RESUMO
OBJECTIVES: To examine the cross-sectional association between baseline depressive symptoms and the presence of type 2 diabetes (T2D), and its association with glycated hemoglobin (HbA1c) and other metabolic variables, and the prospective association of depressive symptoms and HbA1c after 1 year of follow-up. METHODS: n = 6224 Mediterranean older adults with overweight/obesity and metabolic syndrome (48% females, mean age 64.9 ± 4.9 years) were evaluated in the framework of the PREDIMED-Plus study cohort. Depressive symptoms were assessed using the Beck Depression Inventory-II and HbA1c was used to measure metabolic control. RESULTS: The presence of T2D increased the likelihood of higher levels of depressive symptoms (χ2 = 15.84, p = 0.001). Polynomial contrast revealed a positive linear relationship (χ2 = 13.49, p = 0.001), the higher the depressive symptoms levels, the higher the prevalence of T2D. Longitudinal analyses showed that the higher baseline depressive symptoms levels, the higher the likelihood of being within the HbA1c ≥ 7% at 1-year level (Wald-χ2 = 24.06, df = 3, p < .001, for the full adjusted model). Additionally, depressive levels at baseline and duration of T2D predicted higher HbA1c and body mass index, and lower physical activity and adherence to Mediterranean Diet at 1 year of follow-up. CONCLUSIONS: This study supports an association between T2D and the severity of depressive symptoms, suggesting a worse metabolic control from mild severity levels in the short-medium term, influenced by lifestyle habits related to diabetes care. Screening for depressive symptoms and a multidisciplinary integrative therapeutic approach should be ensured in patients with T2D.
Assuntos
Depressão , Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/psicologia , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/complicações , Feminino , Masculino , Pessoa de Meia-Idade , Seguimentos , Depressão/epidemiologia , Depressão/etiologia , Idoso , Estudos Transversais , Hemoglobinas Glicadas/análise , Estudos Prospectivos , Dieta Mediterrânea , Prevalência , Índice de Massa Corporal , Obesidade/psicologia , Obesidade/epidemiologia , Obesidade/complicações , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/psicologiaRESUMO
OBJECTIVES: We tested the effects of a weight-loss intervention encouraging energy-reduced MedDiet and physical activity (PA) in comparison to ad libitum MedDiet on COVID-19 incidence in older adults. DESIGN: Secondary analysis of PREDIMED-Plus, a prospective, ongoing, multicentre randomized controlled trial. SETTING: Community-dwelling, free-living participants in PREDIMED-Plus trial. PARTICIPANTS: 6,874 Spanish older adults (55-75 years, 49% women) with overweight/obesity and metabolic syndrome. INTERVENTION: Participants were randomised to Intervention (IG) or Control (CG) Group. IG received intensive behavioural intervention for weight loss with an energy-reduced MedDiet intervention and PA promotion. CG was encouraged to consume ad libitum MedDiet without PA recommendations. MEASUREMENTS: COVID-19 was ascertained by an independent Event Committee until December 31, 2021. COX regression models compared the effect of PREDIMED-Plus interventions on COVID-19 risk. RESULTS: Overall, 653 COVID-19 incident cases were documented (IG:317; CG:336) over a median (IQR) follow-up of 5.8 (1.3) years (inclusive of 4.0 (1.2) years before community transmission of COVID-19) in both groups. A significantly lowered risk of COVID-19 incidence was not evident in IG, compared to CG (fully-adjusted HR (95% CI): 0.96 (0.81,1.12)). CONCLUSIONS: There was no evidence to show that an intensive weight-loss intervention encouraging energy-reduced MedDiet and PA significantly lowered COVID-19 risk in older adults with overweight/obesity and metabolic syndrome in comparison to ad libitum MedDiet. Recommendations to improve adherence to MedDiet provided with or without lifestyle modification suggestions for weight loss may have similar effects in protecting against COVID-19 risk in older adults with high cardiovascular risks.
