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Objective:To observe the effect of peripheral 5-hydroxytryptophan (5-HT)-induced neutrophil extracellular trap (NET) on lung injury in septic mice.Methods:Wild-type (WT type) and Tph1 knockout (KO) C57 mice (6-8 weeks) were selected and divided into WT mice sham group, WT mice sepsis group, Tph1 KO mice sham group and Tph1 KO mice sepsis group according to the random number table method. Mice in the sham group received sham surgery (only open the abdominal cavity to flip the cecum without ligation and puncture, and then close the abdominal cavity); the mice in the sepsis group received cecal ligation and puncture (CLP) to establish sepsis model. The mice were sacrificed 12 hours after the operation, and the levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in bronchialalveolar lavage fluid (BALF) were detected by enzyme linked immunoadsordent assay (ELISA); at the same time, the lung tissues were collected, and the pathological changes of lung tissues were observed under light microscope, and the production of NET in lung tissues was observed by immunofluorescence microscope. Results:The pathological results suggested that the lung tissue structure in sham groups was intact without exudation, while the alveolar structures of mice in the sepsis groups were damaged, with obvious exudation in the alveolar cavity and thickened alveolar walls accompanied by a large number of inflammatory cell infiltration, and the degree of lung injury in the sepsis group of WT mice was more severe than that of the sepsis group of Tph1 KO mice. ELISA results showed that there was no statistically significant difference in the contents of TNF-α and IL-6 in mice BALF from different strains of the sham group; while the contents of TNF-α and IL-6 in BALF of septic mice group were significantly higher than those in sham group [WT mice: TNF-α (μg/L) was 158.20±28.46 vs. 14.00±3.28, IL-6 (μg/L) was 304.98±21.78 vs. 57.70±12.30; Tph1 KO mice: TNF-α (μg/L) was 85.88±20.13 vs. 14.95±1.53, IL-6 (μg/L) was 169.50±45.61 vs. 55.05±12.68, all P < 0.01], and the above index levels in the sepsis group of WT mice were significantly higher than the sepsis group of Tph1 KO mice [TNF-α (μg/L): 158.20±28.46 vs. 85.88±20.13, IL-6 (μg/L): 304.98±21.78 vs. 169.50±45.61, both P < 0.01]. Immunofluorescence staining showed that a very small amount of NET formation was detected in the mice lungs from the sham group; a large amount of NET formation was detected in the lung tissues in the sepsis group, which were significantly higher than those in sham group [WT mice: (34.75±7.27)% vs. (1.75±0.96)%, Tph1 KO mice: (14.25±5.74)% vs. (2.50±1.29)%, both P < 0.01], and the amount of NET produced in the lung tissues of the WT mice sepsis group was significantly higher than that of the Tph1 KO mice sepsis group [(34.75±7.27)% vs. (14.25±5.74)%, P < 0.01]. Conclusions:In sepsis, the increased production of inflammatory factors in the mice lung tissues induces to lung injury. The mechanism may relate to the increased production of NET in the lung tissues mediated by peripheral 5-HT synthesized by enterochromaffin cells and released into the blood; inhibiting the production of 5-HT in the peripheral blood can effectively reduce the production of NET in the lung tissues, thereby reducing lung injury.
ABSTRACT
ABSTRACT Objective 5-Hydroxytryptophan is the precursor compound of serotonin biosynthesis. The oral absorption of 5-Hydroxytryptophan is close to 100% and, unlike serotonin, it crosses the blood-brain barrier freely. 5-Hydroxytryptophan has been used as a food supplement for many years to treat anxiety and depression. Recent studies have shown that 5-Hydroxytryptophan suppresses the pro-inflammatory mediators and is effective in some inflammatory diseases, such as arthritis and allergic asthma. However, the role of 5-Hydroxytryptophan supplements on acute peripheral inflammation has not been investigated yet. In this study, the in vivo anti-inflammatory activity of 5-Hydroxytryptophan was evaluated with a carrageenan-induced paw oedema test in mice. Methods For the investigation of the acute antiinflammatory activity, single oral doses of 5-Hydroxytryptophan (1.5, 5 and 20mg/kg) were given to mice 1.5 hours prior to the carrageenan test. For chronic activity, the same oral doses were administered daily for two weeks prior to the carrageenan test on the 14th day. To induce inflammation, 0.01mL of 2% carrageenan was injected into the paws of mice. Results Supplementation with 5-Hydroxytryptophan significantly reduced inflammation in a dose-independent manner which was irrespective of the duration of exposure (per cent inhibition in acute experiments was 35.4%, 20.9%, 24.0%, and per cent inhibition in chronic experiments was 29.5%, 35.3%, 40.8% for the doses of 1.5, 5, and 20mg/kg, respectively). Conclusion Our findings demonstrate for the first time that 5-HTP supplements have the potential of suppressing the measures of acute peripheral inflammation. It is suggested that, apart from several diseases where serotonin is believed to play an important role, including depression, patients with inflammatory conditions may also benefit from 5-HTP.
