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1.
Australas J Ageing ; 43(1): 11-30, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38014903

RESUMO

OBJECTIVE: To identify facilitators and barriers to older adults' participation in telehealth interventions for primary prevention and health promotion. METHODS: Relevant articles were searched using keywords in Embase and MEDLINE. Study characteristics, type of telehealth interventions and technology involved, as well as facilitators and barriers to their use, were extracted from selected articles. The Unified Theory of Acceptance and Use of Technology 2 (UTAUT2) model was used to organise data. RESULTS: A total of 24 articles (pertaining to 20 studies) were included. Nine facilitators and 11 barriers influencing the participation in telehealth interventions for primary prevention and health promotion among older adults were identified. The most recurrent facilitators were related to the individual's performance expectancy and effort expectancy, as well as the presence of a social dimension associated with the intervention (i.e. having a good relationship with the other participants in the program). The two most prevalent barriers were also related to effort expectancy and performance expectancy, followed by barriers related to the inherent characteristics of the technology and older adults' health condition. Experience, age and gender were also found to moderate technology use and acceptance. CONCLUSIONS: This rapid review highlights the importance of adopting a holistic perspective when designing telehealth interventions aimed at preventive and health promotion purposes among older adults.


Assuntos
Promoção da Saúde , Telemedicina , Humanos , Idoso , Promoção da Saúde/métodos , Telemedicina/métodos , Prevenção Primária
2.
J Geriatr Phys Ther ; 45(1): 34-49, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34928239

RESUMO

BACKGROUND AND PURPOSE: Musculoskeletal disorders (MSKDs) are the most common causes of disabilities for older adults. The aim of this systematic review and meta-analysis is to assess the effectiveness of multimodal interventions including exercise rehabilitation for older adults with chronic MSKDs. METHODS: A literature search was conducted up to February 2019 in 5 bibliographical databases to identify randomized controlled trials (RCTs) that compared multimodal interventions including exercise rehabilitation with usual medical care or no intervention. Randomized controlled trials were assessed with the Cochrane risk-of-bias tool. Meta-analyses were performed and pooled mean differences (MDs) or standardized mean differences (SMDs) were calculated. RESULTS: Sixteen RCTs (n = 2322 participants) were included. One RCT was considered at low risk of bias, 8 had some concerns of bias, and 7 had a high risk of bias. Participants suffered from hip or knee osteoarthritis (OA) (n = 12 RCTs), low back pain (LBP) (n = 2 RCTs) and generalized chronic pain (GCP) (n = 2 RCTs). Multimodal interventions were significantly more effective than usual care to decrease pain (visual analog scale, out of 10 points) in the short term, MD: -0.71 (95% confidence interval [CI] -1.08 to -0.34, n = 900), and in the long term: MD: -0.52 (95% CI -0.98 to -0.05, n = 575), but these differences are not considered clinically important. In terms of disabilities, multimodal interventions were also significantly more effective than usual care. The SMDs were -0.47 (95% CI -0.61 to -0.34, n = 903) and -0.29 (95% CI -0.46 to -0.13, n = 568) for OA trials in the short and long terms, respectively, and -0.47 (95% CI -0.81 to -0.12, n = 211) for LBP and GCP trials in the short term. The magnitude of these effects may be considered as small to moderate. CONCLUSION: Multimodal intervention including exercise rehabilitation combined with usual medical care is an efficacious therapeutic option to reduce disabilities in older adults with chronic MSKDs. A significant but not clinically important effect was observed for pain. The most beneficial component of the multimodal interventions in terms of education, exercises, or medication remains to be determined.


