Acute blockade of endogenous melatonin by Luzindole, with or without peripheral LPS injection, induces jejunal inflammation and morphological alterations in Swiss mice

This study investigated the acute blockade of endogenous melatonin (MLT) using Luzindole with or without systemic lipopolysaccharide (LPS) challenge and evaluated changes in inflammatory and oxidative stress markers in the mouse jejunum. Luzindole is an MT1/MT2 MLT receptor antagonist. Both receptors occur in the small intestine. Swiss mice were treated with either saline (0.35 mg/kg, ip), Luzindole (0.35 mg/kg, ip), LPS (1.25 mg/kg, ip), or Luzindole+LPS (0.35 and 1.25 mg/kg, ip, respectively). Jejunum samples were evaluated regarding intestinal morphometry, histopathological crypt scoring, and PAS-positive villus goblet cell counting. Inflammatory Iba-1, interleukin (IL)-1β, tumor necrosis factor (TNF)-α, nuclear factor (NF)-kB, myeloperoxidase (MPO), and oxidative stress (NP-SHs, catalase, MDA, nitrate/nitrite) markers were assessed. Mice treated with Luzindole, LPS, and Luzindole+LPS showed villus height shortening. Crypt damage was worse in the LPS group. Luzindole, LPS, and Luzindole+LPS reduced the PAS-goblet cell labeling and increased Iba-1-immunolabelled cells compared to the saline group. Immunoblotting for IL-1β, TNF-α, and NF-kB was greater in the Luzindole group. The LPS-challenged group showed higher MPO activity than the saline and Luzindole groups. Catalase was reduced in the Luzindole and Luzindole+LPS groups compared to saline. The Luzindole group showed an increase in NP-SHs, an effect related to compensatory GSH activity. The acute blockade of endogenous MLT with Luzindole induced early changes in inflammatory markers with altered intestinal morphology. The other non-detectable deleterious effects of Luzindole may be balanced by the unopposed direct action of MLT in immune cells bypassing the MT1/MT2 receptors.

Melatonin decreases cocaine-induced locomotor activity in pinealectomized rats

Objective: Several studies have shown that the time of day regulates the reinforcing effects of cocaine. Additionally, melatonin and its MT1 and MT2 receptors have been found to participate in modulation of the reinforcing effects of such addictive drugs as cocaine. Loss of the diurnal variation in cocaine-induced locomotor sensitization and cocaine-induced place preference has been identified in pinealectomized mice. In addition, several studies in rodents have shown that administration of melatonin decreased the reinforcing effects of cocaine. The objective of this study was to evaluate the effect of melatonin on cocaine-induced locomotor activity in pinealectomized rats at different times of day (zeitgeber time [ZT]4, ZT10, ZT16, and ZT22). Methods: Naïve, pinealectomized Wistar rats received cocaine at different times of day. Melatonin was administered 30 min before cocaine; luzindole was administered 15 min prior to melatonin and 45 min before cocaine. After administration of each treatment, locomotor activity for each animal was recorded for a total of 30 min. Pinealectomy was confirmed at the end of the experiment through melatonin quantitation by ELISA. Results: Cocaine-induced locomotor activity varied according to the time of day. Continuous lighting and pinealectomy increased cocaine-induced locomotor activity. Melatonin administration decreased cocaine-induced locomotor activity in naïve and pinealectomized rats at different times of day. Luzindole blocked the melatonin-induced reduction in cocaine-induced locomotor activity in pinealectomized rats. Conclusion: Given its ability to mitigate various reinforcing effects of cocaine, melatonin could be a useful therapy for cocaine abuse.

Antiedematogenic activity of the indole derivative N-salicyloyltryptamine in animal models

