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1.
Heart Fail Rev ; 29(1): 179-189, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37861854

RESUMEN

Heart failure (HF) with preserved ejection fraction (HFpEF) is a common condition in clinical practice, affecting more than half of patients with HF. HFpEF is associated with morbidity and mortality and with considerable healthcare resource utilization and costs. Therefore, early diagnosis is crucial to facilitate prompt management, particularly initiation of sodium-glucose co-transporter 2 inhibitors. Although European guidelines define HFpEF as the presence of symptoms with or without signs of HF, left ventricular EF ≥ 50%, and objective evidence of cardiac structural and/or functional abnormalities, together with elevated natriuretic peptide levels, the diagnosis of HFpEF remains challenging. First, there is no clear consensus on how HFpEF should be defined. Furthermore, diagnostic tools, such as natriuretic peptide levels and resting echocardiogram findings, are significantly limited in the diagnosis of HFpEF. As a result, some patients are overdiagnosed (i.e., elderly people with comorbidities that mimic HF), although in other cases, HFpEF is overlooked. In this manuscript, we perform a systematic narrative review of the diagnostic approach to patients with HFpEF. We also propose a comprehensible algorithm that can be easily applied in daily clinical practice and could prove useful for confirming or ruling out a diagnosis of HFpEF.


Asunto(s)
Insuficiencia Cardíaca , Anciano , Humanos , Comorbilidad , Ecocardiografía , Péptidos Natriuréticos , Volumen Sistólico , Función Ventricular Izquierda
2.
FASEB J ; 34(1): 945-959, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31914664

RESUMEN

The dynamics of cytoplasmic free Ca2+ concentration ([Ca2+]i) in pancreatic ß cells is central to our understanding of ß-cell physiology and pathology. In this context, there are numerous in vitro studies available but existing in vivo data are scarce. We now critically evaluate the anterior chamber of the eye as an in vivo, non-invasive, imaging site for measuring [Ca2+]i dynamics longitudinally in three dimensions and at single-cell resolution. By applying a fluorescently labeled glucose analogue 2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)Amino)-2-Deoxyglucose in vivo, we followed how glucose almost simultaneously distributes to all cells within the islet volume, resulting in [Ca2+]i changes. We found that almost all ß cells in healthy mice responded to a glucose challenge, while in hyperinsulinemic, hyperglycemic mice about 80% of the ß cells could not be further stimulated from fasting basal conditions. This finding indicates that our imaging modality can resolve functional heterogeneity within the ß-cell population in terms of glucose responsiveness. Importantly, we demonstrate that glucose homeostasis is markedly affected using isoflurane compared to hypnorm/midazolam anesthetics, which has major implications for [Ca2+]i measurements. In summary, this setup offers a powerful tool to further investigate in vivo pancreatic ß-cell [Ca2+]i response patterns at single-cell resolution in health and disease.


Asunto(s)
Calcio/química , Células Secretoras de Insulina/metabolismo , Anestésicos/farmacología , Animales , Cámara Anterior/cirugía , Calcio/metabolismo , Cruzamientos Genéticos , Femenino , Glucosa/farmacología , Prueba de Tolerancia a la Glucosa , Heterocigoto , Homeostasis , Hiperglucemia/metabolismo , Hiperinsulinismo/metabolismo , Islotes Pancreáticos/citología , Trasplante de Islotes Pancreáticos , Isoflurano/farmacología , Ratones , Ratones Endogámicos C57BL , Midazolam/farmacología , Fenotipo
3.
FASEB J ; 33(1): 204-218, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-29957055

RESUMEN

Although convincing in genetic models, the relevance of ß-cell insulin resistance in diet-induced type 2 diabetes (T2DM) remains unclear. Exemplified by diabetes-prone, male, C57B1/6J mice being fed different combinations of Western-style diet, we show that ß-cell insulin resistance occurs early during T2DM progression and is due to a combination of lipotoxicity and increased ß-cell workload. Within 8 wk of being fed a high-fat, high-sucrose diet, mice became obese, developed impaired insulin and glucose tolerances, and displayed noncompensatory insulin release, due, at least in part, to reduced expression of syntaxin-1A. Through reporter islets transplanted to the anterior chamber of the eye, we demonstrated a concomitant loss of functional ß-cell mass. When mice were changed from diabetogenic diet to normal chow diet, the diabetes phenotype was reversed, suggesting a remarkable plasticity of functional ß-cell mass in the early phase of T2DM development. Our data reinforce the relevance of diet composition as an environmental factor determining different routes of diabetes progression in a given genetic background. Employing the in vivo reporter islet-monitoring approach will allow researchers to define key times in the dynamics of reversible loss of functional ß-cell mass and, thus, to investigate the underlying, molecular mechanisms involved in the progression toward T2DM manifestation.-Paschen, M., Moede, T., Valladolid-Acebes, I., Leibiger, B., Moruzzi, N., Jacob, S., García-Prieto, C. F., Brismar, K., Leibiger, I. B., Berggren, P.-O. Diet-induced ß-cell insulin resistance results in reversible loss of functional ß-cell mass.


