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 289 records · Page 16Linked to original sources
PubMed1980

A radioenzymatic assay for free and conjugated normetanephrine and octopamine excretion in man.

A radioenzymatic method for the measurement of free and conjugated normetanephrine (NMN) and octopamine (OCT) is described for human urine. The assay is based on the conversion of NMN or OCT to radiolabeled metanephrine (MN) or synephrine (SYN) by phenylethanolamine-N-methyl transferase (PNMT), using tritium-labeled S-adenosyl-methionine [3H]SAM as methyl donor. Thin-layer chromatographic separation yields an assay of high specificity. The sensitivity of the assay is 5 and 2.5 pg of NMN or OCT, respectively. The normal value of free and conjugated NMN was found to be 23 +/- 13 and 102 +/- 49 ng/mg creatinine. Four patients with pheochromocytoma had highly increased levels of free and conjugated NMN. The urinary excretions of free and total octopamine were 5.7 +/- 2.8 and 34.8 +/- 16.6 ng/mg of creatinine, respectively, in normal patients.

Adult↗
PubMed1987

Effects of triethyltin on brain octopamines and their metabolism in the rat.

The effects of triethyltin given acutely on the cerebral level of p- and m-octopamines were studied in rats. These octopamines were reduced drastically in hypothalamus and brainstem, while noradrenaline and dopamine were only slightly decreased. No important changes were observed in the activities of tyrosine hydroxylase, dopamine beta-hydroxylase or monoamine oxidase. However, the activity of aromatic L-amino acid decarboxylase was significantly reduced. The addition of the inhibitor of dopa decarboxylase, Ro 44602, caused a total inhibition of this enzyme activity. These results are discussed in terms of the possible use of the triethyltin-induced cerebral oedema as a model for the study of some aspects of the phenolamine changes related to cerebral oedema processes.

Animals↗
PubMed1989

Central administration of p-octopamine to mice: assessment of antinociception.

Administration of p-octopamine by intracerebroventricular (i.c.v.) or intrathecal (i.t.) routes, but not orally, produced antinociception in the acetylcholine-induced abdominal constriction test (ED50 = 24.8 and 3.6 micrograms, respectively). Likewise, i.c.v. and i.t., but not peripheral (up to 200 mg/kg s.c.), administration increased latency in the 48 degrees C hot-plate test (ED50 = 11.5 micrograms i.c.v. and 0.2 micrograms i.t.). These actions were relatively long-lasting and not blocked by naloxone. Antinociception following i.c.v. administration was abolished in reserpinized mice or by pretreatment with i.t. phentolamine (2 micrograms). These results suggest a moderate antinociceptive action of p-octopamine involving non-opioid, reserpine-sensitive, central pathways.

Analgesics↗
PubMed1982

Possible role of octopamine and tyramine in the antihypertensive and antidepressant effects of tyrosine.

The administration of a dose of 200 mg/kg of tyrosine (as either the free amino acid or the ethyl ester) increased the 24-hour excretion of p-hydroxyphenethyleneglycol (p-HPG) and p-hydroxyphenylethanol, metabolites of octopamine and tyramine, by 147 and 50%, respectively. One hour after this dose of tyrosine, brain levels of p-HPG and p-hydroxyphenylacetic acid (p-HPA), another metabolite of tyramine, were increased by 82 and 196%, respectively. Pretreatment with Ro4-4602, a peripheral decarboxylase inhibitor, reduced by 50% the tyrosine-induced increases in brain p-HPA levels, suggesting that tyramine was partially formed in the brain parenchyma. Tyrosine caused only slight, but non-significant increases in brain levels of catecholamine metabolites. These results suggest that tyrosine-induced increases in the production of tyramine and octopamine in brain may account for some of the effects of tyrosine, such as its antihypertensive and reported antidepressant properties.

Animals↗
PubMed1994

Octopamine-sensitive adenylyl cyclase and G proteins in Ceratitis capitata brain during aging.

The loss of the ability in signalling transduction constitutes an attractive hypothesis to explain the age-related loss of functions in the nervous system. In this paper we have examined adenylyl cyclase and G proteins in Ceratitis capitata brain during aging. The intermediate level of complexity of the Mediterranean fruit fly and its short lifespan make it a particularly interesting system for aging studies. Adenylyl cyclase basal activity decreased in the course of aging. By contrast, neither guanine nucleotide-induced activation of adenylyl cyclase nor Gs protein levels were modified. However, adenylyl cyclase activation by octopamine, which is a major neurotransmitter, neuromodulator and neurohormone in insects, was lost during aging. This observation correlated with a decrease in octopamine binding to brain plasma membranes that was due to a decrease in both receptor affinity and binding sites. On the other hand, we observed an increase in the expression of C. capitata Go protein with age, as revealed by pertussis toxin-catalysed ADP-ribosylation and immunoblotting experiments, that was not correlated with an increase in beta subunit levels. This report constitutes the first direct evidence for the participation of a Go protein in aging in the nervous system.

