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1.
BMC Pregnancy Childbirth ; 16(1): 203, 2016 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-27485050

RESUMEN

BACKGROUND: Vitamin D insufficiency may be associated with depressive symptoms in non-pregnant adults. We performed this study to evaluate whether low maternal vitamin D levels are associated with depressive symptoms in pregnancy. METHODS: This study was a secondary analysis of a randomized trial designed to assess whether prenatal omega-3 fatty acid supplementation would prevent depressive symptoms. Pregnant women from Michigan who were at risk for depression based on Edinburgh Postnatal Depression Scale Score or history of depression were enrolled. Participants completed the Beck Depression Inventory (BDI) and Mini International Neuropsychiatric Interview at 12-20 weeks, 26-28 weeks, 34-36 weeks, and 6-8 weeks postpartum. Vitamin D levels were measured at 12-20 weeks (N = 117) and 34-36 weeks (N = 112). Complete datasets were available on 105 subjects. Using regression analyses, we evaluated the relationship between vitamin D levels with BDI scores as well as with MINI diagnoses of major depressive disorder and generalized anxiety disorder. Our primary outcome measure was the association of maternal vitamin D levels with BDI scores during early and late pregnancy and postpartum. RESULTS: We found that vitamin D levels at 12-20 weeks were inversely associated with BDI scores both at 12-20 and at 34-36 weeks' gestation (P < 0.05, both). For every one unit increase in vitamin D in early pregnancy, the average decrease in the mean BDI score was .14 units. Vitamin D levels were not associated with diagnoses of major depressive disorder or generalized anxiety disorder. CONCLUSIONS: In women at risk for depression, early pregnancy low vitamin D levels are associated with higher depressive symptom scores in early and late pregnancy. Future investigations should study whether vitamin D supplementation in early pregnancy may prevent perinatal depressive symptoms. TRIAL REGISTRATION: https://clinicaltrials.gov/ REGISTRATION NUMBER: NCT00711971.


Asunto(s)
Depresión/sangre , Periodo Posparto/sangre , Complicaciones del Embarazo/sangre , Trimestres del Embarazo/sangre , Vitamina D/análogos & derivados , Adulto , Depresión/prevención & control , Depresión Posparto/sangre , Depresión Posparto/prevención & control , Suplementos Dietéticos , Método Doble Ciego , Ácidos Grasos Omega-3/administración & dosificación , Femenino , Humanos , Pruebas de Detección del Suero Materno/métodos , Embarazo , Complicaciones del Embarazo/prevención & control , Complicaciones del Embarazo/psicología , Escalas de Valoración Psiquiátrica , Análisis de Regresión , Factores de Riesgo , Vitamina D/sangre
2.
Matern Child Health J ; 20(11): 2268-2279, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27461022

RESUMEN

Introduction Mood disorders impact many pregnant women, particularly those who have experienced symptoms prior to conception, and there are significant barriers, including stigma and access, to seeking and receiving appropriate treatments. Antidepressants are a helpful option in treating perinatal depression, but research on risks and benefits of antidepressant use in pregnancy is difficult given lack of "gold standard" comparative trials. Methods This paper summarizes current state of knowledge on the safety of antidepressants during pregnancy by providing a summary of the literature published in the past 3 years (January 2013-October 2015). We identified 21 reviews and meta-analyses that were included in this summary report. This report is meant to provide a user-friendly, yet comprehensive guide summarizing the abundant, and in part contradicting, literature on risks and benefits of antidepressants during pregnancy, in order to assist busy primary care prescribers in educating their patients. Our goal is also to contrast the risks/benefits of untreated depression in pregnancy versus treatment with antidepressant medication in pregnancy, and in such support prescribers in their decision-making. Results The past 3 years have yielded an abundance of publications on the topic, in part, with conflicting findings adding to confusion and concern among providers, patients, and their families. Many reported studies have methodological problems limiting their impact. Data on adverse effects of medications on pregnancy and fetal outcomes have to be weighed against the impact of untreated illness and poor health habits associated with untreated illness on the same outcomes. Discussion Medical-decision making is often complex and seldom free of risks. Obviously, as providers we cannot guarantee that fetal exposure to antidepressants is totally free of risk, yet this is true for any medicine taken in pregnancy. However, to date, perinatal psychiatry has collected enough evidence to suggest that, if the clinical picture warrants it, the use of many antidepressants, especially the SSRIs, is favorable compared to exposing mother and child to untreated depressive illness.