Asunto(s)
Diabetes Mellitus Experimental/patología , Diabetes Mellitus Tipo 2/patología , Dieta Alta en Grasa/efectos adversos , Sacarosa en la Dieta/efectos adversos , Resistencia a la Insulina , Células Secretoras de Insulina/patología , Insulina/metabolismo , Animales , Células Cultivadas , Diabetes Mellitus Experimental/etiología , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/etiología , Diabetes Mellitus Tipo 2/metabolismo , Células Secretoras de Insulina/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL
5.
Rev Endocr Metab Disord ; 20(2): 161-171, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31020455

RESUMEN

Obesity is a public health problem present in both developed and developing countries. The white adipose tissue (WAT) is the main deposit of lipids when there is an excess of energy. Its pathological growth is directly linked to the development of obesity and to a wide number of comorbidities, such as insulin-resistance, cardiovascular disease, among others. In this scenario, it becomes imperative to develop new approaches to the treatment and prevention of obesity and its comorbidities. It has been documented that the browning of WAT could be a suitable strategy to tackle the obesity epidemic that is developing worldwide. Currently there is an intense search for bioactive compounds with anti-obesity properties, which present the particular ability to generate thermogenesis in the brown adipose tissue (BAT) or beige. The present study provide recent information of the bioactive nutritional compounds capable of inducing thermogenesis and therefore capable of generate positive effects on health.


Asunto(s)
Tejido Adiposo Blanco/metabolismo , Obesidad/metabolismo , Tejido Adiposo Pardo/metabolismo , Animales , Metabolismo Energético/fisiología , Humanos , Termogénesis/fisiología
6.
Clin Sci (Lond) ; 130(7): 525-38, 2016 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-26733721

RESUMEN

Resistant albuminuria, developed under adequate chronic blockade of the renin-angiotensin system, is a clinical problem present in a small number of patients with chronic kidney disease (CKD). The mechanism underlying this resistant albuminuria remains unknown. Matrix metalloproteinases (MMPs) are involved in the pathophysiology of cardiovascular and renal diseases. In the present study we tested the role of MMPs in resistant albuminuria. First we evaluated gelatinase MMP-2 and MMP-9 activity by zymography in the Munich Wistar Frömter (MWF) rat, a model of progressive albuminuria, and subsequently in patients with resistant albuminuria. Markers of oxidative stress were observed in the kidneys of MWF rats, together with a significant increase in pro-MMP-2 and active MMP-9 forms. These changes were normalized together with reduced albuminuria in consomic MWF-8(SHR) rats, in which chromosome 8 of MWF was replaced with the respective chromosome from spontaneously hypertensive rats. The MMP-2 and MMP-9 protein levels were similar in patients with normal and resistant albuminuria; however, high circulating levels of collagen IV, a specific biomarker of tissue collagen IV degradation, were observed in patients with resistant albuminuria. These patients showed a significant increase in gelatinase MMP-2 and MMP-9 activity, but only a significant increase in the active MMP-9 form quantified by ELISA, which correlated significantly with the degree of albuminuria. Although the expression of the tissue inhibitor of MMP-9 (TIMP)-1 was similar, a novel AlphaLISA assay demonstrated that the MMP-9-TIMP-1 interaction was reduced in patients with resistant albuminuria. It is of interest that oxidized TIMP-1 expression was higher in patients with resistant albuminuria. Therefore, increased circulating MMP-9 activity is associated with resistant albuminuria and a deleterious oxidative stress environment appears to be the underlying mechanism. These changes might contribute to the progression of CKD in these patients.