RESUMO Objetivo O 5-hidroxitriptofano (5-HTP) é o composto precursor da biossíntese da serotonina. A absorção oral do 5-HTP é próxima a 100% e, ao contrário da serotonina, atravessa a barreira hematoencefálica livremente. O 5-HTP tem sido usado como suplemento alimentar por muitos anos na ansiedade e na depressão. Estudos recentes demonstraram que o 5-HTP suprime os mediadores pró-inflamatórios e é eficaz em algumas doenças inflamatórias, como artrite e asma alérgica. No entanto, o papel dos suplementos de 5-HTP na inflamação periférica aguda ainda não foi investigado. Neste estudo, a atividade anti-inflamatória in vivo do 5-HTP foi avaliada por meio do teste de edema de pata induzido por carragenina em ratos. Métodos Para a atividade aguda, doses orais únicas de 5 -HTP (1,5, 5 e 20 mg/kg) foram dados aos ratos 1,5 horas antes do teste da carragenina. Para a atividade crônica, as mesmas doses orais foram dadas cada dia durante duas semanas antes do teste da carragenina no 14º dia. 0,01ml da carragenina a 2% foi injetado nas patas dos ratos a fim de induzir a inflamação. Resultados A suplementação com 5-HTP reduziu significativamente a inflamação de uma maneira independente da dose, que foi independente da duração da exposição (por cento de inibição em experimentos agudos; 35,4%, 20,9%, 24,0% e por cento de inibição em experimentos crônicos; 29,5%, 35,3%, 40,8% para as doses de 1.5, 5 e 20 mg/kg respectivamente). Conclusão Nossas conclusões demonstram pela primeira vez que os suplementos de 5-HTP têm potencial para suprimir os sintomas de inflamação periférica aguda. É sugerido que, além de várias doenças em que se acredita que a serotonina tem uma função importante, incluindo a depressão, os pacientes com doenças inflamatórias também podem se beneficiar do 5-HTP.
Subject(s)
Animals , Male , Mice , Carrageenan , 5-Hydroxytryptophan/administration & dosage , Dietary Supplements , Edema/drug therapy , Anti-Inflammatory Agents/administration & dosageABSTRACT
Background: 4-propil-2H-benzo[h]-cromen-2-ona (FCS-304) is a semisynthetic coumarin with MAO-A inhibitory activity and positive results in forced swimming and tail suspension test in mice, but until now, it has not been studied in other screening antidepressant models in mice and rats. Objectives: The aim of this work was to assess the serotonin like effect of FCS-304 in the 5-hydroxytryptophan (5-HTP) test in mice, in the behavioral despair test in rats, and in the reserpine test in rats. Methods: Potentiation of 5-HTP (100 mg/kg, i.p.), induced head twitches were assessed in mice, previously treated with FCS-304 (50-75-150 mg/kg, p.o.). The behavioral despair test was performed in rats treated with FCS-304, recording the immobility time attained by the animals subjected to forced swimming. Antagonism of reserpine-induced ptosis was examined in rats, assessing the level of palpebral closure. Imipramine (30 mg/kg, p.o.) and vehicle (canola oil) served as positive and negative controls, respectively. Results: FCS-304 significantly potentiated 5-HTP induced head twitches in mice, in a dose dependent manner. In rats, FCS-304 significantly decreased the immobility time in the behavioral despair test and antagonized reserpine induced ptosis. Conclusions: These results add support to propose that FCS-304 could elicit antidepressant effects related to MAO-A inhibitory activity.
