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

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

We studied the effect of brain natriuretic peptide (BNP) on the accumulation of cyclic GMP and the phosphorylation and activity of tyrosine hydroxylase, compared with that of atrial natriuretic peptide (ANP), in cultured bovine adrenal medullary cells. 1. BNP as well as ANP increased cellular cyclic GMP accumulation in a concentration-dependent manner (10-1000 nmol/l). BNP (1 mumol/l) and ANP (1 mumol/l) produced a 60-fold and 30-fold increase in cyclic GMP accumulation, respectively. 2. The stimulatory effects of BNP and ANP on cyclic GMP accumulation were observed even when Ca2+ or Na+ was removed from the incubation medium. 3. 12-O-Tetradecanoylphorbol 13-acetate (TPA), an activator of protein kinase C, inhibited the stimulatory effect of BNP on cyclic GMP accumulation in a concentration-dependent manner (1-100 nmol/l). Furthermore, the BNP-induced accumulation of cyclic GMP was attenuated by forskolin (1 mumol/l), an activator of adenylate cyclase. 4. BNP (1 mumol/l) and ANP (1 mumol/l) caused a significant increase in phosphorylation and activity of tyrosine hydroxylase in the cells. 5. In digitonin-permeabilized cells, cyclic GMP (1-100 mumol/l) activated tyrosine hydroxylase in the presence of ATP and Mg2+. These results suggest that BNP stimulates the accumulation of cyclic GMP in a manner similar to that of ANP. The increased accumulation of cyclic GMP by these peptides may be negatively modulated by protein kinase C and cyclic AMP and may cause the phosphorylation and activation of tyrosine hydroxylase in cultured bovine adrenal medullary cells.
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PMID:Stimulatory effects of brain natriuretic peptide on cyclic GMP accumulation and tyrosine hydroxylase activity in cultured bovine adrenal medullary cells. 167 41

Intracerebroventricular (ICV) administration of atrial natriuretic peptide (ANP) induces an increase of urinary volume and sodium excretion in conscious male hydrated rats. The involvement of brain dopaminergic neurones in the ICV-ANP renal action was investigated. Diuretic and natriuretic action of ANP was prevented by inhibition of tyrosine hydroxylase activity with alpha-methyl-p-tyrosine treatment and was absent following selective central dopaminergic denervation with ICV administration of 6-hydroxydopamine in combination with desmethylimipramine (IP). Our results suggest that ANP acts centrally, at least in part, via an interaction with endogenous dopamine neurones.
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PMID:Further evidence for a dopaminergic involvement in the renal action of centrally administered atrial natriuretic peptide in rats. 168 28

Knowledge about the distribution and origins of peptide-containing nerves in the innervated and transplanted heart is lacking. Immunohistochemical and histochemical techniques were used to visualize human cardiac innervation before and after transplantation. In the recipient heart cardiac nerve fibers and fascicles displayed immunoreactivity for general neural (protein gene product 9.5 and synaptophysin) and Schwann cell markers (S-100). A major proportion of cardiac nerves displayed neuropeptide tyrosine and tyrosine hydroxylase immunofluorescence staining. Subpopulations of nerves contained somatostatin, vasoactive intestinal polypeptide, calcitonin gene-related peptide, substance P- or neurokinin-like immunoreactivity, and acetylcholinesterase activity. Tissues from cardiac allografts (5 weeks to 63 months after transplantation) contained nerves and ganglion cells that were acetylcholinesterase positive and immunoreactive for the general neural markers. These nerves were less numerous than in recipient hearts and rarely displayed neuropeptide immunostaining. Atrial natriuretic peptide immunoreactivity was localized to myocardial cells in transplanted hearts as well as explanted recipient and postmortem hearts. While most human cardiac allografts remain functionally extrinsically denervated, they appear to contain viable intrinsic nerves, and myocardial cells retain the capacity to produce atrial natriuretic peptide.
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PMID:Immunohistochemical demonstration of human cardiac innervation before and after transplantation. 231 94

The hypothalamus provides a major projection to the spinal cord that innervates primarily lamina I of the dorsal horn and the sympathetic and parasympathetic preganglionic cell columns. We have examined the chemical organization of the neurons that contribute to this pathway by using combined retrograde transport of fluorescent dyes and immunohistochemistry for 15 different putative neurotransmitters or their synthetic enzymes. Our results demonstrate that 5 cytoarchitectonically distinct cell groups in the hypothalamus contribute to the spinal projection and that each has its own predominant chemical types. In the paraventricular nucleus, substantial numbers of hypothalamo-spinal neurons stain with antisera against arginine vasopressin (25-35%), oxytocin (20-25%), and met-enkephalin (10%). About 25% of the neurons with spinal projections in the retrochiasmatic area stain with an antiserum against alpha-melanocyte-stimulating hormone. Nearly 100% of the hypothalamo-spinal neurons in the tuberal lateral hypothalamic area stain with this same antiserum, but these cells do not stain for other proopiomelanocortin-derived peptides, and so probably contain a cross-reacting peptide. This population must be distinguished from an adjacent cell group, in the perifornical region, where many spinal projection neurons stain with antisera against dynorphin (25%) or atrial natriuretic peptide (20%). Finally, in the dorsal hypothalamic area as many as 55-75% of the neurons with spinal projections are dopaminergic, on the basis of their staining with an antiserum against tyrosine hydroxylase. These 5 neurochemically distinct projections from the hypothalamus to the spinal cord are discussed in the context of their possible functional significance.
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PMID:Neurochemical organization of the hypothalamic projection to the spinal cord in the rat. 290 38