Asunto(s)
Albuminuria/enzimología , Riñón/enzimología , Metaloproteinasa 9 de la Matriz/sangre , Insuficiencia Renal Crónica/enzimología , Anciano , Albuminuria/sangre , Albuminuria/diagnóstico , Albuminuria/genética , Albuminuria/prevención & control , Bloqueadores del Receptor Tipo 1 de Angiotensina II/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Animales , Antihipertensivos/uso terapéutico , Modelos Animales de Enfermedad , Resistencia a Medicamentos , Femenino , Humanos , Hipertensión/diagnóstico , Hipertensión/tratamiento farmacológico , Hipertensión/fisiopatología , Riñón/efectos de los fármacos , Masculino , Metaloproteinasa 2 de la Matriz/sangre , Persona de Mediana Edad , Oxidación-Reducción , Estrés Oxidativo , Unión Proteica , Ratas Wistar , Insuficiencia Renal Crónica/sangre , Insuficiencia Renal Crónica/diagnóstico , Insuficiencia Renal Crónica/genética , Insuficiencia Renal Crónica/prevención & control , Transducción de Señal , Inhibidor Tisular de Metaloproteinasa-1/sangre
7.
Physiol Genomics ; 47(7): 281-9, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25969455

RESUMEN

Munich Wistar Frömter (MWF) rats develop spontaneous albuminuria that is linked to autosomal genetic loci and inherit a nephron deficit in both female and male animals, respectively. However, albuminuria and kidney damage are clearly more pronounced in males. Here we tested whether androgens and the androgen receptor influence albuminuria in male MWF. We first demonstrated in a pilot study that orchiectomy (Ox) of male MWF led to a significant suppression of urinary albumin excretion (UAE), while continuous testosterone supplementation in MWF Ox led to UAE levels similar to sham-operated (Sham) MWF rats. Subsequently, we performed a comparative main study between male MWF and normal Wistar rats to evaluate the effect of the androgen receptor on UAE development in adult animals up to the age of 18 wk. MWF Sham developed a marked increase in UAE compared with Wistar Sham (48.30 ± 6.16 vs. 0.42 ± 0.08 mg/24 h, P < 0.0001). UAE was significantly lower in MWF Ox compared with MWF Sham (-55%, P < 0.0001). In MWF Ox animals supplemented with testosterone and treated with the androgen receptor antagonist flutamide (OxTF) UAE at 18 wk was even lower compared with MWF Ox (-71%, P < 0.01) and similar to age-matched female MWF. The mRNA expression of renal tubular injury markers Kim1 and NGAL was increased in MWF Sham compared with Wistar Sham (P < 0.0008, respectively) and expression decreased significantly in MWF OxTF (P < 0.0004, respectively). Thus, the sexual dimorphism in albuminuria development in MWF can be attributed to testosterone and the androgen receptor in male rats.


Asunto(s)
Albuminuria/inducido químicamente , Orquiectomía/efectos adversos , Receptores Androgénicos/metabolismo , Caracteres Sexuales , Testosterona/efectos adversos , Antagonistas de Receptores Androgénicos/farmacología , Animales , Estudios de Casos y Controles , Femenino , Flutamida/farmacología , Masculino , Proyectos Piloto , Ratas , Ratas Wistar , Estadísticas no Paramétricas , Superóxidos/metabolismo , Testosterona/administración & dosificación , Testosterona/sangre
8.
Stem Cells ; 31(7): 1309-20, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23533182

RESUMEN

Adipose tissue (AT) has become accepted as a source of multipotent progenitor cells, the adipose stromal cells (ASCs). In this regard, considerable work has been performed to harvest and characterize this cell population as well as to investigate the mechanisms by which transplanted ASCs mediate tissue regeneration. In contrast the endogenous release of native ASCs by AT has been poorly investigated. In this work, we show that native ASCs egress from murine AT. Indeed, we demonstrated that the release of native ASCs from AT can be evidenced both using an ex vivo perfusion model that we set up and in vivo. Such a mobilization process is controlled by CXCR4 chemokine receptor. In addition, once mobilized from AT, circulating ASCs were found to navigate through lymph fluid and to home into lymph nodes (LN). Therefore, we demonstrated that, during the LN activation, the fat depot encapsulating the activated LN releases native ASCs, which in turn invade the activated LN. Moreover, the ASCs invading the LN were visualized in close physical interaction with podoplanin and ER-TR7 positive structures corresponding to the stromal network composing the LN. This dynamic was impaired with CXCR4 neutralizing antibody. Taken together, these data provide robust evidences that native ASCs can traffic in vivo and that AT might provide stromal cells to activated LNs.