Adenosine Diphosphate Ribose↗
PubMed1984

Octopamine alters rhythmic activity in the isolated cardiac ganglion of the crab, Portunus sanguinolentus.

When applied to the isolated cardiac ganglion of Portunus, octopamine decreases the ganglionic burst frequency and increases the burst duration in a dose-dependent manner over the concentration range 10(-8) M to 10(-6) M. These effects are accompanied by a hyperpolarization (maximum 5 mV) of the cardiac ganglion motor neurones and a decrease in the magnitude of the interburst pacemaker potential in these neurones. The evidence that octopamine plays a cardiomodulatory role in vivo is discussed.

Action Potentials↗
PubMed1993

Decreased cortical octopamine level in basal forebrain lesioned rats: a microdialysis study.

Ibotenic acid-induced lesion of the basal forebrain resulted after 13 days in a 90% reduction of octopamine (OA) in the frontoparietal cortex of adult rats, whereas dihydroxyphenylacetic (DOPAC), homovanillic (HVA) and 5-hydroxyindoleacetic (5-HIAA) acids were not modified as measured by microdialysis and high-performance liquid chromatography (HPLC) with electrochemical detection. At this time, cortical choline acetyltransferase (ChAT) activity was decreased by 34%. The results are discussed with respect to possible octopamine involvement in reduced age-associated performance in neurodegenerative processes.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1991

A dopamine- and octopamine-sensitive adenylate cyclase in the nervous system of Octopus vulgaris.

1. Adenylate cyclase activity was assayed in the optic lobe of Octopus vulgaris. 2. Both octopamine and dopamine stimulate the octopus adenylate cyclase, apparently by competing with the same receptor site. 3. (+/-)-2-Amino-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene-HBr (6,7-ADTN) and a number of phenylethanolamine derivatives stimulate the octopus adenylate cyclase activity. 4. The dopamine D-1 antagonists R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl- 2,3,4,5-tetrahydro-1H-3-benzazepine-HCl (SCH-23390) and (+/-)-7-bromo-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H- 3-benzazepine-HCl (SKF-83566) are unable to antagonize the effects of dopamine and octopamine, and similarly ineffective is the agonist (+/-)-1-phenyl-2,3,4,5-tetrahydro-1H-3- benzazepine-7,8-diol-HCl (SKF-38393). 5. No detectable binding of labelled SCH-23390 occurs on membrane preparations from octopus optic lobe.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1984

Pharmacology of the octopamine-stimulated adenylate cyclase of the locust and tick CNS.

The presence of an octopamine-stimulated adenylate cyclase is shown in homogenates of the cerebral ganglion of the locust Schistocerca americana gregaria and the synganglion of the tick Boophilus microplus. A detailed study of the pharmacology of the activation of the enzyme of the two species is reported and compared with the pharmacology of octopamine receptors in other invertebrate preparations.

Adenylyl Cyclase Inhibitors↗
PubMed1988

Derivatives of epinephrine, norepinephrine, octopamine and histamine formed by homogenates of Trichostrongylus colubriformis, a nematode parasite of ruminants.

1. Radiolabeled epinephrine, norepinephrine, octopamine and histamine were introduced into homogenates of mixed sexes of the nematode Trichostrongylus colubriformis and the labeled derivatives formed during incubation were identified by HPLC. Vanillylmandelic acid (VMA), 4-hydroxy-3-methoxyphenyl glycol (HMPG) and metanephrine were formed from epinephrine. 2. VMA, HMPG and normetanephrine were produced from norepinephrine. 3. Octopamine was converted into norepinephrine, synephrine and epinephrine. 4. Imidazole-4-acetic acid, 1,4-methylimidazole acetic acid and acetylhistamine were formed from histamine. 5. Inhibitors of monoamine oxidase, catechol-O-methyltransferase and phenylethanolamine-N-methyltransferase were tested for their effects on the formation of certain of these derivatives, and the results suggested that these enzymes were active in the homogenate.

