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Over the last few years, an increasing interest in the scientific research of natural antioxidant molecules from plants capable to attenuate, or even prevent, stress oxidative-related disorders, such as diabetes, inflammatory, and neurological pathologies has been observed. Serotonin and melatonin are two of these molecules, being widely found in Mediterranean foodstuffs, fruits, vegetables, and medicinal herbs. The consumption of foods containing both antioxidants can raise their physiologic concentrations in blood and, consequently, enhance antioxidant defenses, improve mood, and treat sleep disorders, depression, and anxiety. Currently, there exist several analytical methods suitable for the determination of melatonin and serotonin in fruits and edible plants. Among them, the most used include chromatographic techniques and immunological assays. This work aims to present a comprehensive overview of the biosynthesis of these indolamines in nature, the most common techniques used to detect and quantify both compounds in fruits, vegetables, medicinal herbs, and other food sources, as well as to address their health benefits, particularly their antioxidant, neuroprotective, and sleep-promoting effects.

—We studied the dopamine-, serotonin-, and norepinephrinergic systems in various brain structures of BALB/c male mice on days 15, 42, and 64 of postnatal development (PND) in the model of autism spectrum disorder induced by sodium valproate administration (400 mg/kg, s/c) to pregnant females. It was found that the level of both catechol- and indolamines in the brain structures of control 15-day-old mice is considerably lower than in 64-day-old adult animals. Prenatal administration of sodium valproate (SV) caused a decrease in all parameters of monoaminergic neurotransmission in the striatum of mouse offspring aged 15 days but did not lead to neurochemical changes in other studied brain structures. By PND 42, the general pattern of changes in neurotransmitter concentrations did not differ from the developmental dynamics of neurotransmitter system maturation in the control group. The level of DA kept increasing and by PND 64, did not differ from controls. The parameters of serotonergic system changed similarly, with the peak serotonin concentration by PND 42 and a significant decrease by PND 64, whereas the level of 5-HIAA in the striatum increased gradually with maximum differences observed by PND 64. Thus, the data obtained suggest that administration of SV to pregnant females affects the activity of the dopamine- and serotonergic brain systems in the progeny, inducing its decrease in the striatum by PND 15 followed by recovery to control level by PND 64.

Early diagnosis of Parkinson’s disease (PD) remains a challenge to date. New evidence highlights the potential clinical value of circulating trace amines (TAs) in early-stage PD and their involvement in disease progression. A new ultra performance chromatography mass spectrometry (UPLC-MS/MS) method was developed to quantify plasmatic TAs, and the catecholamines and indolamines pertaining to the same biochemical pathways. Three groups of subjects were recruited: 21 de novo, drug untreated, PD patients, 27 in treatment PD patients and 10 healthy subjects as controls. Multivariate and univariate data analyses were applied to reveal metabolic changes among the groups in attempt to discover new putative markers for early PD detection and disease progression. Different circulating levels of tyrosine (p = 0.002), tyramine (p 0.75). The findings of this pilot cross-sectional study suggest that biochemical anomalies of the aminergic and indolic neurotransmitters occur in PD patients. Compounds within the TAs family may constitute putative markers for early stage detection and progression of PD.

Indolamines are tryptophan-derived specialized metabolites that belong to the huge and ubiquitous indole alkaloids group. Serotonin and melatonin are the best-characterized members of this family, given their many hormonal and physiological roles in animals. Following their discovery in several plant families, the study of plant indolamines has flourished over the last few decades and their involvement in many important processes has been proposed, including stress responses, growth and development, and reproduction, leading to their classification by some authors as a new category of phytohormones. However, the complex puzzle of the indolamines is far from resolved, particularly the biological roles of tryptamine, the early tryptophan-derived serotonin precursor representing the central hub of downstream plant indolamines and many specialized indole alkaloids. Tryptophan decarboxylase, which catalyzes the synthesis of tryptamine, appears to strictly regulate the flux of carbon and nitrogen from the tryptophan pool into the indolamine pathway. Furthermore, tryptamine accumulates to high levels in the reproductive organs of many plant species, and therefore cannot be classed as a mere intermediate but rather as an end product with potentially important functions in fruits and seeds. This review summarizes current knowledge on the role of tryptamine and its close relative serotonin, emphasizing the need for a clear understanding of the functions of, and mutual relations between, these two indolamines and their biosynthesis pathways in plants.

Serotonin (5-HT) is member of a family of indolamine molecules that participate in a wide variety of biological processes. Despite its important role in the regulation of local blood systems, little is known about the physiological function of 5-HT in reproductive organs, its functional implications, and its role in the reproduction of mammals. In the present work, we evaluated the localization and distribution of 5-HT (using histochemical analysis of indolamines) and different components of the serotoninergic system in rat testes. We detected local synthesis and degradation through immunofluorescence and western blot analyses against the TPH1, MAOA, 5-HTT, and VMAT1 serotonin transporters. We also identified the localization and distribution of the 5-HT1B, 5-HT2A, and 5-HT3Areceptors. RT-PCR results showed the presence of the Tph1, Maoa, Slc6a4, and Htr3a genes in testes and in the brain stem (Tph1 was used as a negative control). High-performance liquid chromatography was used to determine the presence of 5-HT and the activity of tryptophan hydroxylase in testes homogenatesin vitro. Our observations suggest that TPH1 activity and local 5-HT synthesis befall in rat testes. We propose that 5-HT could participate in the regulation of testosterone synthesis and in the spermatogenesis process via local serotoninergic system. However, more studies are needed before concluding that rat testes, or those of other mammals, contain an active form of tryptophan hydroxylase and produce 5-HT.

Kiwifruit (Actinidia deliciosa cv. Hayward) is a commercially important crop with highly nutritional green fleshy fruits. The post-harvest maturation of the fruits is well characterized, but little is known about the metabolic changes that occur during fruit development. Here we used untargeted metabolomics to characterize the non-volatile metabolite profile of kiwifruits collected at different time points after anthesis, revealing profound metabolic changes before the onset of ripening including the depletion of many classes of phenolic compounds. In contrast, the phytohormone abscisic acid accumulated during development and ripening, along with two indolamines (serotonin and its precursor tryptamine), and these were monitored in greater detail by targeted metabolomics. The role of indolamines in kiwifruit development is completely unknown, so we also characterized the identity of genes encoding tryptophan decarboxylase in A. deliciosa and its close relative A. chinensis to provide insight into the corresponding biological processes. Our results indicate that abscisic acid and indolamines fulfill unrecognized functions in the development and ripening of kiwifruits.

