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Determination of melatonin and monoamines in rat pineal using reversed-phase ion-interaction chromatography with fluorescence detection.

A method is reported for the ion-interaction, reversed-phase separation of 24 compounds (chiefly monoamines) arising from the metabolism of tyrosine and tryptophan. These compounds were separated as two groups. The first group comprised 3,4-dihydroxyphenylethylene glycol, tyrosine, 3-methoxy-4-hydroxyphenyl glycol, 5-hydroxytryptophan, norepinephrine, 3,4-dihydroxyphenylacetic acid, epinephrine, 5-hydroxyindole-3-acetic acid, homovanillic acid, 5-hydroxytryptophol, dopamine, tryptophan. N-acetylserotonin, N-acetyltryptophan, 5-methoxytryptophan and serotonin. The mobile phase consisted of a 6.8:93.2 (v/v) mixture of acetonitrile and an aqueous solution containing 0.16 M ammonium phosphate, 0.06 M citric acid, 0.15 mM disodium EDTA, 10 mM dibutylamine and 6 mM sodium 1-octanesulphonate at pH 4.50. The second group of compounds comprised 6-hydroxymelatonin, 5-methoxyindole-3-acetic acid, indole-3-acetic acid, 5-methoxytryptamine, tryptamine, 5-methoxytryptophol, melatonin and tryptophol. The mobile phase consisted of a 16:84 (v/v) mixture of acetonitrile and an aqueous solution containing 0.05 M ammonium phosphate, 0.05 M citric acid, 0.15 mM disodium EDTA, 25 mM dibutylamine and 5 mM sodium 1-octanesulphonate at pH 5.30. Detection was by fluorescence measurement (lambda ex = 280 nm, lambda em = 340 nm). The proposed method exhibited linear calibration over the biochemically significant concentration range, with detection limits in the 10-200 pg range. Excellent precision for peak areas and retention times was observed, even over a period of 24 h. The applicability of amperometric detection (at 0.72V) is also demonstrated. The method is applied to the determination of monoamines in individual rat pineals. Low nanogram levels of tyrosine, norepinephrine, 5-hydroxyindole-3-acetic acid, tryptophan, serotonin and 6-hydroxymelatonin, and picogram levels of 5-hydroxytryptophan, 5-hydroxytryptophol, 5-methoxyindole-3-acetic acid, indole 3-acetic acid, 5-methoxytryptophol and melatonin were indicated in most of the samples.

Animals↗

Analysis of 5-methoxytryptamine at the femtomole level in the rat and quail brain by gas chromatography-electron-capture negative-ion chemical ionization mass spectrometry.

A sensitive method for the measurement of endogenous 5-methoxytryptamine in brain tissue has been developed using capillary column gas chromatography-electron-capture negative-ion chemical ionization mass spectrometry. 5-Methoxytryptamine was first converted to N-[2H3]acetyl-5-methoxytryptamine by reaction with hexa-deuterated acetic anhydride, followed by reaction with pentafluoropropionic anhydride to yield the highly electron-capturing 3,3'-spirocyclic pentafluoro-propionyl indolenine derivative. Quantitative analysis was carried out by selected-ion monitoring of the [M-HF].- and [M-HF-DF].- ion intensity of the 3.3'-spirocyclic pentafluoropropionyl indolenine derivative, using 5-methoxy-[alpha, alpha, beta, beta-2H4]tryptamine as the internal standard. The presence of 5-methoxytryptamine in the brain tissue was demonstrated. In the absence of a monoamine oxidase inhibitor, the mean +/- S.D. levels of 5-methoxytryptamine in the rat and quail whole brain were found to be 30 +/- 6 and 347 +/- 52 pg/g, respectively. The possible physiological functions of 5-methoxytryptamine as a neuromodulator and/or neurotransmitter have to be considered.

5-Methoxytryptamine↗

Formaldehyde-derived tetrahydroisoquinolines and tetrahydro-beta-carbolines in human urine.

