RESUMO
The most efficient approach to laser interferometric force sensing to date uses monochromatic carrier light with its signal sideband spectrum in a squeezed vacuum state. Quantum decoherence, i.e., mixing with an ordinary vacuum state due to optical losses, is the main sensitivity limit. In this Letter, we present both theoretical and experimental evidence that quantum decoherence in high-precision laser interferometric force sensors enhanced with optical cavities and squeezed light injection can be mitigated by a quantum squeeze operation inside the sensor's cavity. Our experiment shows an enhanced measurement sensitivity that is independent of the optical readout loss in a wide range. Our results pave the way for quantum improvements in scenarios where high decoherence previously precluded the use of squeezed light. Our results hold significant potential for advancing the field of quantum sensors and enabling new experimental approaches in high-precision measurement technology.
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BACKGROUND: Psychiatric symptoms/syndromes such as depression, apathy, anxiety or psychotic episodes are present in a range of neurological disorders including Parkinson's disease. The Structured Clinical Interview for DSM-IV (SCID) represents the gold standard for the assessment of psychiatric disorders but is often too time-consuming for application in clinical practice. METHODS: 66 participants were examined using the screening items and the first two questions of section A of the SCID as well as the complete version of the SCID, part I. The accuracy of the screening and the complete SCID was evaluated, and logistic regression was conducted to analyze factors associated with measure disagreement between the two procedures. RESULTS: Overall, psychiatric disorders were identified by screening in 40/66 (60.6%), as against 31/66 (47.0%) using the complete SCID. Compared to the complete SCID, the sensitivity and specificity of the screening items were 88% and 59%, respectively. CONCLUSION: Based on its good sensitivity, the SCID screening may be used in clinical practice to yield an overview of psychiatric disorders that may require treatment. Due to its moderate specificity, however, the complete version of the SCID should be subsequently used in cases whenever the SCID screening is positive. In any case, the SCID screening must be regarded as inadequate for the detection of psychotic symptoms.
Assuntos
Manual Diagnóstico e Estatístico de Transtornos Mentais , Entrevista Psicológica , Transtornos Mentais/diagnóstico , Transtornos Mentais/psicologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos Psicóticos/diagnóstico , Transtornos Psicóticos/psicologia , Reprodutibilidade dos Testes , Fatores SocioeconômicosRESUMO
Hypersalivation describes a relatively excessive salivary flow, which wets the patient himself and his surroundings. It may result because of insufficient oro-motor function, dysphagia, decreased central control and coordination. This reduces social interaction chances and burdens daily care. Multidisciplinary diagnostic and treatment evaluation is recommended already at early stage and focus on dysphagia, and saliva aspiration. Therefore, a multidisciplinary S2k guideline was developed. Diagnostic tools such as fiberoptic endoscopic evaluation of swallowing and videofluoroscopic swallowing studies generate important data on therapy selection and control. Especially traumatic and oncologic cases profit from swallowing therapy programmes in order to activate compensation mechanisms. In children with hypotonic oral muscles, oralstimulation plates can induce a relevant symptom release because of the improved lip closure. In acute hypersalivation, the pharmacologic treatment with glycopyrrolate and scopolamine in various applications is useful but its value in long-term usage critical. The injection of botulinum toxin into the salivary glands has shown safe and effective results with long lasting saliva reduction. Surgical treatment should be reserved for isolated cases. External radiation is judged as ultima ratio. Therapy effects and symptom severity has to be followed, especially in neurodegenerative cases. The resulting xerostomia should be critically evaluated by the responsible physician regarding oral and dental hygiene.