Assuntos
Dor Crônica , Dor Lombar , Dor Musculoesquelética , Idoso , Dor Crônica/terapia , Terapia por Exercício , Humanos , Dor Lombar/terapia , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto
3.
Physiother Can ; 73(4): 329-340, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34880537

RESUMO

Purpose: Our objective was to examine the psychometric qualities (reliability and validity) and clinical utility of quantitative tools in measuring the static and dynamic standing balance of individuals after stroke. Method: We searched four databases (PubMed/MEDLINE, PEDro, Embase, and CINAHL) for studies published from January 2018 through September 2019 and included those that assessed the psychometric properties of standing balance tests with an adult stroke population. We evaluated the quality of the studies using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist and assessed each test on a utility assessment scale. Results: A total of 22 studies met the inclusion criteria, and 18 quantitative tools for assessing static or dynamic standing balance of individuals with stroke were analyzed. Findings support good or excellent reliability for all tests, whereas correlations for validity ranged from weak to strong. Study quality was variable. Dynamic balance tests had better clinical utility scores than static ones. Five tests had complete psychometric analyses: quiet standing on a force platform, five-step test, sideways step, step length, and turn tests.


Objectif : examiner les qualités psychométriques (fiabilité et validité) et l'utilité clinique d'outils quantitatifs pour mesurer l'équilibre statique et dynamique en position debout après un accident vasculaire cérébral (AVC). Méthodologie : leschercheurs ont extrait des études évaluant les propriétés psychométriques de tests d'équilibre en position debout dans une population d'adultes ayant eu un AVC de quatre bases de données (PubMed/MEDLINE, PEDro, Embase et CINAHL) entre janvier 2018 et septembre 2019. Ils ont évalué la qualité des études au moyen des directives COSMIN (acronyme anglais de normes consensuelles pour sélectionner les instruments de mesure en santé) et l'utilité clinique pour chaque test. Résultats : au total, 22 études respectaient les critères d'inclusion. Les chercheurs ont recensé et analysé 18 tests d'équilibre statique ou dynamique en position debout pour la population d'adultes victime d'un AVC. Tous les tests étaient d'une bonne ou excellente fiabilité, alors que les corrélations de validité étaient de faibles à fortes. La qualité des études était variable. Les tests d'équilibre dynamique donnaient un meilleur score d'utilité clinique que les tests d'équilibre statique. Cinq tests étaient dotés d'une analyse psychométrique complète : l'équilibre bipodal sur une plateforme de force, le test des cinq pas, les tests des pas latéraux, la longueur d'un pas et le demi-tour. Conclusion : les tests quantitatifs d'équilibre en position debout ont de bonnes qualités psychométriques et une validité modérée après un AVC. Les tests d'équilibre dynamique ont de meilleures propriétés psychométriques et de meilleurs scores d'utilité clinique que les tests d'équilibre statique. Pour évaluer pleinement l'équilibre après un AVC, il faut toutefois effectuer les deux types de tests.

4.
Gen Comp Endocrinol ; 167(2): 215-27, 2010 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-20302871

RESUMO

We have cloned and sequenced a cDNA from the surf clam (Spisula solidissima, a pelecypod mollusc) that encodes an octopamine receptor which we have named Spi-OAR. The sequence of Spi-OAR shares many similarities with two Aplysia and three Drosophila octopamine receptors belonging to a sub-group of beta-adrenergic-like octopamine receptors. Using an expression vector and transient transfections of Spi-OAR into HEK 293 cells, we observed an increase of cAMP upon addition of octopamine and, to a lesser extent, of tyramine, but not after addition of dopamine, serotonin, or histamine. Using a battery of known agonists and antagonists for octopamine receptors, we observed a rather unique pharmacological profile for Spi-OAR through measurements of cAMP. Spi-OAR exhibited some constitutive activity in HEK 293 cells and no Ca(2+) responses could be detected following addition of octopamine to Spi-OAR-transfected cells. RT-PCR analysis revealed ubiquitous expression of Spi-OAR mRNA in all adult tissues, oocytes and early embryos examined. While addition of serotonin to isolated clam oocytes resulted in meiotic activation, similar additions of octopamine had no effect, suggesting that its potential role in clam reproductive physiology differs significantly from that of serotonin. This work identifies Spi-OAR as a novel mollusc octopamine receptor closely related to other invertebrate beta-adrenergic-like octopamine receptors, with possible reproductive and other physiological functions. This initial characterization of Spi-OAR makes possible further investigations and comparisons with more studied and familiar insect or gastropod mollusc octopamine receptors.