Animals↗
PubMed2005

Tyramine Functions independently of octopamine in the Caenorhabditis elegans nervous system.

Octopamine biosynthesis requires tyrosine decarboxylase to convert tyrosine into tyramine and tyramine beta-hydroxylase to convert tyramine into octopamine. We identified and characterized a Caenorhabditis elegans tyrosine decarboxylase gene, tdc-1, and a tyramine beta-hydroxylase gene, tbh-1. The TBH-1 protein is expressed in a subset of TDC-1-expressing cells, indicating that C. elegans has tyraminergic cells that are distinct from its octopaminergic cells. tdc-1 mutants have behavioral defects not shared by tbh-1 mutants. We show that tyramine plays a specific role in the inhibition of egg laying, the modulation of reversal behavior, and the suppression of head oscillations in response to anterior touch. We propose a model for the neural circuit that coordinates locomotion and head oscillations in response to anterior touch. Our findings establish tyramine as a neurotransmitter in C. elegans, and we suggest that tyramine is a genuine neurotransmitter in other invertebrates and possibly in vertebrates as well.

Amino Acid Sequence↗
PubMed1988

Liquid chromatographic procedures for the analysis of compounds in the serotonergic and octopamine pathways of lobster hemolymph.

High-performance liquid chromatography, with serial electrochemical and ultraviolet detectors, was used with a reduced activity catecholamine C18 column to separate and quantify compounds important in the serotonergic and octopamine pathways in lobster hemolymph. The chromatographic mobile phase was composed of potassium dihydrogenphosphate buffer, trichloroacetic acid, sodium dodecyl sulfate, the sodium salt of ethylenedinitrilotetraacetic acid and the organic solvents, acetonitrile and methanol. The compounds serotonin, 5-hydroxyindoleacetic acid, tryptophan, 5-hydroxytryptophan, tryptamine, melatonin, octopamine and tyrosine were well resolved within 13 min. Good electrode maintenance, the use of a silica gel precolumn and careful sample preparation were necessary to give a stable baseline, high resolution of these compounds and reproducibility of retention times and peak heights. The electrochemical detector extended the range of detection to the picogram level. Because of the instability of the solutes and of the chromatographic baseline, sample preparation procedures were investigated. Deproteinization with ammonium sulfate gave the best recovery of the compounds of interest and the most stable baseline with the electrochemical detector. Peaks in the hemolymph were characterized by addition of standards, dual detection (electrochemical and ultraviolet) and the enzyme peak shift technique. With this methodology, important endogenous neurohormones in the hemolymph of lobsters can be quantitatively determined with respect to the molt cycle.

Animals↗
PubMed2003

Increased EAG responses of tortricid moths after prolonged exposure to plant volatiles: evidence for octopamine-mediated sensitization.

As measured by electroantennograms (EAG), both male and female obliquebanded leafrollers, Choristoneura rosaceana (Harris), and redbanded leafrollers, Argyrotaeniavelutinana (Walker), were similarly sensitive to host-related plant volatiles: trans-2-hexenal, benzaldehyde, 1-hexenol, cis-3-hexen-1-ol, geraniol, linalool, (+)-limonene, hexenal and trans-2-hexenol. Females of both species were similarly sensitive to the shared major component of their sex-attractant pheromone ((Z)11-14:Ac). Continuous 60 min pre-exposure of male and female C. rosaceana and A. velutinana to successively higher concentrations of a mixture of the nine plant volatiles in Teflon chambers with continuous air exchange caused a dosage-dependent increase in subsequent responsiveness (sensitization) to green leaf volatiles, as measured by EAGs. In addition, 60 min of pre-exposure of male C. rosaceana to certain individual volatiles ((+)-limonene, geraniol, benzaldehyde) increased EAGs nearly as much as did the mixture of nine volatiles. Pre-exposures to the nine plant-volatile mixture at concentrations achieved by 100 microg and 1 mg loading dosages in 100 microl of mineral oil significantly increased EAG depolarization to pheromone (cross-sensitization) in males but not females of both moth species. Antennae of male C. rosaceana pre-injected with 100 microg of octopamine (OA) without volatile pre-exposure exhibited sensitization nearly identical to that induced by pre-exposing moths to sensitizing concentrations of the plant-volatile mixture. Moreover, injection of the OA antagonist chlorpromazine (CP) blocked sensitization by the plant-volatile pre-exposure. Collectively, these findings suggest that exposures of tortricid moths to certain host-plant related volatiles may modulate subsequent olfactory sensitivity to behaviorally relevant chemical cues and that plant-volatile induced sensitization may be octopamine mediated.