Human urine samples were examined for the occurrence of formaldehyde-derived tetrahydroisoquinolines and tetrahydro-beta-carbolines generated by condensation of the methanol oxidation product with biogenic amines. Positive results were obtained for the tryptamine condensation product 1,2,3,4-tetrahydro-beta-carboline and the serotonine condensation product 6-hydroxy-1,2,3,4-tetrahydro-beta-carboline as well as for the condensation products with tyramine, dopamine, adrenaline and noradrenaline 1,2,3,4-tetrahydroisoquinoline, 6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, N-methyl-4,6,7-trihydroxy-1,2,3,4-tetrahydroisoquinoline, 4,6,7-trihydroxy-1,2,3,4-tetrahydroisoquinoline, and the metabolite 6-methoxy-7-hydroxy-1,2,3,4-tetrahydroisoquinoline. Negative results were obtained for N-methyl-1,2,3,4-tetrahydroisoquinoline and 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline, N-methyl-1,2,3,4-tetrahydro-beta-carboline, 6-methyl-1,2,3,4-tetrahydro-beta-carboline, and 6-methoxy-1,2,3,4-tetrahydro-beta-carboline in samples of chronic alcoholics as well as in the urine of healthy volunteers. No correlation between alcohol ingestion or state of alcoholization could be demonstrated.

Alcoholism↗

A multidisciplinary overview of intoxicating snuff rituals in the western hemisphere.

Part one of the paper discusses ethnobotanical, chemical and general pharmacological aspects of intoxicating snuff rituals in the western hemisphere. Four categories of ritual snuff ingredients arise from this multidisciplinary approach: It is well established that the plant contains one or more psychoactive principles and the Indian use of the plant as a ritual snuff ingredient is confirmed or quite probable: Anadenanthera, Erythroxylum, Nicotiana, Virola; It is well established that the plant contains one or more psychoactive principles, but the Indian use of the plant as a ritual snuff ingredient is not well recorded or even unlikely: Banisteriopsis, Cannabis, Datura, Ilex guayusa; The Indian use of the plant as a ritual snuff ingredient is confirmed or quite probable, but it is not well established that the plant contains one or more psychoactive principles: Justicia pectoralis, Pagamea macrophylla, Tanaecium nocturnum; The Indian use of the plant as a ritual snuff ingredient is not well recorded, and it is not well established that the plant contains one or more psychoactive principles: Acorus calamus, Capsicum, Macquira sclerophylla, Piper interitum. Part two of the paper discusses the nasal pharmacokinetics and efficacy of possible ritual snuff constituents. The literature yields convincing clinical evidence that atropine, cocaine, nicotine and scopolamine are effective following nasal application, but experimental confirmation of the efficacy of nasal tryptamine alkaloids is still awaited. In self-experiments, 6.4 mg/kg of caffeine produced substantial plasma levels via the nasal route, but 0.5 mg/kg of harmine did not produce measurable plasma levels, when taken as a nasal powder. Without additional experiments, it is difficult to give a definite explanation for this negative result.

Atropine↗

Species identification and chemical analysis of psychoactive fungi in the Hawaiian islands.

Several fungi species collected in the Hawaiian Islands have been reported to be psychoactive. Previous chemical analyses together with the present study indicate that 5 coprophilous and one non-coprophilous species occurring in the islands are now known to contain psychoactive alkaloids. At least some of these species are consumed in the Hawaiian Islands, as well as elsewhere, for non-traditional, recreational purposes. These include Copelandia cyanescens (Berk. et Br.) Singer, Copelandia tropicalis (Ola'h) Singer and Weeks (syn. Panaeolus tropicalis Ola'h), Copelandia anomala Murrill, and Panaeolus subbalteatus (Berk. and Br.) Sacc., which have already been described from the Hawaiian Islands. Three more mind-altering fungi and one non-psychoactive species are reported from this archipelago for the first time. These psychoactive fungi include Copelandia bispora (Malençon et Bertault) Singer and Weeks from O'ahu, Copelandia cambodginiensis (Ola'h et Heim) Singer and Weeks from O'ahu, and Amanita muscaria (L.) Hooker from Kaua'i. Panaeolus goossensiae Beeli identified from O'ahu contains tryptamine compounds; however, the psychoactive alkaloids psilocybin and psilocin were not found in this dung species.

Animals↗

[3H]serotonin binds to two classes of sites in Drosophila head homogenate.