Assuntos
Bivalves/genética , Receptores de Amina Biogênica/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Aminas Biogênicas/farmacologia , Bivalves/metabolismo , Linhagem Celular , Clonagem Molecular , AMP Cíclico/metabolismo , DNA Complementar/genética , Feminino , Humanos , Masculino , Dados de Sequência Molecular , Octopamina/farmacologia , Filogenia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Receptores de Amina Biogênica/agonistas , Receptores de Amina Biogênica/antagonistas & inibidores , Receptores de Amina Biogênica/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Transfecção
5.
Can Geriatr J ; 21(3): 284-289, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30271514

RESUMO

BACKGROUND: An exercise program involving patients, caregivers, and professionals, entitled SPecific Retraining in INTerdisciplinarity (SPRINT), has been developed to prevent functional decline during hospitalization of older patients. GOAL: Assess the feasibility of implementing SPRINT in the context of a Geriatric Assessment Unit (GAU). METHODS: GAU's health-care professionals were instructed with the SPRINT. All new patients were evaluated by a physiotherapist shortly after admission to validate the eligibility criteria and allocation category of exercises. Questionnaires on physical activities were filled out by professionals, patients, and caregivers at baseline and after intervention. Quantitative and qualitative information was collected on adherence to the program. RESULTS: SPRINT was applied to 19 of the 50 patients admitted during the three-month pilot study. A daily average of one exercise session per patient was performed, most frequently with a nurse (37%), physician (20%), care attendant (13%) or by the patient alone (22%). The caregivers participated only 4% of the time. Barriers and facilitators in applying SPRINT have been identified. CONCLUSIONS: SPRINT appears relevant and applicable within GAUs. Future studies should be conducted to assess its safety and effectiveness in preventing hospital-related functional decline.

6.
Life Sci ; 81(25-26): 1627-37, 2007 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-18023821

RESUMO

The involvement of neurotransmitters in mammalian female reproductive tissues has been the object of several studies in past decades. This review focuses on new evidence that serotonin (or 5-hydroxytryptamine, 5-HT) may be an important key player, acting locally in mammalian ovaries and female genital tracts where it may influence granulosa and cumulus cells as well as oocytes and early embryos. Pioneering studies reporting 5-HT in ovaries and other female reproductive tissues and cells are now complemented by the identification of specific 5-HT receptor subtypes (5-HT(1D), 5-HT(2A-B) and 5-HT(7)) in granulosa or cumulus cells, oocytes and early embryos. Additional serotonergic players, including the 5-HT transporter (SERT or Slc6A4) expressed in oocytes and embryos, and the 5-HT-producing enzyme tryptophan hydroxylase-1 (TPH1) expressed in cumulus cells, now make up a complete and autonomous local serotonergic network. Direct demonstrations of intracellular Ca(2+) and cAMP signaling by 5-HT in cumulus cells and its capacity to regulate progesterone secretion by granulosa cells further illustrate some of its potential functions in ovarian physiology. Recent evidence shows that mouse mothers with knocked-out TPH1 have embryos with impaired early development, establishing that maternal 5-HT is required for normal embryonic development. This local regulation of reproductive processes by 5-HT in mammals might have derived from better-known, and possibly ancestral, serotonergic networks similarly at play in several primitive animals, and potential implications for human reproduction may also be foreseen. Specific roles played by 5-HT in mammalian reproduction remain to be further investigated, and now span from steroidogenesis and oocyte maturation to early embryonic development.