Antecedentes: 4-propil-2H-benzo[h]-cromen-2-ona (FCS-304) es una cumarina semisintética inhibidora de MAO-A con efectos positivos en las pruebas de nado forzado y suspensión por la cola en ratones, sin embargo, hasta ahora no se había estudiado en otros modelos de tamizado antidepresivo en ratones y ratas. Objetivos: el objetivo de este trabajo fue evaluar el efecto de tipo serotoninérgico de FCS-304 en la prueba de potenciación de 5-hidroxitriptofano (5-HTP) en ratones, y su respuesta en la prueba de desesperanza conductual en ratas y en la prueba de reserpina en ratas. Métodos: se evaluó la potenciación de las sacudidas de cabeza inducidas por 5-HTP (100 mg/kg, i.p.), en ratones tratados con FCS-304 (50-75-150 mg/Kg, v.o.). La prueba de desesperanza conductual se realizó en ratas tratadas con FCS-304, expuestas a nado forzado. El antagonismo de la ptosis palpebral inducida por reserpina se examinó en ratas determinando el grado de apertura ocular. Imipramina (30 mg/kg, v.o.) y el vehículo (aceite de canola, 0,1 mL/10 g), sirvieron como controles positivo y negativo, respectivamente. Resultados: FCS-304 incrementó significativamente el recuento de sacudidas de cabeza inducidas por 5-HTP en ratones, en función de la dosis. En ratas, FCS-304 fue efectiva para disminuir el tiempo de inmovilidad en la prueba de desesperanza inducida por nado forzado y el grado de ptosis palpebral inducido por reserpina. Conclusiones: estos resultados dan soporte para proponer que FCS-304 ejercería efectos de tipo antidepresivo relacionados con la inhibición de MAO-A.
Subject(s)
Humans , Rats , Serotonin Agents , 5-Hydroxytryptophan , Coumarins , Antidepressive AgentsABSTRACT
Specific temporal phase relation of neural oscillations appears to be the regulator of gonadal development in many seasonally breeding species. To find out the specific phase angle of two neural oscillations that triggers gonado-inhibitory or gonado-stimulatory response, and to test the internal coincidence model, sexually immature male Japanese quail were administered with the serotonin precursor, 5-hydroxytryptophan and the dopamine precursor, L-dihydroxyphenylalanine at hourly intervals of 6, 7, 8, 9, 10, 11 and 12 h (5 mg/100 g body weight/day for 12 days under continuous condition of light, LL). Thereafter all the groups were shifted to long photoperiod (LD16:8). During post-treatment period, in general, a significant suppression of gonadal activity was seen in the 7 h and 8 h quail and an increase in the 11 h and 12 h quail compared to the control and these effects were maintained until 105 days post treatment when the study was terminated. These findings suggest that, in addition to the effects of photoperiod, the gonadal development of Japanese quail may be also modulated by internal coincidence of serotonergic and dopaminergic oscillations (induced by the administration of their precursor drugs) and the gonadal response varies depending on the time interval between the administrations of two drugs on a circadian basis. These results also demonstrate inversion of gonadal response from 7/8 h (suppressive) to 11/12 h (stimulatory) phase relation of the two oscillations and suggest that similar to photoperiodic time measurement, Japanese quail may also detect changes in the phase angle of circadian oscillations to modulate its gonadal activity.
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Objective: To research the adsortpion and separation function of ion-exchange resin on 5-hydroxytryptophan (5-HTP) in extract from the seeds of Griffonia simplicifolia and to screen the ion-exchange resin with high selective adsorption. Methods: The static adsorptive properties of eight different types of ion-exchange resins were evaluated using adsorptive content, desorption rate, adsorption rate, and adsorption temperature as indexes in order to optimize the resin. And the effects of different pH values, injection rates, injection concentration, eluent concentration, and elution rates on adsorptive properties of resins were investigated. Results: The 001 × 7 cation exchange resin showed the best comprehensive adsorption property. The loading solution concentration was 10.8 mg/mL, the pH value was 3.5, the flow rate of loading solution was 4.0 mL/min, and 3BV 7.0% ammonia water solution in 3.0 mL/min velocity was used to elute. In this process, the product was obtained with the 5-HTP purity of greater than 99.0% and the ash content of less than 1.0%, product average yield was 7.95% and the product quality could meet the market demand. Conclusion: The 001 × 7 cation exchange resin shows a better comprehensive adsorption property. It could be used to isolate and purify the 5-HTP for scale production.