Assuntos
Sialorreia/etiologia , Sialorreia/terapia , Adulto , Terapia Comportamental , Toxinas Botulínicas Tipo A/efeitos adversos , Toxinas Botulínicas Tipo A/uso terapêutico , Criança , Terapia Combinada , Comportamento Cooperativo , Transtornos de Deglutição/diagnóstico , Transtornos de Deglutição/etiologia , Transtornos de Deglutição/terapia , Medicina Baseada em Evidências , Terapia por Exercício , Alemanha , Glicopirrolato/efeitos adversos , Glicopirrolato/uso terapêutico , Humanos , Comunicação Interdisciplinar , Ortodontia , Pneumonia Aspirativa/diagnóstico , Pneumonia Aspirativa/etiologia , Pneumonia Aspirativa/prevenção & controle , Escopolamina/efeitos adversos , Escopolamina/uso terapêutico , Sialorreia/diagnósticoRESUMO
BACKGROUND: Primary focal dystonia (PFD) is characterised by motor symptoms. Frequent co-occurrence of abnormal mental conditions has been mentioned for decades but is less well defined. In this study, prevalence rates of psychiatric disorders, personality disorders and traits in a large cohort of patients with PFD were evaluated. METHODS: Prevalence rates of clinical psychiatric diagnoses in 86 PFD patients were compared with a population based sample (n = 3943) using a multiple regression approach. Furthermore, participants were evaluated for personality traits with the 5 Factor Personality Inventory. RESULTS: Lifetime prevalence for any psychiatric or personality disorder was 70.9%. More specifically, axis I disorders occurred at a 4.5-fold increased chance. Highest odds ratios were found for social phobia (OR 21.6), agoraphobia (OR 16.7) and panic disorder (OR 11.5). Furthermore, an increased prevalence rate of 32.6% for anxious personality disorders comprising obsessive-compulsive (22.1%) and avoidant personality disorders (16.3%) were found. Except for social phobia, psychiatric disorders manifested prior to the occurrence of dystonia symptoms. In the self-rating of personality traits, PFD patients demonstrated pronounced agreeableness, conscientiousness and reduced openness. CONCLUSIONS: Patients with PFD show distinct neuropsychiatric and personality profiles of the anxiety spectrum. PFD should therefore be viewed as a neuropsychiatric disorder rather than a pure movement disorder.
Assuntos
Sintomas Afetivos/epidemiologia , Distúrbios Distônicos/psicologia , Transtornos Mentais/epidemiologia , Personalidade , Adulto , Idade de Início , Idoso , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Prevalência , Fatores de RiscoRESUMO
Exposure to a short photoperiod improved the thermogenic capacity, and cold resistance of Djungarian hamsters and increased the respiratory power of their brown adipose tissue. Exposure to a long photoperiod caused a decrease in thermogenic measurements. This thermotropic action of the short photoperiod was detectable only during late summer and fall. A similar thermotropic response could be elicited by implanting hamsters with melatonin, indicating that the pineal may be involved in photoperiodic control of thermoregulatory effectors.
Assuntos
Tecido Adiposo Marrom/fisiologia , Regulação da Temperatura Corporal/efeitos dos fármacos , Luz , Melatonina/farmacologia , Animais , Cricetinae , Periodicidade , Glândula Pineal/fisiologia , Estações do AnoRESUMO
Seasonal animals use different strategies to reduce energy expenditure in the face of reduced seasonal food availability. For example, the ground squirrel enters a hibernation state with reduced metabolism, hypothermia and suppressed central nervous system activity, whereas the Djungarian hamster (Phodopus sungorus) employs daily bouts of torpor associated with reduced body temperature and energy expenditure. Studies in the hibernating ground squirrel implicate an increase in histamine synthesis and histamine H(3) receptor expression in the brain as a central mechanism governing hibernation. In the present study, we demonstrate an up-regulation of H(3) receptors in several brain nuclei in the Djungarian hamster during bouts of daily torpor, a shallow form of hypothermia, suggesting that histaminergic pathways may play a general role in maintaining low body temperature and torpor state in mammals. These regions include the arcuate nucleus, dorsomedial hypothalamus, suprachiasmatic nucleus, dorsal lateral geniculate nucleus and tuberomammillary nucleus. Interestingly, expression of the mRNA for orexins, a group of neuropeptides that increase wakefulness, remains unchanged during the arousal from daily torpor, suggesting that this classic 'arousal' pathway is not involved in the transition from a hypothermic to the euthermic state.
