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At least 1,315 records · Page 73Linked to original sources
PubMed2006

[Molecular mechanisms and chemotaxonomy in the indole alkaloids derived from secologanin. (One drop in the sea, the sea in one drop)].

On the occasion of having won the Lajos Winkler Medal, at first the author confessed his intellectual relation to the famous scientist. Then he presented his results in the study on the three-dimensional molecular structure and chemotaxonomy of the more than 2500 alkaloids derived from secologanin and tryptamine, and isolated from three plant families, only. The multiple genetic and structural connections among the individual compounds were supported by current and common organic reaction mechanisms. The unified and well articulated picture obtained on detailed search in electronic data bases demonstrated the order of the parts in the whole. The final section of the lecture appreciated the interplay of multiplicity and unity in our culture and education as well.

Electronic Data Processing↗
PubMedDate not supplied

Pharmacokinetics of tryptamide following intravenous administration in rats.

Plasma and tissue levels of N-3-pyridoyl-tryptamine (tryptamide) vs. time were determined in rats following iv administration of various doses: 6.25, 12.5, 25.0 and 37.5 mg/kg. The course of changes was described by the two-compartment open model. The distribution rate constant (alpha, min-1), the elimination rate constant (beta, min-1), the body clearance (Cltot, ml/min) and its fraction absorbed (f,%) values changed depending on the dose and were respectively: 0.107-0.266, 0.0068-0.0126, 5.39-11.59 and 31.77-66.70.

Animals↗
PubMed1990

Comparison of serotoninergic to muscarinic cholinergic stimulation of phosphoinositide-specific phospholipase C in rat brain cortical membranes.

Stimulation of phosphoinositide-specific phospholipase C (PLC) by muscarinic cholinergic and serotoninergic agonists was measured in rat brain cortical membranes by using exogenously supplied substrates. Serotonin, tryptamine, 5-fluorotryptamine and 5-methyltryptamine stimulated PLC with EC50 values of 1.7, 11.2, 15.0, and 29.4 microM, respectively. Maximal PLC stimulation by serotoninergic agonists, which were all equally efficacious, was about 30% of that attained by carbachol. Ketanserin blocked serotoninergic but not cholinergic activation of PLC, whereas, conversely, atropine blocked the latter but not the former response. The rank order of potency for muscarinic agonists was oxotremorine-M greater than pilocarpine = arecoline greater than carbachol = bethanecol. Unlike the case with tissue slices, all of these muscarinic agonists exhibited full efficacy in this assay of PLC stimulation. Activation of PLC by the neurotransmitters or their analogs was dependent on the addition of guanosine 3'-O-thiotriphosphate (GTP gamma S). Stimulation of PLC by GTP gamma S alone or in combination with 5-methyltryptamine had an apparent EC50 of about 0.4 microM. However, when carbachol or other muscarinic agonists were used, the EC50 for GTP gamma S was significantly lower. We have previously shown that dopamine working through D1 receptors inhibits the PLC response to carbachol by preventing this shift in the apparent EC50 for GTP gamma S. Dopamine did not have a similar effect on 5-methyltryptamine stimulation of PLC. The results indicate that the postreceptor mechanisms of PLC activation are distinct for muscarinic as opposed to serotoninergic agonists in brain cortex.

Animals↗
PubMed1990

Catecholamines and indolalkylamines of the pia mater and spinal cord in vertebrates.

Fluorimetric methods were used to determine adrenaline, dopamine, noradrenaline, serotonin and tryptamine in the pia mater of the brain and spinal cord of various vertebrates (fishes, birds, mammals) and of man. The histochemical method using glyoxylic acid showed the presence of biogenic monoamines in adrenergic nerve fibres and in the monoaminocytes. Their total amount in the pia mater is roughly the same, except in man, in whom it is significantly lower. From the higher adrenergic axon concentration on the one hand and the lower number of monoaminocytes on the other, it can be concluded that the neuronal factor has a more important role in the regulation of brain haemodynamics in man.

Animals↗
PubMed1990

Primary amine drug selective electrodes with special crown ethers as neutral carriers.

