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At least 1,297 records · Page 72Linked to original sources
PubMed1978

Butanol extracts from myelin fragments-II. Some properties of 5-hydroxytryptamine binding.

The myelin fragments of rat brain stem were treated with butanol-water mixtures, and the butanol extracts (total extract=TE) were incubated with 5 x10(-7) M of C14.5-HT. After incubation, protein, lipid phosphorus and radioactivity were analyzed by Sephadex LH20 column chromatography. Two peaks of components eluted in chloroform-methanol 4:1 (peak I and II) showed the binding capacity for C14.5-HT. The displacement studies with unlabeled 5-HT (5 X 10(-4) M) suggested that peak II was the saturable binding component to 5-HT. On the other hand, butanol extracts from the synaptic membranes of rat brain stem did not show binding for C14.5-HT. Various compounds were studied to determine their inhibitory effects on the saturable binding of 5-HT to TE. The results indicated that acetylcholine, dopamine and tryptamine inhibited the 5-HT binding but LSD, reserpine, colchicine, vinblastine, 5-hydroxytryptophan (5-HTP) and 5-hydroxy-3-indole acetic acid (5-HIAA) had no effect.

Acetylcholine↗
PubMed2000

Induction of N-hydroxycinnamoyltyramine synthesis and tyramine N-hydroxycinnamoyltransferase (THT) activity by wounding in maize leaves.

Both N-p-coumaroyl- and N-feruloyltyramine accumulated in response to wounding in leaf segments of maize. The amount of N-hydroxycinnamoyltyramines started to increase 3-6 h after wounding and peaked at 12 h. Thereafter, the amount of N-p-coumaroyltyramine decreased rapidly, while the N-feruloyltyramine content remained at a high level. The accumulation of N-hydroxycinnamoyltyramines was accompanied by an increase in the tyramine N-hydroxycinnamoyltransferase (THT) activity. This increase was initially detected 3 h after wounding and reached a maximum at 36 h, the level of activity being 40 and 11 times that in the leaves before wounding and in the control leaves, respectively. Partial purification of THT from wounded leaves by (NH4)2SO4 precipitation and subsequent two steps of anion-exchange chromatography resulted in a 12.5-fold increase in specific activity. Kinetic studies with this partially purified enzyme revealed that the best substrates were tyramine and feruloyl-CoA, although tryptamine and sinapoyl-CoA also efficiently served as substrates. The apparent native molecular weight of the enzyme was determined by gel filtration as 40 kDa.

Acyltransferases↗
PubMed1976

Critical evaluation of measurement of platelet monoamine oxidase in man.

Some biochemical characteristics such as substrate specificity, substrate affinity and inhibitor sensitivity of monoamine oxidase of human blood platelets were investigated. Tyramine, tryptamine and beta-phenylethylamine were used as substrates. The apparent Michaelis constants, maximal velocity rates and I50 for the inhibitor tranylcypromine were determined. The data were analyzed according to Lineweaver-Burk and Dixon. The influence of amitriptyline, a prototype of tricyclic antidepressants, on the selected variables (Km, V, I50), was studied. The parameters investigated showed remarkably low interindividual differences when healthy volunteers were tested. The inhibitor activity of amitriptyline towards platelet monoamine oxidase depends on the substrate used. Amitriptyline concentrations which showed a pronounced effect on the enzyme characteristics are significantly higher than plasma levels of the drug found under therapeutic conditions.

Adult↗
PubMed1980

Identification of tetrahydronorharmane (tetrahydro-beta-carboline) in human blood platelets.

The present paper shows that tetrahydronorharmane (tetrahydro-beta-carboline) exists in human platelets. The concentration of tetrahydronorharmane in platelets from 10 ml platelet rich plasma was in the range of 9.3 to 25.6 pmol (n=8). Ingestion of tryptamine hydrochloride (n=4) three times daily for three consecutive days and of 19.6 mmol D,L-tryptophan (n=7) the evening (10 p.m.) before the blood collection did not lead to an increase of tetrahydronorharmane in platelets.

Adult↗
PubMed2004

Serotonergic and dopaminergic influence of the duration of embryogenesis and intracapsular locomotion of Lymnaea stagnalis L.