Melatonin and serotonin are important phytochemicals enabling plants to redirect growth in response to environmental stresses. Despite much research on their biosynthetic routes, localization of their biosynthetic enzymes and recent identification of a phytomelatonin receptor, localization of the molecules themselves has to date not been possible. Elucidation of their locations in living tissues can provide an effective tool to facilitate indolamine research across systems including both plants and animals. In this study, we employed a novel technique, quantum dot nanoparticles, to directly visualize melatonin and serotonin in axenic roots. Melatonin was absorbed through epidermal cells, travelled laterally, and accumulated in endodermal and rapidly dividing pericycle cells. Serotonin was absorbed by cells proximal to the crown with rapid polar movement toward the root tip. Thermal stress disrupted localization and dispersed melatonin and serotonin across cells. These data demonstrate the natural movement of melatonin and serotonin in roots directing cell growth and suggest that plants have a mechanism to disperse the indolamines throughout tissues as antioxidants in response to environmental stresses.

As biomarkers, endogenous neurotransmitters play critical roles in the process of neuropsychiatric diseases, and neurotransmitter levels in different brain regions can contribute to neurological disease diagnosis and treatment. Due to the lack of a blank matrix for endogenous neurotransmitters, surrogate-matrix and surrogate-analyte approaches have been used for the determination of neurotransmitters to solve this problem. In this study, we capitalised on the high accuracy, precision, and throughput of UHPLC-MS/MS and developed new methods based on the two approaches. Both approaches satisfied FDA and EMA validation criterias after an appropriate parallelism assessment, and they were used to further quantify the three endogenous neurotransmitters, including dopamine (DA), serotonin (5-HT) and γ-aminobutyric acid (GABA) in rat brain four regions (cortex, striatum, hypothalamus and hippocampus) which represent the catecholamines, indolamines, and amino acids, respectively. Comparison of the results in the same rats (n = 10) showed there was no significant difference in DA, 5-HT, or GABA levels between the two approaches (P > 0.05). The concentrations of DA and GABA were highest in striatum and hypothalamus, respectively, and the levels of 5-HT were paralleled in striatum and hippocampus almost 2-fold higher than other regions. This is the first study to compare these two approaches in the determination of endogenous neurotransmitter content in the rat brain, and the surrogate-matrix approach proved to be simple, rapid, and reliable, considering cost, matrix similarity, and practicality.

Ruthenium polypyridine complexes have proved to be useful caging groups for visible-light photodelivery of biomolecules. In most photoreactions, one ligand is expelled upon irradiation, yielding ruthenium mono-aqua complexes and no other photoproduct. In this work we show that a long-lived transient photoproduct is generated when the ruthenium complexes involve indolamines. The spatial conformation of this species is compatible with a cyclic structure that contains both the amine and the normally non-coordinating aromatic ring coordinated to the ruthenium center. Fil: Carrone, Guillermo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina Fil: Zayat, Leonardo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina Fil: Slep, Leonardo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina Fil: Etchenique, Roberto Argentino. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina

Capillary electrophoresis (CE) has been investigated for the analysis of some neurotransmitters, dopamine (DA), 3-methoxytyramine (3-MT) and serotonin (5-hydroxytryptamine, 5-HT) at nanomolar concentrations in urine. Field-amplified sample injection (FASI) has been used to improve the sensitivity through the online pre-concentration samples. The cationic analytes were stacked at the capillary inlet between a zone of low conductivity - sample and pre-injection plug - and a zone of high conductivity - running buffer. Several FASI parameters have been optimized (ionic strength of the running buffer, concentration of the sample protonation agent, composition of the sample solvent and nature of the pre-injection plug). Best results were obtained using H(3)PO(4)-LiOH (pH 4, ionic strength of 80 mmol L(-1)) as running buffer, 100 μmol L(-1) of H(3)PO(4) in methanol-water 90/10 (v/v) as sample solvent and 100 μmol L(-1) of H(3)PO(4) in water for the pre-injection plug. In these conditions, the linearity was verified in the 50-300 nmol L(-1) concentration range for DA, 3-MT and 5-HT with a determination coefficient (r(2)) higher than 0.99. The limits of quantification (10 nmol L(-1) for DA and 3-MT, 5.9 nmol L(-1) for 5-HT) were 500 times lower than those obtained with hydrodynamic injection. However, if this method is applied to the analysis of neurotransmitters in urine, the presence of salts in the matrix greatly reduces the sensitivity of the FASI/CE-UV method.Therefore, a solid phase extraction (SPE) on a dedicated imprinted polymer (MIP) was developed to extract specific neurotransmitters, catecholamines, metanephrines and indolamines, from urine. Matrix salts were thus discarded after sample extraction on AFFINIMIP™ Catecholamine & Metanephrine (100mg) cartridge. Therefore, lower limits of quantification were determined in artificial urine (46 nmol L(-1) for DA, 11 nmol L(-1) for 3-MT and 6 nmol L(-1) for 5-HT).The application of this protocol MIP-SPE/FASI-CE-UV analysis of neurotransmitters in human urine gave rise to electropherograms with a very good base line and signal to noise ratios above 15.

Seven varieties of cherry from the “Valle del Jerte” in the Spanish Region of Extremadura were analyzed quantitatively and qualitatively for their content of the amino acid tryptophan. Tryptophan is an essential amino acid in humans, being the precursor of the indolamines serotonin and melatonin which are biogenic amines with great importance in human sleep function. It is also of great importance in the synthesis of indole alkaloids in fruit. The objective of the present work was to determine the levels of tryptophan in “Valle del Jerte” (Extremadura, Spain) cherry varieties by high-performance liquid chromatography with fluorescence detection. Tryptophan was found in all seven varieties tested, the mean concentration being 54.48 ± 17.14 g/ml. There were major differences between the varieties. The highest levels corresponded to the variety Navalinda and the lowest to Pico colorado. The tryptophan content of all the cherry varieties tested, in particular Navalinda, will have importance as the precursor for the biosynthesis of the biogenic amines.

In this study, we examined the relative efficacies of alpha-tocopherol, N-acetyl-serotonin, and melatonin in reducing ascorbate-Fe(2+) lipid peroxidation (LPO) of rat testicular microsomes and mitochondria. Special attention was paid to the changes produced on the highly polyunsaturated fatty acids (PUFAs) C20:4 n6 and C22:5 n6. The LPO of testicular microsomes or mitochondria produced a significant decrease of C20:4 n6 and C22:5 n6. Both long-chain PUFAs were protected when the antioxidants were incorporated either in microsomes or mitochondria. By comparison of the IC50 values obtained between alpha-tocopherol and both indolamines, it was observed that alpha-tocopherol was the most efficient antioxidant against the LPO induced by ascorbate-Fe(2+) under experimental conditions in vitro, IC50 values from the inhibition of alpha-tocopherol on the chemiluminescence were higher in microsomes (0.14 mM) than in mitochondria (0.08 mM). The protective effect observed by alpha-tocopherol in rat testis mitochondria was higher compared with microsomes, associated with the higher amount of [C20:4 n6] + [C22:5 n6] in microsomes than that in mitochondria. Melatonin and N-acetyl-serotonin were more effective in inhibiting the LPO in mitochondria than that in microsomes. Thus, a concentration of 1 mM of both indolamines was sufficient to inhibit in approximately 70% of the light emission in mitochondria, whereas a greater dosage of 10 times (10 mM) was necessary to produce the same effect in microsomes. It is proposed that the vulnerability to LPO of rat testicular microsomes and mitochondria in the presence of both indolamines is different because of the different proportion of PUFAs in these organelles.

