Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Octopamine”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 937 records · Page 52Linked to original sources
PubMed1995

A primordial dopamine D1-like adenylyl cyclase-linked receptor from Drosophila melanogaster displaying poor affinity for benzazepines.

We report here the isolation from Drosophila melanogaster of a 2.0 kb cDNA clone encoding a 385 amino acid protein (dDA1) displaying, within putative transmembrane domains, highest amino acid sequence homology (49-53%) to members of the vertebrate dopamine D1-like receptor family. When expressed in either Sf9 or COS-7 cells, dDA1 did not bind the specific D1-like receptor antagonist [3H]SCH-23390 or numerous other dopaminergic, adrenergic or serotoninergic ligands with high affinity. However, like vertebrate dopamine D1-like receptors, dDA1 stimulated the accumulation of cAMP in response to DA (EC50 approximately 300 nM) and 6,7-ADTN (EC50 approximately 500 nM). The dopaminergic rank order of potency (DA > NE >> 5-HT) and the lack of stimulation by other possible neurotransmitters (octopamine, tyramine, tryptamine) or DA metabolites (e.g. N-acetyl dopamine) found in Drosophila suggests that this receptor functionally belongs to the dopamine D1-like subfamily. Benzazepines, which characteristically bind to vertebrate dopamine D1-like receptors with high affinity, were relatively poor in stimulating (SKF-38393, SKF-82526; EC50 > 10 microM) dDA1-mediated accumulation of cAMP. Of the numerous compounds tested, a few dopaminergic antagonists inhibited DA-stimulated production of cAMP in a concentration-dependent manner, albeit with considerably reduced affinity, and with the rank order of potency: (+)-butaclamol(Kb approximately 125nM) > SCH-23390(Kb approximately 230nM) > alpha-flupenthixol (Kb approximately 400 nM) > chlorpromazine > or = spiperone (Kb approximately 680 nM) > or = clozapine. In situ hybridization revealed that dDA1 receptor mRNA is expressed as a maternal transcript, and at later blastoderm stages is restricted to apical regions of the cortical peripheral cytoplasm. The generation of inter-species D1 receptor chimeras may help to identify those particular sequence-specific motifs or amino acid residues conferring high affinity benzaepine receptor interactions.

Adenylyl Cyclases↗
PubMed1985

Properties of an in vitro bioassay for hypertrehalosemic hormone of Blaberus discoidalis cockroaches.

The ability of the fat body to respond to the hypertrehalosemic action of corpora cardiaca-allata (CC + CA) extracts was measured in vitro with tissue from adult, male Blaberus discoidalis cockroaches. Only trehalose increased in the hemolymph when gland extracts were injected in vivo; likewise, only trehalose levels responded when fat bodies were exposed to gland extracts in vitro. Although fat bodies from 0-day-old animals gave the least response to gland extracts, all animals 5 or more days old showed elevated responses. A linear dose-response occurred between 0.02 and 0.08 CC + CA pair. Fat bodies did not show an in vitro, hypertrehalosemic response to insulin, glucagon, proctolin, dopamine, epinephrine, norepinephrine, serotonin, octopamine, or tyramine. A strong hypertrehalosemic response was found to both synthetic adipokinetic hormone and red-pigment concentrating hormone; however, reversed-phase, thin-layer chromatography of CC + CA extracts and adipokinetic hormone indicated that the hypertrehalosemic effect and the adipokinetic hormone were separate. This in vitro system comprises a relatively rapid, simple, and accurate bioassay for the hypertrehalosemic neurohormone of insects.

Adipose Tissue↗
PubMed1987

The effect of dibutyryl cAMP on sodium uptake by isolated perfused gills of Callinectes sapidus.

Hemolymph, collected from 25 and 100% seawater acclimated Callinectes sapidus and perfused through the isolated gill, causes increases in Na+ uptake in the gill. Similarly, dibutyryl cAMP causes increases in Na+ uptake when perfused through the gill. Since pericardial organ (PO) extracts dopamine and octopamine are known to increase cAMP levels in the perfused gill, it is suggested that these substances from the PO may be the hemolymph factors which increase Na+ uptake via the mediation of cAMP as second messenger.

Animals↗
PubMed1996

A new method for double immunolabelling with primary antibodies from identical species.