[3H]serotonin binds to two classes of sites in a crude membrane preparation of Drosophila melanogaster heads, with apparent Kd values of 1.4 and 130 nM, and a concentration of 0.2 and 1.5 pmol/mg protein, respectively. High salt concentration and a guanyl nucleotide decrease the number of the high-affinity binding sites. Low concentrations of ergot alkaloids, various tryptamine derivatives, neuroleptic drugs, but not of phentholamine , propranolol and dopamine, displace [3H]serotonin from its high affinity sites. The relevance of the [3H]serotonin-binding sites to serotonin receptors in Drosophila is discussed.

Animals↗

The effect of furazolidone on fertility of male chickens.

In mature chickens, furazolidone (0.4% w/w, 10 days) decreased the weight of the testes, but did not affect significantly the concentrations of testosterone in testes and plasma, nor the concentrations of ascorbic acid, protein or cholesterol in the testes. Feeding furazolidone at a concentration of 0.08% w/w for 10 days decreased significantly the weights of the testes, wattles and combs. Treatment also produced significant reductions in the concentration of testosterone in plasma and testes, and some reductions in ascorbic acid, protein and cholesterol concentrations in the testes. Administration of furazolidone by crop tube at doses of 40 or 80 mg/kg for five days caused significant decreases in the concentrations of testicular and plasma testosterone, and reductions in ascorbic acid, protein and cholesterol concentrations in the testes. The sizes of the testes, wattles and combs were also significantly reduced. Monoamine oxidase activity in the testes was significantly inhibited by furazolidone. In all the treated birds testicular concentrations of 5-hydroxy-tryptamine were significantly raised, except in those fed the drug at a dose of 0.04% w/w for 10 days.

Animals↗

The responses of isolated preparations of Bunodosoma caissarum (Correa, 1964) (Cnidaria, Anthozoa) to drugs.

Body wall strips and oral rings of Bunodosoma caissarum respond to the application of at least four categories of drugs with sustained contractions. Propionylcholine, butyrylcholine and nicotine never failed to evoke a response; acetylcholine eventually was inactive. Occasionally, a correlation between dose and response was possible. Adrenaline and noradrenaline also elicited responses, although, occasionally, both were ineffective. Tryptamine and serotonin (less) were also effective. L-Glutamate was particularly effective and its action could be depressed by GABA. Histamine, betaine, taurine and aspartate were ineffective. The results are discussed in terms of depolarization due to specific membrane receptors or to unspecific causes.

Acetylcholine↗

Chlorphentermine inhibits pulmonary mitochondrial monoamine oxidase.

Oxidation of six amine substrates by rat, rabbit and guinea-pig lung mitochondrial monoamine oxidase (MAO) was investigated polarographically with a Clark oxygen electrode in the presence of chlorphentermine (CP). This amphiphilic drug decreased the deamination of serotonin, norepinephrine, tyramine and dopamine significantly in all three species. However, the oxidation of tryptamine and benzylamine was unchanged. Amine oxidation by MAO in guinea-pig lung mitochondria was much more sensitive to the CP-mediated inhibition than rat or rabbit. A kinetic study of serotonin oxidation in the absence and presence of CP showed that both Vmax and Km were affected. These combined data indicate that CP is a specific inhibitor of pulmonary, mitochondrial monoamine oxidase form A with mixed-type inhibition.

Animals↗

The action of parotoid venom on the heart of the toad (Bufo ictericus ictericus Spix 1824) and its effects on the inhibition caused by vagal stimulation.

1. The administration of crude venom of the parotoid glands of the toad Bufo ictericus ictericus to the in situ (via abdominal vein) or isolated heart of this anuran causes both chronotropic and inotropic effects. 2. While under action of parotoid venom, the heart of the animal is insensitive to vagus nerve stimulation. 3. This blocking of vagal action is dose dependent and it is suggested that it results from a functional antagonism between the venom constituents and the acetylcholine liberated by the nerve endings on stimulation. 4. The venom constituents probably involved in this antagonism are catecholamines (adrenaline and noradrenaline), tryptamine derivatives (serotonin and bufotenidin) and genins (bufagin and bufotoxin), possibly also ATP. 5. Adrenaline, noradrenaline and serotonin, or a mixture of the three, mimic, at least partially, the blocking of vagal action caused by crude venom. 6. The blocking action of crude venom can be prevented by previously or simultaneously adding acetylcholine to the infused crude venom. This prevention is dose dependent. 7. The blocking action persists in the boiled venom and in the material dialysed from crude venom.

