Search

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.

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.

The hydroxyl radical (•OH) scavenging activities of Melatonin, an endogenously produced neurohormone and its related indolamines like N-acetyl tryptophan (NAT) and N-acetyl serotonin (NAS) have been investigated using density functional theory. The mechanism involves 4 steps: initial radical addition to position-3 of the indole ring, keto-amine to enol-imine tautomerization, cyclisation, and finally, addition of a second •OH leading to a cyclic end product. Incorporation of an explicit water molecule in tautomerization step leads to a significant reduction in the barrier of this step, so that the subsequent cyclisation step becomes rate-limiting. In agreement with the very high reactivity of •OH, the initial and final addition of •OH to indolamine are found to be barrierless. Radical adduct formed in the initial step was found to be very stable due to the extensive conjugation present in the substrate. Our calculations show that melatonin is the most effective radical scavenger among the three molecules chosen. NAS was found to exhibit antiradical property comparable to that of melatonin. In contrast to the general observation of reduced antioxidant activity of tryptophan, a non-natural derivative of tryptophan used here (NAT) is found to have good radical scavenging activity. This work further implies that non-natural derivatives of indolamines might as well be useful in the detoxification of free radicals as they exhibit almost comparable antioxidant efficiency as that of melatonin.

Neuromolecular imaging (NMI) visually links electrical and chemical brain activity with neurotransmitter release in vivo, in real time and online to identify biomarkers to diagnose and treat neurodegenerative disorders such as Parkinson's disease (PD). NMI combined with BRODERICK PROBE laurate nanobiosensors image neuromolecules as the molecular transmitter crosses synaptically in the same motor neurons in basal ganglia as striatal motor neurons in basal ganglia direct movement. With NMI, striatal motor neurons function as electrical devices to synchronize instantaneously with the BRODERICK PROBE nanobiosensor to signal functional physiology (non-PD) or dysfunctional pathology (PD). In non-PD, neurons signal monoamines, precursors, and metabolites selectively with and without L-3,4-dihydroxyphenylalanine ( l -DOPA), while in PD, neurons signal peptides revealing the likely etiology of PD as the BRODERICK PROBE sees inside the PD brain and allows a direct cause and effect in PD per se and then further provides a direct online image inside the non-PD brain. NMI studies were further contrasted with PD versus non-PD responses after administration of the pharmaceutical, indirect agonist, bromocriptine (Parlodel). PD and non-PD animals were videotracked, and images were readily seen on a laptop via a potentiostat using a semiderivative electrical circuit. PD lesions with 6-hydroxydopamine (6-OHDA) were performed in substantia nigra pars compacta by Charles River surgeons. Administered l -DOPA doses were 50 and 100 mg/kg intraperitoneally; the same experimental paradigm was used to image PD versus non-PD animal models. Results showed that the baseline release of biogenic amine molecules was significantly above detection limits in non-PD animals and further increased dramatically in a linear dose response pattern after l -DOPA administration, whereas the PD model showed distinct pathology for baseline signally in basal ganglia. There were little or no biogenic amines. In fact, peptides and amino acid, l -tryptophan, were signaled instead of biogenic amines; and after l -DOPA, dramatic off-scale peptide and amino acid release was imaged, and the response was nonlinear. Indeed, there was no statistical difference between responses after the low dose in contrast to the higher dose l -DOPA in the PD animal model. Thus, NMI demonstrates for the first time that the actual online absence of the biogenic amine, catecholamine, dopamine, and the periodic absence of the indoleamine, serotonin, are empirical biomarkers for PD. Significant biomarkers present in PD and absent in non-PD animals include peptide neurotransmitters, dynorphin and somatostatin; l -DOPA significantly increased dynorphin, a glutamate toxin, and somatostatin, a protector in PD, but could not enable release of catecholamines or indolamines. It is intriguing that PD animals released the precursor to serotonin, that is, l -tryptophan, to a strikingly similar degree as was seen in signals imaged for the peptide biomarkers in PD, showing that the neurotransmitter biogenic amine, serotonin, as well at l -tryptophan, and the absence of dopamine are live biomarkers for PD, in fact, as critical as are the peptide biomarkers. The data enable cutting-edge and never-before-shown advances in the field of PD and nanobiotechnology specifically for unique diagnostic, surgical, and pharmacotherapeutic relief from debilitating PD.