Ionophores selectively sensitive to primary amines have been synthesized which display low potentiometric selectivity coefficients for K+, Na+ and NH4+ ions, secondary and tertiary amines as well as quaternary ammonium ions. These ionophores include macrocyclic polyethers with dinaphthyl subunits and azocrown ether with nitrogen donor atoms. The feasibility of these ionophores for preparing primary amine drug selective electrodes was investigated in detail. Practically usable PVC membrane electrodes sensitive to primary amine drugs, such as mexiletine, dopamine, metaraminol and tryptamine, and aliphatic primary amines have been prepared with these ionophores as neutral carriers. Direct potentiometric methods for assaying these drugs have been proposed by using the prepared electrodes. The proposed primary amine drug selective electrodes are remarkably superior to those based on ion-associates. Compared with the electrodes based on common ethers, the interference by K+, Na+ and NH4+ ions is substantially reduced. A digital simulation of the electrochemical process concerning the membrane transport was performed and some interesting conclusions have been drawn.

Dopamine↗
PubMed1988

Amine production by Streptococcus lactis under different growth conditions.

The highest amount of histamine, tyramine and tryptamine were produced by S. lactis at 30 degrees C in 24 h at pH = 5.0. Maximum amount of different amines was noted in a growth medium lacking NaCl. After addition of NaCl even at 0.5% concentration, slight inhibitory effect on the synthesis of these amines was obtained.

Biogenic Monoamines↗
PubMedDate not supplied

Central antiserotonin action of fluperlapine.

The effect of fluperlapine--a new nonclassical neuroleptic--on the central serotoninergic system was studied. Fluperlapine antagonizes the head-twitch response induced by 5-hydroxytryptophan in mice and rats (the ED50 values are 0.3 mg/kg ip and 0.89 mg/kg ip respectively), counteracts forepaw clonic convulsions and tremor induced by tryptamine in rats (ED50 = 9.0 mg/kg ip and 7.5 mg/kg ip respectively), and abolishes hyperthermia induced by fenfluramine. In the flexor reflex preparation in spinal rats fluperlapine depresses the reflex only when given in higher doses. The drug given in low doses abolishes the stimulation of the flexor reflex evoked by quipazine and LSD (serotonin agonists) but not by clonidine (noradrenaline agonist). Higher doses of fluperlapine antagonise also the stimulatory effect of clonidine. Our findings demonstrate that fluperlapine shows potent central antiserotonin activity.

Animals↗
PubMed1986

Toxicity of mosquitocides on freshwater mussel larvae.

The effect of four insecticides also used for mosquito-killing (Fyfanon ULV, K-Othrin ULV, Unitox 7 ULV and Unitox 20 ULV) was studied on the larvae (glochidia) of two freshwater mussel species, Anodonta cygnea and Anodonta anatina. In addition to the determination of the 24-96 h LC50 values of the insecticides, studies were also performed on their effect exerted on a physiological process, the tryptamine-(TA)-induced activation of the larvae in normal and 24 h test. On the basis of the LC50 values, Fyfanon and Unitox 20 were found to be the most toxic to the studied mussel larvae, however, the TA-induced adductor muscle activity, as physiological process, was also inhibited by Unitox 7 in relatively low concentrations. This effect may reduce the chance of further development of the larvae, by exerting harmful effect on the number of freshwater mussels.

Animals↗
PubMed1988

[Interaction of the anxiolytic agent buspirone with serotonin and other synaptic receptors in the human brain].

Buspirone and Mj 138-05 (up to 0.1 mM) did not displace specifically bound (3H) tryptamine, (3H) strychnine, (3H) flunitrazepam and (3H) imipramine in human cortical and hippocampal membrane preparations. At the same time both compounds displayed similar to serotonin affinity (IC50 in the range of 2-6 microM) for (125I)-LSD specific binding sites in the human cortex and hippocamp. IC50 of serotonin and buspirone and Mj 138-05 for (3H) LSD (2 nM) specific binding sites in the hippocamp was determined as 0.14 microM, 2.3 microM and 6.1 microM, respectively; and for (3H) serotonin specific binding sites in the hippocamp as 0.005 microM, 3.8 microM and 21 microM, respectively. The affinity for human cortex (3H) LSD binding sites was 10-fold lower in case of serotonin and 4-fold lower in case of buspirone and Mj 138-05 than in the hippocamp. However, the affinity for (3H) serotonin binding sites in the cortex was the same as in the hippocamp in case of serotonin and 12-15-fold lower than in the hippocamp in case of buspirone and Mj 138-05. It is concluded that in human brain buspirone and Mj 138-05 interact with micromolar affinity with 5 HT2 and are capable of binding to a subpopulation of 5 HT1 receptors in the hippocamp.