Acetylcholine↗

Species differences in lung mitochondrial monoamine oxidase activities.

Pulmonary mitochondrial monoamine oxidase (MAO) activity was examined in preparations from rat, rabbit and guinea-pig with 12 different amines as substrates: serotonin, norepinephrine, and octopamine (type A specific); tryptamine, benzylamine, 5-methoxytryptamine, 5-methyltryptamine, p-methoxyphenylethylamine, and 3,4-dimethoxyphenethylamine (type B specific); and tyramine, dopamine and 3-methoxytyramine (type A + B specific). The oxidation of type A and type A + B substrates was greater in guinea-pig lung mitochondria than in rat or rabbit preparations. Except for benzylamine, the oxidation of type B substrates was similar in all three species. Benzylamine was not oxidized by guinea-pig lung mitochondria but was actively metabolized by rat and rabbit preparations.

Animals↗

Noradrenaline, dopamine, 5-hydroxytryptamine and tryptophan concentrations in the brains of four cohabiting species of fish.

1. The concentrations of the neurotransmitters noradrenaline, dopamine and 5-hydroxy-tryptamine and the amino acid tryptophan were determined in the telencephalon, optic lobes and rest of the brains of four species of fish collected from a stream in central Saskatchewan. 2. The species investigated were white sucker (Catostomus commersoni), longnose sucker (Catostomus catostomus), longnosed dace (Rhinichthys cataractae) and northern pike (Esox lucius). 3. Significant differences were found in the concentrations of amines in different regions of the brain within species and within the same brain region between species. 4. These results may be related to the phylogenetic differences or to patterns in brain development evolved by fish species to adapt to particular lifestyles.

Animals↗

Biogenic amines and active peptides in extracts of the skin of thirty-two European amphibian species.

1. Extracts prepared from fresh or dried skins of 32 European amphibian species were submitted to chemical (colour reactions) and biological screening to determine the occurrence and contents of biogenic amines and peptides active on smooth muscle preparations and blood pressure. 2. Only indolealkylamines were detectable in the skins. They were represented by tryptamine, 5-hydroxytryptamine, and its N-methylated, cyclized and sulphoconjugated derivatives. 3. The peptide families identified in the extracts were as follows: bombesins (bombesin and alytesin), bradykinins (bradykinin, bradykinin 1-8, bradykinin 1-7), chemotactic peptides (RECP I, II and III), bombinins and TRH. Bombesins, bombinins and TRH (thyrotropin-releasing hormone) were isolated from skin extracts of discoglossid frogs; chemotactic peptides and again TRH from extracts of ranid frogs. 4. Further research will certainly lengthen the list of active peptides in the skin of European amphibians, as is the case with Australian, American and African amphibians.

Amino Acid Sequence↗

The concentration of dopamine and related monoamines in arteries and some other tissues of the sheep.

1. The highest concentrations of dopamine were observed in the sheep coronary interventricular artery (1.0 micrograms/g) and the lowest in the aorta (0.15 micrograms/g). Varying proportions of noradrenaline was also present in the arteries examined with dopamine:noradrenaline ratios ranging from 0.08 to 1.11. 2. p-Tyramine is the trace amine present in highest concentration in both the lung and the caudate nucleus (21.3 and 10.5 ng/g, respectively) while the levels of beta-phenylethylamine, m-tyramine and tryptamine are lower and range between 1.6 and 4.2 ng/g. 3. The results show that sheep arteries, lung and duodenum contain considerable amount of dopamine that is presumably associated with chromaffin cells. It is most likely that these cells also contain 5-hydroxytryptamine while the localization of trace amines remains to be elucidated.

Animals↗

An analysis of the 5-hydroxytryptamine (serotonin) receptor subtypes of central neurones of Helix aspersa.