Assuntos
COVID-19 , Doenças Cardiovasculares , Dieta Mediterrânea , Síndrome Metabólica , Humanos , Feminino , Idoso , Masculino , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/prevenção & controle , Síndrome Metabólica/complicações , Sobrepeso/complicações , Estudos Prospectivos , Doenças Cardiovasculares/etiologia , COVID-19/epidemiologia , COVID-19/prevenção & controle , COVID-19/complicações , Obesidade/complicações , Obesidade/epidemiologia , Obesidade/terapia , Estilo de Vida , Redução de PesoRESUMO
AIMS: The association between caffeinated coffee consumption and atrial fibrillation remains unclear. Recent studies suggest an inverse association only between a moderate caffeinated coffee consumption and atrial fibrillation, but others have reported no association. The aim of our study was to prospectively assess the association between caffeinated coffee consumption and atrial fibrillation in two Spanish cohorts, one of adults from a general population and another of elderly participants at high cardiovascular risk. METHODS AND RESULTS: We included 18,983 and 6479 participants from the 'Seguimiento Universidad de Navarra' (SUN) and 'Prevención con Dieta Mediterránea' (PREDIMED) cohorts, respectively. Participants were classified according to their caffeinated coffee consumption in three groups: ≤3 cups/month, 1-7 cups/week, and >1 cup/day. We identified 97 atrial fibrillation cases after a median follow-up of 10.3 years (interquartile range 6.5-13.5), in the SUN cohort and 250 cases after 4.4 years median follow-up (interquartile range 2.8-5.8) in the PREDIMED study. No significant associations were observed in the SUN cohort although a J-shaped association was suggested. A significant inverse association between the intermediate category of caffeinated coffee consumption (1-7 cups/week) and atrial fibrillation was observed in PREDIMED participants with a multivariable-adjusted hazard ratio = 0.53 (95% confidence interval 0.36-0.79) when compared with participants who did not consume caffeinated coffee or did it only occasionally. No association was found for higher levels of caffeinated coffee consumption (>1 cup per day), hazard ratio = 0.79 (95% confidence interval 0.49-1.28). In the meta-analysis of both PREDIMED and SUN studies, the hazard ratio for intermediate consumption of caffeinated coffee was 0.60 (95% confidence interval 0.44-0.82) without evidence of heterogeneity. Similar findings were found for the association between caffeine intake and atrial fibrillation risk. CONCLUSION: Intermediate levels of caffeinated coffee consumption (1-7 cups/week) were associated with a reduction in atrial fibrillation risk in two prospective Mediterranean cohorts.
Assuntos
Fibrilação Atrial , Café , Adulto , Idoso , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/epidemiologia , Café/efeitos adversos , Estudos de Coortes , Humanos , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores de RiscoRESUMO
INTRODUCTION AND OBJECTIVES: Metabolic syndrome (MetS) is a combination of various cardiovascular risk factors with a major impact on morbidity and premature mortality. However, the impact of MetS on self-reported health-related quality of life (HRQoL) is unknown. This study evaluated the HRQoL in a Spanish adult population aged 55 years and older with MetS. METHOD: A cross-sectional analysis was performed with baseline data from the PREDIMED-Plus multicentre randomized trial. The participants were 6430 men and women aged 55-75 years with overweight/obesity (body mass index ≥27 and ≤40kg/m2) and MetS. The SF-36 questionnaire was used as a tool to measure HRQoL. Scores were calculated on each scale of the SF-36 by gender and age. RESULTS: Participants showed higher scores in the social function (mean 85.9, 95% CI; 85.4-86.4) and emotional role scales (mean 86.8, 95% CI; 86.0-87.5). By contrast, the worst scores were obtained in the aggregated physical dimensions. In addition, men obtained higher scores than women on all scales. Among men, the worst score was obtained in general health (mean 65.6, 95% CI; 65.0-66.2), and among women, in body pain (mean 54.3, 95%CI; 53.4-55.2). A significant decrease was found in the aggregated physical dimensions score among participants 70-75 years old, but an increased one in the aggregated mental dimensions, compared to younger participants. CONCLUSIONS: Our results reflect that the MetS may negatively affect HRQoL in the aggregated physical dimensions, body pain in women, and general health in men. However, this adverse association was absent for the psychological dimensions of HRQoL, which were less affected.
