RESUMEN
Lysergic acid diethylamide (LSD) and two phenethylamine classes (NBOHs and NBOMes) are the main illicit drugs found in seized blotter papers. The preliminary identification of these substances is of great interest for forensic analysis. In this context, this work constitutes the inaugural demonstration of an efficient methodology for the selective detection of LSD, NBOHs, and NBOMes, utilizing a fully 3D-printed electrochemical double cell (3D-EDC). This novel 3D-EDC enables the use of two working electrodes and/or two supporting electrolytes (at different pHs) in the same detection system, with the possibility of shared or individual auxiliary and pseudo-reference electrodes. Thus, the selective voltammetric detection of these substances is proposed using two elegant strategies: (i) utilizing the same 3D-EDC platform with two working electrodes (boron-doped diamond (BDD) and 3D-printed graphite), and (ii) employing two pH levels (4.0 and 12.0) with 3D-printed graphite electrode. This comprehensive framework facilitates a fast, robust, and uncomplicated electrochemical analysis. Moreover, this configuration enables a rapid and sensitive detection of LSD, NBOHs, and NBOMes in seized samples, and can also provide quantitative analysis. The proposed method showed good stability of the electrochemical response with RSD <9 % for Ip and <5 % for Ep, evaluating all oxidation processes observed for studied analytes (n = 7) at two pH levels, using the same and different (n = 3) working electrodes. It demonstrates a broad linear range (20-100 and 20-70 µmol L-1) and a low LOD (1.0 µmol L-1) for quantification of a model molecule (LSD) at the two pHs studied. Hence, the 3D-EDC combined with voltammetric techniques using BDD and 3D-printed graphite electrodes on the same platform, or only with this last sensor at two pH values, provide a practical and robust avenue for preliminary identification of NBOHs, NBOMes, and LSD. This method embodies ease, swiftness, cost-efficiency, robustness, and selectivity as an on-site screening tool for forensic analysis.
Asunto(s)
Técnicas Electroquímicas , Electrodos , Dietilamida del Ácido Lisérgico , Impresión Tridimensional , Dietilamida del Ácido Lisérgico/análogos & derivados , Dietilamida del Ácido Lisérgico/química , Dietilamida del Ácido Lisérgico/análisis , Técnicas Electroquímicas/métodos , Fenetilaminas/análisis , Drogas Ilícitas/análisis , Humanos , Límite de Detección , Grafito/químicaRESUMEN
An ultrafast, efficient, and eco-friendly method combining magnetic solid phase extraction and capillary electrophoresis with diode array detection have been developed to determine ractopamine residues in food samples. A restricted access material based on magnetic and mesoporous molecularly imprinted polymer has been properly synthesized and characterized, demonstrating excellent selectivity and high adsorbent capacity. Short-end injection capillary electrophoresis method was optimized: 75 mM triethylamine pH 7 as BGE, -20 kV, 50 mbar by hydrodynamic injection during 8 s, and capillary temperature at 25 °C; reaching ultrafast ractopamine analysis (â¼0.6 min) with good peak asymmetry, and free from interfering and/or baseline noise. After sample preparation optimization, the conditions were: 1000 µL of sample at pH 6, 20 mg of adsorbent, stirring time of 120 s, 250 µL of ultrapure water as washing solvent, 1000 µL of methanol: acetic acid (7: 3, v/v) as eluent, and the adsorbent can be reused four times. In these conditions, the analytical method showed recoveries around to 100 %, linearity ranged from 9.74 to 974.0 µg kg-1, correlation coefficient (r) ≥ 0,99 in addition to adequate precision, accuracy, and robustness. After proper validation, the method was successfully applied in the analysis ractopamine residues in bovine milk and bovine and porcine muscle.
Asunto(s)
Impresión Molecular , Polímeros Impresos Molecularmente , Fenetilaminas , Animales , Porcinos , Extracción en Fase Sólida/métodos , Electroforesis Capilar/métodos , Fenómenos Magnéticos , Impresión Molecular/métodos , Cromatografía Líquida de Alta Presión/métodosRESUMEN
The introduction of arylmethyl substituents on the amine nitrogen atom of phenethylamines and tryptamines often results in profound increases in their affinity and functional activity at 5-HT2 serotonin receptors. To probe the sensitivity of this effect to substantially larger N-substituents, ten derivatives of the well-characterized psychedelic phenethylamine 2C-B were prepared by appending different dibenzo[b,d]furylmethyl (DBFM) moieties to the basic nitrogen. The DBFM group attached to the amino group through its 1-, -2-, or 3-position decreased affinity and agonist activity at the 5-HT2A/2C receptors. Substitution through the 4-position usually favored affinity for all three 5-HT2 receptor subtypes with compound 5 exhibiting 10- and 40-fold higher affinities at the 5-HT2A and 5-HT2C receptors, respectively, but less than fourfold selectivity among the three receptor subtypes. Nevertheless, all were relatively weak partial 5-HT2AR agonists, mostly in the low micromolar range, but full or nearly full agonists at the 5-HT2C subtype as determined in a calcium mobilization assay. Molecular docking simulations suggested that the dibenzofuryl portion dives more deeply into the orthosteric binding site of the 5-HT2A than the 5-HT2C receptor, interacting with the Trp3366.48 toggle switch associated with its activation, while the phenylamine moiety lies close to the extracellular side of the receptor. In conclusion, a very bulky N-substituent on a phenethylamine 5-HT2 receptor agonist is tolerated and may increase affinity if its orientation is appropriate. However, the Gq protein-mediated potencies are generally low, with low efficacy (relative to 5-HT) at the 5-HT2A receptor, somewhat higher efficacy at the 5-HT2B subtype, and full or nearly full efficacy at the 5-HT2C subtype.