Hyperglycemia and ketoacidosis are the two most serious factors in acute metabolic complications of both type 1 and type 2 diabetes. Dysfunction of the central nervous system is a well-documented complication of diabetes. We and others have previously reported that acute or chronic diabetes in animal's results in altered brain neurotransmitter levels. In this study, we investigated the effects of acute (7 days) glucose-induced hyperglycemia and sodium acetoacetate (NaAcAc) or ammonium chloride (NH4Cl) induced acidosis on the level of indolamines (5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA)) as well as PKC-alpha expression/activity in discrete areas of rat brain. Glucose-induced (500 mg/kg, bw) hyperglycemic ( approximately 249 mg%) rats showed significant (p

The purpose of the present study was to evaluate the effect of 4-pregnen-17-hydroxy-3-one (A) and two steroids homologues: 3beta-acetoxy-5,16-pregnadien-20-one (B) and 3beta-acetoxy-16alpha-17alpha-epoxy-4-pregnen-20-one (C). Male Wistar rats were treated with o-cresol combined (A, B or C) steroids. Lipid peroxidation status as result of measurement reactive substances to thiobarbituric acid (TBARS) as well as serotonin (5-HT) and its precursor 5-hydroxytryptophan (5-HTP) were measured. The prostate glands were weighed, the 5alpha-reductase activity was determined. The animals treated with A, B, and C steroids showed a slight increase in both 5alpha-reductase activity and prostate size. 5-HT and 5-HTP levels did not change significantly, and TBARS showed an increase in the group treated with B steroid and a decrease in the A steroid group with significant differences in both groups (p0.05) versus control group. Results suggest that A steroid reduces TBARS in rat brain, perhaps as a result of the interaction between the testosterone unsaturated carbons and OH(-) groups with free radicals.

The serotonin system has been implicated in the modulation of endocrine and behavioral components of reproduction. In this study, we examined endogenous hypothalamic indolamines during sexual differentiation and long-term effects of exogenous steroids during this time. In Experiment 1, Japanese quail were studied during the last half of embryonic development and early post-hatch. Samples were taken at embryonic day 10 (E10), E12, E14, E16, hatch (day 0), and days 3 and 5, post-hatch. Hypothalamic indolamines, including serotonin (5-HT) and its metabolite, 5-hydroxy indole acetic acid (5-HIAA) were measured by HPLC-EC detection. Females had relatively higher hypothalamic 5-HT at E14 than males, with both sexes showing increasing levels thereafter. By day 5, post-hatch, hypothalamic 5-HT content was higher in males than in females. When turnover was estimated by comparing relative concentrations of 5-HT to 5-HIAA, males were significantly higher at E12 and E14 than females. These data suggest that there are stage specific changes in the serotonin system, as well as sexually dimorphic patterns in the ontogeny and activity of this system. In Experiment 2, we investigated the effects of embryonic steroid hormone treatment on the serotonin system and on male sexual behavior. Birds were treated with either estradiol benzoate (EB), testosterone propionate (TP) or sesame oil (vehicle control) at selected embryonic days (E10, E12, E14, E16, 0, D3, and D5). At 4 weeks post-hatch, birds were transferred to short photoperiod (16D:8L) for 3 weeks to prevent photostimulated reproductive development. At 7 weeks of age, males were implanted with a 20 mm silastic capsule filled with testosterone and sexual behavior was tested 1 week later. Brains were collected from both males and females, and preoptic area (POA) indolamines were measured. Steroid treatment at E10 or E12 resulted in the loss of male sexual behavior. Moreover, males treated with EB or TP on E12 also had increased POA 5-HT content as adults, compared to control males. Females treated with EB on either E10 or E 12 also had higher POA 5-HT content than control or TP treated females. These data provide evidence for sexual dimorphism in the hypothalamic 5-HT system at specific stages during embryonic development. Moreover, males were sensitive to exogenous EB and TP on E12, whereas females appeared to be affected by EB only and appeared to be sensitive to steroid effects over a longer period of time in development. Moreover, exogenous steroids at E12 in males also correlated with impaired sexual behavioral. These data suggest that long-term effects of embryonic steroid exposure may be mediated in part through effects on the serotonin neurotransmitter system.

We investigated innervation to body wall muscles as well as distribution of 5-HT (serotonin) and its effects on longitudinal muscles of body wall (LMBW) of the sea cucumber Apostichopus japonicus. With serial sections we found neural branches and fibers extending from hyponeural part of radial nerve towards LMBW and circular muscles of body wall. With the aqueous aldehyde (Faglu) method yellow fluorescence indicating indolamines was observed in LMBW and in the mesentery connecting LMBW to the body wall. With indirect immunohistochemistry 5-HT-like immunoreactivity was observed in LMBW and in mesentery. These results strongly suggested that both LMBW and mesentery contained 5-HT. The effects of monoamine neurotransmitters were studied in LMBW. Putative neurotransmitters tested were 5-HT, adrenaline, noradrenaline, dopamine, and DOPA at the concentration of 10(-6) M. The application of 5-HT caused no contraction or relaxation, but it inhibited the contraction induced by 10(-6)-10(-5) M acetylcholine (ACh). Catecholamines were ineffective by themselves and had no effects on the contraction induced by ACh. The present histological, histochemical, and pharmacological studies strongly suggested that holothurian LMBW was innervated by inhibitory serotonergic neurons of the hyponeural nervous system.

