Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.14.16.2 (tyrosine hydroxylase)
 14,760 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The recurrent laryngeal nerve (RLN) consists of various motor, sensory and autonomic nerve fibers, although it has not been established whether different neuronal types exhibit a similar ability to regenerate. To address this question, freezing was used to injure the cat RLN fibers and the presence or absence of immunoreactivity for neuropeptides or transmitter-synthesizing enzymes was then examined as a marker to classify the fibers. In the control RLN, calcitonin gene-related peptide-immunoreactive (CGRP-IR) fibers were the highest in number and were distributed throughout the nerve fascicles. The number of substance P-immunoreactive (SP-IR) fibers was about 40% that of CGRP-IR fibers, while a portion of CGRP-IR fibers was found to contain SP immunoreactivity. Relatively low numbers of tyrosine hydroxylase-immunoreactive (TH-IR) and neuropeptide Y (NPY-IR) nerve fibers were seen which tended to form clusters. The distribution pattern of NPY-IR fibers was very similar to that of TH-IR fibers. In the regenerating RLN 1 week after the freezing injury, the fastest growing axons were CGRP-IR, while the regenerating rates of SP-IR, TH-IR and NPY-IR fibers were slower than that of CGRP-IR fibers. These results suggest that the ability for neurite regeneration varies among neuron types and that CGRP-IR fibers possess the most rapid ability to regenerate.
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PMID:Neurite regeneration in the cat recurrent laryngeal nerve: an immunohistochemical study. 128 3

The rostral ventrolateral medulla (RVLM) contains sympathoexcitatory neurons that exert a powerful control over the sympathetic outflow to the cardiovascular system. In the cat there is a concentration of such neurons (but not neurons subserving other functions) within a narrow longitudinal column in the RVLM termed the subretrofacial (SRF) nucleus. Furthermore, it has been suggested that there are subgroups of cells, located at different rostrocaudal levels of the SRF nucleus, that preferentially or exclusively control different vascular beds (e.g. in the kidney and hindlimb). The aim of this study was to map quantitatively the rostrocaudal distribution within the nucleus of different cell types, defined according to morphological and/or chemical criteria, and to correlate this with the regional vasomotor effects (in hindlimb and kidney) evoked by stimulation of SRF cells at the corresponding rostrocaudal levels. SRF cells were highly heterogeneous with respect to both their morphology and chemical properties. They varied greatly in size (equivalent diameter ranging from 10-40 microns) as well as in shape and orientation. An immunohistochemical examination using the avidin-biotin procedure revealed that many SRF cells (estimated 57% of all SRF cells) were immunoreactive for tyrosine hydroxylase (TH, a marker of catecholamine cells). In addition, there were SRF cells immunoreactive for neuropeptide Y (NPY, 11% of total), enkephalin (ENK, 16% of total), and serotonin (5HT, 10% of total), but not for substance P, galanin or somatostatin. Different cell types, defined according to their morphology and/or chemical properties, were unevenly distributed throughout the nucleus. In the most caudal part of the SRF nucleus, virtually all cells were TH-positive, and the large majority (estimated 80%) were NPY-positive, suggesting that many cells at this level contained both TH and NPY. In contrast, in the most rostral part of the SRF nucleus, only 30% of cells were TH-positive, and no NPY-positive cells were observed. Both 5HT- and ENK-positive cells were found throughout the rostrocaudal extent of the nucleus, but predominantly within its rostral part. Furthermore, TH-positive cells in the rostral SRF nucleus were on average significantly larger (mean equivalent diameter 18-43% greater) than TH/NPY-positive cells in the caudal part of the nucleus, but smaller than 5HT- or ENK-positive cells at the same level. Overall, rostral cells (regardless of their chemical type) were larger than caudal cells within the SRF nucleus (mean equivalent diameter 13-28% greater).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Rostrocaudal differences in morphology and neurotransmitter content of cells in the subretrofacial vasomotor nucleus. 137 28