From early to later stages of Type I Diabetes Mellitus (TIDM), signalling molecules including brain indolamines and protein kinases are altered significantly, and that has been implicated in the Metabolic Disorders (MD) as well as impairment of retinal, renal, neuronal and cardiovascular systems. Considerable attention has been focused to the effects of diabetes on these signalling systems. However, the exact pathophysiological mechanisms of these signals are not completely understood in TIDM, but it is likely that hyperglycemia, acidosis, and insulin resistance play significant roles. Insulin maintains normal glycemic levels and it acts by binding to its receptor, so that it activates the receptor's tyrosine kinase activity, resulting in phosphorylation of several substrates. Those substrates provide binding/interaction sites for signalling molecules, including serine/threonine kinases and indolamines. For more than two decades, our research has been focused on the mechanisms of protein kinases, CaM Kinase and Serotonin transporter mediated alterations of indolamines in TIDM. In this review, we have also discussed how discrete areas of brain respond to insulin or some of the pharmacological agents that triggers or restores these signalling molecules, and it may be useful for the treatment of specific region wise changes/disorders of diabetic brain.

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.

A facile and efficient one-pot three-component synthesis of spiroazepinoindolones has been developed. Using DMF as solvent without any additional acid or metal catalysts, the three-component reaction of readily available isatins, indolamines, and Meldrum's acid affords a new class of spiroheterocycles in moderate yield.

Several studies have shown the presence of melatonin and related compounds in grapes and wines. The latter provides evidence of the possibility to enhance the nutraceutical properties of premium wines. However, there are many external factors that can influence the levels of this indolamine in grape and wines. In this study, the monitoring of melatonin and its tentatively identified isomer was carried out during the entire winemaking process in Vitis vinifera cv. Malbec by ultra high-performance liquid chromatography-tandem mass spectrometry. Laboratory and pilot studies were carried out to elucidate the role of grape, yeasts, and tryptophan in the evolution of the indolamines during the fermentation process. Melatonin was detected in grape extract within the range 120-160 ng/g while its isomer was found in musts and finished wines. Our results demonstrate that Saccaromyces cervisiae plays a decisive role in contributing to the content of melatonin and its isomer in wine.

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.

Brain glycogen could be considered as an energy store for neuronal activity, with high relevance in epilepsies. We selected two lines of mice based upon their latency to methionine sulfoximine (MSO) dependent-seizures: MSO-Fast and MSO-Slow, and their neurochemical characterization was attempted in order to look for the mechanisms of epileptogeny. We determined the MSO effect on brain glycogen in the two selected lines and their eight parental strains, and on indolamines and catecholamines. The increase in brain glycogen content induced by MSO is significantly lower in MSO-Fast than in MSO-Slow. At the onset of seizures the degradation of accumulated glycogen was higher in MSO-Slow mice than in MSO-Fast ones. Moreover, a positive correlation was observed between the magnitude of latency toward MSO-induced seizures and brain glycogen content in the eight parental strains used for selection. A striking proportionality between the content of glycogen and 5-hydroxytryptamine (5-HT) was observed in cerebral cortices of both selected lines. However, the cortical 5-HT level is higher in MSO-Fast than in MSO-Slow, and it is significantly decreased at the onset of seizures in both lines. Brain glycogen content is implicated in the developed model of mice with different latency to MSO-dependent seizures: The higher the brain glycogen content, the longer the latency; and 5-HT is involved in the control of latency to seizures-induced by MSO in these two lines. Our model of MSO "sensitive" (MSO-Fast) and "resistant" (MSO-Slow) mice could lead to a better understanding of MSO mechanisms of epileptogenesis, and the relationship between epileptogenic and glycogenic MSO effects.

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.