[Tyrosine, octopamine, tryptophan, serotonin, putrescine, spermidine, spermine, norepinephrine, epinephrine, and dopamine were measured by means of high performance liquid chromatography (HPLC) in gills (anterior and posterior) and haemolymph extracts of the freshwater Chinese mitten crab, Eriocheir sinensis. These results may be considered as basic data to be used as control physiological doses, to which to refer for injection or for in vitro perfusion experiments. No significant difference has been detected between anterior respiratory and posterior salttransporting gills. After 10 days acclimation to sea water, a significant increase of haemolymph norepinephrine and dopamine has been observed. Exposure to hydrostatic pressure (101 ATA for 5 hours) also results in an octopamine increase in the haemolymph. In addition, there is a tryptophan increase in both the anterior and the posterior gills. Results are discussed in terms of possible correlations of the concentrations of polyamines, indoleamines, and catecholamines with osmoregulation and behaviour. Les concentrations en tyrosine, octopamine, tryptophane, serotonine, putrescine, spermidine, spermine, norepinephrine, epinephrine et dopamine d'extraits branchiaux (branchies anterieures et posterieures) et hemolymphatiques ont ete mesurees en chromatographie liquide a haute performance chez le crabe chinois Eriocheir sinensis d'eau douce dans le but, notamment, de disposer de valeurs de reference a utiliser comme niveaux physiologiques controles auxquels se referer lors d'experiences d'injection ou de perfusions in vitro. Aucune difference significative n'a ete detectee entre les branchies anterieures "respiratoires" et les branchies posterieures "transportrices de sels". A l'issue de 10 jours d'acclimatement a l'eau de mer, on assiste a une augmentation significative de la norepinephrine et de la dopamine hemolymphatiques. De meme, une exposition de 5 heures a 101 ATA de pression hydrostatique aboutit a une augmentation de l'octopamine hemolymphatique. On assiste, par ailleurs aussi, a un accroissement de la concentration en tryptophane dans les deux types de branchies. Les correlations possibles entre les concentrations en polyamines, indolamines, catecholamines ainsi que l'osmoregulation et le comportement sont l'objet d'une discussion approfondie., Tyrosine, octopamine, tryptophan, serotonin, putrescine, spermidine, spermine, norepinephrine, epinephrine, and dopamine were measured by means of high performance liquid chromatography (HPLC) in gills (anterior and posterior) and haemolymph extracts of the freshwater Chinese mitten crab, Eriocheir sinensis. These results may be considered as basic data to be used as control physiological doses, to which to refer for injection or for in vitro perfusion experiments. No significant difference has been detected between anterior respiratory and posterior salttransporting gills. After 10 days acclimation to sea water, a significant increase of haemolymph norepinephrine and dopamine has been observed. Exposure to hydrostatic pressure (101 ATA for 5 hours) also results in an octopamine increase in the haemolymph. In addition, there is a tryptophan increase in both the anterior and the posterior gills. Results are discussed in terms of possible correlations of the concentrations of polyamines, indoleamines, and catecholamines with osmoregulation and behaviour. Les concentrations en tyrosine, octopamine, tryptophane, serotonine, putrescine, spermidine, spermine, norepinephrine, epinephrine et dopamine d'extraits branchiaux (branchies anterieures et posterieures) et hemolymphatiques ont ete mesurees en chromatographie liquide a haute performance chez le crabe chinois Eriocheir sinensis d'eau douce dans le but, notamment, de disposer de valeurs de reference a utiliser comme niveaux physiologiques controles auxquels se referer lors d'experiences d'injection ou de perfusions in vitro. Aucune difference significative n'a ete detectee entre les branchies anterieures "respiratoires" et les branchies posterieures "transportrices de sels". A l'issue de 10 jours d'acclimatement a l'eau de mer, on assiste a une augmentation significative de la norepinephrine et de la dopamine hemolymphatiques. De meme, une exposition de 5 heures a 101 ATA de pression hydrostatique aboutit a une augmentation de l'octopamine hemolymphatique. On assiste, par ailleurs aussi, a un accroissement de la concentration en tryptophane dans les deux types de branchies. Les correlations possibles entre les concentrations en polyamines, indolamines, catecholamines ainsi que l'osmoregulation et le comportement sont l'objet d'une discussion approfondie.]

Background: Rheumatoid arthritis is an autoimmune disorder in which patients not only suffer from joint misery but also face its associated depression. Objectives: To evaluate the anti-arthritic effects of leflunomide (5 mg.kg-1.day-1) and meloxicam (5 mg.kg-1.day-1) when given together on progression of rheumatoid arthritis and its associated depression in Adjuvant-Induced Arthritic (AIA) rats. Methodology: AIA was induced in female Sprague-Dawley rats. Paw volumes was measured to evaluate arthritic progression while brain indolamines (tryptophan, serotonin and its metabolite 5-hydroxyindoleacetic acid) were estimated by HPLC-EC method to determine associated depression. Leflunomide and meloxicam were given orally and intraperitoneally throughout the experiment. Results: Leflunomide and meloxicam inhibited RA progression significantly (p

Quantitative analysis of signaling molecules from single cells and cellular materials requires careful validation of the analytical methods. Strategies have been investigated that enable single neurons and neuronal tissues to be stored before being assayed for many low-weight, biologically active molecules, such as serotonin, dopamine, and citrulline. Both metacerebral cell and pedal ganglia homogenates isolated from Pleiuohbrain-Chae californica have been studied by capillary electrophoresis with two complimentary laser-induced fluorescence detection methods. For homogenized ganglia samples, several cellular analytes (such as arginine and citrulline) are unaffected by standing at room temperature for days. Many other analytes in the biological matrix, including the catecholamines and indolamines, degrade by 20% within 10 h at room temperature. Rapidly freezing samples or preserving them with ascorbic acid preserves more than 80% of the dopamine and about 70% of the serotonin even after five days. In addition, serotonin and dopamine remain completely stable for at least five days by combining the ascorbic acid preservation and freezing at -20 degrees C. The timing of preservation is critical in maintaining the original composition of the biological samples. Using our optimum storage protocol of freezing the sample within 2 h after isolation, we can store frozen homogenate ganglia samples for more than four weeks before assay while still obtaining losses less than 10% of the original serotonin and dopamine. The nanoliter-volume single cell samples, however, must be analyzed within 4 h to obtain losses of less than 10% for serotonin related metabolites.

Copper toxicity has been implicated in various neurodegenerative disorders such as Wilson's disease and Alzheimer's disease. Free copper in the brain is toxic and leads to neuronal and cellular damage, through free radical generation. Melatonin has been investigated as a possible copper ion chelator. Melatonin could prevent copper-induced neuronal and cellular damage through binding with copper and preventing copper-induced free radical generation. The effect of copper on pineal indolamine synthesis has not been studied extensively. In the present study, copper (2 mg/kg) and melatonin (12 mg/kg) were administered daily to Wistar rats for a 2-week and 6-week period. Pineal organ culture was utilized to monitor pineal indolamine synthesis. The pineals from the 2-week copper/melatonin-treated group showed a statistically significant decrease in 5-methoxytryptophol synthesis (p < 0.01), compared to the pineals from the copper-treated group. Conversly, in the 6-week experiment, 5-methoxytryptophol synthesis was increased in both the copper- and copper/melatonin-treated groups. There was a statistically significant decrease in the N-acetyl serotonin level in the pineals from the 6-week copper-treated animals, as compared to the control- and copper/melatonin-treated group (p < 0.01). These results imply that copper reduces N-acetyltransferase activity, which results in a decrease in N-acetyl serotonin synthesis. Melatonin when coadministered with copper appears to prevent the N-acetyltransferase inhibition by copper. Copper exerts contradictory effects on 5-methoxytryptophol synthesis. Further investigations need to be carried out to examine the effects of copper on the pineal enzymes.