Assuntos
Embrião de Mamíferos/metabolismo , Desenvolvimento Embrionário/fisiologia , Oócitos/metabolismo , Folículo Ovariano/metabolismo , Serotonina/metabolismo , Transdução de Sinais/fisiologia , Animais , Bovinos , Comunicação Celular/fisiologia , Cricetinae , Células do Cúmulo/metabolismo , Embrião de Mamíferos/enzimologia , Feminino , Células da Granulosa/metabolismo , Humanos , Masculino , Camundongos , Oócitos/enzimologia , Folículo Ovariano/enzimologia , Gravidez , Progesterona/metabolismo , Ratos , Receptores de Serotonina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Suínos , Triptofano Hidroxilase/metabolismo
7.
Gene ; 341: 67-75, 2004 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-15474289

RESUMO

Biogenic amines exert various physiological effects in cnidarians, but the receptors involved in these responses are not known. We have cloned a novel G protein-coupled receptor cDNA from an anthozoan, the sea pansy Renilla koellikeri, that shows homology to mammalian catecholamine receptors and, to a lesser extent, to peptidergic receptors. This putative receptor, named Ren2, has a DRC pattern that replaces the well-conserved DRY motif on the cytoplasmic side of the transmembrane III and lacks the cysteine residues usually found in the second extracellular loop and C-terminus tail. Both the second extracellular loop and the N-terminal tail were seen to be short (six and three amino acids, respectively). Northern blot analysis suggests that the receptor gene codes for two transcripts. Localization of these transcripts by in situ hybridization demonstrated abundant expression in the epithelium of the pharyngeal wall, the oral disk and tentacles as well as in the endodermal epithelium lining the gastrovascular cavities.


Assuntos
Receptores Acoplados a Proteínas G/genética , Renilla/genética , Processamento Alternativo , Sequência de Aminoácidos , Animais , Sequência de Bases , Northern Blotting , Clonagem Molecular , DNA Complementar/química , DNA Complementar/genética , Hibridização In Situ , Dados de Sequência Molecular , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos
8.
Dev Growth Differ ; 24(2): 163-171, 1982.
Artigo em Inglês | MEDLINE | ID: mdl-37282037

RESUMO

Barnea caridida oocytes release acid (1.35 pmole H+ /oocyte) upon fertilization. After artificial activation by an excess of KCl, germinal vesicle breakdown (GVBD) occurs normally and a quite similar, but not identical, acid release is recorded (1.10 pmole H+ /oocyte). KCl activation of Barnea oocytes is completely inhibited in 100 mM sodium-acetate sea water at pH 6.5 and fertilization does not result in activation when the oocytes are transferred after one minute into 100 mM sodium-acetate sea water at pH 6.3. When D-600, a calcium transmembrane fluxes inhibitor, is added 20 seconds after fertilization, GVBD is inhibited but a normal acid release is recorded. The presence of at least 10 mM sodium ions in the external medium is required for 100% activation of these oocytes by an excess of KCl. These results suggest that while an intracellular pH increase may be a requisite for GVBD, this can not be a sufficient condition to trigger it unless a calcium influx is allowed to occur. Moreover, the acid release does not result from a Ca++ -H+ exchange transport but appears more likely to be due to a Na+ -H* exchange as it has been demontrated in sea urchin eggs.

9.
Dev Growth Differ ; 25(5): 469-475, 1983.
Artigo em Inglês | MEDLINE | ID: mdl-37282030

RESUMO

Trifluoperazine, a calmodulin-antagonist, is shown to inhibit egg activation by ionophore A 23187 in sea urchin (I50 : 43 µM), by trypsin in echiufoids (I50 : 22 µM) and by KCl in bivalves (I50 : 34 µM). In each case the inhibition could be reversed by washing the eggs and the trifluoperazine-sensitive period was clearly limited. In Barnea and Urechis, trifluoperazine inhibits calcium uptake. A common trifluoperazine-sensitive step, possibly involving calmodulin, may thus be shared by a variety of animal groups during egg activation.