ABSTRACT The N-salicyloyltryptamine (NST) is an indole derivative compound analogue to the alkaloid N-benzoyltryptamine. In the present study, the antiedematogenic activity of NST was investigated in animal models. Firstly, the acute toxicity for NST was assessed according to the OECD Guideline no. 423. The potential NST-induced antiedematogenic activity was evaluated by carrageenan-induced paw edema in rats, as well as by dextran-, compound 48/80-, histamine-, serotonin-, capsaicine-, and prostaglandin E2-induced paw edema in mice. The effect of NST on compound 48/80-induced ex vivo mast cell degranulation on mice mesenteric bed was investigated. No death or alteration of behavioral parameters was observed after administration of NST (2000 mg/kg, i.p.) during the observation time of 14 days. The NST (100 and 200 mg/kg, i.p.) inhibited the carrageenan-induced edema from the 1st to the 5th hour (**p<0.01; ***p<0.001). The edematogenic activity induced by dextran, compound 48/80, histamine, serotonin, capsaicin, and prostaglandin E2 was inhibited by NST (100 mg/kg, i.p.) throughout the observation period (**p<0.01; ***p<0.001). The pretreatment with NST (50, 100 or 200 mg/kg, i.p) attenuates the compound 48/80-induced mast cell degranulation (**p<0.01; ***p<0.001). Thus, the inhibition of both mast cell degranulation and release of endogenous mediators are probably involved in the NST-induced antiedematogenic effect.

Ação de metabólitos da via das triptaminas em linhagens de melanomas / Action of tryptamines pathway metabolites in melanoma strains

O triptofano (Trp) é essencial para muitos processos fisiológicos e seu metabolismo apresenta-se alterado em doenças como no câncer. O Trp é degradado por três vias: via das quinureninas; via serotonérgica e via das triptaminas. A primeira está envolvida com a tolerância e o imune escape de células tumorais, já a segunda leva a produção de serotonina e melatonina, com uma diversidade de funções biológicas e que possuem atividades antitumorais reconhecidas. A terceira rota é a menos estudada e a função dos compostos sintetizados ainda é desconhecida. Trabalhos do grupo mostram que a via das triptaminas é ativa em melanomas e que triptamina (TRY) e dimetiltriptamina (DMT), metabólitos produzidos por esta via, também possuem atividade antitumoral. Nosso objetivo é avançar sobre a compreensão de como esta via afeta o metabolismo e crescimento tumoral. Para tanto, estudamos mais detalhadamente a via em linhagens de melanoma. A adição de TRY e DMT nas culturas modificou a produção de compostos das outras rotas de metabolização do Trp. Além disso, TRY e DMT afetaram a invasividade das células tumorais e TRY aumentou a atividade citotóxica de células mononucleares frente a melanomas. Observamos que apesar dos efeitos biológicos da via das quinureninas estar amplamente relacionado a ligação dos metabólitos no receptor de aril hidrocarbonetos, para a via das triptaminas o receptor parece não estar associado com a atividade antitumoral descrita. Nossos resultados apontam para a importância da via das triptaminas na dinâmica tumoral e a necessidade de estudos mais amplos relacionados ao metabolismo do Trp

Tryptophan (Trp) is essential for many physiological processes and its metabolism is modified in several diseases such as in cancer. TRP is broken down into three pathways: kynurenine path, serotonergic path and tryptamine path. The first is involved in tolerance and immune escape of cancer cells, while the second leads to the production of serotonin and melatonin, which have a variety of biological functions and recognized antitumor activity. The third route is the least studied and the biological function of the synthesized compounds is still unknown. Our group shows that tryptamine path is active in melanomas and tryptamine (TRY) and dimethyltryptamine (DMT), metabolites produced by this route, also have antitumor activity. Our goal is make progress on understanding how tryptamine route affects metabolism and tumor growth. Therefore, we studied in detail this pathway in melanoma cell lines. The addition of TRY and DMT into the cultures leds the production of metabolites of other Trp routes. Moreover, TRY and DMT affect the invasiveness of tumor cells and TRY increased antitumor activity of the immune system against melanomas. We observed that despite biological effects of kynurenine path be largely related to metabolites binding aryl hydrocarbon receptor, for tryptamine pathway the receptor seems not to be associated with the described antitumor activity. Our results point the importance of tryptamine pathway in tumor dynamics and the need for broader studies related to Trp metabolism

Migraña: una visión global hacia el enfoque terapéutico en el servicio de urgencias / Migraine: an overview to the therapeutic approach in the emergency room

El manejo agudo de la migraña es un proceso desafiante en el servicio de Urgencias. Su tratamiento debe estar basado en la severidad de los síntomas que definen una aproximación farmacológica estratificada. En casos moderados a severos, los agentes de elección son los triptanes, agentes antimigrañosos específicos que proveen rápida mejoría del dolor y disminución de la discapacidad. Dicho tratamiento debe iniciarse en las etapas iniciales del dolor y antes de la instauración del fenómeno de alodinia cutánea para garantizar una respuesta óptima para dicho tratamiento.

