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)

In order to study the relationship between retinal projections and immunohistochemically identified neurotransmitter systems in the primary visual centers of the brain in lizards, intraocular injections of horseradish peroxidase were combined with immunohistochemistry. Antibodies raised against six substances were applied: choline acetyltransferase (ChAT), serotonin (5-HT), tyrosine hydroxylase (TH), dopamine (DA), substance P (SP), and leu-enkephalin (LENK). In the primary visual centers of the lizards Gekko gecko and Gallotia galloti, notable overlap was observed between retinofugal fibers with: 1) ChAT-immunoreactive fibers in almost all primary visual centers; 2) 5-HT-immunoreactive fibers in the ventral lateral geniculate body and the basal optic nucleus; 3) TH-immunoreactive fibers in the nucleus ovalis and the dorsal lateral geniculate body; 4) SP- and LENK-immunoreactive fibers in the perirotundal belt; and 5) TH- and SP-immunoreactive fibers in the pretectal posterodorsal nucleus. The latter nucleus also contains dopaminergic cell bodies that lie outside the retinal target area but have dendrites extending into it. Several differences were noted in the distribution of 5-HT, TH-, DA-, and LENK-immunoreactive fibers in the tectum of the midbrain in the two species studied. Distinct laminae of 5-HT-immunoreactive fibers (layer 9) and TH- and DA-immunoreactive fibers (layers 9 and 11) are present in G. gecko but absent or, at least, less distinct in G. galloti. On the contrary, the optic layers in the tectum of G. galloti show a rather dense plexus of LENK immunoreactive fibers, whereas the corresponding layers in G. gecko are devoid of LENK-immunoreactivity. Since only a very few ChAT immunoreactive fibers were observed in the optic nerve of G. galloti, most of the observed immunoreactive fibers in the primary visual centers are considered to have an extraretinal origin. Putative sources of the cholinergic, the monoaminergic, and the peptidergic innervation of the primary visual centers in reptiles include the isthmic nucleus, the raphe nuclei, the substantia nigra and the nucleus of the posterior commissure, as reported in other amniotes.
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PMID:Cholinergic, monoaminergic and peptidergic innervation of the primary visual centers in the brain of the lizards Gekko gecko and Gallotia galloti. 128 May 14

The central nervous system location of neurochemicals that are widely distributed among extant animals may give us clues to changes that occurred in the brains of these animals during evolution. We have been studying the brains of cartilaginous fishes, a heterogeneous group whose central nervous system varies considerably. Squalus acanthias, the spiny dogfish shark, was chosen to represent the squalomorphs, a group of living sharks known to possess many primitive characters. The distribution of tyrosine hydroxylase (TH+), serotonin (5-HT+), and leu-enkephalin (LENK+) positive cells within the brainstem of Squalus was determined by use of antibodies to these substances. All the major raphe groups described for mammals were found in Squalus. The 5-HT+ cells in raphe nuclei were more uniformly distributed in Squalus than in Heterodontus, the horn shark. Other nuclei that were 5-HT+ and LENK+, and that have been identified in mammals, included reticularis paragigantocellularis lateralis, a B9 cell group, and reticularis magnocellularis. The postcommissural nucleus and pretectal area contained 5-HT+ and LENK+ cells. These cells have been described in a holocephalian, in teleosts, and in reptiles but not in other elasmobranchs or in mammals. Cells that were TH+ were located in prominent A1/A2, A6 (locus coeruleus), A9 (substantia nigra), and A10 (ventral tegmental area) cell groups, and in a very small A5 group. We conclude that the variation in chondrichthian brainstems exceeds that in mammals, and we suggest that this variation is related to life-style and the long evolutionary history of these fishes.
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PMID:Distribution of tyrosine hydroxylase, serotonin, and leu-enkephalin immunoreactive cells in the brainstem of a shark, Squalus acanthias. 134 3