10.
Biol Bull ; 202(1): 23-33, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11842012

RESUMO

In the surf clam, Spisula solidissima, serotonin was reported to induce spawning when injected into the gonads. At nanomolar concentrations, it facilitates the fertilizability of oocyte by sperm, at micromolar concentration, it triggers the meiotic maturation of prophase 1-arrested oocytes, thus mimicking the effect of sperm. To further understand the role of serotonin in the gametogenic and spawning processes, we used both immunohistochemistry and high-pressure liquid chromatography linked with electrochemical detection to detect serotonin in the gonads of the surf clam. We found serotonin-containing varicose fibers covering the surface of the germinal epithelium in both sexes. The area occupied by the serotonergic innervation field encircling gonad acini varied according to the gonadal stages (active phase, ripe phase, partially spawned phase, spent phase). We also found large variations in the serotonin concentration between specimens during the gametogenic cycle. The serotonin concentration was correlated with gonad growth: it decreased in the ripe phase in comparison with the previous phase, the active phase. We attribute the decrease to the increase of total gonad mass in this stage. In contrast, as spawning begins, the total gonad mass declines while the gonad serotonin concentration increases to a level similar to that found in active phase. The finding that prior to spawning, serotonin is present in the gonads within fibers exhibiting distinct varicosities suggests that it is implicated in spawning.


Assuntos
Bivalves/metabolismo , Serotonina/análise , Animais , Cromatografia Líquida de Alta Pressão , Feminino , Gametogênese , Gônadas/química , Imuno-Histoquímica , Masculino , Microscopia de Fluorescência , Reprodução/fisiologia , Serotonina/fisiologia
11.
Physiother Theory Pract ; 26(3): 173-83, 2010 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-20331374

RESUMO

The GEM scale is an objective assessment tool evaluating walking safety of elderly individuals. It includes 33 walking items divided into three subscales (A, B, and C). The purpose of this study was to estimate the internal consistency and factorial validation of the scale. Seventy-four subjects (> or = 65 years) recruited from geriatric units were assessed by a total of 11 physical therapists. The internal consistency data were analyzed by using the Cronbach alpha coefficient. An exploratory factor analysis was performed to analyze the factorial structure of the scale and determine the construct validation. The internal consistency for the three subscales revealed high Cronbach alpha (subscales A = 0.90; B = 0.76, and C = 0.85). The preliminary analyses of the factorial validation did not confirm the original structure of the scale. For subscales A and B, a three-factor solution was supported by the analyses and explained 61% of the total variance. For subscale C, a four-factor solution was extracted and explained 87% of the total variance. The three subscales showed excellent item homogeneity. The factorial validation results support a new structure for the GEM scale regrouping the items in two sub-scales under different factors. The reorganization of the walking items into representative factors will allow a better understanding and interpretation of the scale.


Assuntos
Acidentes por Quedas/prevenção & controle , Análise Fatorial , Avaliação Geriátrica/métodos , Análise de Componente Principal , Caminhada , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Variações Dependentes do Observador , Valor Preditivo dos Testes , Psicometria , Reprodutibilidade dos Testes
12.
Physiother Can ; 60(3): 274-82, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-20145760

RESUMO

PURPOSE: The GEM scale is an objective assessment tool, specifically developed for older adults, to evaluate walking safety using standardized tasks. The purpose of this study was to estimate the interrater and test-retest agreement of the GEM scale. METHOD: Participants (n = 41; >/= 65 years) were recruited from geriatric units and assessed independently and simultaneously by three raters on two occasions using the GEM scale. Kappa coefficients and percentage agreement were calculated for each item of the scale. RESULTS: A majority of walking items (n = 22) showed fair to substantial interrater agreement (kappa >/= 0.25) and substantial to almost perfect test-retest agreement (kappa >/= 0.60). Mean percentage agreement was high for both interrater and test-retest agreement (79% +/- 15% and 83% +/- 16% respectively). Moreover, detailed analyses demonstrated that the relatively low agreement of some items resulted from changes in the performance of some participants and the low variability of scores. Although some walking items showed less agreement, the final decision regarding the participants' ability to walk safely resulted in moderate to substantial interrater and test-retest agreement. CONCLUSION: The GEM scale is a new assessment tool that can now be used with estimated interrater and test-retest properties to allow therapists to objectively evaluate walking safety among the elderly.