Asunto(s)
Tejido Adiposo/citología , Ganglios Linfáticos/citología , Células Madre Mesenquimatosas/citología , Tejido Adiposo/metabolismo , Animales , Diferenciación Celular/fisiología , Procesos de Crecimiento Celular/fisiología , Quimiocina CXCL12/metabolismo , Inmunofenotipificación , Ganglios Linfáticos/metabolismo , Masculino , Células Madre Mesenquimatosas/metabolismo , Ratones , Ratones Endogámicos C57BL , Receptores CXCR4/metabolismo
9.
J Fish Biol ; 80(5): 1213-26, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22497380

RESUMEN

Between 2000 and 2002, three artisanal landing sites were sampled in southern Chile, with data on population structure and reproductive development collected from 5477 yellownose skates Zearaja chilensis. Total length (L(T) ) ranged from 33 to 158 cm for females and 34 to 155 cm for males. No sexual dimorphism was evident in disc size (length or width) or in L(T)-mass relationships. The smallest mature female was 95 cm L(T) and the size at which 50% were mature (L(T50) ) was 109 cm. Males matured between 80 and 90 cm L(T) with a L(T50) of 88 cm. Although the largest Z. chilensis captured by the artisanal fishery was 155 cm L(T) , 89% of landings comprised relatively small, immature fish. This situation may compromise the stock integrity if intrinsic vulnerability and probable long-life span of Z. chilensis are considered. Consequences for the survival of the species and possible signs of a fishery collapse must be reviewed by management authorities by consideration of both artisanal and industrial landings in Chile.


Asunto(s)
Reproducción , Rajidae/fisiología , Animales , Tamaño Corporal , Chile , Conservación de los Recursos Naturales , Femenino , Fertilidad , Explotaciones Pesqueras , Masculino , Océano Pacífico , Caracteres Sexuales , Maduración Sexual
10.
Rev Chilena Infectol ; 28(3): 269-73, 2011 Jun.
Artículo en Español | MEDLINE | ID: mdl-21879155

RESUMEN

Mucormycosis or zygomycosis is a rare opportunistic infection caused by aerobic saprophytic fungus that belongs to the class of Zygomycetes Mucorales family. These organisms live in the environment and enter the body by air, gastrointestinal or skin routes, through solutions of continuity of the skin. This microorganism is generally not pathogenic for immunocompetent hosts, being the development of the disease linked with the immune status of the subject. Its mortality is around 50-60%; sometimes in spite of early diagnosis and treatment initiation it has a fatal course. Six clinical forms of mucormycosis are described: rhinocerebral, cutaneous, pulmonary, disseminated, gastrointestinal and miscellaneous form. Two cases of patients with primary cutaneous mucormycosis diagnosed in the Pathology Unit of Hernan Henriquez Aravena Hospital of Temuco, Chile are presented here.


Asunto(s)
Dermatomicosis/diagnóstico , Mucormicosis/diagnóstico , Adulto , Anfotericina B/uso terapéutico , Antifúngicos/uso terapéutico , Dermatomicosis/tratamiento farmacológico , Dermatomicosis/patología , Humanos , Masculino , Persona de Mediana Edad , Mucormicosis/tratamiento farmacológico , Mucormicosis/patología , Índice de Severidad de la Enfermedad
11.
J Fish Biol ; 77(4): 963-71, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20840623

RESUMEN

The external morphology of the egg capsule of Bythaelurus canescens and its fixation to the substratum are described. Bythaelurus canescens egg capsules are typically vase-shaped, dorso-ventrally flattened, pale yellow in colour when fresh and covered by 12-15 longitudinal ridges. The anterior border of the capsule is straight, whereas the posterior border is semicircular. Two horns bearing long, coiled tendrils arise from the anterior and posterior ends of the capsule. The presence of longitudinal ridges and long coiled tendrils at both anterior and posterior ends of the capsule readily distinguish these egg capsules from those of other chondrichthyans occurring in the south-east Pacific Ocean.