Asunto(s)
Antidepresivos/uso terapéutico , Depresión/tratamiento farmacológico , Complicaciones del Embarazo/diagnóstico , Resultado del Embarazo , Inhibidores de Captación de Serotonina y Norepinefrina/uso terapéutico , Antidepresivos/efectos adversos , Depresión/diagnóstico , Depresión/psicología , Femenino , Humanos , Embarazo , Complicaciones del Embarazo/psicología , Riesgo , Inhibidores de Captación de Serotonina y Norepinefrina/efectos adversos , Teratogénesis
3.
Am J Obstet Gynecol ; 208(4): 313.e1-9, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23531328

RESUMEN

OBJECTIVES: Maternal deficiency of the omega-3 fatty acid, docosahexaenoic acid (DHA), has been associated with perinatal depression, but there is evidence that supplementation with eicosapentaenoic acid (EPA) may be more effective than DHA in treating depressive symptoms. This trial tested the relative effects of EPA- and DHA-rich fish oils on prevention of depressive symptoms among pregnant women at an increased risk of depression. STUDY DESIGN: We enrolled 126 pregnant women at risk for depression (Edinburgh Postnatal Depression Scale score 9-19 or a history of depression) in early pregnancy and randomly assigned them to receive EPA-rich fish oil (1060 mg EPA plus 274 mg DHA), DHA-rich fish oil (900 mg DHA plus 180 mg EPA), or soy oil placebo. Subjects completed the Beck Depression Inventory (BDI) and Mini-International Neuropsychiatric Interview at enrollment, 26-28 weeks, 34-36 weeks, and at 6-8 weeks' postpartum. Serum fatty acids were analyzed at entry and at 34-36 weeks' gestation. RESULTS: One hundred eighteen women completed the trial. There were no differences between groups in BDI scores or other depression endpoints at any of the 3 time points after supplementation. The EPA- and DHA-rich fish oil groups exhibited significantly increased postsupplementation concentrations of serum EPA and serum DHA respectively. Serum DHA- concentrations at 34-36 weeks were inversely related to BDI scores in late pregnancy. CONCLUSION: EPA-rich fish oil and DHA-rich fish oil supplementation did not prevent depressive symptoms during pregnancy or postpartum.


Asunto(s)
Depresión/prevención & control , Ácidos Docosahexaenoicos/uso terapéutico , Ácido Eicosapentaenoico/uso terapéutico , Complicaciones del Embarazo/prevención & control , Adulto , Depresión/diagnóstico , Método Doble Ciego , Ácidos Grasos Omega-3/uso terapéutico , Femenino , Humanos , Embarazo , Complicaciones del Embarazo/diagnóstico
4.
Complement Ther Clin Pract ; 18(4): 235-40, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23059438

RESUMEN

Prenatal psychopathology may have an adverse impact on mother and baby, but few women receive treatment. We offered a 10-week mindfulness yoga (M-Yoga) intervention to psychiatrically high-risk pregnant women as an alternative to pharmacological treatment. Participants (N = 18) were primiparous, 12-26 weeks pregnant, and had elevated scores (>9) on the Edinburgh Postnatal Depression Screen at baseline. In addition to a baseline diagnostic assessment, women completed self-ratings on depression, mindfulness, and maternal-fetal attachment before and after M-Yoga. Findings suggest that M-Yoga was feasible, accepted and effective. Symptoms of depression were significantly reduced (p = 0.025), while mindfulness (p = 0.007) and maternal-fetal attachment (p = 0.000) significantly increased. Overall, this pilot study is the first to demonstrate that M-Yoga may be an effective treatment alternative or augmentation to pharmacotherapy for pregnant women at high risk for psychopathology.