There are several double immunolabelling methods but each has its drawbacks. More often than not, antibodies with the required specificities are available in only one species and their use normally produces false labels due to cross-reactivity. We describe a new and reliable technique for staining with primary antibodies from the same species, that can even be employed on tissues of the donor species. The protocol avoids cross-reactivities without loss in sensitivity, uses commercially available reagents and takes advantage of enzymatic detection, although it can be adapted for fluorescent labelling. Briefly, tissue is incubated with one primary antibody, followed by a peroxidase-coupled secondary antibody which is detected using amino ethyl carbazol to give a red reaction product. Meanwhile, the next primary antibody is coupled in vitro to a biotinylated secondary antibody and excess binding sites quenched with normal immune serum from the same species as the primary antibody. This complex is applied to tissue and detected by the avidin-biotin/alkaline phosphatase technique using naphthol-AS-MX-phosphate/Fast Blue BB to produce a blue label. In addition to extensive controls, the reliability and broad applicability of this method has been confirmed in (1) murine skin cryostat sections to co-visualize antigen-presenting cells (MHC class II-immunoreactive; "-ir') with either antigen detecting T lymphocytes (CD4-ir) or Langerhans cells (NLDC-145-ir) and (2) locust (Insecta) abdominal ganglion paraffin sections, where it is known that immunoreactivities for octopamine and a FMRFamide-related peptide are colocalized in only one, uniquely identifiable neuron.

Animals↗
PubMed1987

Radioenzymatic analysis of neurotransmitters.

Since the late 1960's, radioenzymatic assays have gradually come to replace the less sensitive and less specific spectrofluorometric and bioassay procedures previously used to determine many of the neurotransmitters. These assays provide the means to measure picogram quantities of most of these substances, and have enabled determinations to be made in very small volumes of body fluids, in brain perfusates and individual brain nuclei, and in large individual cells of some simple animals. This paper reviews briefly some of the radioenzymatic techniques presently available for assaying norepinephrine (NE), epinephrine (E), dopamine (DA), serotonin, and the trace amines octopamine (OA), phenylethanolamine (PEOHA), phenylethylamine (PEA), tyramine (TA) and tryptamine (T).

Acetylserotonin O-Methyltransferase↗
PubMed1986

Mitochondrial alterations in the brain of the rat caused by chlorphentermine.

The effects of chlorphentermine on the bioenergetics and activity of monoamine oxidase in mitochondria from the brain of the rat were examined. Oxidation rates of glutamate and succinate were investigated in the presence of chlorphentermine (0.1-5.0 mM). In small concentrations (0.1-1.0 mM), chlorphentermine decreased the respiratory control ratio and the adenosine diphosphate oxygen (ADP/O) ratio, and stimulated state four respiration. State three respiration and the uncoupled state were also decreased, but to a lesser degree. In the presence of larger concentrations of chlorphentermine (1.0-5.0 mM), the respiration in states four, three, and in the uncoupled state, as well as the respiratory control ratio and ADP/O ratio, were decreased significantly. These data indicate that chlorphentermine functions as an uncoupler of oxidative phosphorylation. Oxidation of norepinephrine, serotonin, octopamine, tyramine and dopamine by monoamine oxidase (MAO), an enzyme marker of the outer mitochondrial membrane, was inhibited in the presence of 0.01 to 0.1 mM of chlorphentermine. Oxidation of tryptamine and benzylamine was unaffected. A kinetic study of the oxidation of serotonin in the absence and presence of chlorphentermine (0.025-0.1 mM) indicated that both the Vmax and Km were affected. This drug is an inhibitor of monoamine oxidase of mitochondria of the brain with mixed type inhibition. These combined data show that chlorphentermine affects biochemical processes in both inner and outer mitochondrial membranes.

Animals↗
PubMed1992

The innervation of the closer muscle of the mesothoracic spiracle of the locust.

The closer muscle of the mesothoracic spiracle of the locust, Schistocerca gregaria is innervated by two excitatory motoneurones and also by processes of a peripherally located neurosecretory cell. Within the muscle, ultrastructural studies show the presence of two types of excitatory nerve terminal which differ in the content of dense cored vesicles and in their distribution. The ventral segment of the muscle is innervated predominantly by terminals with small clear vesicles and only an occasional dense-cored vesicle. The central part of the muscle is innervated predominantly by terminals with small clear vesicles and larger numbers of dense-cored vesicles. The dorsal segment of the muscle is innervated exclusively by a neurosecretory type innervation. The small neurohaemal organ of the median nerve close to the spiracle muscle is immunoreactive to an antibody raised against bovine pancreatic polypeptide but no immunoreactive processes enter the muscle itself. The muscle possesses specific octopaminergic receptors that increase cyclic AMP levels and the possibility that the neurosecretory input to the muscle is provided by either a central or peripheral octopamine containing neurone is discussed.