Asunto(s)
Óvulo/fisiología , Tiburones/fisiología , Animales , Femenino , Océano Pacífico , Especificidad de la Especie
12.
Free Radic Biol Med ; 139: 35-45, 2019 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-31100477

RESUMEN

Caloric restriction (CR) improves endothelial function through the upregulation of adenosine monophosphate-activated protein kinase (AMPK) and endothelial nitric oxide synthase (eNOS). Moreover, hydrogen peroxide (H2O2) is upregulated in yeast subjected to CR. Our aim was to assess if mild short-term CR increases vascular H2O2 formation as a link with AMPK and eNOS activation. Twelve-week old Zucker obese (fa/fa) and control Zucker lean male rats were fed a standard chow either ad libitum (AL, n=10) or with a 20% CR (CR, n=10) for two weeks. CR significantly improved relaxation to ACh in fa/fa rats because of an enhanced endogenous production of H2O2 in aortic rings (H2O2 levels fa/faAL=0.5 ±â€¯0.05 nmol/mg vs. H2O2 levels fa/faCR=0.76 ±â€¯0.07 nmol/mg protein; p<0.05). Expression of mitochondrial superoxide dismutase (Mn-SOD) and total SOD activity were increased in aorta from fa/fa animals after CR. In cultured aortic endothelial cells, serum deprivation or 2-deoxy-d-glucose induced a significant increase in: i) superoxide anion and H2O2 levels, ii) p-AMPK/AMPK and p-eNOS/eNOS expression and iii) nitric oxide levels. This effect was reduced by catalase and strongly inhibited by Ca2+/calmodulin-dependent kinase II (CamkII) silencing. In conclusion, we propose that mild short-term CR might be a trigger of mechanisms aimed at protecting the vascular wall by the increase of H2O2, which then activates AMPK and nitric oxide release, thus improving endothelium-dependent relaxation. In addition, we demonstrate that CAMKII plays a key role in mediating CR-induced AMPK activation through H2O2 increase.


Asunto(s)
Proteínas Quinasas Activadas por AMP/genética , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/genética , Restricción Calórica , Peróxido de Hidrógeno/metabolismo , Óxido Nítrico Sintasa de Tipo III/genética , Obesidad/genética , Proteínas Quinasas Activadas por AMP/metabolismo , Animales , Aorta Torácica/metabolismo , Aorta Torácica/patología , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Catalasa/genética , Catalasa/metabolismo , Desoxiglucosa/farmacología , Células Endoteliales/citología , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Regulación de la Expresión Génica , Masculino , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo III/metabolismo , Obesidad/metabolismo , Obesidad/patología , Ratas , Ratas Zucker , Transducción de Señal , Superóxido Dismutasa/genética , Superóxido Dismutasa/metabolismo , Superóxidos/metabolismo , Vasodilatación
13.
Front Physiol ; 10: 553, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31133882

RESUMEN

Bariatric surgery (BS) results in sustained weight loss and may reverse inflammation, metabolic alterations, extracellular matrix remodeling and arterial stiffness. We hypothesize that increased stiffening in omental arteries from obese patients might be associated with an increase in MMP activity and a decrease in p-AMPK, together with systemic oxidative stress and inflammation. Moreover, BS could contribute to reversing these alterations. This study was conducted with 38 patients of Caucasian origin: 31 adult patients with morbid obesity (9 men and 22 women; mean age 46 years and BMI = 42.7 ± 1.0 kg/m2) and 7 non-obese subjects (7 women; mean age 45 years and BMI = 22.7 ± 0.6 kg/m2). Seventeen obese patients were studied before and 12 months after BS. The stiffness index ß, an index of intrinsic arterial stiffness, was determined in omental arteries and was significantly higher in obese patients. Levels of phosphorylated AMPK (p-AMPKThr-172) and SIRT-1 were significantly lower in peripheral blood mononuclear cells (PBMCs) from obese patients than those from non-obese patients (p < 0.05) and were normalized after BS. Total and active MMP-9 activities, LDH, protein carbonyls and uric acid were higher in obese patients and reduced by BS. Moreover, there was a correlation between plasmatic LDH levels and the stiffness index ß. BS has a beneficial effect on abnormal MMP-9, LDH and AMPK activities that might be associated with the development of arterial stiffness in obese patients. Since these parameters are easily measured in blood samples, they could constitute potential biomarkers of cardiovascular risk in morbid obesity.