Since its discovery in the past century by Green, Page and Rapport (1948), to the present time, several physiological actions of serotonin has been discovered. Besides physiological functions, several components of serotoninergic system and its participation in some neurological diseases (i.e. depression, schizophrenia) also have been reported. During previous decades, a lot of experimental techniques have allowed us to locate, detect, analyze and describe the serotoninergic system and its role in different organs and tissues; at the time of 60’s and 70’s of century XX, techniques such as histochemistry for indolamines or Falck-Hillarp method, fluorescence microscopy and the realization of measurements of concentrations in tissues or blood using chromatography enabled significant progress in the study of this indolamine

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.

Arylalkylamine N-acetyltransferase (NAT) from the female colleterial glands of Periplaneta americana showed activity peaks at pH 6.0 and 9.5 and the pH profile changed during oogenesis. The left gland contained higher activity than the right gland but the right gland also contained recognizable activity. The patterns in activity change depended on the substrate used, tryptamine (TN) or serotonin (5-HT). When TN was used as the substrate, the alkaline peak was higher than the acidic peak. In contrast, when 5-HT was used, the acidic peak was much higher than the alkaline peak. This suggests that at least two NATs are present in this species that are specific to pH and substrate species. Of the four combinations of the two pH ranges and two substrate indolamines, the enzyme activity that showed a similar change to the oocyte maturation was obtained in the combination of pH 6.0 and TN. TN was actually detected in the colleterial glands by fluorescent measurements according to Hess and Uderfriend [J. Pharmacol. Exp., 127 (1959) 175-177]. It peaked on the 6th day of emergence, which corresponded to the first rise of oocyte length and yolk accumulation, whereas a small peak appeared in the phase of the second rise. TN, or more likely N-acetyl TN, may therefore be involved in the regulation of oocyte maturation which could be a novel mechanism in oocyte maturation.

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.]

A facile and efficient one-pot three-component synthesis of spiroazepinoindolones has been developed. Using DMF as solvent without any additional acid or metal catalysts, the three-component reaction of readily available isatins, indolamines, and Meldrum's acid affords a new class of spiroheterocycles in moderate yield.

Compounds that have the property to disrupt the neuroendocrine signaling and the metabolisms of hormones and neuromediators in organisms are termed neuroendocrine disrupters. Previously named endocrine disrupters, the scientific community realized that many neuromediators are also involved in other systems or functions such as growth, food intake (behavior), gonad development, and sexual differentiation. These observations suggested that neural and endocrine signaling, especially those involved in reproduction, were associated or physiologically coupled. Estrogenic compounds capable of acting as estrogen mimics in respect to biochemical targets in cells are by far the most studied type of endocrine disrupters in the wild. Indeed, estrogen binding to receptors leads to important physiological changes, including the mobilization of energy reserves and the production of vitellogenin, the egg-yolk protein precursor in oviparous organisms. Vitellogenin represents the main food source for the developing embryos post hatch. This response could also be obtained in males or in juveniles. Expression of vitellogenin in males was also the first step leading to intersex or male feminization in fish and mussels. Both generic and specific assays to detect for the presence of estrogenic effects and estradiol-17β binding sites in aquatic organisms are presented. The evaluation of catecholamines (dopamine and noradrenaline) and indolamines (serotonin) using less specific (fluorescence assay) and more specific means (competitive immunoassay) is also presented to accommodate various laboratory sizes and budgets. Finally, some enzyme-based assays are also presented for acetylcholine and catecholamine/indolamine turnover studies using prepared nerve button synaptic membranes, which are operationally termed synaptosomes.