The purpose of the present study was to investigate the viability, growth characteristics and neuropeptide expression of intraocular superior cervical ganglia (SCG) grafts from neonatal (1-3 d), mature (4-5 months) and aged (20-24 months) rats. In vivo measurements, Falck-Hillarp histochemistry using iris whole mounts to assess catecholamine fiber outgrowth and immunocytochemical localization of tyrosine hydroxylase (TH-), neuropeptide Y (NPY-), leu-enkephalin (ENK-) and calcitonin gene-related peptide (CGRP-) like immunoreactivity (LI) were used. Measurements indicated a marked decrease in volume during the first week after grafting and a more gradual decrease thereafter. This was most evident in newborn SCG. With prolonged survival time, the newborn ganglia demonstrated more varicose nerve terminals and increased catecholamine fiber outgrowth and arborization. Extensive and complex outgrowth of catecholamine fibers with varicose nerve terminals occurred more rapidly with mature and aged ganglia. In situ, all ganglion cell bodies and fibers demonstrated TH-LI. Localization of TH-LI after grafting indicated an increase in fiber density and a decrease in cell body density of 65%, 40% and 40% in newborn, mature and aged ganglia respectively. NPY-LI in cell bodies had a perinuclear fluorescence pattern consistent with localization in the Golgi apparatus. Grafting of newborn, mature and aged SCG resulted in a 20%, 20% and 35% decrease respectively of cell bodies containing NPY-LI. A concommitant increase in fiber diameter, fluorescence intensity and extent of arborization was observed. The characteristic distribution of ENK-LI in cell bodies and axons in mature and aged ganglia was not affected by grafting. However, there was a greater than 50% reduction in the number of cell bodies expressing ENK-LI. CGRP-LI, localized in fibers and axon terminals in SCG in situ, was not identified after grafting. In summary, we have demonstrated that SCG from all age groups form extensive fiber networks and continue neuropeptide expression after intraocular grafting. This was seen best in mature and aged donors and may suggest a role for SCG transplants in the replacement of monoaminergic neurons in the CNS.
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PMID:Effects of donor age on superior cervical ganglion transplants: evaluation of Falck-Hillarp histochemistry and immunocytochemistry. 167 95

Applying a double-immunofluorescence technique, the porcine ovary is demonstrated to receive two populations of NPY-immunoreactive nerve fibres originating from the inferior mesenteric ganglion: one with colocalized tyrosine hydroxylase and supplying predominantly the ovarian vasculature, and a second, solely NPY-immunoreactive and almost exclusively associated with growing follicles. A third group of tyrosine hydroxylase- and dopamine-beta-hydroxylase-positive, but NPY-negative nerve fibres is associated with ovarian blood vessels and, to a minor extent, with ovarian follicles. As revealed by retrograde tracing, the vast majority of postganglionic neurons projecting to the ovary is located in a discrete area of the ganglion, suggesting a somatotopic organization of the porcine inferior mesenteric ganglion. Moreover, the findings indicate that three subpopulations of postganglionic sympathetic neurons with different chemical codes supply different target components of the porcine ovary. The physiological relevance of the described neurons in the nervous control of ovarian functions remains to be elucidated.
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PMID:The origin of ovarian neuropeptide Y (NPY)-immunoreactive nerve fibres from the inferior mesenteric ganglion in the pig. 168 53

The axonal transport blocker colchicine has been extensively used in immunohistochemical studies to induce accumulation of neuroactive compounds, especially neuropeptides, in neuronal somata and thus improve their visualization. To assess whether colchicine might, in addition, influence the synthesis of such compounds, we have now used in situ hybridization to examine the levels of mRNAs encoding for several neuropeptides (galanin [GAL], cholecystokinin [CCK], somatostatin [SOM], neuropeptide Y [NPY]) and neurotransmitter-synthesizing enzymes (choline acetyltransferase [ChAT], tyrosine hydroxylase [TH], amino acid decarboxylase [AADC], and glutamic acid decarboxylase [GAD]) after intraventricular administration of the drug. The results show that colchicine differentially modifies the levels of several mRNA species in different brain areas. Thus GAL mRNA levels increase in virtually all regions examined, including the basal forebrain, hypothalamus, dorsal raphe nucleus, locus coeruleus, and nucleus tractus solitarii. In addition, after colchicine treatment, GAL mRNA appears to be induced in the ipsilateral hemisphere in regions such as the cortex, hippocampus, striatum, lateral septum, and some nuclei of the thalamus as well as within white matter, where it cannot be detected in control animals. Although GAL mRNA in the vast majority of cases is neuronal, some findings indicate a possible glial localization. In parallel, colchicine depletes ChAT mRNA and increases GAD mRNA in the basal forebrain and striatum and decreases AADC mRNA in the dorsal raphe nucleus and locus coeruleus. In the latter nucleus, NPY and TH mRNA levels are increased by colchicine. In contrast, TH mRNA and also CCK mRNA levels decrease in the substantia nigra. In the cortex, hippocampus, and thalamus ipsilateral to colchicine injection CCK mRNA levels are markedly decreased, whereas SOM mRNA is decreased and NPY mRNA increased in the hippocampus but unchanged in the cortex. The results are discussed with reference to the possible artifacts that the use of colchicine might induce in immunohistochemical mapping studies and in relation to possible neurotoxic actions of colchicine, in some cases perhaps related to impaired retrograde transport of growth factor(s).
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PMID:Differential effects of intracerebroventricular colchicine administration on the expression of mRNAs for neuropeptides and neurotransmitter enzymes, with special emphasis on galanin: an in situ hybridization study. 170 58