14.
J Am Heart Assoc ; 8(9): e010090, 2019 05 07.
Artículo en Inglés | MEDLINE | ID: mdl-31030596

RESUMEN

Background Hypertension is the major risk factor for cardiovascular disease, the most common cause of death worldwide. Resistance arteries are capable of adapting their diameter independently in response to pressure and flow-associated shear stress. Ryanodine receptors (RyRs) are major Ca2+-release channels in the sarcoplasmic reticulum membrane of myocytes that contribute to the regulation of contractility. Vascular smooth muscle cells exhibit 3 different RyR isoforms (RyR1, RyR2, and RyR3), but the impact of individual RyR isoforms on adaptive vascular responses is largely unknown. Herein, we generated tamoxifen-inducible smooth muscle cell-specific RyR2-deficient mice and tested the hypothesis that vascular smooth muscle cell RyR2s play a specific role in elementary Ca2+ signaling and adaptive vascular responses to vascular pressure and/or flow. Methods and Results Targeted deletion of the Ryr2 gene resulted in a complete loss of sarcoplasmic reticulum-mediated Ca2+-release events and associated Ca2+-activated, large-conductance K+ channel currents in peripheral arteries, leading to increased myogenic tone and systemic blood pressure. In the absence of RyR2, the pulmonary artery pressure response to sustained hypoxia was enhanced, but flow-dependent effects, including blood flow recovery in ischemic hind limbs, were unaffected. Conclusions Our results establish that RyR2-mediated Ca2+-release events in VSCM s specifically regulate myogenic tone (systemic circulation) and arterial adaptation in response to changes in pressure (hypoxic lung model), but not flow. They further suggest that vascular smooth muscle cell-expressed RyR2 deserves scrutiny as a therapeutic target for the treatment of vascular responses in hypertension and chronic vascular diseases.


Asunto(s)
Canales de Potasio de Gran Conductancia Activados por el Calcio/metabolismo , Músculo Liso Vascular/metabolismo , Miocitos del Músculo Liso/metabolismo , Canal Liberador de Calcio Receptor de Rianodina/genética , Retículo Sarcoplasmático/metabolismo , Animales , Aorta/metabolismo , Aorta/fisiopatología , Arterias/metabolismo , Arterias/fisiopatología , Presión Sanguínea/fisiología , Señalización del Calcio , Miembro Posterior/irrigación sanguínea , Hipoxia/metabolismo , Hipoxia/fisiopatología , Flujometría por Láser-Doppler , Pulmón/irrigación sanguínea , Ratones , Ratones Noqueados , Músculo Liso Vascular/fisiopatología , Miografía , Técnicas de Placa-Clamp , Inhibidores de Fosfodiesterasa/farmacología , Arteria Pulmonar/metabolismo , Arteria Pulmonar/fisiopatología , Canal Liberador de Calcio Receptor de Rianodina/metabolismo , Vasoconstricción
15.
Nat Commun ; 10(1): 3700, 2019 08 16.
Artículo en Inglés | MEDLINE | ID: mdl-31420552

RESUMEN

Little is known about the role of islet delta cells in regulating blood glucose homeostasis in vivo. Delta cells are important paracrine regulators of beta cell and alpha cell secretory activity, however the structural basis underlying this regulation has yet to be determined. Most delta cells are elongated and have a well-defined cell soma and a filopodia-like structure. Using in vivo optogenetics and high-speed Ca2+ imaging, we show that these filopodia are dynamic structures that contain a secretory machinery, enabling the delta cell to reach a large number of beta cells within the islet. This provides for efficient regulation of beta cell activity and is modulated by endogenous IGF-1/VEGF-A signaling. In pre-diabetes, delta cells undergo morphological changes that may be a compensation to maintain paracrine regulation of the beta cell. Our data provides an integrated picture of how delta cells can modulate beta cell activity under physiological conditions.


Asunto(s)
Islotes Pancreáticos/ultraestructura , Comunicación Paracrina , Estado Prediabético/patología , Seudópodos/ultraestructura , Células Secretoras de Somatostatina/ultraestructura , Animales , Glucemia/metabolismo , Humanos , Factor I del Crecimiento Similar a la Insulina/metabolismo , Células Secretoras de Insulina/citología , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/ultraestructura , Microscopía Intravital , Islotes Pancreáticos/citología , Islotes Pancreáticos/metabolismo , Islotes Pancreáticos/patología , Ratones , Ratones Transgénicos , Microscopía Electrónica , Imagen Óptica , Optogenética , Estado Prediabético/metabolismo , Seudópodos/metabolismo , Células Secretoras de Somatostatina/citología , Células Secretoras de Somatostatina/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo
17.
Nutr. hosp ; 39(1): 27-32, ene. - feb. 2022. tab
Artículo en Inglés | IBECS (España) | ID: ibc-209664