13.
Physiother Can ; 60(3): 264-73, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-20145759

RESUMO

PURPOSE: The Grille d'évaluation de la sécurité à la marche (GEM scale) is a performance-based tool developed to fill the need for an objective assessment of walking safety for older adults. It underwent a three-phase process of content validation. METHOD: A mailed questionnaire was used to assess the representativeness of the walking items (5-point pertinence scale). Subsequently, two physiotherapist focus groups (n = 20) were held to further evaluate the relevance of the scale and the walking items. Finally, a pilot study was completed with 3 raters administering the GEM scale to 12 hospitalized patients. RESULTS: Comments and descriptive statistics (percentages) were analyzed from the questionnaire results and focus groups. On completion of the pilot study, which assessed 12 patients on the GEM scale, additional analyses were performed to address the theoretical background, the administration manual, the walking items, the scoring scale, and interpretation of the scale. Following each step, modifications were made to reflect the results of the analyses. CONCLUSION: The three-phase content-validation process demonstrated the relevance of this instrument and its representativeness as a walking safety assessment tool for older adults.

14.
Mol Pharmacol ; 68(6): 1678-87, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16131615

RESUMO

cAMP and intracellular Ca2+ are important second messengers involved in mammalian follicular growth and oocyte meiotic maturation. We investigated the capacity of the neurohormone serotonin (5-hydroxytryptamine, 5-HT) to regulate intracellular cAMP and Ca2+ in mouse oocytes and surrounding cumulus cells. On the basis of a reverse transcription-polymerase chain reaction study, 5-HT7 receptor mRNA is expressed in cumulus cells, oocytes, and embryos up to the four-cell stage, and 5-HT2A and 5-HT2B receptor mRNAs are expressed in cumulus cells only, whereas 5-HT2C, 5-HT4, and 5-HT6 receptors are expressed in neither oocytes nor cumulus cells. The addition of 5-HT (10 nM to 10 microM) to isolated metaphase II oocytes had no effect on their internal cAMP or Ca2+ levels, whereas it caused dose-dependent cAMP and Ca2+ increases in cumulus cells. This cAMP increase in cumulus cells could be mimicked by 5-HT agonists with the following order of potency: 5-HT > 8-hydroxy-2-(di-n-propylamino) tetralin = alpha-methyl-5-HT = 5-carboxamidotryptamine maleate > 2-[1-(4-piperonyl)piperazinyl]benzo-triazole, thereby supporting a preferential involvement of 5-HT7 receptors. As measured with cumulus cells preloaded with fura-2/acetoxymethyl ester (AM), the addition of 5-HT also caused dose-dependent Ca2+ increases, which were probably linked to detected 5-HT2A and 5-HT2B receptors. Adding the Ca2+ ionophore ionomycin to cumulus cells resulted in both Ca2+ and cAMP elevations, whereas preincubation of cells with the Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA)-AM abolished the 5-HT-induced Ca2+ increase and reduced the cAMP increase, indicating cross-talk between the 5-HT-sensitive Ca2+ and cAMP pathways. Our results show that 5-HT may be a local regulator in mouse cumulus-oocyte complexes through its actions on cAMP and Ca2+ signaling, as mediated by 5-HT2A, 5-HT2B, and 5-HT7 receptors.