Asunto(s)
Alucinógenos , Serotonina , Agonistas del Receptor de Serotonina 5-HT2 , Receptor de Serotonina 5-HT2A , Simulación del Acoplamiento Molecular , Fenetilaminas , Nitrógeno , Receptor de Serotonina 5-HT2CRESUMEN
Ring-substituted phenethylamines are believed to induce psychedelic effects primarily by interacting with 5-hydroxytryptamine 2 (5-HT2A) receptors in the brain. We assessed the effect of the psychedelic substances 25H-NBOMe and 25H-NBOH on the depressive-like behavior of male adult rats. Naive Wistar rats were divided into groups to assess the effects of different doses (0.1 mg/kg, 1 mg/kg, and 3 mg/kg) of 25H-NBOMe and 25H-NBOH. The substances were administered intraperitoneally and the hallucinogenic properties were evaluated using the head twitch response test (HTR). Additionally, we assessed their locomotor activity in the open field test (OFT) and depressive-like behavior in the forced swimming test (FST). Our data demonstrated that all doses of synthetic psychedelic substances evaluated exhibited hallucinogenic effects. Interestingly, we observed that both 25H-NBOMe and 25H-NBOH produced a significantly greater motivation to escape in the FST, compared to the control group. Furthermore, we found no significant differences in locomotor activity during the OFT, except for the dose of 3 mg/kg, which induced a reduction in locomotion. This study provides new insights into a potential psychedelic substance, specifically by demonstrating the previously unknown antidepressant properties of a single dose of both 25H-NBOMe and 25H-NBOH. These findings contribute to the ongoing progress of experimental psychiatry toward developing safe and effective clinical practices in the field of psychedelics research.
Asunto(s)
Alucinógenos , Ratas , Masculino , Animales , Alucinógenos/farmacología , Ratas Wistar , Antidepresivos/farmacología , Fenetilaminas/farmacología , NataciónRESUMEN
The influence of under-fermented (UF) cocoa (0 to 65 %) on bioactive amines in chocolate and their in vitro bioaccessibility was investigated. The same amines were found in all treatments; however, treatments were divided into two groups regarding total amines [0 & 20 % UF (34 mg/kg) and 35 to 65 % UF (17 mg/kg)] and phenolic levels [lower and higher, respectively]. Serotonin, tyramine, putrescine, cadaverine, agmatine and phenylethylamine were higher in chocolate with ≤ 20 % UF cocoa. Histamine and spermidine were not affected. Digestibility studies indicated that low levels of amines were present in the oral phase. Gastric digestion was effective in releasing tyramine, spermidine and phenylethylamine from conjugates. Serotonin and agmatine were not detected after in vitro digestion of chocolate with ≥ 35 % UF cocoa. Histamine was released during in vitro intestinal digestion. By adding different proportions of UF cocoa during chocolate production, the levels and bioaccessibility of amines can be modulated.
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Agmatina , Cacao , Chocolate , Espermidina , Histamina , Serotonina , Tiramina , Fenetilaminas , Fermentación , Aminas BiogénicasRESUMEN
PURPOSE: This study aimed to validate a modified QuEChERS method followed by ultra-high performance liquid chromatography-tandem mass spectrometry to determine 79 new psychoactive substances (NPS) and other drugs in blood and urine. METHODS: Prescription drugs (n = 23), synthetic cathinones (n = 13), phenethylamines (n = 11); synthetic cannabinoids (n = 8), amphetamines (n = 7) and other psychoactive substances (n = 17) were included in the method. 500 µL of biological fluid was extracted with 2 mL of water/ACN (1:1), 500 mg of anhydrous MgSO4/NaOAc (4:1) added, followed by a supernatant cleanup with 25 mg of primary secondary amine and 75 mg of anhydrous MgSO4. Quantification was done using matrix-matched calibration curves and deuterated internal standards. RESULTS: The method was satisfactorily validated for blood and urine at limit of quantifications ranging from 0.4 to 16 ng/mL, and applied to the analysis of 54 blood (38 postmortem and 16 antemortem) and 16 antemortem urine samples from 68 forensic cases. All urine samples and 59.3% of the blood samples were positive for at least one analyte. Twenty-two analytes were detected in at least one biological sample, including the synthetic cathinones ethylone (222 ng/mL, antemortem blood), eutylone (246 and 446 ng/mL, urine), and N-ethylpentylone (597 and 7.3 ng/mL, postmortem and antemortem blood, respectively). CONCLUSIONS: The validated method was shown to be suitable for the analysis of blood and urine forensic samples and an important tool to collect information on emerging drug threats and understanding the impact of NPS and other drugs in poisoning cases.