Assuntos
Síndrome Metabólica , Qualidade de Vida , Idoso , Índice de Massa Corporal , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e QuestionáriosRESUMO
BACKGROUND & AIMS: Little is known about the impact of specific dietary patterns on the development of obesity phenotypes. We aimed to determine the association of longitudinal changes in adherence to the traditional Mediterranean diet (MedDiet) with the transition between different obesity phenotypes. METHODS: Data of 5801 older men and women at high cardiovascular risk from PREDIMED trial were used. Adherence to MedDiet was measured with the validated 14p-Mediterranean Diet Adherence Screener (MEDAS). Using the simultaneous combination of metabolic health- and body size-related parameters participants were categorized into one of four phenotypes: metabolically healthy and abnormal obese (MHO and MAO), metabolically healthy and abnormal non-obese (MHNO and MANO). Cox regression models with yearly repeated measures during 5-year of follow-up were built with use of Markov chain assumption. RESULTS: Each 2-point increase in MEDAS was associated with the following transitions: in MAO participants, with a 16% (95% CI 3-31%) greater likelihood of becoming MHO; in MHO participants with a 14% (3-23%) lower risk of becoming MAO; in MHNO participants with a 18% (5-30%) lower risk of becoming MHO. In MANO women, but not in men, MEDAS was associated with 20% (5-38%) greater likely of becoming MHNO (p for interaction by gender 0.014). No other significant associations were observed. CONCLUSIONS: Better adherence to the traditional MedDiet is associated with transitions to healthier phenotypes, promoting metabolic health improvement in MAO, MANO (only in women), and MHO, as well as protecting against obesity incidence in MHNO subjects.
Assuntos
Índice de Massa Corporal , Dieta Mediterrânea/estatística & dados numéricos , Avaliação Geriátrica/métodos , Obesidade/dietoterapia , Cooperação do Paciente/estatística & dados numéricos , Idoso , Feminino , Humanos , Estudos Longitudinais , Masculino , FenótipoRESUMO
BACKGROUND AND AIMS: There is ongoing controversy about the effect of a low to moderate alcohol consumption on atrial fibrillation (AF). Our aim is to assess the association between adherence to a Mediterranean alcohol drinking pattern and AF incidence. METHODS AND RESULTS: A total 6527 out of the 7447 participants in the PREDIMED trial met our inclusion criteria. A validated frequency food questionnaire was used to measure alcohol consumption. Participants were classified as non-drinkers, Mediterranean alcohol drinking pattern (MADP) (10-30 g/d in men and 5-15 g/day in women, preferably red wine consumption with low spirits consumption), low-moderate drinking (<30 g/day men y and < 15 g/day women), and heavy drinking. We performed multivariable Cox regression models to estimate hazard ratios (HR) with 95% confidence intervals (95% CI) of incident AF according to alcohol drinking patterns. After a mean follow up of 4.4 years, 241 new incident AF cases were confirmed. Alcohol consumption was not associated to AF incidence among low-moderate drinkers (HR: 0.96; 95%CI: 0.67-1.37), adherents to MADP (HR: 1.15 95%CI: 0.75-1.75), or heavy drinkers (HR: 0.92; 95%CI: 0.53-1.58), compared with non-drinkers. CONCLUSIONS: In a high cardiovascular risk adult population, a Mediterranean alcohol consumption pattern (low to moderate red wine consumption) was not associated with an increased incidence of AF. CLINICAL TRIALS: URL: http://www.controlled-trials.com. Unique identifier: ISRCTN35739639.
Assuntos
Consumo de Bebidas Alcoólicas/tendências , Fibrilação Atrial/epidemiologia , Dieta Mediterrânea , Comportamento Alimentar , Vinho , Idoso , Idoso de 80 Anos ou mais , Consumo de Bebidas Alcoólicas/efeitos adversos , Consumo de Bebidas Alcoólicas/epidemiologia , Fibrilação Atrial/diagnóstico , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Espanha/epidemiologia , Fatores de Tempo , Vinho/efeitos adversosRESUMO
Melatonin has been found in the digestive tract of many vertebrates. However, the enzymatic activity of the arylalkylamine-N-acetyltransferase (AANAT) and the hydroxindole-O-methyltransferase (HIOMT), the last two enzymes of melatonin biosynthesis, have been only measured in rat liver. Therefore, the first objective of the present study is to investigate the functionality of these enzymes in the liver and gut of goldfish, analyzing its possible daily changes and comparing its catalytic properties with those from the retina isoforms. The daily rhythms with nocturnal acrophases in retinal AANAT and HIOMT activities support their role in melatonin biosynthesis. In foregut AANAT activity also show a daily rhythm while in liver and hindgut significant but not rhythmic levels of AANAT activity are found. HIOMT activity is not detected in any of these peripheral tissues suggesting an alternative role for AANAT besides melatonin synthesis. The failure to detect functional HIOMT activity in both, liver and gut, led us to investigate other physiological substrates for the AANAT, as dopamine, searching alternative roles for this enzyme in the goldfish gut. Dopamine competes with tryptamine and inhibits retinal, intestinal and hepatic N-acetyltryptamine production, suggesting that the active isoform in gut is AANAT1. Besides, gut and liver produces N-acetyldopamine in presence of acetyl coenzyme-A and dopamine. This production is not abolished by the presence of folic acid (arylamine N-acetyltransferase inhibitor) in any studied tissue, but a total inhibition occurs in the presence of CoA-S-N-acetyltryptamine (AANAT inhibitor) in liver. Therefore, AANAT1 seems to be an important enzyme in the regulation of dopamine and N-acetyldopamine content in liver. Finally, for the first time in fish we found that dopamine, but not N-acetyldopamine, regulates the gut motility, underlying the broad physiological role of AANAT in the gut.