Assuntos
Sinalização do Cálcio/efeitos dos fármacos , AMP Cíclico/metabolismo , Oócitos/metabolismo , Serotonina/farmacologia , Animais , Cálcio/metabolismo , Comunicação Celular , Embrião de Mamíferos , Camundongos , Camundongos Endogâmicos , RNA Mensageiro/análise , Receptor Cross-Talk , Receptores de Serotonina/metabolismo , Sistemas do Segundo Mensageiro/efeitos dos fármacos
15.
Biol Reprod ; 73(2): 358-65, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15858217

RESUMO

Serotonin (5-hydroxytryptamine [5-HT]), is a neurohormone found in various nonneural tissues, including the gonads of many invertebrates, in which it regulates spawning and oocyte meiotic maturation. The possibility that a local serotonergic network might also exist in the female gonads of vertebrate species, including mammals, remains poorly documented. To clarify this possibility, we investigated mouse cumulus cells, oocytes, and embryos for three key serotonergic components, namely, 5-HT itself; the rate-limiting enzyme for its production, tryptophan hydroxylase 1 (TPH1); and the 5-HT-specific transporter (SLC6A4) required for modulating its cellular effects. Using a combination of reverse transcription-polymerase chain reaction analysis and immunofluorescence confocal microscopy, we showed that mouse cumulus cells, oocytes, and embryos contain 5-HT and SLC6A4, while only cumulus cells possess the 5-HT-producing enzyme TPH1 and may thus be the local source of 5-HT observed in their neighboring cells. With a semiquantitative assay in single cells, we demonstrated that 5-HT can actively be taken up by isolated oocytes when it is supplied exogenously in vitro. This 5-HT transport in isolated oocytes is driven by a classical serotonin transporter, expressed up to the blastocyst stage, that is sensitive to the antidepressants fluoxetine and fluvoxamine, which belong to the selective serotonin reuptake inhibitor family. All together, our results show that 5-HT may be produced locally by cumulus cells and that it can be actively taken up by mammalian oocytes and embryos as part of a likely larger serotonergic network possibly regulating various developmental processes much earlier than previously thought.


Assuntos
Blastocisto/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Oócitos/metabolismo , Serotonina/metabolismo , Triptofano Hidroxilase/metabolismo , Animais , Antidepressivos de Segunda Geração/farmacologia , Blastocisto/enzimologia , Comunicação Celular/fisiologia , Cricetinae , Feminino , Fluoxetina/farmacologia , Fluvoxamina/farmacologia , Glicoproteínas de Membrana/antagonistas & inibidores , Glicoproteínas de Membrana/genética , Moduladores de Transporte de Membrana , Proteínas de Membrana Transportadoras/antagonistas & inibidores , Proteínas de Membrana Transportadoras/genética , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Confocal , Microscopia de Fluorescência , Microscopia de Contraste de Fase , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/genética , Oócitos/enzimologia , Gravidez , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Serotonina/genética , Proteínas da Membrana Plasmática de Transporte de Serotonina , Triptofano Hidroxilase/genética
16.
J Neurochem ; 86(5): 1149-61, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12911623

RESUMO

Biogenic amine receptors mediate wide-ranging hormonal and modulatory functions in vertebrates, but are largely unknown in primitive invertebrates. In a representative of the most basal multicellular animals possessing a nervous system, the cnidarian Renilla koellikeri, aminergic-like receptors were previously characterized pharmacologically and found to engender control of the animal's bioluminescent and peristaltic reactions. Using degenerate oligonucleotides in a RT-PCR strategy, we obtained a full-length cDNA encoding a polypeptide with typical G protein-coupled receptor (GPCR) characteristics and which displayed a significant degree of sequence similarity (up to 45%) to biogenic amine receptors, particularly dopamine and adrenergic receptors. The new receptor, named Ren1, did not resemble any one specific type of amine GPCR and thus could not be identified on the basis of sequence. Ren1 was expressed transiently and stably in cultured mammalian cells, as demonstrated by immunocytochemistry and western blotting. Functional analysis of transfected HEK293, LTK- and COS-7 cells, based on both cAMP and Ca2+ signalling assays, revealed that Ren1 was not activated by any of the known biogenic amines tested and several related metabolites. The results indicated, however, that cells stably expressing Ren1 contained, on average, an 11-fold higher level of cAMP than the controls, in the absence of agonist stimulation. The high basal cAMP levels were shown to be specific for Ren1 and to vary proportionally with the level of Ren1 expressed in the transfected cells. Taken together, the data suggested that Ren1 was expressed as a constitutively active receptor. Its identification provides a basis for examination of the early evolutionary emergence of GPCRs and their functional properties.


