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

Motor neurons that innervate the longitudinal muscle of the guinea pig ileum were identified by retrograde transport from the longitudinal muscle plexus in organotypic culture. Motor neurons had short projections, less than 3.5 mm long, and never had Dogiel type II morphology; most labeled neurons had morphological characteristics of Dogiel type I neurons. Immunoreactivity for choline acetyltransferase was present in 97% of retrogradely labeled nerve cell bodies, reflecting the dominant cholinergic input to the longitudinal muscle layer. Substance P immunoreactivity was present in 48% of motor neurons, indicating that it or a similar tachykinin that mediates noncholinergic excitatory transmission is likely to be released by a subset of cholinergic motor neurons. This strongly suggests that the difference in frequency dependence of substance P and acetylcholine release is attributable to different release mechanisms rather than to activation of separate populations of motor neurons. Immunoreactivity for the calcium-binding protein calretinin was present in 87% of longitudinal muscle motor neurons. The neurochemical coding of longitudinal muscle motor neurons indicated that they constitute about one quarter of all myenteric neurons and are distinct from circular muscle motor neurons.
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PMID:Identification of motor neurons to the longitudinal muscle of the guinea pig ileum. 137 56

Double-labelling immunohistochemistry and retrograde transport of the carbocyanine dye, DiI, were used to establish the pathways of submucous neurons to the mucosa of the guinea-pig small intestine. Following the application of DiI to a villus, DiI-labelled nerve cell bodies were found in the submucous plexus up to 8.3 mm circumferentially and 3.8 mm longitudinally. The size of each of the four characterised classes of submucous neurons was determined and their distributions and projections mapped. Cells characterised by vasoactive intestinal polypeptide immunoreactivity accounted for 52% of DiI-labelled cells and had the longest projections. Cells characterised by neuropeptide Y (19%) or by calretinin immunoreactivity (13% of all DiI-labelled neurons) had relatively short projections and cells with substance P immunoreactivity (20%) had intermediate lengths of projection. When DiI was applied directly to the submucous plexus, filled neurons of all classes had significantly shorter projections, indicating that they must run for considerable distances in other pathways to the mucosa, probably via the non-ganglionated plexus. On average, each villus is innervated by at least 70 submucous neurons. From quantitative estimates there are 9 submucous neurons per villus. Thus, each submucous neuron is likely to supply about 8 villi. This demonstrates a high degree of convergence and divergence in the innervation of the mucosa.
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PMID:Projections and pathways of submucous neurons to the mucosa of the guinea-pig small intestine. 138 75

Immunoreactivity for calretinin, a calcium-binding protein, was studied in neurones in the guinea-pig small intestine. 26 +/- 1% of myenteric neurones and 12 +/- 3% of submucous neurones were immunoreactive for calretinin. All calretinin-immunoreactive neurones were also immunoreactive for choline acetyltransferase and hence are likely to be cholinergic. In the myenteric plexus, two subtypes of Dogiel type-I calretinin-immunoreactive neurones could be distinguished from their projections and neurochemical coding. Some calretinin-immunoreactive myenteric neurones had short projections to the tertiary plexus, and hence are likely to be cholinergic motor neurones to the longitudinal muscle. Some of these cells were also immunoreactive for substance P. The remaining myenteric neurones, immunoreactive for calretinin, enkephalin, neurofilament protein triplet and substance P, are likely to be orad-projecting, cholinergic interneurones. Calretinin immunoreactivity was also found in cholinergic neurones in the submucosa, which project to the submucosal vasculature and mucosal glands, and which are likely to mediate vasodilation. Thus, calretinin immunoreactivity in the guinea-pig small intestine is confined to three functional classes of cholinergic neurones. It is possible, for the first time, to distinguish these classes of cells from other enteric neurones.
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PMID:Calretinin immunoreactivity in cholinergic motor neurones, interneurones and vasomotor neurones in the guinea-pig small intestine. 171 38

Immunoreactivity for the calcium binding protein, calretinin (calretinin-ir), was demonstrated in cell bodies of vagal and glossopharyngeal sensory ganglia (jugular, petrosal, and nodose ganglia) and in associated nerve fibers. In the jugular and petrosal ganglia, many calretinin-ir neurons were also immunoreactive for calcitonin gene-related peptide and substance P. In the nodose ganglion, most of the calretinin-ir neurons lacked these peptides. None of the calretinin-ir neurons in these ganglia were also immunoreactive for tyrosine hydroxylase.
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PMID:Calretinin-immunoreactivity in vagal and glossopharyngeal sensory neurons of the rat: distribution and coexistence with putative transmitter agents. 172 Sep 97