Assuntos
Arilalquilamina N-Acetiltransferase/metabolismo , Arilalquilamina N-Acetiltransferase/fisiologia , Dopamina/metabolismo , Dopamina/fisiologia , Motilidade Gastrointestinal/fisiologia , Trato Gastrointestinal/metabolismo , Carpa Dourada/fisiologia , Acetilação , Animais , Arilalquilamina N-Acetiltransferase/antagonistas & inibidores , Ritmo Circadiano/fisiologia , Inibidores Enzimáticos/farmacologia , Trato Gastrointestinal/efeitos dos fármacos , Técnicas In Vitro , Fígado/enzimologia , Melatonina/metabolismo , Retina/metabolismo , Serotonina/análogos & derivados , Serotonina/metabolismo , Triptaminas/metabolismoRESUMO
The aim of the present study was to localize and characterize 2-iodo-melatonin ([(125)I]Mel) binding sites in peripheral tissues of the teleost Tinca tinca. A wide distribution of [(125)I]Mel binding sites in peripheral locations of the tench is found, with highest densities being measured in the heart, gills and kidney, and low density of [(125)I]Mel binding sites in gastrointestinal tract, spleen, liver and gonads. Saturation, kinetics, and pharmacological approaches revealed the presence of, at least, two different [(125)I]Mel binding sites in the tench peripheral tissues. The unique characterized subtype in the heart fulfils all the criteria for a canonical melatonin receptor belonging to MT(1) family (the binding is saturable, reversible, and inhibited by GTP analogs), and gives support for the presence of a functional melatonin receptor in the heart of the tench. In contrast, kinetic and pharmacological studies in the kidney revealed the preponderance of a melatonin binding site belonging to the MT(3)-like receptor subtype. Moreover, the decrease of specific binding in both, heart and kidney membranes, and the decrease of affinity in the kidney, produced by the addition of a non-hydrolysable GTP analog, and sodium cations suggest the presence of G(i/o)-proteins (that mediate inhibition of cAMP formation) coupled to such melatonin binding sites. Our results also point to different G(i/o)-proteins involved in the underlying mechanism of melatonin binding sites activation in the kidney. Additionally, the kinetics of [(125)I]Mel binding in kidney membrane preparations is a highly thermosensitive process, being necessary to perform the assays at 4 °C since the equilibrium was not reached at 25 °C assay temperature. The time needed to complete association of [(125)I]Mel at such low temperature is only 15s, whereas 100s is required to displace [(125)I]Mel specific binding by the unlabeled melatonin in kidney membranes. Present results support previous reports on melatonin effects in the regulation of different physiological functions in teleost (as cardiovascular physiology and osmoregulation) acting through peripheral specific receptors.
Assuntos
Cyprinidae/metabolismo , Brânquias/metabolismo , Rim/metabolismo , Melatonina/metabolismo , Miocárdio/metabolismo , Receptores de Melatonina/metabolismo , Animais , Sítios de Ligação , Proteínas de Ligação ao GTP/metabolismo , Radioisótopos do Iodo , TemperaturaRESUMO
BACKGROUND: Serotonin (5-HT) plays a critical role in several gastrointestinal functions in vertebrates. In teleosts lacking enterochromaffin cells, intestinal 5-HT originates from serotonergic enteric neurons. In the present study, the foregut of a stomachless teleost, the goldfish (Carassius auratus), was used to evaluate the in vitro effect of 5-HT on fish intestinal motility. We also studied the role of melatonin (MEL), an indoleamine sharing the biosynthetic pathway with 5-HT, as regulator of serotonergic activity. METHODS: An organ bath system, with longitudinal strips from the goldfish intestinal bulb attached to an isometric transducer was used to record foregut smooth muscle contractions. KEY RESULTS: Concentration-dependent curves of the contractile response exerted by 5-HT and its agonists, 5-methoxytryptamine (5-MT) and 5-carboxamidotryptamine (5-CT), suggest a receptor-mediated action, supported by the blockade by a general 5-HT antagonist, methysergide. The 5-HT-induced contraction was abolished in the presence of atropine, revealing the involvement of cholinergic transmission in gut actions of 5-HT. Furthermore, MEL inhibited the contractile effect of 5-HT and its agonists by up to 50%, which was counteracted by MEL antagonists. CONCLUSIONS & INFERENCES: We can provisionally propose that at least two different 5-HT receptor subtypes are involved in fish intestinal motility, a 5-HT4-like (5-MT-preferring) and a 5-HT7-like (5-CT- and fluphenazine-sensitive) receptor. In summary, our results indicate that 5-HT regulates the contractile activity of goldfish foregut through specific receptors located in cholinergic neurons, and that MEL can modulate these serotonergic actions through high-affinity membrane receptors.