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The purpose of this study was to explore the role of L-5-hydroxytryptophan (L-HTP) and its relationship with the renin-angiotensin system (RAS) on the drinking behavior in Japanese quails. Normally-hydrated quails that received injections of L-HTP (12.5; 25 and 50 mg.kg-1) by the intracoelomic route (ic) expressed an increase in water intake, which was inhibited by captopril, an angiotensin converting enzyme (ACE) inhibitor. In addition, captopril also induced such a response in birds under previous fluid deprivation. High doses of captopril (35-70 mg.kg-1, sc) in normally-hydrated quails decreased the spontaneous water intake while low doses of captopril (2-5 mg.kg-1, sc) did not prompt water intake after L-HTP administration. Losartan, an AT1 receptor antagonist in mammals, did not change the water intake levels in normally-hydrated or water-deprivated birds. Serotonin (5-HT) injections did not provoke its known dipsogenic response.
O objetivo deste estudo foi investigar a influência do L-5-hidroxitriptofano (L-HTP) e sua relação com o sistema renina-angiotensina (SRA) no comportamento dipsogênico de codornas. Codornas normohidratadas que receberam L-HTP em diferentes doses (12,5; 25 e 50 mg.kg-1) por via intracelomática (ic) expressaram um aumento na ingestão de água, o qual foi suprimido pela administração prévia de captopril (inibidor da ECA-enzima conversora de angiotensina). Esta ação inibitória do captopril, em menor intensidade, foi também evidenciada em aves previamente submetidas ao jejum hídrico. O tratamento isolado com captopril (35-70 mg.kg-1) reduziu consideravelmente a ingestão espontânea de água em codornas normohidratadas, enquanto baixas doses (2-5 mg.kg-1) não provocaram aumento na ingestão de água induzida pelo L-HTP. Losartan, um antagonista de receptores AT1 em mamíferos, não foi capaz de modificar os níveis de ingestão hídrica, tanto em aves normohidratadas quanto em aves privadas de água. Serotonina aplicada perifericamente não promoveu a conhecida resposta dipsogênica de mamíferos.
Subject(s)
Animals , Male , /pharmacology , Coturnix/physiology , Drinking Behavior/drug effects , Renin-Angiotensin System/drug effects , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Captopril/pharmacology , Drinking Behavior/physiology , Renin-Angiotensin System/physiology , Time FactorsABSTRACT
This study aimed to demonstrate the influence of the systemic administration of l-5-hydroxy-tryptophan (L-HTP) on the plasma levels of melatonin during the dark period in quails. Throughout daylight, the plasma levels of melatonin did not differ significantly, oscillating between 110.2 ± 15.8 pg.mL-1 and 157.4 ± 34.8 pg.mL-1, from 8 to 16 hours. L-HTP (25 mg.kg-1, through the intracelomic route) administered at 18 hours lessened significantly the nocturnal increase of the plasma levels of melatonin (controls, 327.3 ± 20.1 and 315.8 ± 20.9 pg.mL-1 vs. 242.1 ± 24.8 and 217.5 ± 21 pg.mL-1, respectively, at 20 and 24 hours, P < 0.05). The results obtained showed that the administration of LHTP reduced the nocturnal melatonin release, possibly by bringing about an increase in serotonin synthesis and synaptic release in the pineal. Therefore, the serotoninergic transmission from the raphe towards the pineal would constitute a mechanism of modulation of the synthesis and melatonin release in quails.
Este trabalho objetivou demonstrar a influência da administração sistêmica de l-5-hidroxi-triptofano (L-HTP) sobre os níveis plasmáticos de melatonina durante o período noturno em codornas. Ao longo do período claro, os níveis plasmáticos de melatonina não diferiram significativamente, oscilando entre 110,2 ± 15,8 pg.mL-1 e 157,4 ± 34,8 pg.mL-1, de 8 às 16 horas. L-HTP (25 mg.kg-1, via intracelomática), administrado às 18 horas atenuou significativamente a elevação noturna dos níveis plasmáticos de melatonina (controles, 327,3 ± 20,1 e 315,8 ± 20,9 pg.mL-1 vs. 242,1 ± 24,8 e 217,5 ± 21 pg.mL-1, respectivamente, às 20 e 24 horas, P < 0,05). Os resultados obtidos mostraram que a administração de L-HTP reduziu a liberação noturna de melatonina, possivelmente por suscitar um aumento da síntese e liberação sináptica de serotonina na pineal. Portanto, a transmissão serotoninérgica da rafe para a pineal constituiria um mecanismo de modulação da síntese e/ou liberação de melatonina em codornas.