I. Introduction PAST studies of antidepressants have focused almost exclusively on their effects on the metabolism and receptors of monoamine neurotransmitters in various brain regions. These studies have been extended to the molecular effects of antidepressants and have led to a profoundly expanded understanding of their actions in the central nervous system. For example, long-term administration of antidepressants decreases the expression of tyrosine hydroxylase, down-regulates cAMP-dependent protein kinase, modulates the mRNA expression of central β-adrenoceptors and serotonin (5-HT) receptors, and alters the functional activity of specific G protein subunits and adenylyl cyclase (1). Taken together, these and many other recent observations clearly indicate that antidepressants interfere not only with the production and release of catecholamines and indolamines but also with the signal transduction of those neurotransmitters that have long been implicated in the pathogenesis and treatment of depression...

A serotonin N -acetyl transferase (NAT) activity was detected in the brain of Pieris brassicae . The maximal head NAT activity appeared to occur during the wandering-pharate phase. The haemolymph level of serotonin, the selected NAT substrate, presented a maximum on the 3rd day of the 5th instar for both short- and long-photoperiod animals with a longer increase in short-photoperiod animals. The circadian rhythm of head NAT, determined on the same day, appeared bimodal and was affected by pteridines only when they were injected at “specific” times. At the last larval stage, the effect of either serotonin, N -acetylserotonin or melatonin was characterized by inactivity immediately after the injection, leading to death by starvation. In “underchilled” chrysalids, serotonin induced a diapause breakdown while melatonin led to mortality. These data suggest, besides the role of juvenile hormone, ecdysone, and polypeptidic hormones, a role for indolamines during the photoperiodic-dependent development of Pieris .

Electrochemical detection is often used to detect catecholamines and indolamines in brain samples that have been separated by conventional reverse-phase high performance liquid chromatography (HPLC). This paper presents the transfer of an existing chromatographic method for the determination of monoamines in brain tissues using 5 μm granulometry HPLC columns to columns with a particle diameter less than 3 μm. Several parameters (repeatability, linearity, accuracy, limit of detection, and stability of samples) for this new ultrafast high performance liquid chromatography (UHPLC) method were examined after optimization of the analytical conditions. The separation of seven compounds, noradrenaline, dopamine and three of its metabolites, dihydroxyphenylacetic acid, homovanillic acid, and 3-methoxytyramine, and serotonin and its metabolite, 5-hydroxyindole-3-acetic acid was analyzed using this UHPLC-electrochemical detection method. The final method, which was applied to brain tissue extracts from mice, rats, and cats, decreased analysis time by a factor of 4 compared to HPLC, while guaranteeing good analytical performance.

The pineal gland is known to synthesize numerous indolamines. Since delta-sleep-inducing peptide (DSIP, a tryptophan nonapeptide) is found in the pineal gland, its effect on the secretion of indolamines was investigated. DSIP stimulated melatonin (MEL), 5-methoxytryptophol (5-ML) and serotonin (5-HT) synthesis and release, whereas it did not affect pineal cyclic AMP levels. The stimulatory effect of DSIP on MEL secretion was dose dependent between 5 x 10(-6) and 10(-4) M, whereas the minimal effective concentration of DSIP on 5-ML secretion was higher than 10(-5) M. The effect of DSIP (10(-4) M) was compared to the effect of isoproterenol (ISO, 10(-6) M) on MEL and 5-HT release. ISO stimulated MEL secretion and concomitantly decreased 5-HT release. With regard to kinetic characteristics, the effect of DSIP (10(-4) M) on MEL release was faster and of shorter duration than the effect of ISO (10(-6) M; 2 and 4 h, respectively). At 10(-4) M, DSIP potentiated the ISO-induced increase of MEL secretion. The DSIP-stimulated release of MEL was not significantly altered when the pineal glands were treated with 10(-5) M propranolol (a beta-adrenergic antagonist), 10(-5) M prazosin (an alpha 1-adrenergic antagonist) or 10(-5) M naloxone (an opioidergic antagonist). This study demonstrates that the DSIP-induced secretion of indolamines from rat pineal glands may not be elicited through the well-known noradrenergic or opioid systems.

Bright-light therapy (BLT) is established as the treatment of choice for seasonal affective disorder/winter type (SAD). In the last two decades, the use of BLT has expanded beyond SAD: there is evidence for efficacy in chronic depression, antepartum depression, premenstrual depression, bipolar depression and disturbances of the sleep-wake cycle. Data on the usefulness of BLT in non-seasonal depression are promising; however, further systematic studies are still warranted. In this review, the authors present a comprehensive overview of the literature on BLT in mood disorders. The first part elucidates the neurobiology of circadian and seasonal adaptive mechanisms focusing on the suprachiasmatic nucleus (SCN), the indolamines melatonin and serotonin, and the chronobiology of mood disorders. The SCN is the primary oscillator in humans. Indolamines are known to transduce light signals into cells and organisms since early in evolution, and their role in signalling change of season is still preserved in humans: melatonin is synthesized primarily in the pineal gland and is the central hormone for internal clock circuitries. The melatonin precursor serotonin is known to modulate many behaviours that vary with season. The second part discusses the pathophysiology and clinical specifiers of SAD, which can be seen as a model disorder for chronobiological disturbances and the mechanism of action of BLT. In the third part, the mode of action, application, efficacy, tolerability and safety of BLT in SAD and other mood disorders are explored.

1. Apart from octopamine, the same indolamines and catecholamines were detected in the whole nervous system of the cockroach Blaberus craniifer Burm., at the same time. 2. However, levels were found to depend on sex, age, and the anatomic region within the nervous system. 3. Although not established, it is thought that these substances act synchronously from the ganglia. 4. The differences in levels between males and females and between anatomical regions during imaginal life suggest, in this species of cockroach, the physiological importance of the metameric organization in metabolic pathways or functional aspects of biogenic amines.

The effects of different doses of chronically administered carbaryl on rat pineal N-acetyltransferase (NAT) activity, hydroxyindole-O-methyltransferase (HIOMT) activity and pineal and serum melatonin levels during darkness (2300 h and 0100 h) when pineal melatonin synthesis is high were studied. Additionally, pineal levels of 5-hydroxytryptophan (5-HTP), serotonin (5-HT) and 5-hydroxyindole acetic acid (5-HIAA) were estimated. Carbaryl was administered at total doses (over 6 days) of either 50, 125 or 250 mg/kg by gastric gavage. Control rats received vehicle (corn oil) only. During the study, the rats were exposed to light/dark cycles of 14:10 with lights off at 2100 h. Pineal NAT and HIOMT activities and pineal melatonin were increased at 0100 h following carbaryl administration at all three doses. Conversely, serum melatonin was increased at 2300 h after the 250 mg/kg dose of carbaryl while all three doses of the pesticide reduced serum melatonin levels at 0100 h. Pineal 5-HTP, 5-HT and 5-HIAA levels were usually increased at 2300 h but unaffected at 0100 h. The results indicate that carbaryl has significant effects on pineal melatonin synthesis and secretion.