Assuntos
Hibernação/fisiologia , Neuropeptídeos/biossíntese , Receptores Histamínicos H3/biossíntese , Animais , Nível de Alerta/fisiologia , Temperatura Corporal/fisiologia , Cricetinae , Hibridização In Situ , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Orexinas , Phodopus , Fotoperíodo , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Receptores Histamínicos H3/genéticaRESUMO
Spinocerebellar ataxia 17 (SCA17) is a rare genetic disorder characterized by cerebellar, extrapyramidal, pyramidal as well as psychiatric signs. The pathoanatomical basis of this disorder is still not well known. A total of 12 patients and 12 age- and sex-matched controls were examined by in vivo MRI voxel-based morphometry (VBM). Besides general patterns of disease-related brain atrophy, characteristic syndrome-related morphological changes in SCA17 patients were studied. In comparison with normal controls, SCA17 patients showed a pattern of degeneration of the grey matter centred around mesial cerebellar structures, occipito-parietal structures, the anterior putamen bilaterally, the thalamus and other parts of the motor network, reflecting the cerebellar, pyramidal and extrapyramidal signs. A correlation analysis revealed a clear association between the clinical cerebellar, extrapyramidal and psychiatric scores and degeneration in specific areas. Two degeneration patterns were found as follows: regarding motor dysfunction, atrophy of the grey matter involved mainly the cerebellum and other motor networks, in particular the basal ganglia. In contrast, correlations with psychiatric scores revealed grey matter degeneration patterns in the frontal and temporal lobe, the cuneus and cingulum. Most interestingly, there was a highly significant correlation between the clinical Mini-Mental State Examination scores and atrophy of the nucleus accumbens, probably accounting for the leading psychiatric signs.
Assuntos
Ataxias Espinocerebelares/patologia , Adulto , Atrofia , Gânglios da Base/patologia , Encéfalo/patologia , Estudos de Casos e Controles , Cerebelo/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Atividade Motora/fisiologia , Testes Neuropsicológicos , Transtornos Parkinsonianos/genética , Transtornos Parkinsonianos/patologia , Transtornos da Personalidade/diagnóstico , Transtornos da Personalidade/patologia , Paraplegia Espástica Hereditária/patologia , Paraplegia Espástica Hereditária/fisiopatologia , Paraplegia Espástica Hereditária/psicologia , Ataxias Espinocerebelares/fisiopatologia , Ataxias Espinocerebelares/psicologia , Telencéfalo/patologia , Fatores de TempoRESUMO
The Siberian hamster (Phodopus sungorus) is a seasonal mammal, exhibiting a suite of physiologically and behaviourally distinct traits dependent on the time of year and governed by changes in perceived day length (photoperiod). These attributes include significant weight loss, reduced food intake, gonadal atrophy and pelage change with short-day photoperiod as in winter. The central mechanisms driving seasonal phenotype change during winter are mediated by a reduced availability of hypothalamic triiodothyronine (T3), although the downstream mechanisms responsible for physiological and behavioural changes are yet to be fully clarified. With access to a running wheel (RW) in short photoperiod, Siberian hamsters that have undergone photoperiod-mediated weight loss over-ride photoperiod-drive for reduced body weight and regain weight similar to a hamster held in long days. These changes occur despite retaining the majority of hypothalamic gene expression profiles appropriate for short-day hamsters. Utilising the somatostatin agonist pasireotide, we recently provided evidence for an involvement of the growth hormone (GH) axis in the seasonal regulation of bodyweight. In the present study, we employed pasireotide to test for the possible involvement of the GH axis in RW-induced body weight regulation. Pasireotide successfully inhibited exercise-stimulated growth in short-day hamsters and this was accompanied by altered hypothalamic gene expression of key GH axis components. Our data provide support for an involvement of the GH axis in the RW response in Siberian hamsters.