The role of the dopaminergic and serotonergic system was studied during the embryonic development of the pond snail Lymnaea stagnalis, with special attention to the effect of dopamine and serotonin as well as their agonists and antagonists on the rotation of the veliger larvae, and to the effect of precursors and inhibitors of the synthetizing enzymes on the duration of the embryonic life. Serotonin, D-lysergic acid diethylamide and N,N-dimethyltryptamine increased at a concentration of 1 microM the rotation by 50%, 90% and 87% respectively, and among them D-Lysergic acid diethylamide was found to be the most potent agonist. Other serotonergic agonists and antagonists enhanced the frequency of the rotation (from 165% to 355%) at higher threshold concentrations in the following rank order: methysergid > tryptamine > 2,5-dimethoxy-4-iodoamphetamine > 5-carboxyamidotryptamine > bromo-lysergic acid diethylamide > 7-methyltryptamine. Application of 1-(2-methoxyphenyl) piperazine decreased the rotation by 76%. The reuptake inhibitor desipramine completely blocked the rotation and killed the embryos. Dopaminergic agonists accelerated the rotation by 62% to 233%, and their effect was ranged as follows: dopamine > apomorphine > m-tyramine approximately equal to p-tyramine. Chlorpromazine at 100 microM concentration killed the embryos. At a concentration of 100 microg/ml, tyrosine, the precursor of DA, slowed down the embryonic development by increasing the duration of the embryonic life from 8 to 10 days. Decarboxylase inhibitors, alpha-methyl-3,4-dihydroxyphenyl-alanine (25 microg/ml) and m-hydroxybenzylhydrazin (5 microg/ml), killed 50% of the embryos, meanwhile the rest hatched ten days later, compared to the control animals. The development was partially blocked by the serotonin precusor L-tryptophane (50 microg/ml). Trytophan hydroxylase blocker, p-chlorphenylalanine (50 microg/ml) resulted in a distortion of the body pattern of the embryos, and prevented the hatching of most (95%) of the animals.

Amphetamines↗
PubMed2003

Seasonal changes in plasma concentrations of cecum-derived amines in clinically normal ponies and ponies predisposed to laminitis.

OBJECTIVE: To measure concentrations of amines formed in the cecum of clinically normal ponies, determine amine concentrations in plasma samples collected in spring and winter, and compare concentrations of amines and serotonin in plasma samples obtained from clinically normal ponies and ponies predisposed to laminitis. SAMPLE POPULATION: Cecal contents obtained from 10 ponies euthanatized at an abattoir and blood samples obtained from 42 adult ponies. PROCEDURE: Cecal contents were assayed for amines by high-performance liquid chromatography (HPLC). Blood samples were collected at various times of the year from 20 ponies predisposed to acute laminitis and 22 clinically normal ponies. Plasma serotonin concentration was measured by HPLC, and tryptamine (TRP), tyramine (TYR), phenylethylamine (PEA), and isoamylamine (IAA) were measured by liquid chromatography-mass spectrometry. RESULTS: 15 amines were identified in cecal contents. Plasma TRP, TYR, PEA, and IAA concentrations ranged from 10pM to 100nM in both groups of ponies. Plasma concentrations of serotonin or other amines did not differ between clinically normal ponies and those predisposed to laminitis; however, significantly higher concentrations of TRP, PEA, and IAA were found in samples obtained in the spring, compared with winter samples. CONCLUSIONS AND CLINICAL RELEVANCE: Various amines are found in the cecum of ponies, several of which can be detected in the plasma. Concentrations increase significantly in the spring and may reach concentrations close to the threshold for causing vasoconstriction. Release of amines from the cecum into the systemic circulation may contribute to hemodynamic disturbances in horses and ponies with acute laminitis.

Amines↗
PubMed1995

Endogenous toxins and mycotoxins in forage grasses and their effects on livestock.