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Líquidos Corporales , Espectrometría de Masas en Tándem , Cromatografía Líquida de Alta Presión , Medicina Legal , Fármacos del Sistema Nervioso Central , FenetilaminasRESUMEN
The objective of this study was to evaluate the effects of ractopamine and betaine, supplemented alone or in combination, on live performance, carcass and meat quality traits, and gene expression (in both skeletal muscle and subcutaneous adipose tissue) of finishing pigs. Seventy-two pigs averaging 89.0 ± 3.44 kg were assigned to a control diet (CTRL-without ractopamine and betaine); CTRL+20 mg/kg ractopamine (RAC); CTRL+2.5 g/kg betaine (BET); or RAC + 2.5 g/kg betaine (RAC + BET). Pigs fed RAC and RAC + BET had greater average daily gain and carcass yield compared to CTRL. Pigs fed RAC, BET, and RAC + BET had greater loin muscle area, while backfat thickness was lower in pigs fed RAC + BET compared to CTRL. Pork from BET had lower shear-force and greater intramuscular fat content compared to CTRL. Regarding adipose tissue, RAC and BET increased expression of genes related to lipolysis and ß-oxidation. These data indicate that performance and carcass traits of pigs can be improved with ractopamine, whereas betaine (when fed independently from ractopamine) increased the loin muscle area and pork quality.
Asunto(s)
Betaína , Composición Corporal , Agonistas Adrenérgicos beta/farmacología , Alimentación Animal/análisis , Animales , Dieta/veterinaria , Expresión Génica , Carne , Músculo Esquelético , Fenetilaminas/farmacología , Porcinos/genéticaRESUMEN
Ketamine enhances the resilience against stress-induced depressive-like behavior, but its prophylactic efficacy in anxiety-related behaviors remains to be elucidated. Moreover, there is a need for developing novel preventive strategies against depressive- and anxiety-like behavior. AZD6765, a low-trapping NMDA receptor antagonist, shares with ketamine common molecular targets and produces rapid-onset antidepressant effects, suggesting that it could be a prophylactic agent. Therefore, this study investigated the prophylactic effect of ketamine against the depressive- and anxiety-like behavior induced by chronic restraint stress (2â¯h/day, for 10â¯days) in mice. We also investigated if AZD6765 exerts a resilience-enhancing response against these maladaptive behaviors. The contribution of 4E-BP1-related synaptic proteins synthesis (PSD-95/GluA1) in the possible pro-resilience efficacy of ketamine and AZD6765 was investigated. A single administration of ketamine (5â¯mg/kg, i.p.), but not AZD6765 (1 or 5â¯mg/kg, i.p.), given 1â¯week before the stress protocol, was effective in preventing stress-induced depressive-like behavior in the tail suspension test and splash test. Ketamine administered at 1 and 5â¯mg/kg (i.p.), but not AZD6765 (1 or 5â¯mg/kg, i.p.), prevented stress-induced anxiety-related self-grooming alterations. Stress-induced reduction on 4E-BP1 phosphorylation and PSD-95 and GluA1 immunocontent in the prefrontal cortex was prevented by ketamine (5â¯mg/kg, i.p.), but not AZD6765 (1 or 5â¯mg/kg, i.p.). The results indicate that ketamine, but not AZD6765, exerts a pro-resilience response against stress-induced maladaptive behavior, reinforcing that it could be a prophylactic agent to manage individuals at-risk to develop MDD and anxiety.