Assuntos
Cnidários/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Aminas Biogênicas/metabolismo , Sinalização do Cálcio , Linhagem Celular , Clonagem Molecular , Proteínas de Ligação ao GTP/metabolismo , Expressão Gênica , Genes Reporter , Humanos , Rim/citologia , Rim/metabolismo , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Homologia de Sequência de Aminoácidos , Transdução de Sinais/fisiologia , Transfecção , Vertebrados
17.
J Cell Sci ; 115(Pt 2): 311-20, 2002 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-11839783

RESUMO

Surf clam (Spisula solidissima) oocytes are spawned at the prophase I stage of meiosis, and they remain arrested at this stage until fertilization. Full oocyte meiosis reinitiation, first evidenced by germinal vesicle breakdown (GVBD), may be induced by artificial activators mimicking sperm, such as high K(+) or serotonin. Previous reports indicated that treatments thought to increase the level of oocyte cAMP inhibited sperm- or serotonin-induced, but not KCl-induced, GVBD in clam oocytes. These observations extend the well known requirement for a drop in oocyte cAMP levels in mammalian, amphibian or starfish oocytes and support the view that such a drop is universally important throughout the animal kingdom. We have re-examined the cAMP dependency of GVBD in clam oocytes and found that various treatments that raise oocyte cAMP levels did not, surprisingly, affect either KCl- or serotonin-induced GVBD. Such treatments, however, inhibited GVBD upon insemination of the oocytes, but this was due to the failure of sperm to fuse/penetrate the oocytes; thus, it was not an inhibition of oocyte activation as such. Direct measurements of oocyte cAMP levels after activation by serotonin, KCl or sperm showed that, contrary to expectations, there is a rise in cAMP levels before GVBD. Using SQ22536, an adenylyl cyclase inhibitor, the increase in oocyte cAMP level was partly prevented and GVBD proceeded, but with a significant retardation, indicating that the normal cAMP rise facilitates GVBD. Our work sheds light on the diversity of upstream pathways leading to activation of MPF and provides a unique model whereby the onset of meiosis reinitiation is associated with an increase, not a decrease, in oocyte cAMP levels.


Assuntos
Adenina/análogos & derivados , Bivalves/metabolismo , AMP Cíclico/metabolismo , Vesículas Citoplasmáticas/metabolismo , Meiose/fisiologia , Oócitos/metabolismo , Prófase/fisiologia , Regulação para Cima/genética , 1-Metil-3-Isobutilxantina/farmacologia , Adenina/farmacologia , Animais , Bivalves/citologia , Bivalves/genética , Colforsina/farmacologia , Vesículas Citoplasmáticas/efeitos dos fármacos , Vesículas Citoplasmáticas/genética , Interações Medicamentosas/fisiologia , Inibidores Enzimáticos/farmacologia , Feminino , Fertilização/efeitos dos fármacos , Fertilização/fisiologia , Meiose/efeitos dos fármacos , Oócitos/citologia , Oócitos/efeitos dos fármacos , Cloreto de Potássio/metabolismo , Cloreto de Potássio/farmacologia , Prófase/efeitos dos fármacos , Serotonina/metabolismo , Serotonina/farmacologia , Regulação para Cima/efeitos dos fármacos
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