Asunto(s)
Depresión/terapia , Complicaciones del Embarazo/terapia , Yoga , Adulto , Depresión/complicaciones , Estudios de Factibilidad , Femenino , Humanos , Relaciones Materno-Fetales/psicología , Proyectos Piloto , Embarazo , Complicaciones del Embarazo/psicología , Atención Prenatal/métodos , Resultado del Tratamiento
5.
Biochim Biophys Acta ; 1770(12): 1627-35, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17920199

RESUMEN

Two cysteine proteases, GP2 and GP3, have been isolated from ginger rhizomes (Zingiber officinale). GP2 is virtually identical to a previously identified ginger protease GPII [K.H. Choi, and R.A. Laursen, Amino-acid sequence and glycan structures of cysteine proteases with proline specificity from ginger rhizome Zingiber officinale, Eur. J. Biochem. 267 (2000) 1516-1526.], and cleaves native type I collagen at multiple discrete sites, which are in the interior of the triple helical region of this molecule. In reaction with proline-containing peptides GP2 shows preference for Pro in the P2 position, and at least 10-fold higher efficiency of hydrolysis than papain. Comparison of models of GP2 and GP3 with the crystal structure of papain shows that the three enzymes have different S2 pocket structures. The S2 pocket in GP2 and GP3 is half the size of that of papain. GP2 is the only reported plant cysteine protease with a demonstrated ability to hydrolyse native collagen. The results support a role for ginger proteases as an alternative to papain, in commercial applications such as meat tenderization, where collagen is the target substrate.


Asunto(s)
Colágeno/metabolismo , Colagenasas/metabolismo , Cisteína Endopeptidasas/metabolismo , Zingiber officinale/enzimología , Secuencia de Aminoácidos , Colagenasas/química , Colagenasas/aislamiento & purificación , Cisteína Endopeptidasas/química , Cisteína Endopeptidasas/aislamiento & purificación , Electroforesis en Gel de Poliacrilamida , Hidrólisis , Modelos Moleculares , Datos de Secuencia Molecular , Homología de Secuencia de Aminoácido
6.
Cereb Cortex ; 16(9): 1258-65, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16292003

RESUMEN

Muscarinic acetylcholine receptors are extensively involved in cortical cognition and learning-induced or experience-dependent cortical plasticity. The most abundant muscarinic receptor subtype in the cerebral cortex is the M1 receptor, but little is known about its contribution to experience-dependent plasticity of the adult auditory cortex. We have examined the role of the M1 receptor in experience-dependent plasticity of the auditory cortex in mice lacking the M1 (chrm1) gene. We show here that electrical stimulation of the basal forebrain, a major source of cortical cholinergic inputs, facilitated the auditory responses of cortical neurons in both wild types and M1 mutants. The basal forebrain stimulation alone caused change in the best frequencies of cortical neurons that were significantly greater in M1 mutants. When animals received the paired stimuli of electrical stimulation of the basal forebrain and tone, the frequency tuning of cortical neurons systematically shifted toward the frequency of the paired tone in both wild types and M1 mutants. However, the shift range in M1 mutants was much smaller than that in wild-type mice. Our data suggest that the M1 receptor is important for the experience-dependent plasticity of the auditory cortex.


Asunto(s)
Corteza Auditiva/fisiología , Potenciales Evocados Auditivos/fisiología , Plasticidad Neuronal/fisiología , Percepción de la Altura Tonal/fisiología , Receptor Muscarínico M1/metabolismo , Transmisión Sináptica/fisiología , Adaptación Fisiológica/fisiología , Animales , Ratones , Ratones Noqueados , Receptor Muscarínico M1/deficiencia , Receptor Muscarínico M1/genética
7.
J Neurosci ; 25(32): 7449-58, 2005 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-16093396

RESUMEN

In response to glutamatergic synaptic drive, striatal medium spiny neurons in vivo transition to a depolarized "up state" near spike threshold. In the up state, medium spiny neurons either depolarize enough to spike or remain below spike threshold and are silent before returning to the hyperpolarized "down state." Previous work has suggested that subthreshold K+ channel currents were responsible for this dichotomous behavior, but the channels giving rise to the current and the factors determining its engagement have been a mystery. To move toward resolution of these questions, perforated-patch recordings from medium spiny neurons in tissue slices were performed. K+ channels with pharmacological and kinetic features of KCNQ channels potently regulated spiking at up-state potentials. Single-cell reverse transcriptase-PCR confirmed the expression of KCNQ2, KCNQ3, and KCNQ5 mRNAs in medium spiny neurons. KCNQ channel currents in these cells were potently reduced by M1 muscarinic receptors, because the effects of carbachol were blocked by M1 receptor antagonists and lost in neurons lacking M1 receptors. Reversal of the modulation was blocked by a phosphoinositol 4-kinase inhibitor, indicating a requirement for phosphotidylinositol 4,5-bisphosphate resynthesis for recovery. Inhibition of protein kinase C reduced the efficacy of the muscarinic modulation. Finally, acceleration of cholinergic interneuron spiking with 4-aminopyridine mimicked the effects of exogenous agonist application. Together, these results show that KCNQ channels are potent regulators of the excitability of medium spiny neurons at up-state potentials, and they are modulated by intrastriatal cholinergic interneurons, providing a mechanistic explanation for variability in spiking during up states seen in vivo.