Asunto(s)
Analgésicos/farmacología , Antidepresivos/farmacología , Ketamina/farmacología , Fenetilaminas/farmacología , Piridinas/farmacología , Restricción Física , Proteínas Adaptadoras Transductoras de Señales , Animales , Ansiedad , Conducta Animal , Proteínas de Ciclo Celular , Depresión , Suspensión Trasera , Masculino , Ratones , Corteza Prefrontal/efectos de los fármacos , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Restricción Física/psicologíaRESUMEN
BACKGROUND: Estrogens that are used as contraceptives or in replacement therapy are associated with an increase in the risk for developing thrombosis, mainly during the first year of treatment and in women with associated risk factors. OBJECTIVE: To synthesize, characterize and identify the anticoagulant, antiplatelet aggregation and microvesicle-reducing effect of the new aminoestrogen Tyrame. MATERIAL AND METHODS: CD1 strain mice were used, which had Tyrame (0, 1 and 2 mg/100 g) subcutaneously administered. At 24 h, a blood sample was obtained to determine whole-blood clotting time, microvesicles concentration and inhibitory effect on platelet aggregation. RESULTS: Blood clotting time increased up to 1.5 times in comparison with the control. Platelet aggregation inhibition had different magnitude depending on the agonist agent employed, and was complete with collagen. Both effects had a dose-dependent relationship. The microvesicles decreased up to six times with respect to the control. CONCLUSIONS: Tyrame reduces platelet aggregation and microvesicle formation, which emphasizes its potential therapeutic utility as an estrogen free of thrombotic effects.
ANTECEDENTES: Los estrógenos empleados como anticonceptivos o en la terapia de sustitución se asocian a un incremento en el riesgo de desarrollar trombosis, principalmente durante el primer año de tratamiento y en mujeres con factores de riesgo asociados. OBJETIVO: Sintetizar, caracterizar e identificar el efecto anticoagulante, antiagregante plaquetario y reductor de las microvesículas del nuevo aminoestrógeno tyrame. MATERIAL Y MÉTODOS: Se emplearon ratones cepa CD1 a los que se les administró por vía subcutánea tyrame (0, 1 y 2 mg/100 g). A las 24 h se tomó una muestra de sangre para determinar el tiempo de coagulación en sangre total, la concentración de microvesículas y el efecto inhibidor de la agregación plaquetaria. RESULTADOS: El tiempo de coagulación en sangre se incrementó hasta 1.5 veces con respecto al control. La inhibición de la agregación plaquetaria tuvo diferente magnitud dependiendo del agente agonista, siendo completa con colágena. Ambos efectos siguieron una relación dependiente de la dosis. Las microvesículas disminuyeron hasta seis veces con respecto al control. CONCLUSIONES: el tyrame disminuye la agregación plaquetaria y la formación de microvesículas, lo que acentúa su posible utilidad terapéutica como un estrógeno sin efectos trombóticos.
Asunto(s)
Fibrinolíticos , Trombosis , Animales , Anticoagulantes , Fibrinolíticos/farmacología , Ratones , Fenetilaminas/farmacología , Agregación PlaquetariaRESUMEN
Estrogenic steroids and adenosine A2A receptors promote the wound healing and angiogenesis processes. However, so far, it is unclear whether estrogen may regulate the expression and pro-angiogenic activity of A2A receptors. Using in vivo analyses, we showed that female wild type (WT) mice have a more rapid wound healing process than female or male A2A-deficient mice (A2AKO) mice. We also found that pulmonary endothelial cells (mPEC) isolated from female WT mice showed higher expression of A2A receptor than mPEC from male WT mice. mPEC from female WT mice were more sensitive to A2A-mediated pro-angiogenic response, suggesting an ER and A2A crosstalk, which was confirmed using cells isolated from A2AKO. In those female cells, 17ß-estradiol potentiated A2A-mediated cell proliferation, an effect that was inhibited by selective antagonists of estrogen receptors (ER), ERα, and ERß. Therefore, estrogen regulates the expression and/or pro-angiogenic activity of A2A adenosine receptors, likely involving activation of ERα and ERß receptors. Sexual dimorphism in wound healing observed in the A2AKO mice process reinforces the functional crosstalk between ER and A2A receptors.
