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 site of leakage in middle ear vessels was determined and characterized in experimental otitis media in rats. Middle ear effusion was induced by intravenous administration or local application in the tympanic bulla of substance P (SP), acetylcholine, and histamine. In another experiment, a 14 degrees C airstream was blown into the external auditory canal. Colloidal carbon was used to trace leakage sites at the light and electron microscopic levels. All mediators tested and the 14 degrees C airstream resulted in an increased number of leaking vessels in the pars flaccida and the middle ear mucosa. The leakage sites were restricted to capillaries and postcapillary venules. Increased numbers of degranulated pars flaccida mast cells were observed for SP only. Interendothelial gaps formed in leakage vessels after administration of mediators and stimulation of the external auditory canal with a 14 degrees C airstream. Also, cytoplasmic vesicle-like structures within the endothelial cells increased in number following SP and histamine treatment, suggesting that an increased permeability in experimental otitis media does not occur exclusively through interendothelial gaps.
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PMID:Identification and characterization of middle ear vascular leakage sites in experimental otitis media. 169 67

Taste buds in the anterior part of the tongue of adult rats were denervated by unilateral resection of the chorda tympani nerve in the middle ear. Three months later one group of animals was perfused and their tongues were processed for demonstration of substance P (SP) and calcitonin gene-related peptide (CGRP) immunoreactivity. Fungiform taste buds found on the denervated side showed increased numbers of intragemmal SP- and CGRP-immunoreactive (IR) fibers compared to the normal side. Compared to the normal side, the number of taste buds appeared to be fewer on the denervated side. Moreover, taste buds on this side seemed to be only partially restored. Another group of animals was given the neurotoxin capsaicin which causes a depletion of SP and CGRP from sensory axons. The animals were perfused 2 or 3 weeks after the capsaicin treatment, and their tongues prepared for SP and CGRP immunohistochemistry or for histological examination of taste buds. Very few SP- and CGRP-IR fibers were present in capsaicin-treated animals. In these animals almost all fungiform taste buds and papillae on the chorda tympani-injured side disappeared. In contrast, normal numbers of taste buds were still present on the contralateral side where the chorda tympani innervation remained intact. It is conceivable that taste buds on the chorda tympani-innervated part of the tongue, deprived of the normal chorda tympani-innervation, can regenerate and become reinnervated by SP- and CGRP-containing fibers, and that these are essential for partially restoring and maintaining the structure of the denervated taste buds and the fungiform papillae.
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PMID:The role of substance P and calcitonin gene-related peptide containing nerve fibers in maintaining fungiform taste buds in the rat after a chronic chorda tympani nerve injury. 171 May 73

The distribution and intracellular localization of substance P (SP) in middle ear mucosa (MEM), cochlea and spiral ganglion (SG) were studied by immunohistochemical technique and immunoelectron microscopy. There was a widespread distribution of SP positive nerve fibers (NF) along the median and small vessels of MEM. SP-immunoreactivity (SP-IR) positive cells could be seen in the MEM near the promontorium tympani. In the Corti's organ, SP-IR positive products were located at the base of inner hair cells. The majority of positive NF emerged like strings of beads and were radially distributed from osseous spiral laminal to the Corti's organ. About 50% of the SG cells were SP-IR positive. Two types of SP-IR positive NF were found in the VIII cranial nerve by light microscopy. Small clear vesicles with a diameter of 50-70nm were localized in the cytoplasm of the type-I SG cells by immunoelectron microscopy. In the outer membrane and inside the mitochondria, SP-IR positive substances could be distinguished as an electron dense matter. The possibility of SP as an afferent neurotransmitter or modulator in cochlea and the significance of its presence in the MEM were discussed.
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PMID:[Localization of substance P in middle ear mucosa and peripheral auditory pathways in guinea pigs]. 171 17

The mucosal lining of the middle ear cavity, in particular that of the tympanic membrane and its pars flaccida, exhibits a number of sensory nerves containing the neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP). The mucosa is not only rich in nerves and blood vessels but also contains numerous mast cells. It is possible that interactions between histamine-containing mast cells and SP-containing and CGRP-containing nerves--neurogenic inflammation--is one of the mechanisms involved in vessel permeability changes in otitis media with effusion.
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PMID:Mechanisms of otitis media development. Involvement of neurogenic inflammation. 187 Aug 76

Substance P- and neuropeptide Y-like immunoreactivity was demonstrated by immunohistochemical methods in mucosal specimens from the middle ear cleft of the guinea pig and rat. Substance P-like immunoreactivity was seen in corresponding specimens of the rabbit. Substance P-like immunoreactivity was also demonstrated in the tympanic nerve of various animal species and man. These specimens also showed weak immunoreactivity for bombesin. The findings suggest the presence of substance P in the tympanic nerve. Theoretically substance P may act in the middle ear cleft mucosa in several ways. One possibility is its putative role in the neurochemical control of the middle ear aeration. Another hypothetical possibility is a role in the neurogenic inflammation after noxious stimulation of the middle ear mucosa.
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PMID:Neuropeptides in the middle ear mucosa. 245

