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)

A peroxidase anti-peroxidase method was used to investigate and compare the distribution of neuropeptide and catecholamine synthesizing enzyme immunoreactive (IR) ganglion cells and nerve fibres in the intestinal nerve of Remak (INR) of male chickens. In the INR there were three kinds of ganglion cells: tyrosine hydroxylase (TH)-, aromatic L-amino acid decarboxylase (AADC)- and phenylethanolamine-N-methyltransferase (PNMT)-IR cells; AADC- and PNMT-IR but TH-immunonegative cells; and ganglion cells being immunoreactive for methionine enkephalin (mENK)- and somatostatin (SOM). The first one was distributed throughout the INR. The second was restricted in the ileojejunal region, and the last was localized in the rectal region. Substance P- and vasoactive intestinal polypeptide-IR nerve fibres were distributed in common but variable in number around three kinds of ganglion cells. Then TH-IR cells were characterized by the distribution of many calcitonin gene related peptide- and a few cholecystokinin-IR fibres. mENK and SOM-IR cells, and TH-immunonegative cells were distinguished by the distribution of SOM- and galanin-IR fibres. In addition, TH-immunonegative cells were characterized by the distribution of mENK- and neuropeptide Y-IR nerve fibres which were very few in number. Fig. 21 summarizes the connections described in the present study.
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PMID:Immunohistochemical studies on the intestinal nerve of Remak in the male chicken. 780 73

The cellular immediate early genes are involved in the transcriptional events associated with the dopaminergic regulation of neurotransmitter expression within neurons of the neostriatum. To characterize these events in detail, quantitative in situ hybridization histochemistry was used to assess the temporal effects of acute dopamine receptor blockade with eticlopride, a dopamine D2 receptor antagonist, on the messenger RNA expression of the immediate early genes and neurotransmitters/receptors in the caudate-putamen and ventral tegmental area/substantia nigra pars compacta of the rat. Groups of rats were injected with a single dose of either isotonic saline or eticlopride (0.5 mg/kg i.p.) and killed at various time intervals ranging from 5 min to 24 h and frozen brain sections processed by in situ hybridization histochemistry. Using computerized image analysis, the changes in messenger RNA expression for c-fos, c-jun, jun B, jun D, nerve growth factor I-A and nerve growth factor I-B and for neurotensin, glutamate decarboxylase, proenkephalin, the dopamine D1 receptor and the short and long isoforms of the D2 receptor were examined in the caudate-putamen. In the ventral tegmental area and substantia nigra pars compacta, the messenger RNA expression of the above early response genes and that for neurotensin, tyrosine hydroxylase, cholecystokinin and the D2 receptor isoforms were also examined. In the neostriatum, eticlopride caused a rapid increase in c-fos messenger RNA with significantly increased levels at 10 min (P < 0.01). The levels peaked at 30 min and thereafter declined to control levels. A similar profile was observed for jun B messenger RNA, although levels were still significantly (P < 0.01) elevated at 1 h and declined to basal levels thereafter. No significant changes were observed for c-jun, jun D, nerve growth factor I-A and nerve growth factor I-B messenger RNAs. In the dorsolateral neostriatum, there was an increase in proneurotensin messenger RNA 10 min after eticlopride, this increase becoming significant (P < 0.01) at 60 min. Levels were maximal at 2-6 h and decreased after 12 h to basal levels. There were small increases in proenkephalin messenger RNA, but these were not significant (P < 0.05) until 6 h after the injection. Eticlopride did not have any significant effects on the messenger RNA levels for glutamate decarboxylase, the D1 receptor and the short and long isoforms of the D2 receptor.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Temporal changes in the messenger RNA levels of cellular immediate early genes and neurotransmitter/receptor genes in the rat neostriatum and substantia nigra after acute treatment with eticlopride, a dopamine D2 receptor antagonist. 783 Aug 88

Differences in behavioral and neurochemical responses to drugs of abuse and environmental stress have been observed between rats that have a greater locomotor response in a novel environment (high responders: HR) compared to those that have a low response to novelty (low responders: LR). This study examined nuclei associated with the nigrostriatal and mesolimbic systems for differences in mRNA content between HR and LR using Northern blot analysis. These brain regions were chosen because of their role in both drug abuse and stress responses. The mRNAs examined code for either peptide transmitters that interact with the dopaminergic system or components of the dopaminergic system that have not been previously examined for differences between HR and LR. HR rats had approximately 50% lower levels of mRNA for beta-preprotachykinin (PPT) in the core of the nucleus accumbens (NACC) compared to LR. No differences between HR and LR in mRNA levels for dynorphin (DYN), preproenkephalin (PPE), glutamic acid decarboxylase (GAD) or neurotensin (NT) were observed in the core of the NACC. In the shell region of the NACC, HR exhibited a 25% reduction in the level of mRNA for NT compared to LR. No differences between HR and LR in mRNA levels for PPT, DYN, PPE or GAD were observed in the shell of the NACC. In the medial frontal cortex and the dorsal striatum, no differences between HR and LR in mRNA levels for PPT, DYN, PPE, GAD or NT were found. In the substantia nigra and ventral tegmental area no differences between HR and LR in mRNA levels for tyrosine hydroxylase, GAD, cholecystokinin, or NT were noted.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The relationship between MRNA levels and the locomotor response to novelty. 787 16