Asunto(s)
Estradiol/farmacología , Receptor alfa de Estrógeno/genética , Receptor beta de Estrógeno/genética , Neovascularización Fisiológica/efectos de los fármacos , Receptor de Adenosina A2A/genética , Heridas Penetrantes/genética , Adenosina/análogos & derivados , Adenosina/farmacología , Animales , Proliferación Celular/efectos de los fármacos , Células Endoteliales/citología , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Receptor alfa de Estrógeno/antagonistas & inhibidores , Receptor alfa de Estrógeno/metabolismo , Receptor beta de Estrógeno/antagonistas & inhibidores , Receptor beta de Estrógeno/metabolismo , Femenino , Regulación de la Expresión Génica , Pulmón/citología , Pulmón/metabolismo , Masculino , Ratones , Ratones Noqueados , Neovascularización Fisiológica/genética , Fenetilaminas/farmacología , Pirazoles/farmacología , Pirimidinas/farmacología , Receptor Cross-Talk , Receptor de Adenosina A2A/metabolismo , Factores Sexuales , Transducción de Señal , Cicatrización de Heridas/efectos de los fármacos , Cicatrización de Heridas/genética , Heridas Penetrantes/tratamiento farmacológico , Heridas Penetrantes/metabolismo , Heridas Penetrantes/patologíaRESUMEN
Different veterinary drugs have been widely found in surface and groundwater, affecting non-target organisms. Ractopamine (RAC) is one of these drugs found in water bodies. It is a ß-adrenergic agonist used as a feed additive to modulate the metabolism, redirect nutrients from the adipose tissue towards muscles, and increase protein synthesis in swine, cattle, and turkeys. RAC shows toxicological potential, but there is no data about its impacts on the development of non-target organisms, such as zebrafish (Danio rerio). In this study, we evaluated the effect of the exposure to this feed additive on critical parameters (hatching, survival, spontaneous movement, heart rate, and exploratory and locomotor behavior) in zebrafish embryos and larvae. The animals were exposed to RAC hydrochloride at 0.1, 0.2, 0.85, 8.5, and 85 µg/L. Zebrafish exposed to the drug showed increased heart rate at all tested concentrations and alterations on locomotion and exploratory behavior at 85 µg/L. No changes were observed in the survival, hatching rate and spontaneous movement. Our results suggest that RAC present in the environment can induce disabling effects on non-target organisms and elicit an ecological imbalance by increasing the animals' vulnerability to predation due to greater visibility.
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Contaminantes Químicos del Agua , Pez Cebra , Animales , Bovinos , Embrión no Mamífero , Frecuencia Cardíaca , Larva , Fenetilaminas , PorcinosRESUMEN
The use of additives such as ractopamine (Rac) in pregnant sows during early-mid pregnancy is an alternative to increase foetal and progeny growth and development. However, Rac supplementation in finishing pigs can lead to behavioural and physiological changes similar to the typical stress responses. The objective of this study was to evaluate the effects of dietary supplementation with Rac in pregnant sows from day 25 to 50 of gestation (pre-hyperplastic stage) on piglet's vitality, blood parameters, number, diameter and perimeter of muscle fibres in semitendinosus muscle and developmental characteristics of piglets at birth to weaning. Forty-one hybrid sows were divided into three dietary treatments: (1) control diet without Rac (control), (2) addition of 10 mg/kg of Rac (Rac10) and (3) addition of 20 mg/kg of Rac (Rac20). Higher numbers of low-vitality piglets (P<0.05) were observed in Rac-fed sows, regardless of dose, compared with the control group. Very low-density lipoprotein levels were lower in the Rac10 group when compared with the Rac20 group at day 21. Haematocrit was greater, and the mean corpuscular haemoglobin concentration was lower in piglets from Rac-fed sows. No significant statistical differences were detected regarding piglets body weight, average daily gain, blood gasometry, complete blood count and muscle fibre measurements in semitendinosus muscle. The use of Rac in pregnant sows reduced the vitality parameters of piglets but did not improve the performance from birth until weaning and did not negatively influence the haematological parameter and lipid metabolism.
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Fenetilaminas/metabolismo , Sus scrofa/fisiología , Alimentación Animal/análisis , Animales , Animales Recién Nacidos/sangre , Animales Recién Nacidos/fisiología , Dieta/veterinaria , Suplementos Dietéticos/análisis , Femenino , Fenetilaminas/administración & dosificación , Embarazo , Sus scrofa/sangreRESUMEN
The dietary inclusion of feed additives to improve the carcass characteristics of the final product is of great importance for the pork production chain. The aim of our study was to evaluate the effects of the association of ractopamine (RAC) and conjugated linoleic acid (CLA) on the performance traits of finishing pigs during the last 26 days prior to slaughter. In total, 810 commercial hybrid barrows were used. Animals were distributed among treatments according to a randomised block design in a 3 × 3 factorial arrangement, with three RAC levels (0, 5 or 10 ppm) and three CLA levels (0, 0.3 or 0.6%). Pigs fed the diet with 5 ppm RAC had higher average daily feed intake (ADFI) (2.83 kg; P < 0.05) when compared with those fed 10 ppm RAC and the control diet (2.75 and 2.74 kg, respectively). Lower ADFI values (P < 0.01) were observed with the diets containing CLA compared with the control diet with no CLA (2.73 and 2.75 v. 2.85 kg/day, respectively). The average daily weight gain of pigs fed 5 and 10 ppm RAC was +148 and +173 g/dayhigher (P < 0.001), respectively, than those fed the control diet. Dietary RAC levels influenced (P < 0.001) feed conversion ratio (FCR), which was reduced as RAC levels increased, with the pigs fed 10, 5 and 0 ppm RAC presenting FCR values of 2.57, 2.71 and 3.05, respectively. FCR also improved (P < 0.05) with the inclusion of 0.6% CLA relative to the control diet (2.70 v. 2.84, respectively). There was a significant interaction between CLA × RAC levels (P < 0.01) for final BW, loin eye area (LEA) (P < 0.05) and backfat thickness (BT) (P < 0.05). The treatments containing 10 ppm RAC + 0.6% or 0.3% CLA increased LEA and reduced BT. In conclusion, the level of 10 ppm inclusion of RAC increased the overall performance parameters of pigs and therefore improved production efficiency. The combined use of RAC and CLA promoted a lower feed conversion ratio as well as better quantitative carcass traits, as demonstrated by the higher LEA and lower BT. The dietary inclusion of CLA at 0.3% improved feed efficiency, however, without affecting LEA or BT yields.