Neurogenic inflammation is assumed to be an important local defence mechanism against noxious stimuli in various parts of the body. Recent experimental evidence suggests substance P(SP) to be the mediator of this mechanism in the respiratory tract. Immunohistochemically, SP has earlier been reported to be present in the middle ear mucosa of the cat and guinea pig. Our earlier study demonstrated SP-like immunoreactive (SPLI) nerve fibres in the middle ear mucosa and tympanic nerve of the rat, guinea pig and man. This study shows that in experimental animals, many neuron cell bodies of the sensory ganglia of the glossopharyngeal nerve show SPLI. It is suggested that SP may be involved in the neurogenic inflammatory reaction leading to the mucosal middle ear disease.
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PMID:Neural control of the middle ear mucosa. 246 6

Vascular leakage in the middle ear cavity was studied after i.v. administration of various substances in rats and determined by the Evans blue technique. Bradykinin, histamine, serotonin, acetylcholine, substance P (SP) and vasoactive intestinal polypeptide (VIP) resulted in extravasation of Evans blue. In the case of bradykinin and histamine, the leakage was dose dependent. Calcitonin gene-related peptide (CGRP) did not affect vessel permeability. In other experiments the effect of histamine antagonists was tested on production of middle ear effusion, caused by blowing air at 14 degrees C into the external auditory canal (EAC). The increase in vessel permeability in this otitis media model was inhibited by the H2-receptor antagonist cimetidine, at doses 0.1 and 1.0 mg/ml. Diphenhydramine, an H1-receptor antagonist, arrested only partly middle ear fluid accumulation. Our study demonstrated that various inflammatory mediators and neuropeptides are capable of inducing vascular leakage in the middle ear cavity. It was also concluded that H2-receptors are involved in the regulation of middle ear vascular permeability.
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PMID:Middle ear effusion induced by various inflammatory mediators and neuropeptides. An experimental study in the rat. 247 18

Carcinoid tumors of the middle ear are rare, with only three previously reported cases. The authors report the light and electron microscopic and immunohistochemical features of two carcinoid tumors that occurred in a 34-year-old female and a 21-year-old male. Both presented with unilateral hearing loss. By light microscopic examination, both were characterized by trabecula of tall columnar cells with basal nuclei and no mitotic activity. Electron microscopic examination demonstrated large numbers of pleomorphic neurosecretory granules, perinuclear aggregates of intermediate filaments, cell junctions, and surface microvillous processes. Some cells contained intermediate filaments forming tonofilaments and lacked secretory granules. These cells stained for cytokeratin by immunoperoxidase and separated the neuroendocrine cells from the underlying basal lamina. The cells in this tumor stained for the molluscan cardioexcitatory peptide. Cells in both tumors also stained for pancreatic polypeptide. Neither case stained for lysozyme, insulin, glucagon, somatastatin, gastrin, substance P, thyroid-stimulating hormone, adrenocorticotropic hormone, Met-enkephalin, Leu-enkephalin, neuropeptide Y, peptide YY, neurotensin, Bombesin, serotonin, neuron-specific enolose, glial and neural filaments, S-100 protein, cholecystokinin, beta-endorphin, beta-human chorionic gonadotropin, luteinizing hormone/follicle-stimulating hormone, vasoactive intestinal polypeptide, prolactin or calcitonin. Carcinoid tumor of the middle ear can be distinguished from paraganglioma and middle ear adenoma.
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PMID:Carcinoid tumors of the middle ear. 357 33

Acetylcholine dropped onto the meatal surface of the tympanic membrane evoked vasodilatation and a vascular leakage to the middle ear cavity. The vasoreactions were atropine-resistant. Substance P and vasoactive intestinal polypeptide (VIP) injected intravenously caused a marked vascular leakage and VIP also vasodilatation. These blood vessel changes seem to be regulated by the parasympathetic nerves as they were inhibited by vagotomy. Constriction of the tympanic membrane vessels was mediated through alpha-receptors.
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PMID:Pharmacological characterization of receptors on blood vessels in the tympanic membrane involved in otitis media. 383 88

The distribution of nerve fibers in the middle ear mucosa and eardrum of the cat and guinea pig was studied using immunocytochemical and histofluorescence techniques. Nerve fibers containing noradrenaline, vasoactive intestinal peptide, substance P, enkephalin or immunoreactive avian pancreatic polypeptide were demonstrated in the middle ear mucosa. After extirpation of the superior cervical ganglion, nerve fibers containing noradrenaline and avian pancreatic polypeptide disappeared while fibers containing vasoactive intestinal peptide, substance P and enkephalin seemed to remain unaffected.
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PMID:Autonomic innervation of the middle ear. 618 6


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