Aged↗
PubMed1987

Evidence for 5-HT1A binding sites in chick embryo brain and discrimination by 5-methoxytryptamine.

The displacement characteristics of [3H]5-hydroxytryptamine (5-HT1) binding by several serotonergic ligands were studied in the chick embryo brain. Although most of ligands tested displaced [3H]5-HT in a manner suggestive of a single site, displacement curves for (+/-)-8-hydroxy-dipropylaminotetralin (8-OH-DPAT), 5-methoxytryptamine, 5-methyltryptamine and 5-methoxy-N,N-dimethyltryptamine displayed non-unity Hill plots, suggesting multiple site interactions. However, if spiperone (2 microM) was included in the assays, the Hill coefficients of these compounds were all similarly increased toward unity, suggesting that 8-OH-DPAT as well as 5-methoxy and 5-methyl substituted tryptamines, have a high affinity for and can discriminate 5-HT1A binding sites in the chick embryo brain.

5-Methoxytryptamine↗
PubMedDate not supplied

[Deamination of indolalkylamines in hyperthermia].

The experiments on dogs subjected to the outward overheating allow concluding that the quantities of deaminated serotonin in mitochondrial fractions of the brain stem, heart muscles and liver increase twice as compared with the normal levels. Particularly, in the liver the value of Km of this process is equal to 1.6 x 10(-3) M, while without the overheating it is equal to 3.6 x 10(-3) M. Overheating makes the process of tryptamine deamination in mitochondrial fractions of the heart and liver more intensive. However, overheating causes a higher increase of the monoaminooxidase activity with respect to serotonin than with respect to other substrates.

Animals↗
PubMedDate not supplied

[Selection of cell lines resistant to tryptophan analogs].

After prolonged cultivation in the presence of increasing amounts of carboxyl-substituted tryptophan analogs (tryptamine and tryptophanol), cell lines resistant to high concentrations of these compounds were obtained. The initial culture was the Madin-Darby line of spontaneously transformed bovine kidney cells. In the resistant lines the amount of tryptophanyl-tRNA synthetase (E. C. 6.1.1.2) is manyfold increased as shown by two criteria: (i) enzymatic activity (ATP-PPi isotopic exchange) per mg of protein, (ii) binding of in vivo 35S-labeled proteins to polyclonal antibodies against tryptophanyl-tRNA synthetase. It was shown that tryptophanyl-tRNA synthetase is phosphorylated in vivo, and the degree of phosphorylation of the enzyme in initial cells seems to be higher then in the resistant ones. The Km value for tryptophan is not significantly changed for the enzyme from resistant cells. The permeability for tryptophan and its analogs is reduced in the resistant cells. It is proposed that the acquisition of the resistance against tryptophan analogs are due to alterations at the genomic level (for example, gene amplification etc.).

Amino Acyl-tRNA Synthetases↗
PubMed1985

Partial purification and some properties of tryptophan decarboxylase from a Bacillus strain.

Bacteria of different origin were screened for tryptophan decarboxylase activity. The best producer belonged to an unidentified taxonomic entity of the genus Bacillus. In complete medium it produced tryptamine from tryptophan. The decarboxylase could partially be purified from the cells by sonication and DEAE-cellulose chromatography. The enzyme had an Mr of 150 000 and a pH optimum of about 7, was stable up to 37 degrees C, and its Km was about 0.3 mM for tryptophan. The enzyme needed pyridoxal phosphate for maximum activity.

Aromatic Amino Acid Decarboxylase Inhibitors↗
PubMedDate not supplied

Central antiserotonergic and antidopaminergic action of pirenperone, a putative 5-HT2 receptor antagonist.