Assuntos
Peso Corporal/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Receptores da Somatotropina/biossíntese , Somatostatina/análogos & derivados , Animais , Composição Corporal/efeitos dos fármacos , Cricetinae , Ingestão de Alimentos , Hormônio Liberador de Hormônio do Crescimento/biossíntese , Hipotálamo/metabolismo , Iodeto Peroxidase/biossíntese , Masculino , Neuropeptídeo Y/biossíntese , Tamanho do Órgão/efeitos dos fármacos , Phodopus , Fotoperíodo , Pró-Opiomelanocortina/biossíntese , Somatostatina/agonistas , Somatostatina/biossíntese , Somatostatina/farmacologiaRESUMO
Stress causes a rise in body temperature in laboratory animals (stress-induced hyperthermia). However, the direct effect of common stressors in animal research, i.e. transportation between holding and test rooms or isolation of animals, on body temperature has not been investigated to its full extent. To address this question, it is important to have a reliable and simple monitoring technique, which does not induce stress itself. In the present study, we investigated stress-related changes in body temperature of F344/Hw rats after (1) moving the cage within the holding room, (2) moving the cage from the holding room to another test room and (3) social deprivation (isolation). A combination of two different body temperature recording methods was used to clarify their accuracy and stress-inductive character: rectal temperature recording and peritoneal implanted temperature sensors (Thermochron iButtons).The results demonstrate that (1) different stressors induce a significant rise in body temperature, (2) which is detectable for more than 60 min and (3) it is of importance to standardize temperature recording methods in order to avoid confounding effects of the recording method itself. Furthermore, Thermochron iButtons are more accurate and reliable for body temperature studies than rectal recordings.
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Hipertermia Induzida , Ratos Endogâmicos F344/fisiologia , Estresse Fisiológico/fisiopatologia , Animais , Temperatura Corporal/fisiologia , Masculino , Ratos , Estresse Fisiológico/etiologiaRESUMO
Hypersalivation (sialorrhea) is a common complaint of patients with neurodegenerative disorders such as Parkinson's disease or amyotrophic lateral sclerosis and a frequently disabling side effect of atypical antipsychotic drugs. Conventional treatment including oral anticholinergic or antihistamine medication is often limited by adverse effects and lack of efficacy. Over the past few years, several studies reported decreased drooling after injections of botulinum toxin into the salivary glands. This review describes the current state of treatment of sialorrhea with botulinum toxin.
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Toxinas Botulínicas/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Sialorreia/tratamento farmacológico , Humanos , Resultado do TratamentoRESUMO
Evidence has recently begun to accumulate that photoperiodic responses of mammals and birds may affect the control of energy balance and thermoregulation. Exposure to short photoperiod can lower the set point for body temperature regulation in birds and mammals, as well as the voluntarily selected body temperature in ectothermic lizards. This decrease is accompanied by a reorganization of circadian or ultradian rhythms of body temperature, particularly an increase in periods spent at rest with minimum body temperatures. Short photoperiod is also used as an environmental cue for induction of seasonal torpor or facilitation of hibernation. During winter, cold tolerance of small mammals is improved by an increase of nonshivering thermogenesis in brown fat. Thermogenic capacity of brown fat (respiratory enzymes, mitochondria, uncoupling protein) is enhanced in response to short photoperiod. This response is mediated via an increase in the activity of sympathetic innervation in brown fat. Moreover, an exposure to short photoperiod prior to low temperatures may act in preparing brown fat for facilitated thermogenesis during acclimation to cold. This shows that photoperiodic control not only affects energy balance indirectly via the control of reproduction or body mass, but may directly interact with central control of thermoregulation and may influence the process of acclimatization.