Amino Acid Sequence↗
PubMed1988

Alpha 2-adrenoceptors as a target for formamidine pesticides: in vitro and in vivo studies in mice.

While the toxicity in insects of formamidines such as chlordimeform (CDM), its demethylated metabolite DCDM, and amitraz (AMZ) appears to involve activation of an octopamine-sensitive adenylate cyclase, their mechanism of action in mammals remains elusive. There is increasing evidence, however, that alpha 2-adrenoceptors might mediate certain effects of CDM, DCDM, and AMZ. In the present study, we investigated whether formamidines can interact directly with adrenoceptors in mouse forebrain both in vitro and after in vivo administration. Formamidines were potent inhibitors of the binding of [3H]clonidine to alpha 2-adrenoceptors with IC50's of 13 microM, 29 nM, and 130 nM for CDM, DCDM, and AMZ, respectively. Binding of [3H]yohimbine was inhibited with similar potencies. All compounds also inhibited with equal (CDM) or lower potency the binding of [3H]spiperone to dopamine D2 receptors and were weak inhibitors or inactive toward alpha 1- and beta-adrenoceptors, cholinergic muscarinic, GABAA, opiate mu, benzodiazepine, and histamine 1 receptors. Administration of formamidines to mice caused a dose-dependent decrease of [3H]clonidine binding. [3H]Clonidine binding returned to control values within 5 hr following administration of CDM and DCDM, but was still significantly decreased up to 48 hr after AMZ. Among different brain regions, [3H]clonidine binding was decreased to a larger extent in cerebral cortex, hippocampus, and midbrain. In vitro and ex vivo kinetic binding studies indicated that the effect of formamidines on alpha 2-adrenoceptors was due to a decrease in affinity and not to an alteration of the density of [3H]clonidine binding sites. The results of these biochemical studies support the hypothesis that alpha 2-adrenoceptors represent an important target for formamidine neurotoxicity in mammals.

Amidines↗
PubMed1996

Choline esters and biogenic amines in the hypobranchial gland of 55 molluscan species of the neogastropod Muricoidea superfamily.

As many as 55 neogastropod molluscs, all belonging to the Muricoidea superfamily, have been investigated for occurrence and contents, in their hypobranchial gland (HG), of choline esters and, subordinately, biogenic amines. Very high amounts of esters, strictly localized in the median area of the HG, were found in all dye-secreting molluscs. The choline esters were represented by murexine, dihydromurexine and senecioylcholine. A fourth ester, acryloylcholine, occurred in the HG of a single, non dye-secreting mollusc. All the compounds displayed potent neuromuscular blocking actions in all examined vertebrate and invertebrate species, as well as potent nicotinic actions. Muscarinic effects were either lacking or unimportant. In addition to choline esters the HG occasionally contained known and hitherto unknown biogenic amines: tyramine, octopamine, 5-hydroxytryptamine, histamine, urocanylhistamine and imidazole-propionylhistamine. The interest of extending the search of bioactive compounds to carnivorous, predatory molluscs other than those described in this paper and, more, extensively, to any molluscan species provided with 'venomous' glands or apparatuses, is emphasized.

Animals↗
PubMed1985

[3H]-Flunitrazepam binding in the presence of beta-phenylethylamine and its metabolites.

It has recently been reported that the concentration of beta-phenylethylamine (PEA) was elevated in the plasma of an individual experiencing convulsions because of an overdose of tranylcypromine. Also, high concentrations of PEA, injected into mice, were reported to induce convulsions. This convulsive effect was prevented by pretreatment with the benzodiazepines diazepam and chlordiazepoxide. In this study, PEA in concentrations from 0.5 to 100 microM failed to alter the binding of [3H]-flunitrazepam ([3H]-FLU) in membrane preparations from mouse rostral forebrain. The metabolites of PEA: phenylacetic acid, phenylethanolamine, octopamine and tyramine, also failed to affect [3H]-FLU binding. This suggests that although there are substances that act as convulsants by interacting with the benzodiazepine receptor sites, the convulsant effect of PEA and its metabolites is mediated elsewhere.

Animals↗
PubMed1986

Liquid chromatographic separation of enantiomers of adrenergic agonists.