Asunto(s)
Cuerpo Estriado/fisiología , Canales de Potasio KCNQ/fisiología , Neuronas/fisiología , Receptor Muscarínico M1/fisiología , 4-Aminopiridina/farmacología , Animales , Cuerpo Estriado/citología , Cuerpo Estriado/metabolismo , Conductividad Eléctrica , Electrofisiología , Femenino , Técnicas In Vitro , Interneuronas/fisiología , Activación del Canal Iónico/fisiología , Canales de Potasio KCNQ/antagonistas & inhibidores , Canales de Potasio KCNQ/genética , Canal de Potasio KCNQ2/metabolismo , Canal de Potasio KCNQ3/metabolismo , Masculino , Ratones , Ratones Noqueados , Neuronas/metabolismo , Fosfatidilinositol 4,5-Difosfato/fisiología , Bloqueadores de los Canales de Potasio/farmacología , Proteína Quinasa C/antagonistas & inhibidores , Proteína Quinasa C/metabolismo , Ratas , Ratas Sprague-Dawley , Receptor Muscarínico M1/agonistas
8.
Hear Res ; 201(1-2): 145-55, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15721569

RESUMEN

Sensory cortices have multiple and distinct functional maps that systematically represent environmental information. Development of these maps is precisely controlled by a number of intrinsic and extrinsic factors. Cortical cholinergic regulation is a crucial factor for normal cortical morphogenesis. In this study, we test the role of the M1 muscarinic acetylcholine receptor, the main muscarinic receptor subtype in the neocortex in the development of tonotopic maps in the auditory cortex. Mice lacking M1 receptors have normal hearing sensitivity but exhibit disrupted tonotopic organization and frequency tuning in the auditory cortex. In contrast, tonotopic organization and frequency tuning remain normal in the auditory midbrain. In addition, cortical layer IV neurons of M1 mutants exhibit significantly shorter or sparser dendrites compared to neurons of wildtype mice. In summary, our data suggest that the M1 receptor appears to be critical for the refinement or normal maturation of cortical tonotopy that is guided by thalamocortical inputs during early development.


Asunto(s)
Potenciales de Acción/fisiología , Corteza Auditiva/fisiología , Receptor Muscarínico M1/fisiología , Estimulación Acústica , Animales , Corteza Auditiva/metabolismo , Mapeo Encefálico , Distribución de Chi-Cuadrado , Ratones , Ratones Noqueados , Modelos Animales , Neuronas/metabolismo
9.
Proc Natl Acad Sci U S A ; 102(2): 273-8, 2005 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-15625111

RESUMEN

Purple acid phosphatases (PAPs) are a family of binuclear metalloenzymes that catalyze the hydrolysis of phosphoric acid esters and anhydrides. A PAP in sweet potato has a unique, strongly antiferromagnetically coupled Fe(III)-Mn(II) center and is distinguished from other PAPs by its increased catalytic efficiency for a range of activated and unactivated phosphate esters, its strict requirement for Mn(II), and the presence of a mu-oxo bridge at pH 4.90. This enzyme displays maximum catalytic efficiency (k(cat)/K(m)) at pH 4.5, whereas its catalytic rate constant (k(cat)) is maximal at near-neutral pH, and, in contrast to other PAPs, its catalytic parameters are not dependent on the pK(a) of the leaving group. The crystal structure of the phosphate-bound Fe(III)-Mn(II) PAP has been determined to 2.5-A resolution (final R(free) value of 0.256). Structural comparisons of the active site of sweet potato, red kidney bean, and mammalian PAPs show several amino acid substitutions in the sweet potato enzyme that can account for its increased catalytic efficiency. The phosphate molecule binds in an unusual tripodal mode to the two metal ions, with two of the phosphate oxygen atoms binding to Fe(III) and Mn(II), a third oxygen atom bridging the two metal ions, and the fourth oxygen pointing toward the substrate binding pocket. This binding mode is unique among the known structures in this family but is reminiscent of phosphate binding to urease and of sulfate binding to lambda protein phosphatase. The structure and kinetics support the hypothesis that the bridging oxygen atom initiates hydrolysis.