Acute management of migraine is a challenging process in the emergency medical service. Its treatment should be based on symptom severity in order to define a stratified approach. In cases with moderate to severe symptoms the agents of choice are the triptans, specific antimigraine agents that provide swift relief of pain and improvement in the overall discapacity. Such treatment should be initiated in the early stages of pain and before the instauration of the cutaneous allodinia phenomenon in order to secure an optimal response to such treatment.

Anticonvulsant property of N-salicyloyltryptamine: evidence of enhance of central GABAergic neurotransmission / Propriedade anticonvulsivante de N-saliciloiltriptamina: proteção significativa com o sistema GABAérgico

AIM: In the present study we verified the anticonvulsant properties of the new tryptamine analogue, N-salicyloyltryptamine (NST), in rodents. METHODS AND RESULTS: In the evaluation of the anticonvulsant activity, NST protected the animals from the incidence of seizures induced by pentylenetetrazole (PTZ) and picrotoxin (PIC), in doses of 100 and 200 mg/kg. NST (100 and 200 mg/kg, i.p.) significantly eliminated the extensor reflex of maximal electric-induced seizure tests in 40 percent of the experimental animals. However, in the PTZ model FLU (10 mg/kg, i.p.), an antagonist of the benzodiazepine (BZD) site in the GABA A-BZD receptor complex, inhibited the prolongation of seizure latency induced by NST. CONCLUSION: Our results demonstrated an anticonvulsant activity of the new analogue that could be, at least in part, associated to the involvement of the GABAergic mechanism.

OBJETIVO: O presente estudo buscou avaliar o possível efeito anticonvulsivante do novo análogo da triptamina, N-saliciloiltriptamina (NST), em roedores. MÉTODOS E RESULTADOS: Na avaliação do efeito anticonvulsivante, os animais tratados com NST (100 e 200 mg/kg, i.p.) foram protegidos de maneira estatisticamente significativa (p<0,05) quanto a latência e incidência do aparecimento das convulsões induzidas pela administração do pentilenotetrazol (PTZ) e da picrotoxina (PIC). O efeito protetor do NST nas convulsões induzidas pelo PTZ foi revertido pela administração do flumazenil (10 mg/kg, i.p.), um antagonista dos receptores GABA-benzodiazepínicos (GABA A-BZD). A administração de NST (100 e 200 mg/kg, i.p.) protegeu de forma estatisticamente significativa (p < 0,05) os animais no teste das convulsões induzidas pelo eletrochoque-auricular em camundongos. CONCLUSÃO: Os resultados do presente estudo sugerem que o efeito anticonvulsivante de NST está associado, pelo menos em parte, ao sistema GABAérgico.

Migraine in the triptan era: progresses achieved, lessons learned and future developments / Migrânea na era dos triptanos: progressos alcançados, lições aprendidas e desenvolvimentos futuros

Triptans, serotonin 5-HT1B/1D receptor agonists, more than revolutionizing the treatment of migraine, stimulated also ground breaking research that provided insights into the anatomy, physiology, and molecular pharmacology of migraine. This knowledge, in turn, is stimulating research on new mechanisms of action for the treatment of migraine. Accordingly, it is opportune to critically review the main advances in migraine science that happened in the triptan era. Herein we first review and conceptualize some of the progresses achieved in migraine science during the triptan era. We then review the class of the triptans - mechanism of action and clinical evidence. We close by briefly discussing the class of CGRP receptor antagonists, which is currently being developed for the acute treatment of migraine.

Os triptanos, agonistas serotoninérgicos 5-HT1B/1D, revolucionaram o tratamento da migrânea promovendo pesquisas que evidenciaram aspectos da anatomia, fisiologia e farmacologia molecular deste tipo prevalente de cefaléia primária. Esse conhecimento, por sua vez vem estimulando ainda mais a descoberta de novos mecanismos de ação para drogas anti-migranosas. Assim, é oportuno rever de forma crítica, os maiores avanços na ciência das cefaléias ocorridos durante a era dos triptanos. Inicialmente reveremos e conceituaremos alguns dos progressos obtidos nesta fase seguido de uma revisão profunda dos mecanismos de ação e evidências clínicas para o uso desta classe de fármacos. Finalmente, discutiremos a nova classe dos antagonistas dos receptores do peptideo geneticamente relacionado à calcitonina (CGRP) atualmente em desenvolvimento.