Adrenergic alpha-Agonists↗
PubMed2002

Behavioural pharmacology of octopamine, tyramine and dopamine in honey bees.

In the honey bee, responsiveness to sucrose correlates with many behavioural parameters such as age of first foraging, foraging role and learning. Sucrose responsiveness can be measured using the proboscis extension response (PER) by applying sucrose solutions of increasing concentrations to the antenna of a bee. We tested whether the biogenic amines octopamine, tyramine and dopamine, and the dopamine receptor agonist 2-amino-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene (6,7-ADTN) can modulate sucrose responsiveness. The compounds were either injected into the thorax or fed in sucrose solution to compare different methods of application. Injection and feeding of tyramine or octopamine significantly increased sucrose responsiveness. Dopamine decreased sucrose responsiveness when injected into the thorax. Feeding of dopamine had no effect. Injection of 6,7-ADTN into the thorax and feeding of 6,7-ADTN reduced sucrose responsiveness significantly. These data demonstrate that sucrose responsiveness in honey bees can be modulated by biogenic amines, which has far reaching consequences for other types of behaviour in this insect.

Adrenergic alpha-Agonists↗
PubMed1978

Fluorimetric detection of octopamine in high-performance liquid chromatography and its application to the assay of dopamine beta-monooxygenase in human serum.

A high-performance liquid chromatographic procedure is described for the determination of octopamine. The method, which is based on the separation on a microparticulate bonded strong cation-exchange resin and measurement of the native fluorescence, has been applied to give a sensitive assay of dopamine beta-monooxygenase (EC 1.14.17.1) activity in human serum with tyramine as the substrate. The procedure, which has been designed for use with an automatic sampler, has a detection limit of about 50 pmoles of octopamine, and the analysis time is approximately 10 min per sample.

Autoanalysis↗
PubMed1982

Simultaneous analyses of phenethylamine, phenylethanolamine, tyramine and octopamine in rat brain using fluorescamine.

A fluorometric method for the simultaneous analyses of phenethylamine, phenylethanolamine, tyramine and octopamine has been developed. The method involves ion-exchange chromatography, derivatization with fluorescamine, solvent extraction and then separation by thin-layer chromatography. The fluorescent spots are then quantitated by scanning. The detection limits of this method are about 10 pmoles for phenethylamine, phenylethanolamine and tyramine, and 20 pmoles for octopamine. The method was used for simultaneous analyses of putative neurotransmitter amines in whole rat brain.

Animals↗
PubMedDate not supplied

Central regulation of photosensitive membrane turnover in the lateral eye of Limulus. I. Octopamine primes the retina for daily transient rhabdom shedding.

Limulus lateral eyes shed and renew a portion of their photosensitive membrane (rhabdom) daily. Shedding, in many species including Limulus, is regulated by complex interactions between circadian rhythms and light. Little is known about how circadian clocks and photoreceptors communicate to regulate shedding. Limulus photoreceptors do not contain an endogenous circadian oscillator, but rely upon efferent outflow from a central clock for circadian timing. To investigate whether the putative efferent neurotransmitter octopamine (OA) communicates circadian rhythms that prime the lateral eye for transient rhabdom shedding, we decoupled photoreceptors from the clock by transecting the lateral optic nerve (contains the retinal efferent fibers). Overnight (6 h) intraretinal injections of 40 microM OA restored transient shedding to lateral eyes with transected nerves to levels comparable to those of intact internal control eyes. To determine whether OA acts alone in communicating circadian rhythms that prime the lateral eye for transient shedding, we "primed" eyes with intact nerves for transient shedding with exogenous OA during subjective day. In nature, lateral eyes shed their rhabdoms only once a day at dawn following overnight efferent priming. Eyes in animals placed in darkness during subjective day, when the retinal efferents are quiescent, and injected for 6 h with 40 microM OA shed their rhabdoms in response to a second introduction to light. Untreated control eyes of the same animals did not. The same results were observed in vitro in lateral eyes treated similarly. Octopamine is the only efferent neurotransmitter/messenger required to make lateral eyes competent for transient shedding. Phentolamine, an OA receptor antagonist, reduced the number of photoreceptors primed for transient shedding and the amount of rhabdom shed in those photoreceptors suggesting that OA acts via a specific OA receptor.

Adrenergic alpha-Agonists↗