Recently, we observed that atrial natriuretic peptide (ANP) immunoreactivity (IR) was present not only in the Purkinje fibres, but also in nerve fibre varicosities in the conduction system of the bovine heart. These findings and previous observations that ANP is able to influence autonomic neurotransmission in the heart, lead us to elucidate the possible occurrence of ANP in the sympathetic and/or parasympathetic nervous systems and/or in various types of peptidergic innervation in the conduction system. The different parts of the conduction system of bovine hearts were dissected out and processed for immunohistochemistry including double-staining, using antisera against ANP, tyrosine hydroxylase and different neuropeptides. We observed that some of the nerve fibre varicosities exhibiting ANP-IR showed substance P-IR and that ANP was present as scattered immunoreactive granules in intracardial, presumably parasympathetic, ganglionic cells. The study shows that ANP is likely to be present in parasympathetic innervation and in afferent nerve endings in the bovine heart conduction system.
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PMID:Atrial natriuretic peptide in the innervation of the bovine heart conduction system: relationship with substance P and autonomic innervation--immunohistochemical studies. 753 9

The primary baroreceptor area (nucleus of the solitary tract-NTS) is anatomically interconnected with the rostral ("vasomotor area") and the caudal ("vasodepressor area") ventrolateral medulla by a well-defined arc of neuronal pathways. The chemical character and the direction of these pathways have been investigated with immunohistochemical and neurochemical techniques in intact and brainstem-operated rats. The transection of the neuronal arc resulted in an accumulation of tyrosine hydroxylase immunoreactivity in a small group of cells in the NTS adjacent to the area postrema, ipsilateral to the knife cut. Decreased angiotensinogen mRNA and atrial natriuretic peptide concentrations were measured in the ventrolateral medulla after the cut, and an accumulation of angiotensin II-immunoreactivity was found in neuronal perikarya in the ipsilateral NTS. Intracranial vagotomy caused marked depletions in glutamate levels in the subcommissural portion of the NTS and in the caudal ventrolateral medulla but nowhere else in the brainstem investigated including the rostral ventrolateral medulla.
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PMID:Neurotransmitters and neuropeptides in the baroreceptor reflex arc: connections between the nucleus of the solitary tract and the ventrolateral medulla oblongata in the rat. 773 61

3-Chloro-L-tyrosine (3CT) is an inhibitor of tyrosine hydroxylase, the rate-limiting enzyme for catecholamine synthesis. In vivo inhibition of tyrosine hydroxylase results in lower catecholamine levels. 3CT (0.5 mg/kg), administered as a bolus i.v. to anesthetized uninephrectomized rats, elicited increases of 72% and 44% in urinary sodium concentration and volume, respectively, whereas a dose of 1 mg/kg caused increases of 27% and 29%. 3CT, 1 mg/kg, resulted in a 2-fold increase in plasma aldosterone (ALD); 0.5 mg/kg was without significant effect. At a dose of 1 mg/kg 3CT significantly antagonized the renal effects of atrial natriuretic peptide (ANP) (1.5 micrograms kg-1 min-1 by intrarenal infusion), expressed as an enhanced excretion of urine volume (102 +/- 14 vs. 70 +/- 11 microliters/min) and sodium (16.1 +/- 1.8 vs. 11.5 +/- 1.7 microEq/min) and increased osmolar clearance (171 +/- 12 vs. 144 +/- 13 microliters/min). A dose of 0.5 mg/kg of 3CT did not produce these same responses to ANP. The increased urine flow caused by 3CT may reflect reduced norepinephrine synthesis. The inverse dose-effect relationship of 3CT on urine flow rate may result from concomitant depletion of dopamine (DA) and elevated circulating ALD. The antagonism of 3CT on responses to ANP is not at the receptor level, because 3CT did not compete for [125I] ANP binding or inhibit ANP-stimulated guanylate cyclase in kidney cell membranes. It was proposed that the reduced basal sympathetic and renal DA tone, together with the elevated ALD level, account for this antagonism.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Chlorotyrosine exerts renal effects and antagonizes renal and gastric responses to atrial natriuretic peptide. 791 Feb 11