Asunto(s)
Fosfatasa Ácida/química , Glicoproteínas/química , Ipomoea batatas/enzimología , Hierro/química , Manganeso/química , Fosfatos/química , Fosfatasa Ácida/antagonistas & inhibidores , Fosfatasa Ácida/metabolismo , Sitios de Unión , Catálisis , Glicoproteínas/antagonistas & inhibidores , Glicoproteínas/metabolismo , Concentración de Iones de Hidrógeno , Cinética
10.
Cancer Chemother Pharmacol ; 52 Suppl 1: S3-15, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12819940

RESUMEN

Any approach applied to drug discovery and development by the medical community and pharmaceutical industry has a direct impact on the future availability of improved, novel, and curative therapies for patients with cancer. By definition, drug discovery is a complex learning process whereby research efforts are directed toward uncovering and assimilating new knowledge to create and develop a drug for the purpose of providing benefit to a defined patient population. Accordingly, a highly desirable technology or approach to drug discovery should facilitate both effective learning and the application of newly discovered observations that can be exploited for therapeutic benefit. However, some believe that drug discovery is largely accomplished by serendipity and therefore appropriately addressed by screening a large number of compounds. Clearly, this approach has not generated an abundance of new drugs for cancer patients and suggests that a tangibly different approach in drug discovery is warranted. We employ an alternative approach to drug discovery, which is based on the elucidation and exploitation of biological, pharmacological, and biochemical mechanisms that have not been previously recognized or fully understood. Mechanism-based drug discovery involves the combined application of physics-based computer simulations and laboratory experimentation. There is increasing evidence that agreement between simulations based on the laws of physics and experimental observations results in a higher probability that such observations are more accurate and better understood as compared with either approach used alone. Physics-based computer simulation applied to drug discovery is now considered by experts in the field to be one of the ultimate methodologies for drug discovery. However, the ability to perform truly comprehensive physics-based molecular simulations remains limited by several factors, including the enormous computer-processing power that is required to perform the formidable mathematical operations and data processing (e.g. memory bandwidth, data storage and retrieval). Another major consideration is the development of software that can generate an appropriate and increasingly complex physical representation of the atomic arrangements of biological systems. During the past 17 years, we have made tremendous progress in addressing some of these obstacles by developing and optimizing physics-based computer programs for the purpose of obtaining increasingly accurate and precise information and by improving the speed of computation. To perform physics-based simulations that involve complex systems of biological and pharmaceutical interest, we have developed methods that enable us to exceed Moore's law. This has been accomplished by parallel processing as well as other methods that have enabled us to study more complex and relevant molecular systems of interest. This paper provides an overview of our approach to drug discovery and describes a novel drug, currently in clinical development, which has directly resulted from the application of this approach.


Asunto(s)
Simulación por Computador , Diseño de Fármacos , Mesna/análogos & derivados , Mesna/química , Sustancias Protectoras/química , Animales , Ensayos Clínicos Fase I como Asunto , Humanos , Dosificación Letal Mediana , Mesna/uso terapéutico , Mesna/toxicidad , Modelos Químicos , Síndromes de Neurotoxicidad/prevención & control , Sustancias Protectoras/uso terapéutico , Sustancias Protectoras/toxicidad
11.
Eur J Neurosci ; 17(7): 1403-10, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12713643

RESUMEN

Muscarinic agonist-induced parasympathomimetic effects, in vivo phosphoinositide hydrolysis and seizures were evaluated in wild-type and muscarinic M1-M5 receptor knockout mice. The muscarinic agonist oxotremorine induced marked hypothermia in all the knockout mice, but the hypothermia was reduced in M2 and to a lesser extent in M3 knockout mice. Oxotremorine-induced tremor was abolished only in the M2 knockout mice. Muscarinic agonist-induced salivation was reduced to the greatest extent in M3 knockout mice, to a lesser degree in M1 and M4 knockout mice, and was not altered in M2 and M5 knockout mice. Pupil diameter under basal conditions was increased only in the M3 knockout mice. Pilocarpine-induced increases in in vivo phosphoinositide hydrolysis were completely absent in hippocampus and cortex of M1 knockout mice, but in vivo phosphoinositide hydrolysis was unaltered in the M2-M5 knockout mice. A high dose of pilocarpine (300 mg/kg) caused seizures and lethality in wild-type and M2-M5 knockout mice, but produced neither effect in the M1 knockout mice. These data demonstrate a major role for M2 and M3 muscarinic receptor subtypes in mediating parasympathomimetic effects. Muscarinic M1 receptors activate phosphoinositide hydrolysis in cortex and hippocampus of mice, consistent with the role of M1 receptors in cognition. Muscarinic M1 receptors appear to be the only muscarinic receptor subtype mediating seizures.