Many established and experimental adrenergic agonists are derivatives of 2-aminoethanol with a phenol or catechol moiety in the 1-position. There is considerable interest in the stereochemical aspects of the actions of such chiral drugs. Surprisingly, however, little has been published on the chromatographic separation of the enantiomers of these compounds, and what has been published involved nearly exclusively capillary gas-liquid chromatography. In this report, the resolution of the racemates of ten adrenergic agents using reversed-phase liquid chromatography is described. The procedure is based on derivatizing the racemic mixture of each agent with the chiral reagent 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl isothiocyanate, followed by separation of the resulting diastereomers on octadecylsilane columns using methanol-aqueous ammonium acetate mixtures as mobile phase. Detection was at 254 nm. The separation of the enantiomers of norphenylephrine and of octopamine was less than complete; the resolution of the other agents, i.e., synephrine, N-ethylnorphenylephrine, p-hydroxyephedrine, p-hydroxynorephedrine, metanephrine, normetanephrine, isoproterenol, and nordefrin, was complete. The derivative of (-)-isoproterenol eluted before that of its antipode. The procedure may be applicable to other similar agents.

Adrenergic Agonists↗
PubMed1980

Dihydroergocryptine binding sites in bovine and rat pineal glands.

High affinity binding of [3H]dihydroergocryptine (DHE) to crude membrane preparations of bovine and rat pineal glands was examined by a rapid filtration procedure through Whatman GFB paper. Scatchard analysis of bovine pineal membranes revealed a single population of binding sites with Kd = (4.8 +/- 1.9) X 10(-8) M (mean +/- S.E.M., n = 3) and binding site concentration = 834 +/- 103 fmol/mg of protein. When various alpha- and beta-adrenergic agonists or antagonists were tested for their ability to inhibit [3H]DHE binding the following Ki values (microM) were obtained: DHE (0.039), phentolamine (0.102), phenoxybenzamine (0.262), methysergide (0.670), L-epinephrine (2.27), serotonin (3.09), L-norepinephrine (3.20), octopamine (30.3), L-propranolol (1710), L-isoproterenol (greater than 2000). In order to obtain information on the pre- or postsynaptic location of pineal DHE binding sites, pineal 900 g supernatants were prepared from rats subjected to bilateral superior cervical ganglionectomy or sham-operation 7 days earlier. Ganglionectomy caused a 53% increase in the number of binding sites without changing significantly their Kd (5.2 X 10(-8) M and 5.5 X 10(-8) M in ganglionectomized and control rats, respectively). These results are compatible with the view that postsynaptic alpha-adrenoceptors are present in the pineal gland.

Animals↗
PubMed1994

Neuritic GABAergic synapses in insect neurosecretory cells.

The localization of synaptic gamma-aminobutyric acid (GABA) receptors on cockroach dorsal unpaired median (DUM) neurons of the last abdominal ganglion was investigated. These neurosecretory cells, mainly octopaminergic, possess a soma located on the dorsal midline of the ganglion, from which emerges a short primary neurite dividing into two symmetrical lateral branches on both lateral edges of the ganglion. GABA pressure ejections onto the soma and onto the neuritic arborization elicited hyperpolarizations. Moreover, electrical stimulation of the anterior connectives evoked a postsynaptic potential, mainly inhibitory. This response and the GABA hyperpolarization of the neuritic field are antagonized by lateral application of picrotoxin while soma GABA hyperpolarization remained unchanged. This suggests that there are two kinds of GABA receptors located (i) onto the soma membrane of the DUM neurons and called extrasynaptic receptors, (ii) on the neuritic arborization, called synaptic receptors and implicated in the connection between neurons coming from the anterior part of the nervous system and the DUM cells. Immunohistological double staining technique reinforced the electrophysiological results by showing the presence of GABA-like immunoreactive processes next to octopamine-like immunoreactive ones.

Animals↗
PubMedDate not supplied

Peptide and amine modulation of the Limulus heart: a simple neural network and its target tissue.

The Limulus heart consists of a relatively simple neural network, the cardiac ganglion, and its target tissue, cardiac muscle. The large size and exceptional in vitro viability of this system has made it relatively easy to extract, purify, and identify endogenous compounds which alter cardiac function. These agents included peptides, such as protolin and Limulus chromatophorotropic factor, and amines such as dopamine, epinephrine, norepinephrine, octopamine, and serotonin. The accessibility and simple organization of the cardiac ganglion has also permitted clear identification of the sites of action of these amines and peptides. The Limulus heart is thus a very favorable system for studying peptide and amine neurohormones at the network, cellular and molecular levels.

Animals↗
PubMedDate not supplied

Monoamine oxidase isoenzymes in rat brain: differential changes during postnatal development but not aging.