It is well established that acetylcholine is a neurotransmitter at several distinct sites in the mammalian enteric nervous system. However, identification of the cholinergic neurons has not been possible due to an inability to selectively label enteric cholinergic neurons. In the present study an immunohistochemical method has been developed to localize choline acetyltransferase, the synthetic enzyme for acetylcholine, in order that cholinergic neurons can be visualized. The morphology, neurochemical coding and projections of cholinergic neurons in the guinea-pig small intestine were determined using double-labelling immunohistochemistry. These experiments have revealed that many myenteric neurons are cholinergic and that they can be distinguished by their specific combinations of immunoreactivity for neurochemicals such as calretinin, neurofilament protein triplet, substance P, enkephalin, somatostatin, 5-hydroxytryptamine, vasoactive intestinal peptide and calbindin. On the basis of their previously described projections, functional roles could be attributed to each of these populations. The identified cholinergic neurons are: motorneurons to the longitudinal muscle (choline acetyltransferase/calretinin); motorneurons to the circular muscle (choline acetyltransferase/neurofilament triplet protein/substance P, choline acetyltransferase/substance P and choline acetyltransferase alone); orally directed interneurons in the myenteric plexus (choline acetyltransferase/calretinin/enkephalin); anally directed interneurons in the myenteric plexus (choline acetyltransferase/somatostatin, choline acetyltransferase/5-hydroxytryptamine, choline acetyltransferase/vasoactive intestinal peptide); secretomotor neurons to the mucosa (choline acetyltransferase/somatostatin); and sensory neurons mediating myenteric reflexes (choline acetyltransferase/calbindin). This information provides a unique opportunity to identify functionally distinct populations of cholinergic neurons and will be of value in the interpretation of physiological and pharmacological studies of enteric neuronal circuitry.
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PMID:Immunohistochemical identification of cholinergic neurons in the myenteric plexus of guinea-pig small intestine. 172 93

The arrangement of the enteric nerve plexuses, and the distributions and projections of chemically specified neurons in the proximal colon of the guinea-pig were studied. The neural plexuses were examined using immunoreactivity to neuron specific enolase, and individual subpopulations were studied using antibodies raised against vasoactive intestinal peptide (VIP), substance P (SP), enkephalin, neuropeptide Y (NPY), gastrin releasing peptide (GRP), galanin, somatostatin, calbindin and calretinin. Nitric oxide producing neurons were studied using NADPH diaphorase histochemistry. The myenteric and submucous plexuses were not uniform around the entire circumference; at the mesenteric aspect of the colon there was almost no longitudinal muscle and the circular muscle was unusually thick and cord-like. In this region there was no tertiary plexus of fibres, and the ganglia of the myenteric and submucous plexuses were elongated in the direction of the circular muscle. Neuronal pathways within the antimesenteric aspect of the colon were investigated using nerve lesioning procedures. VIP, GRP, galanin, calbindin and NADPH diaphorase containing neurons lay in anally projecting pathways within the myenteric plexus, while enkephalin and somatostatin appeared in orally projecting nerve pathways. Few NPY immunoreactive nerve cells were found in the myenteric plexus of the proximal colon. The longitudinal muscle was innervated with VIP, SP, enkephalin and NADPH diaphorase containing fibres. The circular muscle was innervated by axons containing all substances investigated except NPY. Galanin, NPY, somatostatin and VIP fibres, all particularly dense in the mucosa, largely arose from nerve cell bodies in the submucous plexus. The results of the present study indicate that chemically specified neuronal populations in the proximal colon of the guinea-pig are more similar to the distal colon than the ileum, but that neuro-chemical and anatomical differences exist between the proximal and distal colon.
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PMID:Immunohistochemical analysis of neurons and their projections in the proximal colon of the guinea-pig. 751 May 7

The aim of this study was to investigate the neurochemical coding of myenteric neurons in the guinea pig gastric corpus by using immunohistochemical methods. Antibodies and antisera against calbindin (CALB), calretinin (CALRET), choline acetyltransferase (ChAT), calcitonin gene-related peptide (CGRP), dopamine beta-hydroxylase (DBH), beta-endorphin (ENK), neuropeptide Y (NPY), neuron-specific enolase (NSE), nitric oxide synthase (NOS), protein gene product 9.5 (PGP), parvalbumin (PARV), serotonin (5-HT), somatostatin (SOM), substance P (SP), tyrosine hydroxylase (TH), and vasoactive intestinal peptide (VIP) were used. Double- and triple-labeling studies revealed colocalization of certain transmitters and enabled the identification of distinct subpopulations of gastric enteric neurons. NPY/VIP/NOS/ENK were present in 28% of all neurons, whereas 11% had NPY/VIP/DBH/ChAT; NOS-only neurons made up 2% of the population. The combination SP/ChAT/ENK occurred in 21% of the population, whereas SP/ChAT/ENK/CALRET and SP/CHAT/SOM/ +/- CALRET was identified in 5% and 6% of all cells, respectively. 5-HT-containing neurons comprised 2% of all cells and could be further classified by the presence of additional antigens as 5-HT/SP/(ChAT) or 5-HT/VIP/(ChAT). Approximately 21% of all neurons contained only ChAT with no additional antigen present and are referred to as ChAT/-. Gastric myenteric ganglion cells were not immunoreactive for CALB, PARV, CGRP, or TH. The results of this study indicate that gastric myenteric neurons can be characterized on the basis of different chemical coding. Neurochemical coding of corpus myenteric neurons revealed some similarities and significant differences in comparison with other regions of the gut. These differences might reflect adaptation of enteric nerves according to regional specialization and the distinct functions of the proximal stomach as a gastric reservoir.
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PMID:Neurochemical coding of enteric neurons in the guinea pig stomach. 753 52