Asunto(s)
Sistema Nervioso Parasimpático/fisiología , Fosfatidilinositoles/metabolismo , Receptores Muscarínicos/clasificación , Receptores Muscarínicos/fisiología , Convulsiones/fisiopatología , Animales , Apomorfina/farmacología , Temperatura Corporal/efectos de los fármacos , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/fisiopatología , Agonistas de Dopamina/farmacología , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Genotipo , Hipocampo/efectos de los fármacos , Hipocampo/fisiopatología , Hidrólisis , Hipotermia/inducido químicamente , Litio/farmacología , Ratones , Ratones Noqueados , Agonistas Muscarínicos , Oxotremorina/farmacología , Pilocarpina , Pupila/efectos de los fármacos , Receptores Muscarínicos/efectos de los fármacos , Salivación/efectos de los fármacos , Convulsiones/inducido químicamente , Convulsiones/genética
12.
Nat Neurosci ; 6(1): 51-8, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12483218

RESUMEN

Blockade of cholinergic neurotransmission by muscarinic receptor antagonists produces profound deficits in attention and memory. However, the antagonists used in previous studies bind to more than one of the five muscarinic receptor subtypes. Here we examined memory in mice with a null mutation of the gene coding the M1 receptor, the most densely distributed muscarinic receptor in the hippocampus and forebrain. In contrast with previous studies using nonselective pharmacological antagonists, the M1 receptor deletion produced a selective phenotype that included both enhancements and deficits in memory. Long-term potentiation (LTP) in response to theta burst stimulation in the hippocampus was also reduced in mutant mice. M1 null mutant mice showed normal or enhanced memory for tasks that involved matching-to-sample problems, but they were severely impaired in non-matching-to-sample working memory as well as consolidation. Our results suggest that the M1 receptor is specifically involved in memory processes for which the cortex and hippocampus interact.


Asunto(s)
Acetilcolina/metabolismo , Corteza Cerebral/metabolismo , Hipocampo/metabolismo , Trastornos de la Memoria/genética , Vías Nerviosas/metabolismo , Receptores Muscarínicos/deficiencia , Animales , Corteza Cerebral/fisiopatología , Condicionamiento Psicológico/fisiología , Señales (Psicología) , Aprendizaje Discriminativo/fisiología , Estimulación Eléctrica , Miedo/fisiología , Femenino , Hipocampo/fisiopatología , Masculino , Aprendizaje por Laberinto/fisiología , Memoria/fisiología , Trastornos de la Memoria/metabolismo , Trastornos de la Memoria/fisiopatología , Memoria a Corto Plazo/fisiología , Ratones , Ratones Noqueados , Mutación , Vías Nerviosas/fisiopatología , Fenotipo , Receptor Muscarínico M1 , Receptores Muscarínicos/genética
13.
Brain Res ; 944(1-2): 82-9, 2002 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-12106668

RESUMEN

The five subtypes (M1-M5) of muscarinic acetylcholine receptors signal through G(alpha)(q) or G(alpha)(i)/G(alpha)(o). M1, M3 and M5 receptors couple through G(alpha)(q) and function predominantly as postsynaptic receptors in the central nervous system. M1 and M3 receptors are localized to brain regions involved in cognition, such as hippocampus and cortex, but their relative contribution to function has been difficult to ascertain due to the lack of subtype specific ligands. A functional and genetic approach was used to identify the predominant muscarinic receptor subtype(s) mediating responses in mouse hippocampus and cortex, as well as the relative degree of spare muscarinic receptors in hippocampus. The nonselective muscarinic agonist oxotremorine-M stimulated G(alpha)(q)/11-specific GTP-gamma-35S binding in a concentration dependent manner with a Hill slope near unity in wild type mouse hippocampus and cortex. Muscarinic receptor stimulated G(alpha)(q)/11-specific GTP-gamma-35S binding was virtually abolished in both the hippocampus and cortex of M1 receptor knockout (KO) mice. In contrast, there was no loss of signaling in M3 receptor KO mice in either brain region. Muscarinic receptor reserve in wildtype mouse hippocampus was measured by Furchgott analysis after partial receptor alkylation with propylbenzylcholine mustard. Occupation of just 15% of the M1 receptors in mouse hippocampus was required for maximal efficacy of oxotremorine-M-stimulated GTP-gamma-35S binding indicating a substantial level of spare receptors. These findings support a role for the M1 receptor subtype as the primary G(alpha)(q)/11-coupled muscarinic receptor in mouse hippocampus and cortex.