Assuntos
Carpa Dourada/anatomia & histologia , Melatonina/metabolismo , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Músculo Liso/efeitos dos fármacos , Músculo Liso/fisiologia , Serotonina/farmacologia , Animais , Atropina/farmacologia , Relação Dose-Resposta a Droga , Motilidade Gastrointestinal/efeitos dos fármacos , Motilidade Gastrointestinal/fisiologia , Carpa Dourada/metabolismo , Antagonistas Muscarínicos/farmacologia , Antagonistas da Serotonina/metabolismo , Agonistas do Receptor de Serotonina/metabolismoRESUMO
Clock genes are known to be the molecular core of biological clocks of vertebrates. They are expressed not only in those tissues considered central pacemakers, but also in peripheral tissues. In the present study, partial cDNAs for 6 of the principal clock genes (Period 1-3 and Cryptochrome 1-3) were cloned from a teleost fish, the goldfish (Carassius auratus ). These genes showed high homology (approximately 90%) with the respective cDNAs of zebrafish (Danio rerio), the only other teleost from which clock genes have been cloned. The daily expression pattern of each gene in retina, gut, and liver of goldfish was investigated using quantitative RT-PCR and cosinor analysis. All clock genes analyzed in the retina showed circadian rhythmicity; however, only Per 2-3 and Cry 2-3 were rhythmic in goldfish liver and gut. The amplitude and phase of the expression in liver and gut were different from those found in goldfish retina. Such differences suggest that other cues, such as feeding time, may contribute to the entrainment of oscillators in goldfish liver and gut. Our results support the use of goldfish as a teleost model to investigate the location and functioning of the circadian oscillators.
Assuntos
Relógios Biológicos/genética , Ritmo Circadiano/genética , Flavoproteínas , Regulação da Expressão Gênica , Carpa Dourada , Peptídeos e Proteínas de Sinalização Intracelular , Animais , Clonagem Molecular , Criptocromos , Flavoproteínas/genética , Flavoproteínas/metabolismo , Trato Gastrointestinal/citologia , Trato Gastrointestinal/fisiologia , Carpa Dourada/anatomia & histologia , Carpa Dourada/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fígado/citologia , Fígado/fisiologia , Dados de Sequência Molecular , Proteínas Circadianas Period , Retina/citologia , Retina/fisiologia , Distribuição Tecidual , Proteínas de Peixe-ZebraRESUMO
Patients on peritoneal dialysis account for approximately 10% of individuals on dialysis and are very variably distributed throughout Spain, with a national mean of 47 procedures per million inhabitants. The high incidence of cardiovascular disease in patients on peritoneal dialysis is determined by the almost universal presence of traditional cardiovascular risk factors (diabetes, hypertension) and other risk factors secondary to uremia and the inflammatory process associated to atherosclerotic disease. The concomitant presence in clinical practice of highly diverse heart diseases in these patients makes relevant a number of considerations from the cardiological viewpoint that may be of interest for specialists in nephrology. This review analyzes some aspects of four cardiological conditions that are very common in patients on peritoneal dialysis: heart failure, coronary heart disease, valve involvement, and atrial fibrillation.