Assuntos
Regulação da Temperatura Corporal , Luz , Periodicidade , Vertebrados/fisiologia , Ciclos de Atividade , Animais , Temperatura Corporal , Ritmo Circadiano , Hibernação , Lagartos/fisiologia , Estações do AnoRESUMO
The timing of growth in seasonal mammals is inextricably linked to food availability. This is exemplified in the Siberian hamster (Phodopus sungorus), which uses the annual cycle of photoperiod to optimally programme energy expenditure in anticipation of seasonal fluctuations in food resources. During the autumn, energy expenditure is progressively minimised by physiological adaptations, including a 30% reduction in body mass, comprising a reduction in both fat and lean tissues. However, the mechanistic basis of this adaptation is still unexplained. We hypothesised that growth hormone (GH) was a likely candidate to underpin these reversible changes in body mass. Administration of pasireotide, a long-acting somatostatin receptor agonist developed for the treatment of acromegaly, to male hamsters under a long-day (LD) photoperiod produced a body weight loss. This comprised a reduction in lean and fat mass, including kidneys, testes and brown adipose tissue, typically found in short-day (SD) housed hamsters. Furthermore, when administered to hamsters switched from SD to LD, pasireotide retarded the body weight increase compared to vehicle-treated hamsters. Pasireotide did not alter photoperiod-mediated changes in hypothalamic energy balance gene expression but altered the expression of Srif mRNA expression in the periventricular nucleus and Ghrh mRNA expression in the arcuate nucleus consistent with a reduction in GH feedback and concurrent with reduced serum insulin-like growth factor-1. Conversely, GH treatment of SD hamsters increased body mass, which included increased mass of liver and kidneys. Together, these data indicate a role for the GH axis in the determination of seasonal body mass of the Siberian hamster.
Assuntos
Hormônio do Crescimento/fisiologia , Tamanho do Órgão/fisiologia , Phodopus/fisiologia , Fotoperíodo , Receptores de Somatostatina/agonistas , Somatostatina/análogos & derivados , Redução de Peso/fisiologia , Aclimatação/efeitos dos fármacos , Aclimatação/fisiologia , Tecido Adiposo Marrom , Animais , Núcleo Arqueado do Hipotálamo/metabolismo , Cricetinae , Masculino , Núcleos da Linha Média do Tálamo/metabolismo , Tamanho do Órgão/efeitos dos fármacos , Somatostatina/farmacologia , Redução de Peso/efeitos dos fármacosRESUMO
Young adult male and female Djungarian hamsters were exposed to ambient temperatures of 23 or 0 C for 12 h; half of the animals in each group were treated with iopanoic acid to suppress the peripheral conversion of T4 to the thermotropically active thyroid hormone T3 by the enzyme 5'-deiodinase (5'D). Brown adipose tissue (BAT) mRNA for uncoupling protein (UCP), BAT lipoprotein lipase (LPL) activity, and 5'D activity were measured at the conclusion of the study. A temperature of 0 C produced large rises in 5'D and LPL activities and a similar large increase in UCP mRNA within the 12-h exposure period. When 5'D activity was inhibited with iopanoic acid, mRNA for UCP was reduced, while LPL activity was unaffected. The results show that the optimal production of mRNA for BAT UCP depends on the availability of T3; however, T3 is not required for the cold-induced activation of LPL activity in BAT.
Assuntos
Tecido Adiposo Marrom/metabolismo , Proteínas de Transporte , Temperatura Baixa , Iodeto Peroxidase/metabolismo , Proteínas de Membrana/genética , RNA Mensageiro/biossíntese , Tiroxina/metabolismo , Animais , Cricetinae , Iodeto Peroxidase/antagonistas & inibidores , Canais Iônicos , Ácido Iopanoico/farmacologia , Lipase Lipoproteica/metabolismo , Proteínas Mitocondriais , Tri-Iodotironina/metabolismo , Desacopladores , Proteína Desacopladora 1RESUMO
Daily profiles of melatonin content in the retina of Djungarian hamsters were measured throughout the course of a year. Peak levels of retinal melatonin were found at various times of the day at different seasons. In a subsequent study we determined concurrently daily profiles of nine indole metabolites (tryptophan, 5-hydroxytryptophan, 5-hydroxytryptamin, 5-hydroxyindoleacetic acid, 5-hydroxytryptophol, N-acetylserotonin, melatonin, 5-methoxyindoleacetic acid and 5-methoxytryptophol) in samples of hamster retina and pineal gland at the four different seasons. Measurements were made using HPLC coupled to a coulometric electrode detection system. Large seasonal variations in the levels and daily rhythm amplitudes of the different indole metabolites were found in the pineal glands. Due to technical problems and unknown interfering substances only tryptophan and serotonin could be determined in the retinas at all four seasons. Despite this, the ability to measure levels of several metabolites in the same sample and in different tissues of the same animals permitted more accurate comparisons of the components involved in melatonin synthesis. Our data suggest that the level of retinal melatonin is regulated and controlled locally within the retina itself. However, long-term feedback mechanisms from other sources of melatonin are not excluded but are rather likely.