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

In an attempt to define the role of the pineal secretory melatonin and an analogue, 6-hydroxymelatonin (6-OHM), in limiting oxidative stress, the present study investigated the cisplatin (CP)-induced alteration in the renal antioxidant system and nephroprotection with the two indolamines. Melatonin (5 mg/kg), 6-OHM (5 mg/kg), or an equal volume of saline were administered intraperitoneally (i.p.) to male Sprague Dawley rats 30 min prior to an i.p. injection of CP (7 mg/kg). After CP treatment, the animals each received indolamine or saline every day and were sacrificed 3 or 5 days later and plasma as well as kidney were collected. Both plasma creatinine and blood urea nitrogen increased significantly following CP administration alone; these values decreased significantly with melatonin co-treatment of CP-treated rats. In the kidney, CP decreased the levels of GSH (reduced glutathione)/GSSG (oxidized glutathione) ratio, an index directly related to oxidative stress. When animals were treated with melatonin, the reduction in the GSH/GSSG ratio was prevented. Treatment of CP-enhanced lipid peroxidation in the kidney was again prevented in animals treated with melatonin. The activity of the antioxidant enzyme, glutathione peroxidase (GSH-Px), decreased as a result of CP administration, which was restored to control levels with melatonin co-treatment. Upon histological analysis, damage to the proximal tubular cells was seen in the kidneys of CP-treated rats; these changes were prevented by melatonin treatment. 6-OHM has been shown to have some antioxidative capacity, however, the protective effects of 6-OHM against CP-induced nephrotoxicity were less than those of melatonin. The residual platinum concentration in the kidney of melatonin co-treated rats was significantly lower than that of rats treated with CP alone. It is concluded that administration of CP imposes a severe oxidative stress to renal tissue and melatonin confers protection against the oxidative damage associated with CP. This mechanism may be reasonably attributed to its radical scavenging activity, to its GSH-Px activating property, and/or to its regulatory activity for renal function.

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.

The content of melatonin and its precursors in the pineal gland of healthy rats and rats with hereditary retinal degeneration is studied on days 20 and 40 of postnatal development. The measurements are performed between 02:30 and 03:00, when the content of melatonin is maximal. In December, the content of melatonin and N-acetylserotonin in 20-day-old rats with hereditary retinal degeneration is 1.9- and 3.2-fold higher than in healthy controls. The content of norepinephrine in the pineal gland of these rats is increased 1.8-fold. On postnatal day 40, no differences in the pineal content of indolamines are noted. An increase in the content of melatonin in 20-day-old rats with hereditary retinal degeneration in comparison with healthy controls is also observed in May. A decrease in the maximum nocturnal level of melatonin in May in comparison with December is shown both in rats with hereditary retinal degeneration (by 46%) and healthy controls (by 41%) only on postnatal day 40.

In an attempt to define the role of the pineal hormone melatonin and two analogues (5-methoxytryptamine, 5MT, and 6-hydroxymelatonin, 6HM) in limiting oxidative stress, the present study investigated the changes in glutathione, lipid peroxidation, and the activity of the antioxidant enzyme glutathione peroxidase after exercise (swimming for 60 min) with or without treatment with the indolamines mentioned. Lipid peroxidation was measured by estimating tissue levels of malondialdehyde and 4-hydroxyalkenals; the experimental animals in these studies were male Sprague-Dawley rats. In the liver, swimming exercise increased the levels of reduced glutathione (GSH) and also significantly increasing oxidized glutathione (GSSG), while decreasing the GSH/GSSG ratio, an index directly related to oxidative stress. When the animals were treated with melatonin, the concentrations of GSH and GSSG were also increased after swimming; however, no reduction in the GSH/GSSG ratio appeared. In the animals treated with 6HM the changes were the same as in those treated with melatonin. In muscle as well, the concentration of GSH and the GSH/GSSG ratio were decreased following 60 min of swimming. Pretreatment of the rats with melatonin prevented these effects. Pretreatment of the rats with both 5MT and 6HM also prevented the changes. Brain GSH/GSSG ratio was not affected by either exercise or indolamine administration. Swimming enhanced lipid peroxidation in the liver, muscle and brain; however, this was prevented in animals treated with melatonin or 6HM before swimming. Glutathione peroxidase was significantly elevated after exercise in the brain but not in the liver and muscle. It is concluded that swimming imposes a severe oxidative stress and suggests that melatonin and, to a lesser degree, 5MT and 6HM confer protection against the oxidative damage associated with swimming for 60 min. This mechanism may be reasonably attributed to their indole structure, which possibly allows these molecules to act as free-radical scavengers.

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 .