Superior cervical ganglia from 7 human cadavers (3-7 h post mortem) were immunostained for tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (DBH) and 14 different neuropeptides. The results show that ganglionic cells contain TH, DBH, neuropeptide Y (NPY), somatostatin, vasoactive intestinal polypeptide (VIP) and calcitonin gene-related peptide (CGRP). These substances were present predominantly within large ganglionic cells. Inside the ganglion, the number and topographical distribution of various types of immunoreactive cells differed from one another. NPY and CGRP immunoreactivities were found in some TH-positive cells, but that co-localization never exceeded the 30% of the TH cells. Leu-enkephalin showed a weak immunoreactivity, which was restricted to fibers or varicosities. Neuropeptides like substance P, dynorphin A and B, cholecystokinin, galanin, corticotropin-releasing factor, thyrotropin-releasing hormone, angiotensin II and neurotensin showed no immunoreactivity in the human superior cervical ganglion.
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PMID:Neuropeptides in the human superior cervical ganglion. 135 73

Immunofluorescence colocalization techniques were used to examine the extent of coexistence of the endogenous opioid peptide dynorphin with catecholamines and the related opioid peptide enkephalin within neurons of the rat medulla oblongata. Immunoreactivities for dynorphin and the catecholamine-synthesizing enzyme tyrosine hydroxylase were found to coexist within a limited subpopulation of A2 catecholamine cells, localized to the medial nucleus of the nucleus tractus solitarii. Colocalization of the two opioid peptides was found mainly within perikarya situated in the medial and ventrolateral nuclei of the nucleus tractus solitarii. Triple-labeling studies revealed only rare cases of catecholamine/dynorphin/enkephalin coexistence. These data demonstrate that dynorphin is present within a restricted subpopulation of catecholamine neurons in the dorsal medulla oblongata. In addition, the content of either of the opioids enkephalin or dynorphin appears to distinguish subsets of medullary catecholamine neurons.
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PMID:Presence of a dynorphin-like peptide in a restricted subpopulation of catecholaminergic neurons in rat nucleus tractus solitarii. 135 95

4-Methylaminorex is an amphetamine analog which has recently gained attention due to its potential as a stimulant of abuse and the ease with which it is synthesized. Administration of acute and multiple doses of 4-methylaminorex caused rapid (3-h) and long-term (7-day) declines in striatal tryptophan hydroxylase activity with few changes in other serotonergic parameters. The acute response by tryptophan hydroxylase to this drug was reversed by incubating the tissues in a reducing environment suggesting that 4-methylaminorex alters this enzyme through oxidative mechanisms. The 4-methylaminorex-induced long-term reduction in tryptophan hydroxylase activity might be due to neurotoxic action on serotonergic systems. In contrast, although a decline in striatal tyrosine hydroxylase occurred 3 h following a single dose of 4-methylaminorex, no changes in this enzyme were observed at 7 days after acute or multiple dosing with this drug. This result suggests that 4-methylaminorex is not neurotoxic to the dopaminergic neurons. Even though this amphetamine analog apparently does not have long-term effects on dopaminergic systems, it does appear to enhance substantially dopaminergic activity. Evidence for increased dopamine activity resulting from 4-methylaminorex administration included dramatic but temporary rises in the levels of nigral neurotensin, dynorphin A and substance P following multiple drug administration. Similar peptide changes have been observed with other amphetamine-related stimulants and are mediated by increases in dopaminergic activity. In summary, 4-methylaminorex has significant impact on monoaminergic pathways. In general, its spectrum of effects on these systems is like that of the ring-substituted amphetamines, such as methylenedioxymethamphetamine.
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PMID:Response of monoaminergic and neuropeptide systems to 4-methylaminorex: a new stimulant of abuse. 135 36