Immunohistochemical properties of the terminal nerve network in the rat heart were assessed by use of the elution-restaining method. The colocalization of the enzymes involved in catecholamine synthesis (tyrosine hydroxylase--TH. dopamine-beta-hydroxylase--DBH) as well as the respective distributions of the neuropeptides associated with the adrenergic nervous system (neuropeptide tyrosine--NPY, C-terminal flanking peptide of neuropeptide Y--C-PON) were studied in series of serial sections throughout the interatrial septum and the atrioventricular junction. Our data suggest that ganglion cells of sulcus terminalis as well as the epicardial ganglia enclosed between the superior vena cava and ascending aorta are VIP- and TH-negative, but neuropeptide Y- and DBH-immunoreactive. They give rise to three intraseptal nerves directed towards the specialised structures of the atrioventricular junction. These nerve fascicles contain abundant, thick TH-immunoreactive nerve fibres and scarce, thin NPY- and DBH-immunoreactive fibres. The cell bodies of the intramural ganglion cells localized between the right and left branches of the bundle of His (Moravec and Moravec 1984) are strongly TH- and DBH-immunoreactive. They are innervated by thick nerve fibres having the same immunohistochemical properties (NPY- and DBH-immunoreactivities) as those of a subpopulation of the epicardial ganglion cells and seem to supply some of the TH-immunoreactive nerve fibres directed via the intraseptal nerves to the epicardial ganglia. The existence of a multicomponent nerve network, characterized by a reciprocal innervation of the sinus node and atrioventricular node areas, is suggested by our immunohistochemical data.
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PMID:Catecholaminergic and peptidergic nerve components of intramural ganglia in the rat heart. An immunohistochemical study. 170 21

The innervation of the carotid body, carotid sinus, and neighbouring arteries (common carotid artery; external carotid artery; occipital artery; ascending pharyngeal artery) was investigated in guinea-pigs by means of glyoxylic acid-induced catecholamine-fluorescence and immunohistochemistry using a variety of antisera against neuropeptides and tyrosine hydroxylase (TH). Fibres displaying catecholamine-fluorescence, TH- and neuropeptide Y-like immunoreactivity (NPY-LI) were less numerous in the carotid sinus than in all other arterial segments. Vasoactive intestinal polypeptide (VIP)-LI axons were almost lacking in the common carotid, external carotid and occipital arteries, consistently found in the carotid sinus, and more numerous in the ascending pharyngeal artery. Catecholaminergic, TH-, NPY- and VIP-LI fibres were observed deep in the media of the carotid sinus, where the baroreceptor terminals are located. In contrast, they did not enter the media in the adjacent arterial segments. All these fibres disappeared following excision of the superior cervical ganglion, but were unaffected by combined transection of the carotid sinus nerve and resection of the no-dose ganglion, suggesting a sympathetic origin. Double-staining immunofluorescence revealed at least three types of autonomic, presumably sympathetic fibres in the carotid sinus: 1) TH+/NPY+, 2) NPY+/VIP+, and 3) VIP+ fibres. This points to a non-noradrenergic efferent innervation of the carotid sinus in addition to the hitherto known noradrenergic sympathetic fibres. The three populations of autonomic fibres seen in the carotid sinus were also observed in the carotid body, but the paucity of NPY+/VIP+ double-labelled fibres raises doubt as to the functional significance of this particular fibre type in modulating arterial chemoreception. The multiplicity of neurochemically defined autonomic nerves to the carotid baro- and chemoreceptor regions probably reflects functionally separate pathways that are differently regulated and exert different effects.
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PMID:Three types of neurochemically defined autonomic fibres innervate the carotid baroreceptor and chemoreceptor regions in the guinea-pig. 197 5