The goal of the present study was to identify cytochemical markers characteristic of muscle afferents in hatchling chicks. To this end, we stained neurons in the trigeminal mesencephalic nucleus with a variety of markers that label subsets of neurons in avian dorsal root ganglia. We found that trigeminal mesencephalic neurons are surprisingly heterogeneous in their cytochemical make-up, expressing, to varying degrees, substance P, cholecystokinin, carbonic anhydrase, calbindin D-28k, parvalbumin, and S-100 beta. Calbindin D28k and S-100 beta appeared to be expressed equally in medial and lateral divisions of the trigeminal mesencephalic nucleus. In contrast, substance P- and cholecystokinin-immunoreactive neurons were more abundant in the medial division, whereas carbonic anhydrase activity and parvalbumin immunoreactivity were stronger in the lateral division. We were unable to detect met-enkephalin, neuropeptide Y, calcitonin gene-related peptide, vasoactive intestinal peptide, somatostatin, gamma-aminobutyric acid, or tyrosine hydroxylase in the trigeminal mesencephalic nucleus. Moreover, these neurons did not appear to bind the lectin Dolichos biflorus agglutinin. The heterogeneity of expression of markers among trigeminal mesencephalic nucleus neurons, especially between neurons in the medial and lateral divisions, suggests that these neurons are functionally diverse.
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PMID:Cytochemical characteristics of neurons in the trigeminal mesencephalic nucleus of hatchling chicks. 788 44

Quantitative in situ hybridization histochemistry was used to determine the age-related changes in tyrosine hydroxylase (TH) mRNA and cholecystokinin (CCK) mRNA in the ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) of the rat. Coronal sections (10 microns) were cut in a cryostat through the VTA and SNc of brains from 3 months and 33 month old Sprague-Dawley rats and immediately adjacent sections hybridized with 35S-labelled 45-mer oligonucleotide probes specific for either the rat TH or CCK genes. The mRNA levels of each gene were estimated by computerised densitometric analysis of the signal on X-ray film autoradiograms and estimation of the number of mRNA expressing cells as well as the density of expression per cell (grain density) was made from high resolution emulsion autoradiograms. Analysis of the TH mRNA on X-ray film autoradiograms indicated that the levels averaged 25% lower in the SNc (P < 0.01) and 18% lower in the VTA (P < 0.05) of the old rats. However, analysis of the emulsion autoradiograms showed that this reduction in TH mRNA in the VTA and SNc in the old rats was not due to a loss of TH mRNA expressing cells but due to a reduction in the hybridization signal per expressing cell.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Decreased tyrosine hydroxylase mRNA but not cholecystokinin mRNA in the pars compacta of the substantia nigra and ventral tegmental area of aged rats. 790 29

The effects of prenatal cocaine treatment on gene expression in dopaminergic pathways of juvenile rats were investigated by in situ hybridization histochemistry. Pregnant rats from gestational day 8 to 20 were administered one of the following treatments: (A) 40 mg/kg cocaine hydrochloride/3 ml/day s.c.; (B) 0.9% saline/3 ml/day s.c. and pair fed to cocaine-exposed dams; (C) 0.9% saline/3 ml/day s.c. and placement on cellulose-diluted diet to match the caloric intake of the cocaine-treated group without explicit food restriction; (D) no injection and lab chow diet. Levels of mRNA for the dopamine transporter, tyrosine hydroxylase, cholecystokinin, D1 and D2 dopamine receptors and enkephalin were quantitated in relevant dopaminergic regions of forebrain and midbrain of offspring that were sacrificed on postnatal day 21. Quantitative analysis revealed no significant changes in mRNA levels in any of the brain regions examined. In the present animal model, cocaine exposure in utero had no significant effect on mRNA levels of the dopamine transporter, D1 or D2 dopamine receptors, enkephalin, tyrosine hydroxylase, or cholecystokinin in juvenile rats.
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PMID:Dopaminergic and peptidergic mRNA levels in juvenile rat brain after prenatal cocaine treatment. 790 78

The cholecystokinin (CCK)- and tyrosine hydroxylase (TH)-like immunoreactive (LI) axons and boutons were studied in the caudal and medial parts of the rat nucleus accumbens (NAC), using the indirect immunoperoxidase technique, at the electron microscopic level. Both CCK- and TH-LI boutons contained clear synaptic vesicles and large granular vesicles of similar size, but the CCK-LI boutons contained more large granular vesicles than TH-LI boutons. The CCK-LI and TH-LI boutons were heterogeneous. This finding might be related to the various immunoreactive neuronal types innervating the caudomedial NAC. However, the CCK-LI boutons (containing mostly small, round, clear synaptic vesicles) formed mainly asymmetrical synaptic contacts with dendritic spines whereas the TH-LI boutons (containing medium-sized as well as small, round, clear synaptic vesicles) formed mostly symmetrical synaptic contacts with dendritic shafts.
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PMID:Ultrastructural study of CCK and tyrosine hydroxylase immunoreactivity in the rat nucleus accumbens. 791 94