We studied the effects of four indolamines (melatonin, 5-methoxytryptamine, 5-methoxytryptophol, and 5-methoxytryptophan) on ovarian activity in a tropical rodent, the Indian palm squirrel (Funambulus pennati), during the sexually active phase. Injection of the four 5-methoxyindoles at a dose of 20 μg/0.1 mL per animal every evening for 30 days reduced ovarian mass in both intact and pinealectomized animals. Intact animals treated with 5-methoxyindoles had a lower uterine mass than the intact controls. On the other hand, the uterine mass of pinealectomized animals treated with 5-methoxyindoles did not differ from that of their respective controls. Plasma estradiol levels showed a similar pattern to ovarian masses. We conclude that the effect of 5-methoxyindoles in the female palm squirrel is independent of the pineal gland and that 5-methoxytraptophol and 5-methoxytryptophan are more potent than melatonin.

Neuroendocrine cells are present in virtually all organs of the vertebrate body; however, it is yet uncertain whether they exist in the ovaries. Previous reports of ovarian neurons and neuron-like cells in mammals and birds might have resulted from misidentification. The aim of the present work was to determine the identity of neuron-like cells in immature ovaries of the domestic fowl. Cells immunoreactive to neurofilaments, synaptophysin, and chromogranin-A, with small, dense-core secretory granules, were consistently observed throughout the sub-cortical ovarian medulla and cortical interfollicular stroma. These cells also displayed immunoreactivity for tyrosine, tryptophan and dopamine β-hydroxylases, as well as to aromatic L-DOPA decarboxylase, implying their ability to synthesize both catecholamines and indolamines. Our results support the argument that the ovarian cells previously reported as neuron-like in birds, are neuroendocrine cells.

Brain microdialysis is an analytical technique used for the dynamic monitoring of brain neurochemistry in awake, freely moving animals. This technique requires the insertion of a small dialysis catheter, called a microdialysis probe, into a specific brain region, and its perfusion with an artificial extracellular fluid. The microdialysate samples, obtained from the probe outlet, can be analysed using high-performance liquid chromatography with electrochemical detection for the quantification of oxidizable molecules recovered from the extracellular space. In this chapter, we describe a protocol for performing a microdialysis setup and experiment in freely moving rats and mice. Furthermore, the high-performance liquid chromatographic determination of ascorbic acid, uric acid, catecholamines, indolamines and derivatives is described in detail.

Migraine is a paroxysmal disorder characterized by recurrent attacks of headache, with or without associated visual and gastrointestinal disturbances. Migraine can be classified in two main groups, common and classic. Theories trying to explain the pathogenesis of a migraine attack may emphasize either the central or peripheral aspects of the disease. The vascular theory may stress the importance of either central or peripheral blood flow or both. Cerebral vasoconstriction in the early phases of the attack is followed by vasodilatation and pain. Biochemical mediators of vascular responses are not exactly known, but platelets and 5-hydroxytryptamine and thromboxane released from them as well as noradrenaline are potent vasoconstrictors, while kinins and prostaglandins can explain the vasodilatory phase of migraine attacks. This review presents evidence for the role of arachidonic acid metabolites, prostaglandins and leukotrienes in migraine. The evidence comes from the measurements of eicosanoids in biological fluids during and after the attack, infusion studies where vasodilatory prostaglandins mimic the migraneous symptoms, and the good effect of non-steroidal anti-inflammatory drugs in the treatment and prophylaxis of migraine attacks. Additional data are based on experimental biochemical studies in which catecholamines and indolamines have been shown to increase the synthesis of vasodilatory prostaglandins. However, the final evidence still awaits its confirmation.

Biogenic amines in Nematoda have previously been found by means of high-performance liquid chromatography (HPLC) equipped with various detectors. The methods of sample preparation have differed widely. In this study, we tested the influence of experimental conditions (temperature and duration of exposure to light, centrifugation or individual recovery by pipetting each worm, and saccharose gradient versus physiological saline) on catecholamines and indolamines content in Nippostrongylus brasiliensis at various developmental stages (larvae and adults). Amines were determined by liquid chromatography with electrochemical detection. To the best of our knowledge, octopamine, tyramin, N-acetylserotonin and N-acetyldopamine were found and determined for the first time in this nematode. All experimental conditions listed above modify the endogenous amine levels in larval and adult Nippostrongylus brasiliensis. This should be taken into account in the design of future research protocols.

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.