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Suplementos Dietéticos/análisis , Ácidos Linoleicos Conjugados/farmacología , Fenetilaminas/farmacología , Carne Roja/normas , Porcinos/fisiología , Alimentación Animal/análisis , Animales , Composición Corporal/efectos de los fármacos , Dieta/veterinaria , Masculino , Porcinos/crecimiento & desarrollo , Aumento de Peso/efectos de los fármacosRESUMEN
Previous studies found that calcium sensing receptor (CaSR) it's expressed in intercalated cells of the collecting duct and that its activation by calcium in the luminal membrane promotes acidification of urine. Therefore, the aim of the study was to analyze the effects of CaSR stimulus on the biochemical activity of the vacuolar H+-ATPase in a cellular model of intercalated cells, MDCK-C11 cells. Biochemical activity of H+-ATPase was performed using cell homogenates and the inorganic phosphate released was determined by a colorimetric method. Changes in cytosolic ionized calcium ([Ca2+]i) were also determined using Fluo-4. A significant increase of vacuolar H+-ATPase activity was observed when the CaSR was stimulated with agonists such as Gd3+ (300 µM), neomycin (200 µM) and by the calcimimetic R-568 (1 µM). This activity was also stimulated in a dose-dependent fashion by changes in extracellular Ca2+ concentration ([Ca2+]o) between 10-2 and 2 mM. The calciolytic NPS 2143 (150 nM) significantly reduced the vacuolar H+-ATPase activity observed with 2 mM [Ca2+]o. Inhibition of phospholipase C (PLC) activity with U73122 (5 x 10-7 M) reversed the increase in pump activity observed in the presence of Gd3+. Activation of CaSR by the specific CaSR agonist R-568 produced a sustained rise of [Ca2+]i, an effect that disappears when extracellular calcium was removed in the presence of thapsigargin. In summary, CaSR stimulation induces an increase in the vacuolar H+-ATPase activity of MDCK-C11 cells, an effect that involves an increase in [Ca2+]i and require PLC activity. The consequent decrease in intratubular pH could lead to increase ionization of luminal calcium, potentially reducing the formation of calcium phosphate stones.
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Calcio/metabolismo , Células Epiteliales/metabolismo , ATPasas de Translocación de Protón/metabolismo , Receptores Sensibles al Calcio/metabolismo , Animales , Perros , Gadolinio/farmacología , Concentración de Iones de Hidrógeno , Células de Riñón Canino Madin Darby , Neomicina/farmacología , Fenetilaminas/farmacología , Propilaminas/farmacología , Receptores Sensibles al Calcio/agonistas , Tapsigargina/farmacología , Fosfolipasas de Tipo C/metabolismoRESUMEN
Ractopamine hydrochloride is a commercial beta-adrenergic agonist commonly used as a dietary supplement in cattle production for improved feed efficiency and growth promotion. Currently, regulatory target tissues (as approved in the New Animal Drug Application with Food and Drug Administration) for ractopamine residue testing are muscle and liver. However, other tissues have recently been subjected to testing in some export markets for U.S. beef, a clear disregard for scientific maximum residue limits associated with specific tissues. The overall goal of this study was to develop and validate an LC-MS/MS assay to determine whether detectable and quantifiable levels of ractopamine in digestive tract-derived edible offal items (i.e., abomasum, omasum, small intestine, and reticulum) of cattle resulted from tissue residues or residual ingesta contamination of exposed surfaces of tissues (rinsates). Tissue samples and corresponding rinsates from 10 animals were analyzed for parent and total ractopamine (tissue samples only). The lower limit of quantitation was between 0.03 and 0.66 ppb depending on the tissue type, and all tissue and rinsate samples tested had quantifiable concentrations of ractopamine. The highest concentrations of tissue-specific ractopamine metabolism (represented by higher total vs. parent ractopamine levels) were observed in liver and small intestine. Contamination from residual ingesta (represented by detectable ractopamine in rinsate samples) was only detected in small intestine, with a measured mean concentration of 19.72 ppb (±12.24 ppb). Taken together, these results underscore the importance of the production process and suggest that improvements may be needed to reduce the likelihood of contamination from residual ractopamine in digestive tract-derived edible offal tissues for market.