RESUMEN

Background: the six minutes' walk test (6MWT) measures submaximal physical activity. Objective: this study determines the association of children´s nutritional status and body composition with the results of the 6MWT. Methods: a sample of 1419 Chilean children, 4 to 10 years of age, were assessed including anthropometry, body composition by validated equations, the 6MWT test, and in 50 % of the sample heart rate prior the test, at one minute into the test, and at one minute posttest with a Polar watch. Results: the distance walked ranged from 473.1 ± 47.8 meters in preschool children to 584.2 ± 65.7 meters in school children. In heart rate there was a significant difference between obese and eutrophic children. The distance walked in the 6MWT was positively associated with fat-free mass (p < 0.05) and BMI (R2 = 0.49). Body composition influences 6MWT quartile distribution, as well as nutritional status. Age and height explained 49 % of the variance (R2 = 0.42 and 0.47, respectively) in the 6MWT, and there are significant differences in this variable by sex, body composition, and nutritional status. Conclusions: body composition was associated with walking performance in children. Thus, it is important to evaluate height and body composition when assessing the six-minute walk test because of this important relationship (AU)


Introducción: el test de la marcha de seis minutos (TM6M) mide una actividad física submáxima. Este estudio evaluó el efecto del test de la marcha sobre la composición corporal y el estado nutricional en niños. Métodos: en una muestra de 1419 niños chilenos de 4 a 10 años de edad se evaluaron la antropometría, la composición corporal por ecuaciones validadas, el TM6M y, en el 50 % de la muesta, la frecuencia cardíaca mediante un reloj Polar. Resultados: la distancia caminada varió desde 473,1 ± 47,8 metros en los niños preescolares hasta 584,2 ± 65,7 metros en los escolares. En la frecuencia cardíaca hubo una diferencia significativa entre niños obesos y eutróficos. La distancia caminada se asoció positivamente con la masa libre de grasa (R2 = 0,37) y el IMC (R2 = 0,49). Por otra parte, la composición corporal varía en función de los cuartiles de composición corporal y el estado nutricional. La edad y la altura explicaron el 49 % de la varianza de la prueba (R2 = 0,42 and 0,47, respectivamente). Existen diferencias significativas en la distancia recorrida en el TM6M en función del sexo, la composición corporal y el estado nutricional. Conclusiones: composición corporal, talla e IMC se asociaron a la distancia recorrida en el TM6M. Por tanto, se sugiere medir estas variables cuando se evalúe el test de marcha de seis minutos (AU)


Asunto(s)
Humanos , Masculino , Femenino , Preescolar , Niño , Prueba de Paso/métodos , Composición Corporal , Frecuencia Cardíaca , Estatura , Chile
18.
Front Physiol ; 8: 42, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28203206

RESUMEN

Caloric restriction (CR) ameliorates cardiac dysfunction associated with obesity. However, most of the studies have been performed under severe CR (30-65% caloric intake decrease) for several months or even years in aged animals. Here, we investigated whether mild (20% food intake reduction) and short-term (2-weeks) CR prevented the obese cardiomyopathy phenotype and improved the metabolic profile of young (14 weeks of age) genetically obese Zucker fa/fa rats. Heart weight (HW) and HW/tibia length ratio was significantly lower in fa/fa rats after 2 weeks of CR than in counterparts fed ad libitum. Invasive pressure measurements showed that systolic blood pressure, maximal rate of positive left ventricle (LV) pressure, LV systolic pressure and LV end-diastolic pressure were all significantly higher in obese fa/fa rats than in lean counterparts, which were prevented by CR. Magnetic resonance imaging revealed that the increase in LV end-systolic volume, stroke volume and LV wall thickness observed in fa/fa rats was significantly lower in animals on CR diet. Histological analysis also revealed that CR blocked the significant increase in cardiomyocyte diameter in obese fa/fa rats. High resolution magic angle spinning magnetic resonance spectroscopy analysis of the LV revealed a global decrease in metabolites such as taurine, creatine and phosphocreatine, glutamate, glutamine and glutathione, in obese fa/fa rats, whereas lactate concentration was increased. By contrast, fatty acid concentrations in LV tissue were significantly elevated in obese fa/fa rats. CR failed to restore the LV metabolomic profile of obese fa/fa rats. In conclusion, mild and short-term CR prevented an obesity-induced cardiomyopathy phenotype in young obese fa/fa rats independently of the cardiac metabolic profile.