Differential development of monoamine oxidase (MAO) isoenzymes in rat whole brain is described in postnatally developing Sprague-Dawley rats. Total MAO and isoenzyme activity was measured using nonspecific and specific substrates. Total MAO activity measured using tyramine, increased postnatally up to 24 weeks of age and attained a plateau afterward. The increase in total MAO activity was significant at all age groups (18 days to 36 months) investigated as compared to new born rats. MAO-A and MAO-B activities were measured using octopamine and benzylamine respectively. We also observed a marginal increase of MAO-A activity and a significant increase of MAO-B activity upon development. Furthermore, at 12 weeks of age, MAO-B activity increased by 10-fold as compared to new born and was consistent up to 36 months of age. The qualitative localization of the enzyme activity on non SDS-PAGE by nitroblue tetrazolium staining confirmed the increase of MAO-B during the development. It is suggested that the maturational increase of total MAO activity in brain is predominantly due to the increase of MAO-B isoenzyme.

Aging↗
PubMedDate not supplied

Neuropeptides, amines and amino acids in an elementary insect ganglion: functional and chemical anatomy of the unfused abdominal ganglion.

The insect ventral nerve cord consists of metamerically repeated ganglia subserving the thoracic and abdominal segments. The abdominal ganglia control basic functions such as respiration, circulation, heartbeat, diuresis, hindgut motility, functions of the genitalia and ovipositor and abdominal posture. Some of this control is by efferent innervation of target tissues but hormonal control also is exerted by abdominal neurosecretory cells via release from neurohemal organs or other release sites. The present review summarizes what is known about the distribution of neurotransmitters, monoamines and neuropeptides in the abdominal ganglia of different insect species. Special emphasis is on the unfused abdominal ganglion, since this is the least complex of all central ganglia and therefore may reveal the minimum number of neuroactive compounds utilized in neurotransmission, neuromodulation and neurohormonal control. Both GABA and glutamate are present in both interneurons and motoneurons, whereas biogenic amines such as serotonin, dopamine and histamine are found primarily in interneurons (although some cases of sensory cells and efferent neurons are known). Octopamine can be seen both in interneurons, efferent neurons and neurosecretory cells. A large number (about 20 different main types) of neuropeptides has been indicated in abdominal ganglia. Each peptide has a very specific distribution pattern. Depending on the peptide type, the localization is known to be in interneurons, neurosecretory cells or motoneurons, or combinations of these. The structure and known functions of the different neuropeptides in different insect species are summarized in some detail. Both GABA and glutamate appear to have roles as fast neurotransmitters, whereas amines and neuropeptides seem to have modulatory roles both within the CNS and at peripheral targets. After a comprehensive overview of different substances in studied insect species, the unfused abdominal ganglia from the moth Manduca sexta, locusts and cockroaches are dealt with in some detail and a comparison is made with insects possessing fused abdominal ganglia such as blowflies and Drosophila. Some emphasis is made of the presence of neuroactive compounds in neurosecretory cells and other identifiable neurons for which physiological analysis is feasible.

Amino Acids↗
PubMed1992

Production of specific antibody against L-dopa and its ultrastructural localization of immunoreactivity in the house-shrew (Suncus murinus) lateral habenular nucleus.

An antiserum was raised against L-DOPA bound to bovine serum albumin, purified by affinity chromatography, and its specificities were verified by immunoblotting and enzyme-linked immunosorbent assays. The antiserum did not cross-react with dopamine (DA), tyrosine, tyramine, octopamine, norepinephrine or epinephrine. Immunocytochemical studies using the PAP method revealed that tyrosine hydroxylase- and L-DOPA positive but aromatic L-amino acid decarboxylase- and DA-negative neurons were present in the lateral habenular nucleus of the house-shrew (Suncus murinus) brain. Ultrastructurally L-DOPA immunoreactive products were localized in the cytoplasmic matrix and terminals with vesicles.

Animals↗
PubMed1994

Chemical analysis of neurotransmitter candidates in clonal cell lines from Drosophila central nervous system. I. ACh and L-dopa.

To characterize neuronal phenotypes, aminergic neurotransmitters, i.e. acetylcholine (ACh), catecholamine (CA)s and other biogenic amines (serotonin, octopamine), were surveyed in 10 colonial clones from one cell line of Drosophila larval CNS using HPLC-ECD system. ACh, which is a neurotransmitter in Drosophila, was found in 7 out of 10 clones. CAs, their metabolites, and other amines were not detected in any clones. However, all the 10 clones expressed L-dopa, a precursor of CAs. Consequently, seven clones expressed ACh and L-dopa. L-dopa as a novel neurotransmitter candidate was discussed.

Acetylcholine↗