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Agonistas Adrenérgicos beta/análisis , Bovinos/metabolismo , Fenetilaminas/análisis , Animales , Cromatografía Liquida , Residuos de Medicamentos/análisis , Tracto Gastrointestinal/metabolismo , Hígado/metabolismo , Músculos/metabolismo , Espectrometría de Masas en TándemRESUMEN
A growing concern exists over water contamination by veterinary pharmaceuticals from small pig farms in Yucatan, Mexico, where the anaerobic digesters installed as the wastewater treatment system are not operated properly. Therefore, considerable interest exists to develop analytical methods to detect these compounds and characterize their fate in the environment. In this study, the detection of three antibiotics (enrofloxacin, oxytetracycline and sulfamethoxazole) and a ß-agonist (ractopamine) was carried out using fluorescence spectrophotometry, with a semi-quantitative approach and a low environmental impact. Wastewater samples from 10 pig farms were analyzed, detecting concentrations of approximately 0.043 µg mL-1 for enrofloxacin, 1.427 µg mL-1 for oxytetracycline, and 9.748 µg mL-1 for sulfamethoxazole. The detection of these pharmaceuticals in the effluents of treated wastewater from the biodigesters of the pig farms suggests the need to optimize the system and prevent the entry of these compounds into the environment.
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Monitoreo del Ambiente/métodos , Espectrometría de Fluorescencia/métodos , Drogas Veterinarias/análisis , Contaminantes Químicos del Agua/análisis , Animales , Antibacterianos , Granjas , Tecnología Química Verde , México , Fenetilaminas , Porcinos , Aguas Residuales/análisis , Aguas Residuales/químicaRESUMEN
In many countries, ractopamine hydrochloride (RAC) is allowed to be used in animal production as a ß-agonist, which is an energy repartitioning agent able to offer economic benefits such as increased muscle and decreased fat deposition, feed conversion improvement and an increase in average daily weight gain. However, some countries have banned its use and established strict traceability programmes because of pharmacological implications of ß-agonist residues in meat products. In Brazil, commercial RAC is controlled (5-20 mg kg-1) and only added to pig diet during the last 28 days before slaughter. However, the control is more difficult when co-products, like meat and bone meal (MBM), which can be produced from RAC treated animals, are part of the feed composition. Therefore, a study was undertaken to evaluate the presence of RAC residue concentrations in urine and tissues of gilts (n = 40) in four dietary groups: 0%, 7%, 14% and 21% (w/w) of MBM-containing RAC (53.5 µg kg-1). The concentration of RAC residues in MBM, pig tissues and urine was determined by LC-MS. Low RAC concentrations were detected in muscle, kidney, liver and lungs (limit of detection = 0.15, 0.5, 0.5 and 1.0 µg kg-1, respectively); however, no RAC residues were quantified above the limit of quantification (0.5, 2.5, 2.5 and 2.5 µg kg-1, respectively). In urine, the RAC concentration remained below 1.35 µg L-1. These data suggest that MBM (containing 53.5 µg kg-1 RAC) added to diet up to 21% (w/w) could hamper the trade where RAC is restricted or has zero-tolerance policy.
Asunto(s)
Alimentación Animal , Dieta/veterinaria , Residuos de Medicamentos/análisis , Carne , Minerales , Fenetilaminas/análisis , Animales , Productos Biológicos , Femenino , Masculino , Fenetilaminas/orina , PorcinosRESUMEN
The last fifteen years have seen the emergence and overflow into the drug scene of "superpotent" N-benzylated phenethylamines belonging to the "NBOMe" series, accompanied by numerous research articles. Although N-benzyl substitution of 5-methoxytryptamine is known to increase its affinity and potency at 5-HT2 receptors associated with psychedelic activity, N-benzylated tryptamines have been studied much less than their phenethylamine analogs. To further our knowledge of the activity of N-benzyltryptamines, we have synthesized a family of tryptamine derivatives and, for comparison, a few 5-methoxytryptamine analogs with many different substitution patterns on the benzyl moiety, and subjected them to in vitro affinity and functional activity assays vs. the human 5-HT2 receptor subtypes. In the binding (radioligand displacement) studies some of these compounds exhibited only modest selectivity for either 5-HT2A or 5-HT2C receptors suggesting that a few of them, with affinities in the 10-100 nanomolar range for 5-HT2A receptors, might presumably be psychedelic. Unexpectedly, their functional (calcium mobilization) assays reflected very different trends. All of these compounds proved to be 5-HT2C receptor full agonists while most of them showed low efficacy at the 5-HT2A subtype. Furthermore, several showed moderate-to-strong preferences for activation of the 5-HT2C subtype at nanomolar concentrations. Thus, although some N-benzyltryptamines might be abuse-liable, others might represent new leads for the development of therapeutics for weight loss, erectile dysfunction, drug abuse, or schizophrenia.