Assuntos
Fibrilação Atrial , Doença das Coronárias , Insuficiência Cardíaca , Doenças das Valvas Cardíacas , Nefrologia , Diálise Peritoneal , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/etiologia , Doença das Coronárias/diagnóstico , Doença das Coronárias/etiologia , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/etiologia , Doenças das Valvas Cardíacas/diagnóstico , Doenças das Valvas Cardíacas/etiologia , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/terapia , Fatores de RiscoRESUMO
The aim of the present study was to characterize the central melatonin receptors in brain areas and ocular tissues of the teleost Tinca tinca. We investigated the temperature-dependence of 2-iodo-melatonin ([(125)I]Mel) binding in the optic tectum-tegmentum area and the neural retina. The binding of [(125)I]Mel showed a widespread distribution in brain and ocular tissues, with the highest density in the optic tectum-thalamus and the lowest in hindbrain. The [(125)I]Mel affinity was similar in all the studied tissues, and it was on the order of the low pM range. Saturation, kinetic and pharmacological studies showed the presence of a unique MT(1)-like melatonin binding site. In addition, the non-hydrolysable GTP analog, the GTPgammaS, and sodium cations induced a specific binding decrease in the optic tectum and neural retina, suggesting that such melatonin binding sites in the tench are coupled to G protein. Thus, these melatonin binding sites in optic tectum and neural retina fulfil the requirements of a real hormone receptor, the specific binding is rapid, saturable, and reversible, and is inhibited by GTP analogs. Additionally, a clear effect of temperature on such central melatonin receptors was found. Temperature did not modify the B(max) and K(d), but the kinetics of [(125)I]Mel binding resulted in a highly thermosensitive process in both tissues. Both association and dissociation rates (K(+1) and K(-1)) significantly increased with assay temperature (15-30 degrees C), but the K(d) constant (estimated as K(-1)/K(+1)) remained unaltered. In conclusion, this high thermal dependence of the melatonin binding to its receptors in the tench central nervous system supports the conclusion that temperature plays a key role in melatonin signal transduction in fish.
Assuntos
Encéfalo/metabolismo , Cyprinidae/metabolismo , Olho/metabolismo , Receptores de Melatonina/metabolismo , Temperatura , Animais , Sítios de Ligação , Temperatura Corporal/fisiologia , Feminino , Guanosina 5'-O-(3-Tiotrifosfato)/farmacologia , Radioisótopos do Iodo/farmacocinética , Masculino , Melatonina/metabolismo , Melatonina/farmacocinética , Ligação Proteica/efeitos dos fármacos , Sódio/farmacologiaRESUMO
Melatonin is synthesized, with a circadian rhythm, in the pineal organ of vertebrates, high levels being produced during the scotophase and low levels during the photophase. The retina also produces melatonin, although in the case of the European sea bass, its secretion pattern appears to be inverted. In the study described here, radioreceptor assay techniques were used to characterize the melatonin binding sites, their regional distribution and their daily variations. Brain and retina membrane preparations were used in all the binding assays and 2-[125I]iodomelatonin ([125I]Mel) as radioligand at 25 degrees C. The specific binding of [125I]Mel was seen to be saturable, reversible, specific and of high affinity. In all the tissues assayed, the power of the ligands to inhibit [125I]Mel binding decreased in the following order: melatonin>>4-P-PDOT>luzindole> or =N-acetylserotonin, which points to the presence of Mel1-like receptors. The inhibition curves of 4-P-PDOT suggested the presence of two different binding sites in the brain areas, but only one type of site of low affinity in the neural retina. No daily variations in [125I]Mel binding capacity (Bmax) or affinity (Kd) were detected in the brain areas, while a clear rhythm in Kd melatonin receptor affinity and Bmax binding capacity was observed in the retina. Kd and Bmax retinal rhythms were out of phase with the lowest Kd and the highest Bmax occurring at scotophase. This result suggests that retinal melatonin is a paracrine factor able to control receptor desensitization during photophase when ocular melatonin is higher in this species.
Assuntos
Bass/fisiologia , Encéfalo/metabolismo , Ritmo Circadiano/fisiologia , Melatonina/análogos & derivados , Receptores de Melatonina/metabolismo , Retina/metabolismo , Animais , Ligação Competitiva , Radioisótopos do Iodo , Cinética , Melatonina/metabolismo , Melatonina/farmacologia , Ensaio RadioliganteRESUMO
BACKGROUND: Previous studies have shown elevated serum levels of the cytokines IL-4 and sCD23 in atopic patients and parasitic disease. Gastroallergic anisakiasis is an acute parasitic disease, accompanied by IgE-mediated clinical symptoms and an important increase of specific and total IgE. METHODS: Sixteen patients with acute urticaria/angioedema due to parasitism by Anisakis simplex after intake of raw or undercooked fish were selected, and serum samples were taken in the emergency room within 24 h (day 0; n=16), after 1 month (n=16), and after 6 months (n=10). Serum samples were studied for specific IgE against A. simplex, total IgE, sCD23, and IL-4. RESULTS: Mean values for sCD23 did not change in the observation period. Only 4/16 serum samples showed measurable IL-4 levels. Specific IgE and total IgE levels were found to be elevated after 1 month; after 6 months, they fell to nearly basal values. There was a positive correlation between sCD23 and specific IgE at day 0 and follow-up (r=0.55-0.69, P<0.026); a positive correlation between sCD23 and total IgE (r=0.54-0.62, P<0.056). Basal sCD23 could moderately predict the percentual increment of total IgE in the first month (r=0.56, P<0.038). CONCLUSION: Thus, it seems that interindividual variability of sCD23 is an important factor, with higher values predisposing to more production of unrelated IgE, independently of the parasite's action.