The noradrenergic and peptidergic innervation of the extrinsic vessels and microcirculation of the rat cremaster muscle was examined. Catecholamine-containing nerves were identified histochemically by glyoxylic acid-induced fluorescence and tyrosine hydroxylase immunoreactivity (TH-IR). The extrinsic pudic-epigastric artery and vein as well as the entire intramuscular arteriolar network was innervated by noradrenergic axons. The capillaries and intramuscular venules of the cremaster muscle were devoid of a noradrenergic innervation. Immunohistochemical double-labeling demonstrated that most, if not all, of the TH-IR axons also possessed neuropeptide Y immunoreactivity (NPY-IR), implying colocalization of the norepinephrine and NPY in the perivascular nerves. No vasoactive intestinal peptide immunoreactivity (VIP-IR) was found, except for occasional VIP-IR axons associated with the pudic-epigastric artery. Substance P immunoreactive (SP-IR) axons formed a sparse plexus around the arteries and larger arterioles. Calcitonin gene-related peptide immunoreactivity (CGRP-IR) had a similar distribution to the SP-IR axons. CGRP-IR was also observed in axons alongside some smaller arterioles and capillaries. The extrinsic vessels and intramuscular arteriolar network of the rat cremaster muscle are innervated by noradrenergic axons which contain NPY and by presumed sensory nerves containing SP and/or CGRP. Both types of nerves may contribute to regulation of microvascular function.
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PMID:Noradrenergic and peptidergic innervation of the extrinsic vessels and microcirculation of the rat cremaster muscle. 248 4

Cryostat- and vibratome-cut sections of rat kidneys were singly or doubly labeled to visualize immunoreactive tyrosine hydroxylase (THI), dopamine beta-hydroxylase (DBHI), vasoactive intestinal peptide (VIPI), and neuropeptide Y (NPYI). Rats were perfusion fixed with 2-4% paraformaldehyde with or without 0.15% picric acid and rinsed in buffer for 18-48 hr. Single antigens were labeled with horseradish peroxidase in vibratome sections, whereas cryostat sections were used to label one antigen with peroxidase and another with a fluorophore in the same tissue section. A dense plexus of DBHI noradrenergic nerves innervates the renal arterial tree, and such nerves innervate the interlobar veins and renal calyx as well. Immunoreactive NPY is colocalized in most of these nerves, but some intrarenal noradrenergic nerves do not contain NPY but do contain VIP immunoreactivity. The distribution of NPYI nerves resembles that of DBHI nerves, whereas most perivascular noradrenergic nerves immunoreactive for VIP innervate selected arcuate and interlobular arteries. A small population of nonadrenergic, VIPI nerves innervates the renal calyx.
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PMID:Identification of noradrenergic nerve terminals immunoreactive for neuropeptide Y and vasoactive intestinal peptide in the rat kidney. 256 49

In order to maintain a chronic supply of growth factor for medulla cells in vitro, chromaffin cells from rat, African green monkeys and man were co-cultured with C6 glioma cells, which secrete growth factors that sustain sympathetic neurons in vitro. The response of chromaffin cells to coculture was compared to treatment of medullary cells with nerve growth factor (NGF) alone. Dispersed chromaffin cell preparations were obtained by a trypsin-collagenase procedure, and subjected to differential plating on collagen-coated surfaces. With both human and monkey tissue, non-chromaffin cells did attach to the culture plates and an enriched chromaffin cell population could be replated. Rat adrenal medulla cells survived very poorly in vitro and were not enriched in this procedure. Cultured human and monkey chromaffin cells survived as epithelial cells (50%) and showed neuritic outgrowth on 55 to 66% of the cells after eight days when treated with nerve growth factor (NGF). These cells showed strong catecholamine histofluorescence, tyrosine hydroxylase (TH) and dopamine beta hydroxylase (DBH) immunoreactivity. In contrast, only ten percent of adult rat chromaffin cells survived in culture, although NGF treatment rescued an additional 20% of the cells and induced neuritic outgrowth after one week in vitro. C6 glioma cells were treated with mitomycin C bromodeoxyuridine to inhibit mitosis and were plated with the various medulla cells in a one to one ratio. Both human and monkey chromaffin cells expressed extensive and enhanced neuritic arborization within eight days of co-culture, (64-82% respectively) and exhibited intimate contact with the glioma cells as seen at the ultrastructural level. Importantly, survival of adult rat adrenal medulla cells was enhanced to 50% or more with 40% of the cells extending neurites when co-cultured with glioma cells for seven days. Chromaffin cells from all three species reacted for TH, DBH and PNMT in co-culture and were histo-fluorescent. The majority of these cells were also immunoreactive for serotonin and enkephalin, while only 37% of chromaffin cells indicated the presence of NPY. These data indicate that adrenal medulla can be maintained in vitro as the neuronal phenotype when co-cultured with growth factor producing cells and that this strategy may be useful for in vivo transplantation studies.
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PMID:Rodent and primate adrenal medullary cells in vitro: phenotypic plasticity in response to coculture with C6 glioma cells or NGF. 256 44


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