Microdialysis is an extensively used technique for both in vivo and in vitro experiments, applicable to animal and human studies. In neurosciences, the in vivo microdialysis is usually performed to follow changes in the extracellular levels of substances and to monitor neurotransmitters release in the brain of freely moving animals. Catecholamines, such as dopamine and their related compounds, are involved in the neurochemistry and in the physiology of mental diseases and neurological disorders. It is generally supposed that the brain's energy requirement is supplied by glucose oxidation. More recently, lactate was proposed to be the metabolic substrate used by neurons during synaptic activity. In our study, an innovative microdialysis approach for simultaneous monitoring of catecholamines, indolamines, glutamate and energy substrates in the striatum of freely moving rats, using an asymmetric perfusion flow rate on microdialysis probe, is described. As a result of this asymmetric perfusion, two samples are available from the same brain region, having the same analytes composition but different concentrations. The asymmetric flow perfusion could be a useful tool in neurosciences studies related to brain's energy requirement, such as toxin-induced models of Parkinson's disease.

Neurofibrillary tangles and amyloid plaques express acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity in Alzheimer's disease. We had found that traditional AChE inhibitors such as BW284C51, tacrine and physostigmine were more potent inhibitors of the AChE in normal axons and cell bodies than of the AChE in plaques and tangles. We now report that the reverse pattern is seen with indolamines, carboxypeptidase inhibitor, and the nonspecific protease inhibitor bacitracin. These substances are more potent inhibitors of the cholinesterases in plaques and tangles than of those in normal axons and cell bodies. These results show that the enzymatic properties of plaque and tangle-associated cholinesterases diverge from those of normal axons and cell bodies. The selective susceptibility to bacitracin and carboxypeptidase inhibitor indicates that the catalytic sites of plaque and tangle-bound cholinesterases are more closely associated with peptidase or protease-like properties than the catalytic sites of cholinesterases in normal neurons and axons. This shift in enzymatic affinity may lead to the abnormal protein processing which is thought to play a major role in the pathogenesis of AD. The availability of pharmacological and dietary means for altering brain indolamines raises novel therapeutic possibilities for inhibiting the abnormal cholinesterase activity associated with Alzheimer's disease.

The synthesis of (+)-(R)-2-cyano-N,N-dipropyl-8-amino-6,7,8,9-tetrahydro-3H- benz[e]indole [(R)-14, U92016A], a potent 5-HT1A agonist, and related analogs is described. In vitro binding studies show that the (R)-enantiomers of this series possess the highest potency for the 5-HT1A receptor. In vivo hypothermia correlates with this, with the (R)-enantiomers causing a greater temperature drop than the (S)-enantiomers. The most active compound in 5-HT1A binding and in the in vivo models was (R)-14, which was found to be highly potent as an agonist in single cell firing studies, as well as potent and of very high intrinsic activity in mouse hypothermia and the sympathetic nerve discharge (SND) models. An in vivo duration of action study, following SND, showed (R)-14 to possess a long duration of action. The synthesis via a nitrene insertion, determination of absolute configuration, and biological activities of this series is described.

The effects of cutting gonapophyses were evaluated on the ovarian response two or four days after amputation in imaginai molt decapitated females Blaberus craniifer. Sites binding anti‐egg protein antibodies were detected in the periphery of basal oocytes in 68% operated females. In headless Blaberus craniifer, the onset of vitellogenesis which is triggered by extraphysiological doses of juvenile hormone or indolamines, was induced by this surgical procedure. It is suggested that amputation of gonapophyses affects the delivery of natural messengers inducing vitellogenesis at physiological concentration.

The photoresponses of 116 photoreceptors in the excised perfused pineal body of adult trout were intracellularly recorded. Brief flashes produced slower, but otherwise comparable, responses to retinal receptor cells. The absolute sensitivity, as well as the light-induced membrane conductance changes, were also similar to those of retinal cone cells in the same species. Steady illumination decreased the cell sensitivity to superimposed flashes, in accordance with the Weber-Fechner relation, indicating the presence of light adaptation. This conclusion is supported by the non-exponential nature of the amplitude-intensity relation and by the conspicuous shortening of the time-to-peak with increasing flash intensity. The time-dependent response decay typical of retinal photoreceptors was not found, however. The fact that, during constant illumination, the pineal photoresponses maintain the same amplitude set at the initial peak perhaps represents an original mechanism of light adaptation which allows these cells to maintain their voltage-dependent synthesis and secretion of indolamines as a constant relation with daily illumination.