19.
PLoS One ; 12(2): e0171544, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28212445

RESUMEN

BACKGROUND AND AIMS: Fetal undernutrition is a risk factor for heart disease in both genders, despite the protection of women against hypertension development. Using a rat model of maternal undernutrition (MUN) we aimed to assess possible sex differences in the development of cardiac alterations and the implication of hypertension and cardiac oxidative stress. METHODS: Male and female offspring from rats fed ad libitum (control) or with 50% of the normal daily intake during the second half of gestation (MUN) were used. Heart weight/body weight ratio (HW/BW), hemodynamic parameters (anaesthetized rats) and plasma brain natriuretic peptide (BNP, ELISA) were assessed in 21-day, 6-month and 22-month old rats. Plasma testosterone (ELISA) and cardiac protein expression of enzymes related to reactive oxygen species synthesis (p22phox, xanthine-oxidase) and degradation (catalase, Cu/Zn-SOD, Mn-SOD, Ec-SOD) were evaluated in 21-day and 6-month old rats (Western Blot). Heart structure and function was studied at the age of 22 months (echocardiography). RESULTS: At the age of 21 days MUN males exhibited significantly larger HW/BW and cardiac p22phox expression while females had reduced p22phox expression, compared to their respective sex-matched controls. At the age of 6-months, MUN males showed significantly larger blood pressure and cardiac xanthine-oxidase expression; MUN females were normotensive and had a lower cardiac expression of antioxidant enzymes, compared to their respective sex-matched controls. At the age of 22 months, both MUN males and females showed larger HW/BW and left ventricular mass and lower ejection fraction compared to sex-matched controls; only MUN males exhibited hypertension and a larger plasma BNP compared to aged male controls. CONCLUSIONS: 1) During perinatal life females exposed to fetal undernutrition are protected from cardiac alterations, but in ageing they exhibit ventricular hypertrophy and functional loss, like MUN males; 2) cardiac oxidative stress might be implicated in the observed heart alterations in both sexes and 3) the severity of cardiac damage might be greater in males due to hypertension.


Asunto(s)
Trastornos Nutricionales en el Feto , Hipertensión/metabolismo , Estrés Oxidativo , Efectos Tardíos de la Exposición Prenatal/metabolismo , Animales , Peso Corporal , Femenino , Hemodinámica , Hormonas/sangre , Hipertensión/sangre , Hipertensión/patología , Hipertensión/fisiopatología , Masculino , Madres , Miocardio/metabolismo , Miocardio/patología , Péptido Natriurético Encefálico/metabolismo , Tamaño de los Órganos , Embarazo , Efectos Tardíos de la Exposición Prenatal/sangre , Efectos Tardíos de la Exposición Prenatal/patología , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Factores de Riesgo , Caracteres Sexuales , Factores de Tiempo
20.
Nutrients ; 8(6)2016 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-27314388

RESUMEN

Caloric restriction (CR) has proved to be the most effective and reproducible dietary intervention to increase healthy lifespan and aging. A reduction in cardiovascular disease (CVD) risk in obese subjects can be already achieved by a moderate and sustainable weight loss. Since pharmacological approaches for body weight reduction have, at present, a poor long-term efficacy, CR is of great interest in the prevention and/or reduction of CVD associated with obesity. Other dietary strategies changing specific macronutrients, such as altering carbohydrates, protein content or diet glycemic index have been also shown to decrease the progression of CVD in obese patients. In this review, we will focus on the positive effects and possible mechanisms of action of these strategies on vascular dysfunction.


Asunto(s)
Envejecimiento , Restricción Calórica , Enfermedades Cardiovasculares/prevención & control , Enfermedades Metabólicas/prevención & control , Animales , Peso Corporal , Enfermedades Cardiovasculares/etiología , Dieta Reductora , Carbohidratos de la Dieta/administración & dosificación , Proteínas en la Dieta/administración & dosificación , Modelos Animales de Enfermedad , Ingestión de Energía , Índice Glucémico , Humanos , Enfermedades Metabólicas/etiología , Obesidad/complicaciones , Obesidad/dietoterapia , Factores de Riesgo
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