was examined by the PAP immunohistochemical method. Terminals with serotonin-like immunoreactivity (SLI) were identified in lamina I (marginal zone) and lamina IIo (outer substantia gelatinosa). Labelled profiles contained many small, round, clear vesicles and usually a few granular vesicles (70 nm diameter). Most synaptic junctions were symmetrical with sparse pre- and post-synaptic densities. Most frequently, terminals formed axodendritic synapses on large and small dendrites; axosomatic and axospinous contacts were infrequent. In addition SLI terminals were found apposed to unlabelled LGV-type terminals (containing several large granular vesicles of 75-90 nm). The appositions commonly met some criteria of axo-axonic synapses and the SLI terminal was suspected to be presynaptic. The unlabelled LGV terminal was often presynaptic to a dendrite, and it had characteristics similar to those observed for some primary afferents, particularly those which may contain substance P, a proposed transmitter for nociceptive C-fibers. Most of these 'triplet' complexes (SLI terminal apposing and LGV terminal synapsing onto dendrite) were found in the apical region of lamina I. The axodendritic and axosomatic serotoninergic contacts onto dorsal horn neurons may be a basis for some of the reported post-synaptic effects on dorsal horn cells of either local serotonin iontophoresis or of stimulation of the brainstem raphe, the probable origin of the serotoninergic terminals. These effects include both depression and excitation of the responses of the dorsal horn cells to electrical or natural stimulation of primary afferents, particularly C-fibers and nociceptors. Likewise, the contacts of SLI terminals with LGV terminals may provide a morphological substrate for the presynaptic effects also observed for serotonin iontophoresis or raphe stimulation, including changes in the excitability of primary afferent C-fibers.
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PMID:Ultrastructure of chemically defined neuron systems in the dorsal horn of the monkey. III. Serotonin immunoreactivity. 661 58