Intraerythrocytic malaria parasites develop in a highly synchronous manner. We have previously shown that the host hormone melatonin regulates the circadian rhythm of the rodent malaria parasite, Plasmodium chabaudi, through a Ca 2+ -based mechanism. Here we show that melatonin and other molecules derived from tryptophan, i.e. N-acetylserotonin, serotonin and tryptamine, also modulate the cell cycle of human malaria parasite P. falciparum by inducing an increase in cytosolic free Ca 2+ . This occurs independently of the extracellular Ca 2+ concentration, indicating that these molecules induce Ca 2+ mobilization from intracellular stores in the trophozoite. This in turn leads to an increase in the proportion of schizonts. The effects of the indolamines in increasing cytosolic free Ca 2+ and modulating the parasite cell cycle are both abrogated by an antagonist of the melatonin receptor, luzindole, and by the phospholipase inhibitor, U73122.

Hyperglycemia and acidosis are the key factors in diabetic complications. It has been shown that acute or chronic diabetes alters serotonin levels in brain. However, the mechanism of hyperglycemia- or acidosis-induced changes in serotonin levels remains poorly understood. Because Ca2+-dependent protein kinases play a major role in the regulation of serotonin synthesis and release, we investigated the effect of diabetes, hyperglycemia, and acidosis on the level of indolamines [5-hydroxytryptamine (5-HT) and/or 5-hydroxyindoleacetic acid (5-HIAA)] and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) enzyme activity or protein expression in different brain regions. Alloxan-induced (45 mg/kg bw) diabetic rats (30 days) showed increased level of 5-HT in striatum (ST; 183%), midbrain (MB; 199%), pons medulla (PM; 151%), cerebellum (CB; 214%), and cerebral cortex (CCX; 162%) compared with control (P < 0.05), and these changes were reversed after insulin administration. Rats treated with glucose (500 mg/kg bw) for 30 days showed a 146%, 183%, 208%, and 177% (P < 0.05) increase in 5-HT levels in ST, PM, CB, and CCX, respectively. 5-HIAA level increased in hippocampus (HC; 172%) and in MB (145%; P < 0.05). In addition, rats treated with sodium acetoacetate (NaAcAc) for 30 days (60 mg/kg bw) showed significant increases (P < 0.05) of 5-HT level in ST (152%) and MB (174%). However, the levels of 5-HIAA increased only in MB (151%, P < 0.05). Rats treated with NH4Cl, which induced acidosis (150 mg/kg bw), showed an increased level of 5-HT only in HC (165%, P < 0.05). The increased activity and protein expression of CaMKII in ST, MB, PM, CB, and CCX under diabetic conditions were correlated with the levels of indolamines changes during diabetic, hyperglycemic, or acidotic conditions. These results suggest that CaMKII may be involved in the regulation of indolamines in diabetic animals. © 2005 Wiley-Liss, Inc.

The mammalian pineal hormone melatonin (N-acetyl-5-methoxytryptamine), an aminoindole produced by the metabolism of serotonin (5-hydroxytryptamine), has been shown to be a potent scavenger for the highly toxic hydroxyl radical. Three substances that are very important in animal physiology (e.g., in brain metabolism) are noradrenaline, histamine, and serotonin; all three occur in plants. Here we report that serotonin, tryptamine, and melatonin were found in some edible and medicinal plants in Egypt. The results of this screening showed that the pulp of underripe and ripe yellow banana contains 5-hydroxytryptamine at concentrations of 31.4 and 18.5 ng/g, respectively. Corn, rice, barley grains, and ginger showed the highest concentrations of melatonin, at 187.8, 149.8, 87.3, 142.3 ng/100 g, respectively. On the other hand, potato samples were free from all indolamines. Pomegranate and strawberry showed a low level of indolamines (8-12 microg/g serotonin, 4-9 microg/g tryptamine, and 13-29 ng/100 g melatonin).

Some catecholamines and indolamines inhibit lipid peroxidation. Recent studies indicate that catecholaminergic inhibition of lipid peroxidation may be receptor mediated in vivo and in cell cultures. Because oxidative stress is one of the hypothesized pathogenic mechanisms for neurodegenerative diseases, including Alzheimer’s disease (AD), we hypothesized that catecholaminergic and indolaminergic inhibition of lipid peroxidation would be altered in AD as compared to age-matched non-AD. To test this hypothesis we studied the effect of a variety of neurotransmitters and their antagonists on ascorbate-stimulated lipid peroxidation in membrane fragment preparations derived from postmortem human brain. In this in vitro system, the inhibition of lipid peroxidation by dopamine and serotonin did not appear to be receptor mediated. Further, our findings indicate that there is no apparent effect of age or AD on the inhibition of lipid peroxidation by catecholaminergic and indolaminergic agents.

Intra-striatal infusion of a high dose (100 microg/3 microl) of methamphetamine produced long-lasting depletions of striatal dopamine and serotonin in both male and female mice. Male mice exhibited a greater depletion of striatal dopamine and serotonin than female mice. A similar trend of sexual differences was observed when 4 cumulative doses of methamphetamine were administered systemically. Thus, the sexual differences in methamphetamine-induced neurotoxicity in the striatum are probably not due to their differences in peripheral metabolism of methamphetamine. Moreover, ovariectomized (OVX) mice supplemented with 3 daily doses of estradiol benzoate (EB) at high or physiological levels, 3 daily doses of progesterone (P), and 2 doses of EB followed by 1 dose of P all demonstrated higher striatal dopamine levels following methamphetamine treatment as compared to vehicle-supplemented controls. The OVX mice pretreated with 3 daily doses of P exhibited the highest striatal serotonin levels after methamphetamine administration of all groups. In conclusion, sexual differences observed in methamphetamine-induced striatal neurotoxicity may be modulated by ovarian hormones.