Assuntos
Ritmo Circadiano , Melatonina/biossíntese , Periodicidade , Glândula Pineal/metabolismo , Retina/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Cricetinae , Feminino , Masculino , Phodopus , Glândula Pineal/fisiologia , Retina/fisiologia , Estações do Ano , Serotonina/metabolismo , Triptofano/metabolismoRESUMO
The detection of earth strength magnetic fields by rodents has been demonstrated previously by numerous physiological and behavioral techniques. This phenomenon appears to require input from the eyes. In an effort to better understand this phenomenon retinal melatonin synthesis and catecholamine contents were assayed in rats exposed at night to an alteration of the ambient magnetic field. In normal animals both dopamine and norepinephrine levels in the retina were reduced by this stimulus, while retinal melatonin synthesis was unaffected. Animals that had lost their intact photoreceptors as a result of 8 weeks of previous constant light exposure did not show a catecholamine response to the magnetic stimulus. These results support the view that the mammalian retina participates in the relaying of magnetic information into the central nervous system.
Assuntos
Catecolaminas/metabolismo , Campos Eletromagnéticos , Fenômenos Eletromagnéticos , Melatonina/metabolismo , Retina/fisiologia , Animais , Arilamina N-Acetiltransferase/metabolismo , Iluminação , Masculino , Ratos , Ratos Endogâmicos , Retina/metabolismo , Retina/patologiaRESUMO
When Richardson's ground squirrels were kept under light:dark cycles of 14:10 h there was no nocturnal rise in pineal hydroxyindole-O-methyltransferase (HIOMT) activity. Conversely, the 10 h dark period was associated with large nocturnal rises in both pineal serotonin-N-acetyltransferase (NAT) activity and radioimmunoassayable melatonin levels. The nighttime rises in pineal NAT and melatonin were not suppressed by the exposure of the animals to a light irradiance of 925 mu W/cm2 during the normal dark period. On the other hand, when the light irradiance was increased to 1850 mu W/cm2 the rise in pineal NAT activity was eliminated while the melatonin rise was greatly reduced. When ground squirrels were acutely exposed to a light irradiance of 1850 mu W/cm2 for 30 min beginning at 5.5 h after lights out, pineal NAT activity and melatonin levels were reduced to daytime values within 30 min. The half-time (t 1/2) for each constituent was less than 10 min. Exposure to a light irradiance of either 5 s or 5 min (beginning at 5.5 h into dark period) was equally as effective as 30 min light exposure in inhibiting pineal NAT activity and melatonin levels. When animals were returned to darkness after a 30 min exposure to a light irradiance of 1850 mu W/cm2 at night, both pineal NAT activity and melatonin levels were restored to high nighttime levels within 2 h of their return to darkness. The results indicate that the pineal gland of the wild-captured, diurnal Richardson's ground squirrel is 9000 X less sensitive to light at night than is the pineal gland of the laboratory raised, nocturnal Syrian hamster.