Immunohistochemical techniques were used to study the adrenal organs of the anuran species Rana esculenta, Caldula pulchra and Bufo marinus with respect to the distribution and coexistence of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), substance P (SP), calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY), Leu-enkephalin (Leu-ENK). Met-enkephalin-Arg-Phe (MEAP) and dynorphin A 1-17 (DYN). Antisera against enzymes involved in catecholamine synthesis, i.e., dopamine-beta-hydroxylase (DBH) and tyrosine hydroxylase (TH), were used for the identification of chromaffin cells. ANP-immunoreactive (-IR) cells occurred in high densities (30%-70% of the total cell population) in all species investigated. In C. pulchra and B. marinus, BNP-IR cells constituted a population of non-DBH-IR and non-TH-IR cells that were different from the ANP-IR cells. A large proportion of the adrenal cells (10%-55%) were immunoreactive to Leu-ENK, and a minority (2%-5%) showed MEAP-immunoreactivity. DYN-immunoreactivity was not observed. The anurans studied exhibited small numbers of SP-IR, CGRP-IR and NPY-IR cells. Immunoreactivities for ANP + Leu-ENK and Leu-ENK + MEAP were shown to coexist. In C. pulchra and B. marinus, immunoreactions for ANP + NPY, ANP+SP and SP + CGRP were also colocalized. Except for DYN, all neurohormonal peptides also occurred in intra-adrenal nerve fibers. SP-IR fibers also displayed CGRP-immunoreactivity and some Leu-ENK-IR fibers contained MEAP-immunoreactivity. In C. pulchra, NPY-IR fibers were found that also showed ANP-immunoreactivity.
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PMID:Distribution patterns and coexistence of neurohormonal peptides (ANP, BNP, NPY, SP, CGRP, enkephalins) in chromaffin cells and nerve fibers of the anuran adrenal organ. 137 3

The sympathetic and sensory innervation of guinea-pig trachea and lung were studied by means of retrograde neuronal tracing using fluorescent dyes, and double-labelling immunofluorescence. Sympathetic neurons supplying the lung were located in stellate ganglia and in thoracic sympathetic chain ganglia T2-T4; those supplying the trachea resided in the superior cervical and stellate ganglia. Retrogradely labelled sympathetic neurons were usually immunoreactive to tyrosine hydroxylase; the majority also contained neuropeptide Y immunoreactivity. However, a small number were non-catecholaminergic (i.e. tyrosine hydroxylase negative), but neuropeptide Y immunoreactive. Within the airways, tyrosine hydroxylase/neuropeptide Y-immunoreactive axons were found in the smooth muscle layer, around blood vessels including the pulmonary artery and vein, and to a lesser extent in the lamina propria. Periarterial axons contained in addition dynorphin immunoreactivity. Sensory neurons supplying the lung were located in jugular and nodose vagal ganglia as well as in upper thoracic dorsal root ganglia; those supplying the trachea were most frequently found bilaterally in the nodose ganglia and less frequently in the jugular ganglia. A spinal origin of tracheal sensory fibres could not be consistently demonstrated. With regard to their immunoreactivity to peptides, three types of sensory neurons projecting to the airways could be distinguished: (i) substance P/dynorphin immunoreactive; (ii) substance P immunoreactive but dynorphin negative; and (iii) negative to all peptides tested. Substance P-immunoreactive neurons innervating the airways invariably contained immunoreactivity to neurokinin A and calcitonin gene-related peptide. Retrogradely labelled neurons located in the nodose ganglia belonged almost exclusively (greater than or equal to 99%) to the peptide-negative group, whereas the three neuron types each represented about one-third of retrogradely labelled neurons in jugular and dorsal root ganglia. Within the airways, axons immunoreactive to substance P/neurokinin A and substance P/calcitonin gene-related peptide were distributed within the respiratory epithelium of trachea and large bronchi, in the lamina propria and smooth muscle from the trachea down to the smallest bronchioli (highest density at the bronchial level), in the alveolar walls, around systemic and pulmonary blood vessels, and within airway ganglia. Those axons also containing dynorphin immunoreactivity were restricted to the lamina propria and smooth muscle. The origin of nerve fibres immunoreactive for vasoactive intestinal polypeptide, of which a part were also neuropeptide Y immunoreactive, could not be determined by retrograde tracing experiments. Vasoactive intestinal polypeptide-immunoreactive fibres terminating within airway ganglia may be of preganglionic parasympathetic origin, whereas others (e.g. those found in smooth muscle) may arise from intrinsic ganglia.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The sensory and sympathetic innervation of guinea-pig lung and trachea as studied by retrograde neuronal tracing and double-labelling immunohistochemistry. 138 Jan 40