Concentrações plasmáticas de triptamina, tiramina e feniletilamina em eqüinos sob efeitos de sobrecarga de carboidratos e antiinflamatórios não esteroidais / Plasmatic concentrations of tryptamine, tyramine end phenylethylamine in horses under the effect of carbohydrate overload and non-steroid antinflammatory compounds

As concentrações plasmáticas das aminas triptamina (TRP), tyramina (TYR) e pheniletilamina (PEA) foram determinadas por cromatografia gasosa (CG) de 20 eqüinos sob efeito de sobrecarga por carboidratos (SC). Após 36h da SC os animais foram aleatoriamente divididos em quatro grupos (n=5) e receberam a cada 12h por via iv: solução salina 10mL (GC), ketoprofeno 2,2mg/kg (GK), fenilbutazona 4,4mg/kg (GF) e flunixin meglumine 1,1mg/kg (GFM). As concentrações das aminas TYR e PEA variaram de 0,18 a 164,2mg/L, com diferenças nos tempos avaliados, mas não entre os tratamentos (p<0,01). A concentração plasmática de TRP apresentou diferenças entre os tempos e também entre os tratamentos. O GC diferiu dos demais nos momentos 48h e 60h e as concentrações nos grupos GK e GFM foram menores que nos grupos GF e GC às 72h (P= 0,0012). Conclui-se que nas doses utilizadas os antiinflamatórios não esteroidais avaliados não interferem nas concentrações de TYR e PEA. Entretanto, o ketoprofeno e o flunixin meglumine foram efetivos em diminuir a concentração plasmática de TRP.

The concentrations of the bioactives amines tryptamine (TRP), tyramine (TYR) and phenylethylamine (PEA) were determined by gas chromatography in plasma samples of 20 horses submitted to carbohydrate overload. Thirty hours after the overload, the horses were randomly distributed in four groups (n=5) and were submitted to four IV treatments every 12 hours: 10ml of saline (GC), ketoprofen 2.2mg/kg (GK), phenylbutazone 4.4mg/kg (GF), and flunixin meglumine 1.1mg/kg (GFM). Blood samples were collected at various times after the overload (0-72 h). Plasma TYR and PEA concentrations ranged from 0.18 to 164.2mg/L, and differed significantly with time (p<0.01), but did not differ in the treatments. Plasma concentrations of TRP differed between times and treatments. The GC was significantly major than other treatments at 48h and 60h after the overload, and the plasma concentration of TRP in groups GK and GFM was significantly lower than in groups GF and GC at 72 h (p=0.0012). We concluded that the anti-inflammatory drugs evaluated do not interfere in the plasma concentration of TYP and PEA. For TRP, ketoprofen and flunixin meglumine was effective to reduce de plasmatic concentration of this amine.

Influence of melatonin on the development of functional nicotinic acetylcholine receptors in cultured chick retinal cells

The influence of melatonin on the developmental pattern of functional nicotinic acetylcholine receptors was investigated in embryonic 8-day-old chick retinal cells in culture. The functional response to acetylcholine was measured in cultured retina cells by microphysiometry. The maximal functional response to acetylcholine increased 2.7 times between the 4th and 5th day in vitro (DIV4, DIV5), while the Bmax value for [125I]-alpha-bungarotoxin was reduced. Despite the presence of alpha8-like immunoreactivity at DIV4, functional responses mediated by alpha-bungarotoxin-sensitive nicotinic acetylcholine receptors were observed only at DIV5. Mecamylamine (100 µM) was essentially without effect at DIV4 and DIV5, while dihydro-ß-erythroidine (10-100 µM) blocked the response to acetylcholine (3.0 nM-2.0 µM) only at DIV4, with no effect at DIV5. Inhibition of melatonin receptors with the antagonist luzindole, or melatonin synthesis by stimulation of D4 dopamine receptors blocked the appearance of the alpha-bungarotoxin-sensitive response at DIV5. Therefore, alpha-bungarotoxin-sensitive receptors were expressed in retinal cells as early as at DIV4, but they reacted to acetylcholine only after DIV5. The development of an alpha-bungarotoxin-sensitive response is dependent on the production of melatonin by the retinal culture. Melatonin, which is produced in a tonic manner by this culture, and is a key hormone in the temporal organization of vertebrates, also potentiates responses mediated by alpha-bungarotoxin-sensitive receptors in rat vas deferens and cerebellum. This common pattern of action on different cell models that express alpha-bungarotoxin-sensitive receptors probably reflects a more general mechanism of regulation of these receptors.