Assuntos
Acetilserotonina O-Metiltransferasa/metabolismo , Acetiltransferases/metabolismo , Arilamina N-Acetiltransferase/metabolismo , Melatonina/metabolismo , Metiltransferases/metabolismo , Glândula Pineal/metabolismo , Sciuridae/metabolismo , Animais , Ritmo Circadiano , Escuridão , Cinética , LuzRESUMO
Prompted by previous studies suggesting a regulatory role for the inhibitory amino acid gamma-aminobutyric acid (GABA) within the mammalian pineal gland, we carried out a study of rat and gerbil pineal organs to elucidate whether there is evidence for a vesicular storage and release of GABA and/or glycine. Immunohistochemistry revealed the presence of the vesicular inhibitory amino acid transporter in pinealocytes. Moreover, we found that, in addition to glutamate and aspartate, cultured pinealocytes also released glycine upon stimulation by depolarizing concentrations of KCl, whereas the content of GABA in the culture medium did not exceed the detection limit either under control conditions or following KCl application. Therefore, we propose that glycine is a further component of the paracrine signaling system within the pineal organ which is based on the compartment of synaptic-like microvesicles (SLMVs) inside pinealocytes.
Assuntos
Sistemas de Transporte de Aminoácidos , Proteínas de Transporte/metabolismo , Glicina/metabolismo , Glândula Pineal/metabolismo , Vesículas Secretórias/metabolismo , Proteínas de Transporte Vesicular , Animais , Ácido Aspártico/metabolismo , Células Cultivadas/efeitos dos fármacos , Células Cultivadas/metabolismo , Gerbillinae , Ácido Glutâmico/metabolismo , Imuno-Histoquímica , Microscopia Eletrônica , Glândula Pineal/ultraestrutura , Cloreto de Potássio/farmacologia , Ratos , Ratos Wistar , Vesículas Secretórias/ultraestrutura , Proteínas Vesiculares de Transporte de Aminoácidos Inibidores , Ácido gama-Aminobutírico/metabolismoRESUMO
p-Chlorophenylalanine (PCPA) treatment reduced pineal 5-hydroxytryptamine (5-HT) levels by 68.9% of non-PCPA treated levels in intact rat pineal glands and by 95.9% of non-PCPA treated levels in adrenergically denervated rat pineal glands. Although isoproterenol stimulation resulted in increased activity of serotonin N-acetyltransferase (NAT) activity in all experimental groups, pineal melatonin production was maximal only in non-PCPA treated rats, suggesting that 5-HT concentrations may exert considerable influence on the level of melatonin production in the rat pineal gland, independent of the level of NAT activity.
Assuntos
Acetiltransferases/metabolismo , Arilamina N-Acetiltransferase/metabolismo , Melatonina/biossíntese , Glândula Pineal/enzimologia , Animais , Fenclonina/farmacologia , Gânglios Simpáticos/fisiologia , Isoproterenol/farmacologia , Masculino , Glândula Pineal/efeitos dos fármacos , Ratos , Ratos Endogâmicos , Serotonina/metabolismoRESUMO
Serotonin and 5-hydroxyindoleacetic acid were measured in the pineal gland of Syrian hamsters by high performance liquid chromatography over a period of 24 h. A distinct 24 h rhythm was detected for both indoles. Turnover studies revealed a higher rate of serotonin synthesis during the day than during the night. We therefore suggest that the serotonin content in the pineal gland of the Syrian hamster is regulated by changes in its synthesis rate, rather than by changes of serotonin catabolism, via N-acetyltransferase activity.
Assuntos
Ritmo Circadiano , Glândula Pineal/metabolismo , Serotonina/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Cricetinae , Ácido Hidroxi-Indolacético/metabolismo , Masculino , MesocricetusRESUMO
In an attempt to clarify further the role of the hypothalamic paraventricular nuclei (PVN) in the control of pineal function, the effects of 2 min electrical stimulation of these nuclei were investigated in acutely blinded, adult, male Sprague-Dawley rats. Pineal serotonin-N-acetyltransferase (NAT) activity, melatonin content and catecholamine levels were measured by means of radio-enzymatic, radioimmunoassay and high-performance liquid-chromatography methods, respectively. All three pineal parameters underwent significant declines following brief PVN stimulation during the night time. These observations lend credence to the view that the neural pathways transmitting light information to the sympathetic innervation controlling pineal melatonin synthesis.