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

In previous studies on reptiles and elasmobranchs, we determined that some reticular groups are either absent or may be displaced compared to their locations in mammals. For example, nucleus raphe dorsalis, the largest serotoninergic cell group in mammals, is not present in rays, skates, or guitarfish. In the present study, we chose heterodontid sharks, a sister group to these batoids, for an out-group comparison of this and other characters. We identified cells in the brainstem of Heterodontus francisci by use of antibodies against tyrosine hydroxylase, serotonin, or leu-enkephalin and compared the distribution of these nuclei to descriptions in mammals and other elasmobranchs. The majority of tyrosine hydroxylase-positive cells were found in the midbrain tegmentum (A8-A10) and the hypothalamus. In addition, putative A1, A2, A5, A7 (noradrenergic) groups were found in the metencephalon and myelencephalon. Serotonin-positive cells were found in raphe nuclei and scattered lateral to the raphe. We identified probable homologues to raphe pallidus, raphe obscurus, raphe magnus, and raphe centralis superior (B8) cell groups, which have been described in mammals. A cluster of cells dorsomedial to the medial longitudinal fasciculus was identified as raphe dorsalis. The distributions of leu-enkephalin and serotonin immunoreactive cells were similar to each other, but the tyrosine-hydroxylase immunoreactive cells rarely intermingle with the former two immunoreactive cell types. Other reticular groups that contained both serotonin- and leu-enkephalin-positive cells included reticularis (r.) ventralis, r. magnocellularis, r. paragigantocellularis lateralis, r. pontis caudalis, and r. pontis oralis medialis and lateralis. Thus, this shark contains many of the major brainstem raphe and catecholaminergic cell groups described for rats, but the relative distribution of the immunopositive cell groups differs in mammals and cartilaginous fish.
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PMID:Localization of serotonin, tyrosine hydroxylase, and leu-enkephalin immunoreactive cells in the brainstem of the horn shark, Heterodontus francisci. 167 68

In situ hybridization histochemistry and indirect immunofluorescence histochemistry were used to study changes in the expression of vasopressin (VP), oxytocin (OXY), tyrosine hydroxylase (TH), galanin (GAL), dynorphin (DYN) and cholecystokinin (CCK) in hypothalamic magnocellular neurons of the paraventricular (PVN) and supraoptic (SON) nuclei of rats. After prolonged administration of 2% sodium chloride as drinking water (salt-loading), the treatment increased the levels of VP, OXY, TH, GAL, DYN and CCK mRNA in the PVN and SON. The increase in CCK mRNA was, however, proportionally higher in the PVN than in the SON. Within cell bodies of the PVN and SON of salt-loaded rats, a depletion of VP- and OXY-like immunoreactivity (LI) and an increase in TH-LI were seen. In salt-loaded/colchicine-treated rats, a marked decrease in GAL- and DYN-LI, but no specific changes in CCK-LI were observed. Within nerve fibers of the posterior pituitary of salt-loaded rats, a marked depletion of VP-, GAL- and DYN-LI was found. Less pronounced depletion was observed in OXY- and CCK-LI, and no specific changes in TH-LI were seen. The results show that high plasma osmolality induces increased mRNA levels for VP, OXY, TH, GAL, DYN and CCK, presumably indicating increased synthesis, an increased export from cell somata of VP, OXY, GAL and DYN, and a decrease in levels of these peptides in the posterior pituitary, suggesting increased release. The catecholamine-synthesizing enzyme TH, however, which has a cytoplasmic localization and is not released from nerve endings, remains high in the cell bodies and nerve endings during this state of increased activity.
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PMID:Peptides and transmitter enzymes in hypothalamic magnocellular neurons after administration of hyperosmotic stimuli: comparison between messenger RNA and peptide/protein levels. 169 5


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