Asunto(s)
Corteza Cerebral/metabolismo , Proteínas de Unión al GTP Heterotriméricas/metabolismo , Hipocampo/metabolismo , Neuronas/metabolismo , Receptores Muscarínicos/deficiencia , Transducción de Señal/genética , Transmisión Sináptica/genética , Animales , Unión Competitiva/fisiología , Femenino , Subunidades alfa de la Proteína de Unión al GTP Gq-G11 , Guanosina 5'-O-(3-Tiotrifosfato) , Guanosina Difosfato , Masculino , Ratones , Ratones Noqueados , Agonistas Muscarínicos/farmacología , Oxotremorina , Mostaza de Propilbencililcolina , Ensayo de Unión Radioligante , Receptor Muscarínico M1 , Receptor Muscarínico M3 , Receptores Muscarínicos/efectos de los fármacos , Receptores Muscarínicos/genética , Fracciones Subcelulares
14.
J Pharmacol Exp Ther ; 301(1): 129-37, 2002 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11907166

RESUMEN

Although the M(2) muscarinic acetylcholine receptor (mAChR) is the predominant functional mAChR subtype in the heart, some responses of the cardiovascular system to acetylcholine (ACh) may be mediated by other mAChR subtypes. The potential effect of M(1) mAChR on heart function was investigated using M(1) knockout (M(1)-KO) mice. In vivo cardiodynamic analysis showed that basal values of heart rate (HR), developed left ventricular pressure (DLVP), left ventricular dP/dt(max) (LV dP/dt(max)), and mean blood pressure (MBP) were similar between wild-type (WT) and M(1)-KO mice. Injection of the putative M(1)-selective agonist 4-(m-chlorophenyl-carbamoyloxy)-2-butynyltrimethylammonium (McN-A-343) produced an increase in LV dP/dt(max), DLVP, HR, and MBP in WT mice but did not affect hemodynamic function in the M(1)-KO mice. The stimulatory effect of McN-A-343 in WT mice was blocked by pretreatment with propranolol, indicating that stimulation of the M(1) mAChRs on sympathetic postganglionic neurons evoked release of catecholamines. Intravenous injection of ACh in both WT and M(1)-KO mice caused atrioventricular conduction block, without a significant change in the frequency of atrial depolarization, or atrial fibrillation. Immunoprecipitation and reverse transcriptase-polymerase chain reaction failed to detect the expression of M(1) mAChR in cardiac tissue from WT mice. The carbachol-induced increase of phospholipase C activity in cardiac tissues was not different between WT and M(1)-KO mice. These results demonstrate that 1) activation of M(1) mAChR subtype on sympathetic postganglionic cells results in catecholamine-mediated cardiac stimulation, 2) M(1) mAChR is not expressed in mouse heart, and 3) administration of ACh to mice induces arrhythmia.


Asunto(s)
Hemodinámica/fisiología , Receptores Muscarínicos/fisiología , Cloruro de (4-(m-Clorofenilcarbamoiloxi)-2-butinil)trimetilamonio/farmacología , Acetilcolina/farmacología , Animales , Southern Blotting , Carbacol/farmacología , Ganglios Simpáticos/fisiología , Corazón/efectos de los fármacos , Corazón/fisiología , Ratones , Ratones Noqueados , Agonistas Muscarínicos/farmacología , Antagonistas Muscarínicos/farmacología , Fosfatidilinositoles/metabolismo , Pruebas de Precipitina , Quinuclidinil Bencilato/farmacología , ARN/biosíntesis , Receptor Muscarínico M1 , Receptores Adrenérgicos beta/efectos de los fármacos , Receptores Adrenérgicos beta/fisiología , Receptores Muscarínicos/deficiencia , Receptores Muscarínicos/genética , Receptores Nicotínicos/efectos de los fármacos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Estimulación Química , Vagotomía
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