To determine whether sustained hypoxia alters daily rhythms in brain and pituitary neurotransmitters, the daily variations in vasoactive intestinal peptide-like immunoreactivity (VIP-LI), neuropeptide Y-like immunoreactivity (NPY-LI), serotonin (5-HT), and 5-hydroxyindole-3-acetic acid (5-HIAA) content were determined in discrete brain regions, pineal gland and anterior pituitary of hypoxic (10% O2; 14 days) and normoxic rats. Hypoxia suppressed daily variations in VIP-LI in the suprachiasmatic nuclei (SCN) and the anterior pituitary, enhanced the daily rhythmicity in serotonergic elements of the caudal part of the dorsomedial medulla oblongata (DMMc), and even induced daily variations in NPY-LI in the DMMc as well as in the ventrolateral medulla oblongata. In addition, punctual alterations in the rhythmicity of 5-HT and 5-HIAA in the pineal gland and of plasma corticosterone were observed in hypoxic rats. Thus results of this study indicate that a permanent nonphotic stimulus, such as sustained hypoxia, may affect the functioning of the internal clock located in the SCN and may alter the daily rhythmicity in neurotransmitter content of some brain nuclei and the pituitary gland.

Tetrahydrobiopterin (BI-L) is the cofactor for the pteridine-de~ndent monoxygenases (phenylalanine tyrosine and tryptophan hydroxylases) (Kaufmann and Fisher 1974), which play important roles in the biosynthesis of biogenic amines such as catecholamines and indolamines. The biosynthesis of these biogenic amines is regulated by the hydroxylat~on reaction of amino acids such as tyrosine and tryptophan (Nagatsu et al. 1964; Lovenberg et al. 1967), and this hydroxylation reaction is regulated by the concentration of BH4 (Kettler et ~J. !974). These biogenic amines, especially noradrenaliE.e and serotonin, have been thought to be related to affective disorders (Van Praag 1982). Therefore, the relationship between BH4 and depression has been of particular interest, and some controversial results about this relationship have been reported: lowering of the BI-L~ synthesi,~ in the postmortem brains of patients with depression (Blair et al. 1984); no difference between the CSF biopterin levels in patients with depression and in normal controls (Kellner et al. 1980; Levine and Lovenberg 1984); an in

Long-term hypoxia induces changes in neuropeptide-Y-like immunoreactivity (NPY-LI) and/or in the content of serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) at the central level. To determine whether these alterations depend on the integrity of carotid body (CB) chemoreceptors, intact rats or those whose carotid sinus nerve was transected (CSNT) were exposed to hypoxia (10% O2) or to normoxia for 14 days. Thereafter, NPY-LI, 5-HT and 5-HIAA levels in discrete brain regions were determined. The increase in NPY-LI in the ventrolateral medulla oblongata (VLM) of intact hypoxic rats was mostly abolished after CSNT and therefore is mainly mediated by CB chemoreceptors. In contrast, other hypoxia-induced changes were similar or even enhanced in CSNT as compared to intact rats and therefore do not depend on the integrity of CB chemoreceptors. This was the case for the increase of NPY-LI in the striatum and the caudal dorsomedian medulla oblongata (DMM), as well as for all the changes in 5-HT and 5-HIAA in the DMM, the VLM, the raphe nuclei, the striatum and the frontal cortex. We propose that long-term hypoxia alters brain NPY-LI and indolamine content through the stimulation of CB chemoreceptors or ancillary chemoreceptors, as well as through local biochemical or morphological mechanisms.

An isocratic liquid chromatographic method with electrochemical detection for the determination of L-3,4-dihydroxyphenylalanine, dopamine, norepinephrine, epinephrine, serotonin, and their major metabolites, 3,4-dihydroxyphenylacetic acid, 4-hydroxy-3-methoxyphenylacetic acid and 5-hydroxyindole-3-acetic acid in chicken brain tissue is described. Chickens were killed at different ages, the brains were quickly frozen and 300-microm cryostat sections were made. From these sections, two to six tissue micropunches (1 mm in diameter) were punched out from 20 different areas of the hypothalamus and homogenated in 100 microl 0.1 M perchloric acid which included 0.01% cysteine as antioxidant. Fifty-microl supernatants were injected directly onto the LC system, separated on a 3-microm Phase II ODS column (100 x 3.2 mm I.D.) and detected by an electrochemical detector at a potential of +0.75 V. Standard curves, recoveries, analytical precision and detection limits were investigated for each monoamine neurotransmitter and its metabolites. The method was applied to study the influence of food restriction on the concentration of monoamine neurotransmitters in different brain areas, known to be involved in feeding and reproductive behaviour of female broiler chickens. Over 1000 micropunched tissue samples from ad libitum fed and food-restricted female broiler chickens were analyzed. Our results provide a possible role for catecholamines and indolamines in the altered feeding and reproductive behaviour of the broiler chicken.

In this study we investigated the effects of maternal Δ9-tetrahydrocannabinol on the developing serotonergic system. A daily dose of Δ9-tetrahydrocannabinol (5 mg/kg body weight) was administered p.o. to pregnant rats from gestational day 5 to postnatal day 1. Levels of indolamines were measured in four brain areas of the offspring on the day before or after birth. Levels of indolamines depended on the cerebral area, sex and pre- or postnatal age. Maternal exposure to Δ9-tetrahydrocannabinol decreased diencephalic levels of 5-hydroxytryptamine (5-HT), males being more susceptible than females. These perinatal changes could be responsible for the long-term neurophysiological alterations produced by cannabinoids.

Parathion, an organophosphorous insecticide, was previously shown to enhance the nighttime rise in pineal N-acetyltransferase (NAT) activity and serum melatonin levels. The purpose of the present study was to test whether parathion acts on the pineal gland by means of a beta-adrenergic receptor mechanism. Whereas parathion (total dose 6.5 mg/kg body wt over 6 days) by itself significantly augmented nocturnal pineal NAT activity and serum melatonin levels in otherwise untreated rats, the insecticide was ineffective in reference to this enzyme when it was given in conjunction with the beta-adrenergic receptor antagonist propranolol (20 mg/kg body wt, 1 h before lights off). The augmentation of NAT activity by parathion also caused significant reductions in pineal serotonin (5-HT); again, this response was blocked by propranolol treatment. Neither pineal hydroxyindole-O-methyltransferase (HIOMT) activity nor pineal levels of 5-hydroxytryptophan or hydroxyindole acetic acid (5-HIAA) were significantly changed as a result of either parathion or propranolol treatment. The results are consistent with the idea that parathion influences pineal 5-HT metabolism either at the level of the beta-adrenergic receptor or via the sympathetic innervation to the pineal gland.