Alcohol interferes with the central metabolism of the catecholamines and especially with indolamines (5-HT). Thus, the use of an antidepressant such as tianeptine, whose main neurochemical effect is to increase the reuptake of 5-HT, seems to be particularly indicated for the continued treatment of depressed patients after alcohol withdrawal. This study evaluated the therapeutic efficacy and acceptability during long-term administration of tianeptine in depressed patients (major depressive episode or dysthymic disorder) in a multicentre trial, after withdrawal from alcohol abuse or dependence. The results relate to 130 depressed patients, who abstained from alcohol and received treatment for a year. Only one patient dropped-out because of side-effects, and medication was interrupted in 5% of subjects because of alcoholic relapses. Prescribed in the long term, tianeptine did not produce orthostatic hypotension, changes in bodyweight, or alterations in the ECG. All changes found in haematological and biochemical investigations suggested an improvement in patients' physical state. This, and other studies, indicate that tianeptine appears to have the potential to be a safe antidepressant, which might be particularly useful in those patients who are susceptible to the side-effects of psychotropic drugs.

The study of cerebral ischemia in animals is not easy, because cerebral circulation is not the same as in humans. Indeed, in most animals, there is a collateral circulation between the vertebral and carotid arteries before these arteries enter the brain. On the other hand, in gerbils, unilateral ligation produces ischemia in the ipsilateral forebrain and leads to death in 40–60% of the animals. Because the cerebral ischemia so produced is not effective in all gerbils, it is important to select “sensitive” gerbils by funduscopic examination. Only sensitive gerbils are retained for further experimentation. The nature of the aging process is the subject of some speculation. One hypothesis is referred to as the free radical theory. This theory postulates that free radicals are involved in aging and age-related disorders of the brain. Therefore, we have determined levels of neuromediators involved in cerebral ischemia and memory, including catecholamines (dopamine [DA], dihydroxyphenylacetic acid [DOPAC], hydroxyvanillic acid [HVA]) and indolamines (5-hydroxyindolacetic acid [5HIAA], serotonin [5-HT]), amino acids (aspartate, glutamate and GABA), and free radicals (.OH). We have chosen for study the caudate nucleus, hippocampus, and retina, where changes after ischemia/reperfusion insult are well documented. In gerbil brain, levels of .OH and neurotransmitters are low at birth, reach a plateau, and then decrease with aging. After cerebral ischemia (60 min) induced by left carotid occlusion, the reperfusion (30 min) symptoms are classified using a behavioral score (Stroke Index). Moreover, after ischemia/reperfusion insult (IRI), increases in Stroke Index, .OH, glutamate, aspartate, GABA, monoamines, and indolamines are more pronounced in older gerbils. © 1992 Wiley-Liss, Inc.

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.

As 5 alpha-reductase is involved in the metabolism of indolamines in the Harderian glands of Syrian hamsters, we have compared the effects of androgen deprivation and the administration of the potent 5 alpha-reductase inhibitor N,N-diethyl-4-methoxy-3-oxo-4-aza-5-androstene-17-carboxamida on Harderian porphyrin metabolism. Ten days after castration, porphyrin levels had increased to 40 times the values of intact hamsters. However, the inhibition of 5 alpha-reductase, which resulted in a significant decrease in the weight of accessory sex glands, did not modify porphyrin concentrations within the Harderian glands. It is concluded that, contrary to the situation for indolamine metabolism, testosterone per se is the main androgen involved in the sexual differences observed in Harderian porphyrin metabolism.

The application of a tissue-based biosensor for the measurement of the concentration of catecholamines and indolamines is described. The bioelement of the biosensor is a rat liver section and the reaction of the deamination of biogenic amines (monoamineoxidase) was used. The concentration of NH + 4 was measured by using ah ammonium-selective electrode. The biosensor was used for measuring tyramine, dopamine, tryptamine and serotonin in the range ca. 10 −3 –10 −4 M; the lifetime of the biosensor is about 20–25 days. Optimization of the parameters of the biosensor is discussed.