In the present study we have used the detection of Fos, the protein product of c-fos, to determine the distribution of neurons in the medulla and hypothalamus that are activated by changes in central blood volume. Experiments were conducted in both barointact and barodenervated conscious rabbits, to determine the contribution of arterial baroreceptors to the pattern of Fos expression evoked by changes in central blood volume, induced either by intravenous infusion of an isotonic modified gelatin solution, or by partial occlusion of the vena cava. These procedures resulted in a significant increase and decrease, respectively, in right atrial pressure over a 60 min period. In control experiments, barointact and barodenervated rabbits were subjected to the identical procedures except that no changes in central blood volume were induced. In comparison with the control observations, central hypervolaemia produced a significant increase in the number of Fos-immunoreactive neurons in the nucleus tractus solitarius, area postrema, the caudal, intermediate and rostral parts of the ventrolateral medulla, supraoptic nucleus, paraventricular nucleus, arcuate nucleus, suprachiasmatic nucleus and median preoptic nucleus. The overall pattern of Fos expression induced by central hypervolaemia did not differ significantly between barointact and barodenervated animals. Similarly, the overall pattern of Fos expression induced by central hypovolaemia did not differ significantly between barointact and barodenervated animals, but did differ significantly from that produced by hypervolaemia. In particular, central hypovolaemia produced a significant increase in Fos expression in the same regions as above, but also in the subfornical organ and organum vasculosum lamina terminalis. In addition, compared with central hypervolaemia, hypovolaemia produced a significantly greater degree of Fos expression in the rostral ventrolateral medulla and supraoptic nucleus. Furthermore, double-labelling for tyrosine hydroxylase immunoreactivity demonstrated that neurons in the ventrolateral medulla that expressed Fos following hypovolaemia were predominantly catecholamine cells, whereas following hypervolaemia they were predominantly non-catecholamine cells. Finally, double-labelling for vasopressin immunoreactivity demonstrated that the number of Fos/vasopressin immunoreactive cells in the supraoptic nucleus was approximately 10 times greater following hypovolaemia compared with hypervolaemia, but there were very few such double-labelled neurons in the paraventricular nucleus in response to either stimulus. The results demonstrate that central hypervolaemia and hypovolaemia each induces reproducible and specific patterns of Fos expression in the medulla and hypothalamus. The degree and pattern of Fos expression was unaffected by arterial baroreceptor denervation, indicating that it is primarily a consequence of inputs from cardiac receptors, together with an increase in the level of circulating hormones such as atrial natriuretic peptide, angiotensin II or vasopressin. Furthermore, the pattern of Fos expression produced by central hypervolaemia and hypovolaemia is distinctly different from that evoked by hypertension and hypotension, respectively [Li and Dampney (1994) Neuroscience 61, 613-634], particularly in hypothalamic regions. These findings therefore indicate that the central pathways activated by changes in blood volume are, at least in part, separate from those activated by changes in arterial pressure.
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PMID:Activation of brain neurons following central hypervolaemia and hypovolaemia: contribution of baroreceptor and non-baroreceptor inputs. 1065 30

An immunocytochemical technique was used to study the localization and developmental aspects of cyclic GMP (cGMP)-synthesizing structures in the cervical spinal cord of 2-week and 3-month-old Lewis rats in response to the nitric oxide (NO) donor sodium nitroprusside (SNP) and/or atrial natriuretic peptide (ANP). By using cell-specific markers, the cell structures involved were investigated. To visualize cGMP, a combined technique of low- and high-power magnification, using a confocal laser scanning microscope was used. NOS-mediated cGMP synthesis was observed in the cervical spinal cord in laminae I, II and III in 14-day-old rats, which activity was mainly absent at the age of 3 months. The involvement of NO in the NMDA-mediated increase in cGMP immunostaining (cGMP-IS) was demonstrated by the absence of cGMP-IS in slices incubated in the presence of NMDA together with the NOS inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME). This NO-mediated effect of NMDA on cGMP-IS was completely absent in the 3-month-old rats. ANP-mediated cGMP synthesis resulted in an increase in cGMP in laminae I and II, which was generally similar at both ages. Astrocytes in both white and gray matter were found to be cGMP-IS in the basal, NO- and ANP-stimulated conditions. Using confocal laser microscopy, NO-mediated cGMP synthesis was observed in large cholinergic terminals nearby motor neurons in the ventral horn. An extensive colocalization between NO-stimulated cGMP synthesis and parvalbumin-positive (GABAergic) neurons and fibers was observed in all laminae. In the ANP-stimulated condition, a colocalization with parvalbumin structures was found in laminae II and III. No NO- or ANP-mediated cGMP synthesis was found in fibers immunopositive for the presynaptic glutamate transporter, serotonin, or tyrosine hydroxylase.
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PMID:Localization and age-related changes of nitric oxide- and ANP-mediated cyclic-GMP synthesis in rat cervical spinal cord: an immunocytochemical study. 1070 May 71


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