Assuntos
Anisaquíase/imunologia , Hipersensibilidade Imediata/imunologia , Imunoglobulina E/biossíntese , Receptores de IgE/sangue , Animais , Anisakis/imunologia , Anticorpos Anti-Helmínticos/biossíntese , Anticorpos Anti-Helmínticos/sangue , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina E/sangue , Interleucina-4/sangue , Masculino , Pessoa de Meia-IdadeRESUMO
Feeding regulation by monoamines, neuropeptides and certain hormones has been studied in fish, but a possible role of melatonin is unknown. The purpose of the present study was to investigate the effects of melatonin on food intake in goldfish. Fishes were housed in 12L:12D and injected with different doses of either melatonin or 2-iodomelatonin. Two routes of administration, intracerebroventricular and intraperitoneal injections, and two times of the daily photocycle, midday and midnight, were tested. Food intake was measured at 2, 5 and 8 h postinjection. Melatonin and its analog, 2-iodomelatonin intracerebroventricularly injected had no effect on food intake at any time. However, intraperitoneal injections of both indoleamines significantly reduced food intake at different postinjection times. The inhibitory effect of melatonin was blocked by intraperitoneal administration of its antagonist, luzindole. These results demonstrate the in vivo efficiency of luzindole as melatonin antagonist, and thus provide a useful experimental tool to investigate melatonin functions. In conclusion, both melatonin and its agonist 2-iodomelatonin administered peripherally, inhibit food intake in goldfish, and this inhibitory effect appears to be mediated via luzindole-sensitive melatonin receptors. Our results strongly suggest that melatonin is involved in the peripheral satiety mechanisms in goldfish.
Assuntos
Antioxidantes/farmacologia , Ingestão de Alimentos/efeitos dos fármacos , Carpa Dourada/fisiologia , Melatonina/farmacologia , Animais , Antioxidantes/administração & dosagem , Depressão Química , Injeções Intraperitoneais , Injeções Intraventriculares , Melatonina/administração & dosagem , Melatonina/análogos & derivados , Triptaminas/farmacologiaRESUMO
Concentration of dopamine (DA) and its metabolite, 3,4-dihydroxyphenylacetic acid is quantified by high-pressure liquid chromatography with a coulometric detection system in the eye of Xenopus laevis through ontogeny and in adults at two times during photocycle (midday and midnight). Ocular dopaminergic activity remains low during pre- and prometamorphosis and significantly rises in postmetamorphic froglets. This increase is more pronounced at midnight than at midday. The dualism of DA content versus DA release in Xenopus ocular tissue is studied in an eyecup culture system. On a 24-h cycle of DA release from adult Xenopus eyecups the highest DA release by eyecups is produced during daytime, and significantly decreases in darkness. From these results it can be concluded that in spite of the early development of the retinal dopaminergic system in the ontogeny of Xenopus, the final maturation must occur during the metamorphic climax. Endogenous DA release is significantly inhibited by light offset, which explains the higher ocular DA content found at midnight as compared to midday in postmetamorphic froglets and adults.