The effect of repeated administration of 3,4-methylenedioxymethamphetamine (MDMA) on the expression of tyrosine hydroxylase and preprocholecystokinin (CCK) messenger RNAs in substantia nigra was examined by in situ hybridisation histochemistry. Sections hybridised with 35S-labelled oligonucleotides were subjected to computerised image analysis to determine the density of silver grains above positively labelled cells as an index of steady state mRNA levels. In the substantia nigra pars compacta, CCK mRNA levels were significantly reduced in drug-treated animals 24 h and at 2 weeks after the last dose of MDMA (10 mg/kg i.p., twice daily for 4 days). In the same animals, MDMA caused no change in the level of tyrosine hydroxylase mRNA in this brain region. The results show that MDMA can produce changes in dopamine neurones. Furthermore, since tyrosine hydroxylase and cholecystokinin are co-expressed in substantia nigra pars compacta, these results suggest that the expression of the tyrosine hydroxylase and CCK genes are regulated independently.
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PMID:Repeated administration of MDMA down-regulates preprocholecystokinin mRNA expression but not tyrosine hydroxylase mRNA expression in neurones of the rat substantia nigra. 798 49

Immunocytochemical localization of the protein product of the proto-oncogene c-fos allows anatomical identification of physiologically activated neurons. The present study examined the subnuclear distribution of cFos protein in the rat caudal medulla following peripheral administration of cholecystokinin octapeptide, which reduces feeding and gastric motility by a vagally mediated mechanism. To begin phenotypic characterization of neurons activated to express cFos following cholecystokinin treatment, double-labeling techniques were used to identify vagal motor neurons and neurons immunoreactive for tyrosine hydroxylase, neuropeptide Y, and neurotensin. Activated cells were most prevalent in the subnucleus medialis of the nucleus of the solitary tract, less prevalent in the subnucleus commissuralis, and virtually absent in the subnuclei centralis and gelatinosus. Many activated cells occupied the caudal area postrema; some of these were catecholaminergic. In contrast, activated cells were sparse within the medial rostral area postrema. Other activated cells occupied the dorso- and ventrolateral medulla and the midline raphe nuclei. Retrograde labeling of vagal motor neurons confirmed that very few were activated. Those that were activated occupied the caudal dorsal motor nucleus. In the dorsomedial medulla, 51% of catecholaminergic neurons and 39% of neurons positive for neuropeptide Y were activated, but no neurotensin-positive neurons were activated. In the ventrolateral medulla, 25% of catecholaminergic neurons and 27% of neuropeptide Y-positive neurons were activated. By characterizing the subnuclear distribution and chemical phenotypes of neurons activated by exogenous cholecystokinin, these data contribute to elucidation of the neural circuits mediating the behavioral, physiological, and neuroendocrine effects produced by this peptide.
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PMID:Distribution and neurochemical phenotypes of caudal medullary neurons activated to express cFos following peripheral administration of cholecystokinin. 813 58

Stimulation of gastric vagal afferents by systemic administration of cholecystokinin octapeptide (CCK) inhibits gastric motility, reduces food intake, and stimulates pituitary secretion of oxytocin and adrenocorticotropic hormone in rats. To characterize further the central neural circuits responsible for these effects, the present study used triple-labeling immunocytochemical methods to determine whether or not exogenous CCK activates cFos expression in catecholaminergic neurons in the caudal medulla that project to the paraventricular nucleus of the hypothalamus (PVN). To identify these neurons, the retrograde tracer fluorogold (FG) was iontophoresed into the PVN of anesthetized rats under stereotaxic guidance. After 2 weeks, rats were injected with CCK (100 micrograms/kg, i.p.) and then anesthetized and killed 1 hour later by perfusion fixation. Medullary sections were processed for triple immunocytochemical localization of cFos, retrogradely transported FG, and tyrosine hydroxylase (TH). In rats with FG injections centered in the PVN (n = 10), approximately 70% of the FG-labeled neurons in the caudal nucleus of the solitary tract (NST) and ventrolateral medulla (VLM) expressed cFos. Of these activated PVN-projecting neurons, approximately 78% in the NST and 89% in the VLM were catecholaminergic (TH positive). These results indicate that PVN-projecting catecholaminergic neurons within the caudal medulla are activated by peripheral administration of CCK, further implicating these ascending catecholaminergic pathways in the neuroendocrine, physiological, and behavioral effects produced by gastric vagal stimulation.
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PMID:Cholecystokinin activates catecholaminergic neurons in the caudal medulla that innervate the paraventricular nucleus of the hypothalamus in rats. 852 45


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