Asunto(s)
Receptores de Serotonina 5-HT2/metabolismo , Triptaminas/farmacología , 5-Metoxitriptamina/análogos & derivados , 5-Metoxitriptamina/farmacología , Animales , Compuestos de Bencilo/farmacología , Células CHO , Cricetulus , Células HeLa , Humanos , Estructura Molecular , Fenetilaminas , Ensayo de Unión Radioligante , Receptor de Serotonina 5-HT2A/metabolismo , Receptor de Serotonina 5-HT2C/metabolismo , Agonistas del Receptor de Serotonina 5-HT2/farmacología , Triptaminas/síntesis químicaRESUMEN
ß-Phenylethylamine (ß-PEA) is a trace amine with chemical proximity to biogenic amines and amphetamines. It is an endogenous agonist of trace amine-associated receptors (TAARs) that acts as a neuromodulator of classic neurotransmitters in the central nervous system. At high concentrations, ß-PEA contracts smooth muscle, and a role for TAARs in these responses has been postulated. The high dietary intake of trace amines has been associated with such symptoms as hypertension and migraine, especially after the intake of foods containing such compounds. In gastrointestinal tissues, TAAR expression was reported, although the effect of ß-PEA on gastric contractile behaviour is unknown. Here, isolated strips that were obtained from the rat gastric fundus were stimulated with high micromolar concentrations of ß-PEA. Under resting tonus, ß-PEA induced contractions. In contrast, when the strips were previously contracted with KCl, a relaxant response to ß-PEA was observed. The contractile effect of ß-PEA was inhibited by 5-hydroxytryptamine (5-HT) receptor antagonists (i.e., cyproheptadine and ketanserin) but not by the TAAR1 antagonist EPPTB. In gastric fundus strips that were previously contracted with 80 mmol/L KCl, the relaxant effect of ß-PEA intensified in the presence of 5-HT receptor antagonists, which was inhibited by EPPTB and the adenylyl cyclase inhibitor MDL-12,330A. The guanylyl cyclase inhibitor ODQ did not alter the relaxant effects of ß-PEA. In conclusion, ß-PEA exerted dual contractile and relaxant effects on rat gastric fundus. The contractile effect appeared to involve the recruitment of 5-HT receptors, and the relaxant effect of ß-PEA on KCl-elicited contractions likely involved TAAR1 .
Asunto(s)
Fundus Gástrico/efectos de los fármacos , Fundus Gástrico/fisiología , Relajación Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Músculo Liso/fisiología , Fenetilaminas/farmacología , Animales , Fundus Gástrico/metabolismo , Contracción Muscular/efectos de los fármacos , Cloruro de Potasio/farmacología , Ratas , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Serotonina/metabolismoRESUMEN
BACKGROUND/AIMS: In this study, we evaluated the functional impact of facilitatory presynaptic adenosine A2A and muscarinic M1 receptors in the recovery of neuromuscular tetanic depression caused by the blockage of high-affinity choline transporter (HChT) by hemicholinium-3 (HC-3), a condition that mimics a myasthenia-like condition. METHODS: Rat diaphragm preparations were indirectly stimulated via the phrenic nerve trunk with 50-Hz frequency trains, each consisting of 500-750 supramaximal intensity pulses. The tension at the beginning (A) and at the end (B) of the tetanus was recorded and the ratio (R) B/A calculated. RESULTS: Activation of A2A and M1 receptors with CGS21680 (CGS; 2 nmol/L) and McN-A-343c (McN; 3 µmol/L) increased R values. Similar facilitatory effects were obtained with forskolin (FSK; 3 µmol/L) and phorbol 12-myristate 13-acetate (PMA; 10 µmol/L), which activate adenylate cyclase and protein kinase C respectively. HC-3 (4 µmol/L) decreased transmitter exocytosis measured by real-time videomicroscopy with the FM4-64 fluorescent dye and prevented the facilitation of neuromuscular transmission caused by CGS, McN, and FSK, with a minor effect on PMA. The acetylcholinesterase inhibitor, neostigmine (NEO; 0.5 µmol/L), also decreased transmitter exocytosis. The paradoxical neuromuscular tetanic fade caused by NEO (0.5 µmol/L) was also prevented by HC-3 (4 µmol/L) and might result from the rundown of the positive feedback mechanism operated by neuronal nicotinic receptors (blocked by hexamethonium, 120 µmol/L). CONCLUSION: Data suggest that the recovery of tetanic neuromuscular facilitation by adenosine A2A and M1 receptors is highly dependent on HChT activity and may be weakened in myasthenic patients when HChT is inoperative.