Plant toxins are the chemical defenses of plants against herbivory. Grasses have relatively few intrinsic toxins, relying more on growth habit to survive defoliation and endophytic fungal toxins as chemical defenses. Forage grasses that contain intrinsic toxins include Phalaris spp. (tryptamine and carboline alkaloids), sorghums (cyanogenic glycosides), and tropical grasses containing oxalates and saponins. Toxic effects of these grasses include neurological damage (Phalaris staggers), hypoxia (sudangrass), saponin-induced photosensitization (Brachiaria and Panicum spp.), and bone demineralization (oxalate-containing grasses). Endophytic toxins in grasses include ergot alkaloids in tall fescue and tremorgens (e.g., lolitrem B) in perennial ryegrass. Lolitrems cause neurological effects, producing the ryegrass staggers syndrome. Annual ryegrass toxicosis is caused by corynetoxins, which are chemically similar to tunicamycin antibiotics. Corynetoxins are produced by Clavibacter bacteria that parasitize a nematode, Anguina agrostis, that may infect annual ryegrass. Corynetoxins inhibit glycoprotein synthesis, causing defective formation of various blood components of the reticulo-endothelial system. Another mycotoxin in ryegrass is sporidesmin, which causes liver damage and secondary photosensitization (facial eczema). Fusarium toxins such as zearalenone and trichothecenes also occur in forage grasses. Kikuyugrass poisoning results in severe damage to the ruminal epithelium and omasal mucosa, and neurological signs. The causative agent, which may be associated with army worm predation of the grass, has not been identified. The properties and significance of these toxins are reviewed.

Acremonium↗
PubMed2005

[DNA and chemical analyses of commercial fly agaric-related products].

Since June 6, 2002, psilocin and psilocybin-containing fungi (commonly called "magic mushrooms") have been regulated by the Narcotics and Psychotropics Control Law in Japan. However, various fly agaric-related products are now entering the Japanese market via the internet. In this study, fly agaric-related products available in this way were investigated for raw materials by DNA analysis and for additives by chemical analysis. Nucleotide sequence analysis of the mitochondrial 12S rDNA region suggested that these fly agaric-related products originate from A. muscaria or A. muscaria var. persicina. Furthermore, they were classified into three strains based on the ITS2-LSU nucleotide sequence. Harmine derivatives and/or tryptamine derivatives were detected in some of these products by LC/MS analysis. In accordance with this, the matK gene of Peganum harmala was found in all of the harmine derivative-containing samples.

Amanita↗
PubMedDate not supplied

[Role of visual impulsation on the age-dependent receptor properties of synaptosomal membranes].

An investigation was made into the activity of interaction of serotonin and tryptamine with synaptosomes isolated from the visual system of the rabbit brain. It has been found that the synaptosomes of the visual cortex and the anterior colliculi of normal rabbits are characterized by a higher activity in indoleamines binding than those of other parts of the cortex. Early visual deprivation caused a drop in the activity of interaction between the indoleamines and synaptosomes of all the investigated brain regions, more pronounced in the case of the synaptosomes of the visual analyser structures. Recovery of the visual function helped to normalize the activity of the process. The above regular relationships between visual impulse activity and the activity of the transmitter--receptor interaction lead to the conclusion that serotonin plays a specific, apparently neuro-transmitting part in the visual system.

Age Factors↗
PubMed1976

[Biosynthesis of 5- methoxy-N-acetyltryptamine (melatonin) in enterochromaffin cells].

Chromatographic analysis of the alkaline extract of the gastrointestinal mucosa of rabbits rich in enterochromaffin cells displayed the presence of melatonin (5-methoxy-N-acetyltryptamine) and its precursors (5-oxytryptophane, tryptamine, serotonine, mexamine) in it. Detection of precursors indicated that not a passive accumulation, but an active synthesis of melatonin occurred in the enterochromaffin cells. Epiphysis was not the only place of melatonin synthesis. Functional condition of enterochromaffin cells was largely determined by the extent of physiological and pathological reactions of the organism.

5-Hydroxytryptophan↗
PubMed2001

Donitriptan (Pierre Fabre).

Pierre Fabre is developing donitriptan, a piperazide 5-HT1D agonist, as a potential treatment for migraine [175854]. In January 2001, donitriptan had completed phase I trials for migraine and was scheduled to enter phase II development [396027]. This compound has an increased potency and, importantly, markedly higher intrinsic activity in comparison to the well described tryptamine derivatives, naratriptan, zolmitriptan and sumatriptan [295769].

Animals↗
PubMed1975

Regional formation of 6-methoxy-1,2,3,4-tetrahydro-beta-carboline in rat brain extract.