Microorganisms as tools in modern chemistry: the biotransformation of 3-indolylacetonitrile and tryptamine by fungi

O uso de microrganismos para a realização de reações químicas tem sido explorado como uma ferramenta moderna em química. Neste trabalho explorou-se a habilidade dos fungos Beauveria bassiana e Aspergillus niger de modificarem quimicamente a estrutura de compostos indólicos, uma classe de substâncias com diversas atividades biológicas relatadas. A 3-indolacetonitrila foi reduzida, com formação do 3-metilindol por Beauveria bassiana, enquanto Aspergillus niger converteu a triptamina em um derivado oxidado, a 5-hidroxiindol-3-acetamida. A oxidação ocorreu somente no experimento sob agitação e provavelmente está relacionada ao alto grau de oxigenação da reação. A ocorrência de redução e oxidação de derivados indólicos ilustra bem a versatilidade do uso de microorganismos para a condução de uma grande variedade de reações químicas de interesse industrial.

Uma síntese alternativa para o (ñ)-1,2,3,4-tetraidro-{9H-pirido-[3, 4-b]}-indol / An alternative synthesis of 1,2,3,4-tetrahydro-9H-pyrido-{3, 4-b]-indole

O 1,2,3,4,-tetraidro-9H-pirido-[3,4-b]-indol, um composto com propriedades tranqüilizantes, foi preparado a partir do 3-indol-acetaldeido e triptamina através de uma reação de condensação de Pictet-Spengler. Os dados físicos e espectrais do composto são apresentados.

Triptanes mitos y realidades / Tryptates: facts and fancies

Los triptanes son medicamentos de reciente aparición, con una alta especificidad para los receptores de serotonina y una acción terapéutica probada y una alta eficacia. Se analizan las principales características farmacológicas y la indicación clínica de estos medicamentos en el manejo de la migraña, haciendo énfasis en las cualidades de cada uno de ellos y en la experiencia de los diferentes estudios clínicos. Se comentan sus efectos colaterales sus beneficios y desventajas. Se da una orientación basados en las características individuales de los triptanes y apoyada en la literatura reciente y se desaconseja el uso de los derivados del ergot por vía oral, comparando su eficacia a la del efecto placebo

Marcadores biologicos en Psiquiatria / Biological markers in Psychiatry

In order to determine wheter psycopathology is associated with charactheristic neurochemical changes of psychiatric patients, Noradrenergic; Dopaminergic and Serotoninergic urine compounds were quantified in 50 patients (32 females and 18 males) between 20 and 60 years old. They were classified in four groups, according to DSM-IV criteria; in MAJOR DEPRESSION (MD) 30 cases, OBSESSIVE COMPULSIVE DISEASE (OCD) 9 cases, BIPOLAR DEPRESSION (BD)4 cases and SCHIZOPHRENIA (SZ) 7 cases. The following Amine metabolites were determined in 24 hours urine samples Phenylethilamine (PEA); 3-Metho-4-Hidroxy Phenilglycol (MHPG); 5-Hidroxy-indol acetic acid (5HIAA) Homovanilic acid (HVM); Bufotenine (BU); Ometil Bufotenine (OMBU) and 3-5 Metoxy-NN-Dymethyltryptamine (MNNDMT). The results showed a dicrease of Pea levels in 43 per cent of DM; 33 per cent of OCD; 25 per cent of BP and 42 per cent SZ. MOPEG levels were disminished in 53 per cent of DM; 66 per cent of OCD; 25 per cent of BP and 85 per cent of SZ. There was an increase of HVM levels in 10 per cent of DM; 11 per cent of OCD and 25 per cent of BP. There was a dicrease of 5-HIAA levels in 10 per cent of DM while it was increased in 33 per cent and 14 per cent of SZ, BU, OMBU and NNDMT were positive in 71 per cent of SZ; 46 per cent of DM; 55 per cent of OCD and 50 per cent of BP. Our findings are consistent with the hypothesis that PEA; MHPG; 5-HIAA and HVM compounds could be "State markers"of DM and HVM of BP and SZ patients. There is further evidence to support a close interrelationship between the three systems and the urinary excretion of methylates compounds specially in SZ and in DM, OCD and BP patients.