Double-labeling immunofluorescent histochemistry demonstrates that calretinin, a calcium-binding protein, coexists with calcitonin gene-related peptide, vasoactive intestinal peptide, and substance P in the fibers innervating the lamina propria of the rat intestinal villi. An acetylcholinesterase histochemical stain revealed that the majority of calretinin-containing cells in the myenteric ganglia were cholinergic and that about one half of the submucosal calretinin-containing cells colocalized with acetylcholinesterase. In situ hybridization studies confirmed the presence of calretinin mRNA in the dorsal root ganglia, and a ribonuclease protection assay verified the presence of calretinin message in the intestine. The coexistence of calretinin in calcitonin-gene-related-peptide-containing cells that also contained substance P and vasoactive intestinal polypeptide in the dorsal root ganglia suggest that these ganglia are the source of the quadruple colocalization within the sensory fibers of the villi. Although the function of calretinin in these nerves is unknown, it is hypothesized that the coexistence of three potent vasodilatory peptides influences the uptake of metabolized food products within the vasculature of the villi.
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PMID:Quadruple colocalization of calretinin, calcitonin gene-related peptide, vasoactive intestinal peptide, and substance P in fibers within the villi of the rat intestine. 754 20

Calcium-binding proteins and neuropeptides were examined in trigeminal neuronal cell bodies retrogradely labeled with Fast blue (FB) from the maxillary molar tooth pulp of the rat. FB-labeled cells were located in the maxillary division of the trigeminal ganglion. Approximately 30 and 50% of the labeled cells were immunoreactive for parvalbumin and calcitonin gene-related peptide (CGRP), respectively. The coexpression of these substances was observed in 9.5% of FB-labeled cells. On the other hand, 2.4% of FB-labeled cells exhibited calretinin-immunoreactivity (CR-ir) and 20% tachykinin (TK)-ir. The coexpression of CR and TK was observed in 1.9% of FB-labeled cells, i.e., most of CR-ir FB-labeled neurons coexpressed TK-ir. An immuno-EM method revealed that all parvalbumin-ir nerve fibers in the root pulp were myelinated and that CGRP-ir nerve fibers were both myelinated (15%) and unmyelinated (85%). The present study indicated that primary nociceptors innervating the rat molar tooth pulp contained parvalbumin and CR and coexpressed these calcium-binding proteins and neuropeptides. It was suggested that peripheral axons of parvalbumin-ir tooth pulp primary neurons are all myelinated. Most peripheral CR-ir axons are probably unmyelinated because TK-ir myelinated axons have never been demonstrated in any peripheral organ.
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PMID:Parvalbumin- and calretinin-immunoreactive trigeminal neurons innervating the rat molar tooth pulp. 763 81

The cell body size of primary neurons were measured in the trigeminal (TG) and lumbar dorsal root ganglia (DRG) monochrome-stained for calretinin (CR)-like immunoreactivity. A trichrome stain for CR, carbonic anhydrase (CA) and tachykinin (TK) was also employed to estimate possible overlap of cellular distribution of these substances. In the DRG, the cell size spectrum of CR-positive cells was clearly bimodal; a greater proportion (84.1%) of CR-positive cells was distributed in the range > or = 800 microns2 with a mode between 1,500-1,600 microns2, while a smaller proportion (14.8%) < 700 microns2 with a mode of 400-500 microns2. They were evenly distributed throughout the DRG. Although CR-positive TG neurons were smaller than similar DRG neurons, a bimodal distribution pattern remained unchanged. 94.6% of CR-positive cells measured 100-1,400 microns2 with peak ranges of 200-300 microns2 and 400-500 microns2. Most of CR-positive cells in the ophthalmic division were 400 microns2 or larger and small CR-positive cells (< 400 microns2) were concentrated in the maxillary and mandibular divisions. Most of CR-positive DRG cells showed CA activity (76.5%), while those with TK-immunoreactivity were rare (7.2%). In the TG, 38.4% of CR-positive cells were TK-positive. They were mostly smaller than 800 microns2. On the other hand, CA was detected in 43.4% of CR-positive TG cells. Most of the TG cells co-expressing CR and CA were 400 microns2 or larger. Simultaneous co-expression of TK and CA by the CR-positive cells was negligible.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Calretinin-immunoreactive neurons in the trigeminal and dorsal root ganglia of the rat. 769 Jun 67


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