In the presence of 5-methoxytryptamine (5-MeOT), 5-methyltetrahydrofolic acid (5-MTHF) yields 6-methoxy-1,2,3,4-tetrahydro-beta-carboline (6-MeOTHbetaC) in rat brain extracts, possibly via formaldehyde formation catalyzed by methylenetetrahydrofolate reductase. The formation of 6-MeOTHbetaC in selected brain regions, ranging from 452 +/- 40 pmol formed per mg protein per hour in corpus striatum to 119 +/- 17 pmol in cingulate cortex, is significantly correlated with the regional distribution of 1,2,3,4-tetrahydro-beta-carboline (THbetaC) formed from 5-MTHF and tryptamine (r = 0.76, p less than 0.01) as well as that of methylene-beta-phenylethylimine (MbetaphiEI) from 5-MTHF and beta-phenylethylamine (betaphiEA; r = 0.90, p less than 0.01). FAD enhances the activity, lowering both Vmax and Km values with respect to 5-MeOT and Vmax, but not Km, with respect to 5-MTHF.

Animals↗
PubMed1975

Applications of gas chromatography and mass spectrometry in neurochemical studies: determination of indole amine profiles at the picogram level.

Work is presented on the application of sensitive and specific analytical methods for the simultaneous assay of tryptophan and its indolic metabolites (5-hydroxytryptophan, serotonin, 5-hydroxy-indole-acetic acid, tryptamine and indoleacetic acid). Due to their small concentrations in selected areas of the central nervous system, suitable derivatives have been prepared for separation by Gas Chromatography (GC) and detection by electron capture (ECD). Carboxylic acid groups have been methylated with BCl3-methanol and phenolic and amine groups have been acylated to pentafluoropropionyl derivatives. This type of derivatives allow a detectability limit of 5 picograms (5 x 10(-12) gr) if the corresponding reaction kinetics and yields are properly optimized. Response curves are presented. Identifications have been obtained by combined GC-MS and by the use of Kovats indeces in two GC stationary phases. The GC separation of the six compounds indicated above can be performed in less than 5 minutes with quantitative reproducibility. This work opens the possibility of performing comparative studies ("screening") of various physiological and pathological conditions by detecting any changes in the profile representative of a whole metabolic pathway, such as that of the indolic compounds in this case.

Chromatography, Gas↗
PubMedDate not supplied

[The biosynthesis of low-molecular-weight nitrogen-containing secondary metabolite-alkaloids by the resident strains of Penicillium chrysogenum and Penicillium expansum isolated on the board of the Mir space station ].

The analysis of the absorption spectra of the low-molecular-weight nitrogen-containing secondary metabolites--alkaloids--of 4 Penicillium chrysogenum strains and 6 Penicillium expansum strains isolated on board the Mir space station showed that all these strains synthesize metabolites of alkaloid origin (roquefortine, 3,12-dihydroroquefortine, meleagrin, viridicatin, viridicatol, isorugulosuvin, rugulosuvin B, N-acetyl-tryptamine, and a "yellow metabolite" containing the benzoquinone chromophore).

Alkaloids↗
PubMed2003

Diurnal regulation of arylalkylamine N-acetyltransferase activity in chicken retinal cells in vitro: analysis of culture conditions.

PURPOSE: Arylalkylamine N-acetyltransferase (AANAT) is a key regulatory enzyme in the synthesis of melatonin, which displays daily fluctuations in chicken retinal photoreceptors in vivo. The purpose of the present study was to determine if cultures of embryonic neural retina cells express diurnal rhythms of AANAT activity. METHODS: Cell cultures were prepared from chick embryonic day 6 neural retina and incubated for 4 to 8 days in vitro (DIV). Cells were incubated under a daily light-dark (LD) cycle and were harvested day and night. Culture conditions were modified to test the effects of cell density, serum concentration, incubation temperature, S-(4-nitrobenzyl)-6-thioinosine (NBTI), and taurine on AANAT activity. AANAT activity was assayed in cell homogenates by measuring the catalytic formation of N-acetyltryptamine from tryptamine and acetyl coenzyme A. RESULTS: Cells cultured in medium containing 10% fetal bovine serum (FBS) failed to show any diurnal fluctuation in AANAT activity on DIV 5 and 6. However, if the culture medium was replaced on DIV 4 with one containing 1% FBS, and 5 microM NBTI or 5 mM taurine, the cells expressed significant diurnal rhythms of enzyme activity. NBTI was more potent and effective than taurine. Culture conditions were optimized with respect to cell density, serum concentration, incubation temperature, and NBTI concentration. Under optimized conditions, overall cell survival and the density of photoreceptor cells were increased relative to that with the other culture conditions tested. CONCLUSIONS: The results indicate that diurnal rhythms of AANAT activity are expressed in embryonic retinal cells incubated under particular culture conditions. The results show that the mechanisms regulating melatonin synthesis in chicken retinal cells are established during early embryonic life. This culture preparation will be useful in elucidating the photic control mechanisms involved in regulation of melatonin biosynthesis in photoreceptor cells.