Pirenperone, an antagonist of 5-HT2 but not 5-HT1 receptors, has been studied for its central antiserotonergic and antidopaminergic activity. Pirenperone (0.00525-0.1 mg/kg) antagonized dose-dependently stimulation of the hind limb flexor reflex in spinal rats induced by LSD, quipazine or fenfluramine, and hyperthermia induced by serotonin (5-hydroxytryptamine; 5-HT)-like drugs (1-5-hydroxytryptophan, fenfluramine, p-chloroamphetamine, 1-/m-chlorophenyl/-piperazine, quipazine) in heat-adapted rats. Pirenperone also counteracted tryptamine-induced convulsions in rats (ID50 = 0.87 mg/kg); however, this action was weaker than that of metergoline (ID50 = 0.22 mg/kg). Pirenperone (0.1-1.6 mg/kg) produced sedation in mice and rats, and-in doses of 0.4-6.4 mg/kg-catalepsy in rats. Given in doses ranging from 0.1 to 1.6 mg/kg, pirenperone antagonized d-amphetamine-induced locomotor hyperactivity in mice and rats, the hyperactivity induced by apomorphine in rats, apomorphine- or d-amphetamine-induced stereotypy in rats and stimulation of the hind limb flexor reflex induced by the alpha-adrenoceptor agonist-clonidine. Pirenperone (6.4 mg/kg) significantly attenuated apomorphine (1 mg/kg)-induced hypothermia in mice. The results obtained indicate that pirenperone may be regarded as a relatively specific antagonist of the 5-HT2 receptor only when it is employed in very low doses (less than 0.1 mg/kg). Used in higher doses (greater than 0.1 mg/kg), it behaves like a typical neuroleptic, i.e. like a dopamine antagonist with antiserotonergic, antitryptaminergic and antiadrenergic properties.

Animals↗
PubMed1979

Accumulation of N,N-dimethyltryptamine in rat brain cortical slices.

14C-DMT accumulates in rat brain cortical slices incubated at 37 C. This process has many of the properties of an active uptake mechanism. It is temperature-sensitive, sodium-dependent, saturable, and is inhibited by metabolic inhibitors. Tryptamine derivatives were more effective than the catecholamines in competing for 14C-DMT accumulation. A number of psychotropic drugs were inhibitors of 14C-DMT accumulation. In general, irrespective of pharmacologic class, the tertiary amines were more potent than the secondary or primary amines, although there were some exceptions. Most of the accumulated 14C-DMT was associated with the cytoplasmic fraction. Of the portion associated with the crude mitochondrial fraction, 54.4% was associated with nerve-ending fraction.

Animals↗
PubMed1979

Depression: new evidence in support of biological differentiation.

The authors studied monoamine metabolism in patients with bipolar (manic-depressive) and unipolar depressive illness and in normal control subjects under strict dietary conditions before and during administration of carbidopa, a peripheral decarboxylase inhibitor. They found that unipolar depressed patients excreted higher amounts of 3-methoxy-4-hydroxyphenylglycol (MHPG) and 5-hydroxyindoleacetic acid (5-HIAA) in the drug-free period and while receiving carbidopa and significantly less tryptamine only after carbidopa administration. Plasma tryptophan levels differed in the three groups. The authors state that their research design reveals changes in serotonin and nonrepinephrine metabolism in unipolar depressed subjects that distinguish this group from normal and bipolar depressed subjects, suggesting a reduced CNS uptake of tryptophan in unipolar depression.

Adult↗
PubMedDate not supplied

[Transformation of L-tryptophan by Rhizobium phaseoli].

Transformation of L-tryptophan was studied in Rhizobium phaseoli 680. The culture was capable of oxidation decarboxylation, transamination and degradation of L-tryptophan. Four metabolites were identified: tryptamine, indolyl-3-pyruvic, indolyl-3-acetic and anthranilic acids. The fifth metabolite has not been yet identified.

Chromatography, Thin Layer↗
PubMed1983

[Methylated and unmethylated indolamine in the cisternal fluid in acute endogenous psychoses].

Tryptamine (Try), 5-methoxytryptamine (5MeOT), N-methyltryptamine (N-Met), 5-methoxy-N,N-dimethyltryptamine (5MeODMT) and N,N-dimethyltryptamine (DMT) are metabolites of the neurotransmitter 5-hydroxytryptamine (5HT). The cisternal cerebrospinal fluid (CSF) is probably a suitable biological material for investigating the problem of indolamine metabolism in schizophrenic patients. As part of a biological research programme on schizophrenia we have investigated concentrations of cisternal CSF indolamines in a group of acute paranoid patients in comparison with psychiatrically healthy controls. The concentrations of indolamines in the cisternal CSF reveal that psychotomimetic indolamines like 5MeODMT, 5MeOT and DMT and the indolamines N-Met and Try are present in psychological and pathological states. The patients suffering from acute paranoid schizophrenia have high or very high levels of the investigated indolamines in comparison with healthy controls, but there are significant individual differences in the group of these patients. The search for correlations between the level of a single indolamine and individual psychopathological symptoms could provide more specific information for diagnosis or treatment.

Acute Disease↗