Assuntos
Ácido 3,4-Di-Hidroxifenilacético/metabolismo , Dopamina/metabolismo , Olho/metabolismo , Metamorfose Biológica/fisiologia , Periodicidade , Fotoperíodo , Animais , Escuridão , Olho/crescimento & desenvolvimento , Feminino , Larva/crescimento & desenvolvimento , Larva/metabolismo , Masculino , Xenopus laevis/crescimento & desenvolvimentoRESUMO
OBJECTIVE: To describe and assess the clinical usefulness of a new posterior approach for sciatic nerve block to the gluteal zone. PATIENTS AND METHODS: This prospective descriptive study of 40 adults undergoing lower limb surgery measured the difficulty, efficacy and success of the described sciatic nerve block. TECHNIQUE: the patient was placed in Sim's position for a posterior approach. A line was then drawn from the upper part of the iliac spine to the sacral hiatus. From the midpoint of that line, a second line of equal length, perpendicular to the first and medial, was then drawn. The end of that line was the point of puncture. The needle was inserted perpendicular to all planes. Mepivacaine 1.5% (0.3 ml/kg) was injected. RESULTS: The sciatic nerve was located upon the first attempt in 90% of the patients within 21.86 +/- 12.62 s. The block failed in 2.5%. Time taken to establish the block was 19.17 +/- 9.62 m. One transitory, mild complication occurred. No vascular puncture occurred. CONCLUSIONS: We describe a new approach for sciatic nerve block using only two points of osseous reference identified by palpation. The level of efficacy and safety is high.
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Bloqueio Nervoso/métodos , Nervo Isquiático , Nádegas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
The aim of this study was to investigate the role of cyclic AMP in the regulation of tryptophan hydroxylase activity localized in retinal photoreceptor cells of Xenopus laevis, where the enzyme plays a key role in circadian melatonin biosynthesis. In photoreceptor-enriched retinas that lack serotonergic neurons, tryptophan hydroxylase activity is markedly stimulated by treatments that increase intracellular levels of cyclic AMP or activate cyclic AMP-dependent protein kinase, including forskolin, phosphodiesterase inhibitors, and cyclic AMP analogues. In contrast, cyclic AMP has no effect on tryptophan hydroxylase mRNA abundance. Experiments using cycloheximide and actinomycin D demonstrate that cyclic AMP exerts its regulatory effect via posttranslational mechanisms mediated by cyclic AMP-dependent protein kinase. The effect of cyclic AMP is independent of the phase of the photoperiod, suggesting that the nucleotide is not a mediator of the circadian rhythm of tryptophan hydroxylase. Cyclic AMP accumulation is higher in darkness than in light, as is tryptophan hydroxylase activity. Furthermore, the stimulatory effect of forskolin and that of darkness are inhibited by H89, an inhibitor of cyclic AMP-dependent protein kinase. In conclusion, cyclic AMP may mediate the acute effects of light and darkness on tryptophan hydroxylase activity of retinal photoreceptor cells.
Assuntos
AMP Cíclico/fisiologia , Células Fotorreceptoras de Vertebrados/enzimologia , Triptofano Hidroxilase/metabolismo , Xenopus laevis/metabolismo , 1-Metil-3-Isobutilxantina/farmacologia , Animais , Colforsina/farmacologia , AMP Cíclico/metabolismo , Cicloeximida/farmacologia , Dactinomicina/farmacologia , Ativação Enzimática/fisiologia , Feminino , Luz , Inibidores da Síntese de Ácido Nucleico/farmacologia , Inibidores de Fosfodiesterase/farmacologia , Células Fotorreceptoras de Vertebrados/efeitos da radiação , Inibidores da Síntese de Proteínas/farmacologia , RNA Mensageiro/metabolismo , Retina/efeitos da radiação , Triptofano Hidroxilase/genéticaRESUMO
BACKGROUND: gastro-allergic Anisakiasis is a mostly transitory clinical entity caused by Anisakis simplex (A. simplex) and can be suspected by history and confirmed by fiberoptic gastroscopy and specific IgE. OBJECTIVE: we report a case of gastro-allergic Anisakiasis, in which the parasite induces a high specific and total IgE response, and want to follow the specific and total IgE values by a serologic follow up over 10 months. METHODS: an analysis of total IgE and specific IgE against. A. simplex was performed within 24 hours, after 1, 4, 6 and 10 months. At month 4 and month 10 specific IgE against Ascaris lumbricoides and Echinococcus granulosus was determined in order to value cross-reactivity. RESULTS: there is an important raise in specific IgE against Anisakis simplex (up to 903 kU/l) after 6 months and total IgE (up to 15,258 kU/l) after one month. Cross-reactive specific IgE against Ascaris lumbricoides and Echinococcus granulosus can be detected. CONCLUSIONS: we consider a raise of total and specific IgE as a typical feature of helminth infestation and learn that specific and total IgE values are highly variable in the months following the allergic and parasite-specific reaction. The amount of specific IgE against other cross reactive parasites depends directly on the total IgE values.