Animals↗
PubMed1992

Studies with new ergoline derivatives on the effects of central and peripheral 5-hydroxytryptamine receptors.

The antiserotonin properties of a series of new ergoline derivatives were investigated in several pharmacological test systems which have been proposed for the characterization of putative antagonists at central and peripheral 5-HT2 receptors. In radioligand binding studies with [3H]ketanserin among the new ergolines only 1-methyl-2-brom-9,10-dihydrolysergic acid-bis(beta-acetoxyethyl)-amide (AWD 52-336) showed high affinity at cortical 5-HT2 receptors (Ki-5.4 nmol/l). In 5-HT-amplified ADP-induced aggregation of human platelets 6-nor-6-propyl-9,10-dihydro ergometrine (AWD 52-227) and 9,10-dihydrolysergic acid-di-ethanol-amide (AWD 52-302) were potent inhibitors of 5-HT response. Comparison of this two in vitro tests demonstrated a significant correlation (r = 0.636; p < 0.05) between the ability of the ergolines to block the 5-HT aggregation mediated by platelet 5-HT2 receptors and their affinity to [3H]ketanserin-labelled binding sites in rat cortical membranes. In the used in vivo tests (tryptamine tremor, 5-HTP-induced head twitches) 1-methyl-9,10-dihydrolysergic acid-bis(beta-acetoxyethyl)-amide (AWD 52-83) and AWD 52-336 were found to antagonize the behavioural responses with comparatively moderate potency. The results suggest, therefore, that AWD 52-83 and AWD 52-336 may be both central and peripheral acting 5-HT2 antagonists, whereas AWD 52-227 and AWD 52-302 seem to be potent blockers at peripheral 5-HT2 receptors. Furthermore, the obtained results allow to reveal structure-activity relationships of ergolines. Substitution in position 1 in the tetracyclic ergoline ring system may be important with respect to the efficacy at central 5-HT2 receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

5-Hydroxytryptophan↗
PubMed2004

[Morphochemical analysis of hippocampus of rats predisposed (August) or resistant (Wistar) to emotional stress].

The aim of this work was the comparative cytochemical study of some parameters of neurotransmitter and protein metabolism in the hippocampus (CA3 field) of August and Wistar rats, which were used as genetic-functional models demonstrating different brain organization, in particular, in respect to an emotional stress. Using quantitative cytochemical methods it was demonstrated that the activities of aminopeptidase, monoaminooxidase (substrates--tryptamine and serotonin), and glutamate dehydrogenase, were lower in the hippocampus of August rats (predisposed to emotional stress) as compared to that one in Wistar rats (resistant to emotional stress). August rats were also characterized by smaller sizes of neuronal cytoplasm and nuclei and by their lower protein content and concentration. The analysis of the data obtained has shown the existence of neurons with different modalities within the limits of CA3 hippocampal field, and these characteristics are thought to define the morphochemical differences in the hippocampus (CA3 field) of genetically different rats.

Aminopeptidases↗
PubMed2004

[Synthesis of 1-indole substituted beta-carboline alkaloid and its derivatives and evaluation of their preliminary antitumor activities].

AIM: To synthesize eudistomin U and its 6-OCH3/Br derivatives and 5'-Br derivatives as antitumor agents. METHODS: Using tryptamine and indole-3-aldehyde as starting materials, through condensation, Pictet-Spengler cyclization and dehydrogenation three steps, the alkaloids and its derivatives were prepared. RESULTS: The structures of the compounds were determined by 1HNMR, MS and HRMS. Antitumor activity in vitro was tested. CONCLUSION: Eudistomin U and its derivatives were synthesized. The results showed that they all showed antitumor activities against mouse P388 strain.

Alkaloids↗