1. Intracellular recordings were made from identified neurones in the central nervous system of Helix aspersa. Two types of cell were used, those excited by 5-hydroxytryptamine (5-HT) and acetylcholine and those inhibited by 5-HT and dopamine. The actions of a range of 5-HT agonists and antagonists were tested for their ability to interact with 5-HT receptors. 2. 5-Carboxyamidotryptamine, alpha-methyl-5-HT and N-methyl-5-HT were active on cells excited by 5-HT, with similar potencies to 5-HT. Only 5-carboxyamidotryptamine and 5-methoxytryptamine were equiactive with 5-HT on cells inhibited by 5-HT. Most of the non-indole analogues were inactive or very weak agonists on both receptors. 3. MDL 72222 was the most active antagonist tested against 5-HT excitation, showing some selectivity for 5-HT over acetylcholine. Cinanserin and ketanserin also showed selectivity for 5-HT over acetylcholine. 4. Tryptamine was inhibitory on both cell types and was a potent antagonist of 5-HT excitation, showing selectivity for 5-HT over acetylcholine. 5. It is concluded that the 5-HT excitatory receptor recognizes the indole nucleus with substitution on position 5, save for 5-fluorotryptamine which was inhibitory. It does not appear that these 5-HT receptors can be classified in terms of the vertebrate subtypes of 5-HT receptor. However, it should be noted that only two receptor subtypes located on a small number of neurones were studied in these experiments and other 5-HT receptor suptypes may be located on other groups of neurones and peripheral tissues. These receptors may recognize other 5-HT receptor ligands including non-indoles.

Animals↗

Effects of the neuropeptide APGW-amide and related compounds on molluscan muscles--GW-amide shows potent modulatory effects.

1. Effects of the molluscan neuropeptide APGW-amide and related compounds (the crustacean hormone RPCH, FAPGW-amide, PGW-amide, GW-amide and W-amide) were examined in several kinds of molluscan muscles. 2. All the compounds, except W-amide, showed qualitatively similar modulatory effects on contraction or relaxation of the muscles. The potency order of the compounds was found to be GW-amide greater than or equal to APGW-amide greater than FAPGW-amide greater than RPCH greater than PGW-amide. W-amide showed little or no effect even at 10(-4) M. 3. In the ABRM of Mytilus and the radula retractor muscle of Rapana, the active peptides were suggested to exhibit their modulatory effects by acting on the presynaptic sites in the muscles. 4. Nineteen GW-amide analogues, such as Gly-Trp-OH, Gly-Phe-NH2, D-Ala-Trp-NH2 and N-Gly-tryptamine, were also tested on some of the muscles, but all of them showed little or no effect.

Animals↗

Biogenic monoamines in oocytes of echinoderms and bivalve molluscs. A formation of intracellular regulatory systems in oogenesis.

1. Identification of catecholamines and indolylakylamines in the fully grown oocytes or mature eggs of the representatives of echinoderms and bivalve molluscs was made using the fluorometric method. 2. Dopamine is the main catecholamine in the oocytes of all investigated animals. Tryptamine was the main indolylalkylamine. 3. The data presented confirm the presence of the main components of regulatory systems (transmitters, enzymes of their exchange, intracellular messengers, intracellular receptive systems) in the fully grown oocytes. 4. A hypothesis is proposed of the formation of intracellular regulatory systems (monoaminergic, cholinergic, peptidergic and steroidal) in oogenesis.

Animals↗

Effect of octanoate injection on rat blood-brain barrier.

Serum concentrations of short and medium chain fatty acids, including octanoate, are elevated in hepatic encephalopathy and Reye syndrome. Injection of octanoate into animals produces features reminiscent of Reye syndrome, but the mechanisms are unknown. To evaluate the effect of octanoate on blood-brain barrier permeability, three techniques were used. Entry of horseradish peroxidase and trypan blue into brain was not observed after octanoate injection. Brain uptake of tryptamine, tyrosine and methionine was increased significantly by octanoate, while uptake of insulin was unchanged. This study suggests that octanoate may produce central nervous system alterations by facilitating entry of certain low molecular weight compounds into brain. This may represent one mechanism for the development of encephalopathy in liver disease and Reye syndrome.

Animals↗