In vivo microdialysis was used to measure changes in extracellular concentrations of catecholamines and indolamines in freely moving rats in response to administration of endotoxin (lipopolysaccharide, LPS). Dialysis probes were placed stereotaxically in either the medial hypothalamus or the medial prefrontal cortex. We used a repeated-measures design in which each rat received LPS or saline, and each subject was retested with the other treatment one week later. With the dialysis probes in the medial hypothalamus, intraperitoneal (ip) administration of LPS (5 micrograms) increased dialysate concentrations of norepinephrine (NE, 187%), dopamine (DA, 119%), and all their measured catabolites, except normetanephrine. Dialysate concentrations of NE and DA were elevated significantly in the fourth or fifth (20 min) collection period with a peak response at around 2 hr. They returned to baseline by about 4 hr. When the dialysis probes were placed in the medial prefrontal cortex, the same dose of LPS also elevated dialysate concentrations of NE and DA, but the increases were much smaller (ca. 20%). However, a dose of 100 micrograms LPS increased dialysate concentrations of NE and DA from the medial prefrontal cortex to an extent comparable to that of the 5 micrograms dose in the hypothalamus, and the response was more prolonged. Dialysate concentrations of serotonin could not be measured reliably, but those of its catabolite, 5-hydroxyindoleacetic acid (5-HIAA), were also elevated in both regions. The peak of 5-HIAA occurred at around 4 hr. Pretreatment of the rats with indomethacin (10 mg/kg ip) completely prevented the changes due to 100 micrograms LPS in the medial prefrontal cortex.(ABSTRACT TRUNCATED AT 250 WORDS)

Monoamine oxidase (MAO) is a mitochondrial enzyme responsible for the oxidative deamination of catecholamines and indolamines (Alexopoulos et al 1984). Plate!ets contain only MAO-B, whereas human brain contains both MAO-A and MAO-B (Po~,rier et al 1987). The kinetics of platelet MAO-B are believed to be similar to central turnover of monoamines (Georgotas et al 1986), but Young and colleagues (1986) found no connection between platelet and brain MAO-B. Nevertheless, this controversial area has been implicated in attempts to identify a biological marker tbr the evaluation of the size or capacity of the central serotonin system (Hailman et al 1990). In this study we examined platetet MAO-B activity as a biological marker tbr depressive and anxiety disorders, giving par.icular attention to its relation to age of onset.

1. The effects of 5-hydroxytryptamine, 5-hydroxyindoleacetic acid and N -acetyl-5-hydroxytryptamine on oocytes of Blaberus craniifer , in which vitellogenesis was prevented by imaginal molt decapitation, were investigated. 2. Sites binding anti-egg-protein antibodies were detected in the periphery of basal oocytes of treated females, with individual variability. 3. In this ovoviviparous cockroach, the onset of vitellogenesis may thus not be triggered solely by juvenile hormone, and indolamines may play a role in the uptake of haemolymphatic proteins by oocytes.

The aim of the present investigation was to look for the mechanisms causing disturbances in carbohydrate metabolism during the action of the epileptogenic agent methionine sulfoximine The levels of glucose, glycogen, and indolamines were measured in seven different regions of rat brain. Methionine sulfoximine induced a decrease in serotonin level which was roughly dose-dependent. There were no obvious, changes in tryptophan and 5-hydroxyindoleacetic levels in any area. Methionine sulfoximine induced the known increase in glucose and glycogen levels. The direct precursor of serotonin, 5-hydroxytryptophan, and benserazide (a decarboxylase inhibitor) were then injected into rats in association with methionine sulfoximine. In this case, methionine sulfoximine failed to induce seizures. Moreover, the serotonin level was unchanged and the carbohydrate content did not significantly increase. There was only a rise in 5-hydroxyindoleacetic acid level. This work shows a striking parallelism between serotonin decrease and glycogen increase.

Drosophila melanogaster homogenates incubated with tritiated 5-hydroxytryptophan, 5-hydroxytryptamine, or N-acetylserotonin have the ability of converting them into labelled indolamines, including melatonin. All these compounds were characterized by two-dimensional thin-layer chromatography by comparison with nonradiolabelled standards, and melatonin by mass spectrometry and radioimmunoassay. On the other hand, the injection of pharmacological doses of melatonin into 2-day-old female flies diminishes the mating speed and the oviposition rate.

The pineal complex of the three-spined stickleback (Gasterosteus aculeatus L.) was investigated by light and electron microscopy, as well as fluorescence histochemistry for demonstration of catecholamines and indolamines. The pineal complex of the stickleback consists of a pineal organ and a small parapineal organ situated on the left side of the pineal stalk. The pineal organ, including the entire stalk, is comprised mainly of ependymal-type interstitial cells and photoreceptor cells with well-developed outer segments. Both unmyelinated and myelinated nerve fibres are present in the pineal organ. Nerve tracts from the stalk enter the habenular and posterior commissures. A small bundle of nerve fibres connects the parapineal organ and the left habenular body. The presence of indolamines (5-HTP, 5-HT) was demonstrated in cell bodies of both the pineal body and the pineal stalk, and catecholaminergic nerve fibres surround the pineal complex.

Dense bodies containing high amounts of chrome were localized in the perikarya of substantia nigra and dorsal raphe neurons following the cytochemical reaction of endogenous dopamine and serotonin (respectively) with glutaraldehyde-dichromate (GDC). Energy dispersive X-ray analysis of these bodies revealed chrome levels two to four times higher than those recorded from the cytoplasmic background. Pretreatment with paraformaldehyde blocked the GDC reaction within the dense bodies in the substantia nigra (chrome levels similar to background), while the chrome levels in the dense bodies of the raphe neurons remained elevated. This demonstrates that pretreatment with paraformaldehyde allows selective localization of central nervous system serotonin stores by the GDC technique.

The effect of indolamine derivatives on beta-endorphin (beta-end) release has been studied in vitro using rat anterior pituitary cells. Incubation of primary cultures for 2 h with 100 nmol/l of melatonin, serotonin or 5-methoxytryptamine significantly increased the beta-end release in response to 20 nmol/l of ovine corticotropin-releasing factor (oCRF). Incubation of the cultures with 100 nmol/l of L-tryptophan, 5-hydroxy-L-tryptophan, 5-hydroxytryptophol or 5-methoxytryptophol had no effect on basal or CRF-induced beta-end release. The effect of serotonin and melatonin was further tested in a superfusion system of dispersed rat anterior pituitary cells. Superfusion with oCRF (200 nmol/l) for 4 min elicited an immediate rapid increase in beta-end release which lasted 30-40 min. Simultaneous superfusion with melatonin (1 mumol/l) or serotonin (1 mumol/l) significantly increased the effect of oCRF pulses on beta-end release. We conclude that melatonin and serotonin are able to act directly on anterior pituitary cells to potentiate the effect of oCRF on beta-end release.

The present modification of the formaldehyde condensation method for demonstrating catecholamines and indolamines involves generation of the formaldehyde gas at + 80°C followed by reaction at +25 or 0°C. This procedure results in improved sensitivity for demonstrating noradrenaline and dopamine. Because adrenaline and peptides with NH2-terminal tryptophan give no or very weak fluorescence under these reaction conditions the modification also offers possibilities for improved discrimination between primary catecholamines on one hand and adrenaline and tryptophyl peptides on the other. Under the conditions used, the fluorescence yield of 5-hydroxytryptamine did not seem to be improved by variations in the reaction temperature.