Método rápido y sensible para detectar aminas primarias y secundarias no fenólicas en orina humana / A fast and sensitive method to detect primary and secondary non-phenolic amines in human urine

En este trabajo se desarrolló una metodología cromatográfica rápida y precisa para buscar aminas primarias y secundarias O-metiladas, típicas de ciertos desórdenes mentales, en muestras de orina humanas de 24 horas. La extracción de la orina fue llevada a cabo bajo condiciones alcalinas para evitar la interferencia de catecolaminas y ácidos urinarios. Después de la extracción alcalina, a cada muestra se la hizo reaccionar con cloruro de dansilo en acetonitrilo en presencia de bicarbonato de sodio en exceso, para formar las correspondientes dansilamidas. Las fenetilamidas y las indolalquilaminas O-metiladas fueron visualizadas en placas de fase reversa de alta resolución (HP-TLC), por cromatografía líquida de alta resolución (HPLC) y por cromatografía gas-líquido (CGL) y, además, fueron identificadas por cromatografía gas-líquido acoplada con espectrometría de masas (CGL-EM). Este método es lo suficientemente sensible para estos metabolitos en muestras de orina y, por lo tanto, resulta útil para investigaciones biomédicas y clínicas de aminas primarias y secundarias no fenólicas en orina

Propiedades farmacológicas in vitro de algunos extractos de Mimosa tenuiflora (tepescohuite) / In vitro pharmacological properties of some extracts of Mimosa tenuiflora (tepescohuite)

Se investigaron las propiedades de varios extractos de corteza de tepescohuite, Mimosa tenuiflora (Willd.) Poir. utilizando modelos biológicos in vitro, se observó que el extracto de acetato de etilo, cuyo contenido en taninos fue elevado, presentó actividad antimicrobiana; el extracto butanólico, rico en alcaloides, modificó de manera importante la excitabilidad de la musculatura lisa. Los extractos butanólico y metanólico produjeron hemólisis, posiblemente atribuible a su contenido en saponinas. Se discute la variedad de compuestos con propiedades biodinámicas que contiene este producto natural

Efecto producido por la fracción de alcaloides de Mimosa tenuiflora (tepescohuite) sobre el reflejo peristáltico del íleon de cobayo / The effect produced by the alkaloidal fraction of Mimosa tenuiflora (tepescohuite) upon the peristaltic reflex in quinea pig's ilium

De la corteza de tepescohuite, Mimosa tenuiflora (Willd.)Poir. Se obtuvo una fracción de alcaloides compuesta por una indolalquilamina acompañada de otras tres bases monoritarias. Se demuestra que esta fracción es la responsable del efecto inhibidor del reflejo peristáltico descrito en un trabajo anterior

Producción de aminas no volátiles por cepas de enterococos / Production of non-volatile amines by strains of enterococci

En años recientes ha surgido un marcado interés por los problemas relacionados con la presencia de aminas no volátiles en distintos tipos de quesos, en especial desde la puesta en evidencia de un "síndrome del queso". Dado que no ha sido aún totalmente aclarada la capacidad de los distintos grupos microbianos empleados en los procesos de caseificación para producir estas aminas, se estudió la capacidad de producción de tiramina, triptamina e histamina de cepas de enterococos de probable utilización para la elaboración de "startes". Se esayaron 41 epas de enterococos, cultivándolas en leche sola y en leche con el agregado de los aminoácidos precursores. La extracción y análisis cromatográfico para detectar la presencia de animas se llevaron a cabo según el método indicado por Colonna y col. Se determinó que sólo bajos porcentajes de cepas de Streptococcus faecalis subsp. liquefaciens y de Streptococcus durans (34 y 11%, respectivamente) produjeron trazas de tiramina y triptamina al desarrolar en leche sola. En cambio, cuando se cultivaron en presencia de los aminoácidos precursores, elevados porcentajes de cepas de todas las especies produjeron tiramina en altas concentraciones, y porcentajes variables de ellas produjeron triptamina en concentraciones no superiores a 200 ppm. Todas las cepas ensayadas resultaron incapaces de producir histamina, en las dos condiciones de cultivo estudiadas. Se puede concluir que existe una alta probabilidad de que los enterococos produzcan tiramina ...