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1.
Front Digit Health ; 6: 1379290, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38895514

RESUMEN

Introduction: The All of Us Research Program (Program) is an ongoing epidemiologic cohort study focused on collecting lifestyle, health, socioeconomic, environmental, and biological data from 1 million US-based participants. The Program has a focus on enrolling populations that are underrepresented in biomedical research (UBR). Federally Qualified Health Centers (FQHCs) are a key recruitment stream of UBR participants. The Program is digital by design where participants complete surveys via web-based platform. As many FQHC participants are not digitally ready, recruitment and retention is a challenge, requiring high-touch methods. However, high-touch methods ceased as an option in March 2020 when the Program paused in-person activities because of the pandemic. In January 2021, the Program introduced Computer Assisted Telephone Interviewing (CATI) to help participants complete surveys remotely. This paper aims to understand the association between digital readiness and mode of survey completion (CATI vs. web-based platform) by participants at FQHCs. Methods: This study included 2,089 participants who completed one or more surveys via CATI and/or web-based platform between January 28, 2021 (when CATI was introduced) and January 27, 2022 (1 year since CATI introduction). Results and discussion: Results show that among the 700 not-digitally ready participants, 51% used CATI; and of the 1,053 digitally ready participants, 30% used CATI for completing retention surveys. The remaining 336 participants had "Unknown/Missing" digital readiness of which, 34% used CATI. CATI allowed survey completion over the phone with a trained staff member who entered responses on the participant's behalf. Regardless of participants' digital readiness, median time to complete retention surveys was longer with CATI compared to web. CATI resulted in fewer skipped responses than the web-based platform highlighting better data completeness. These findings demonstrate the effectiveness of using CATI for improving response rates in online surveys, especially among populations that are digitally challenged. Analyses provide insights for NIH, healthcare providers, and researchers on the adoption of virtual tools for data collection, telehealth, telemedicine, or patient portals by digitally challenged groups even when in-person assistance continues to remain as an option. It also provides insights on the investment of staff time and support required for virtual administration of tools for health data collection.

2.
Artículo en Inglés | MEDLINE | ID: mdl-38886995

RESUMEN

OBJECTIVE: This case study describes how an All of Us engagement project returned value to community by strengthening high school students' capacity to serve as health advocates. MATERIALS AND METHODS: Project activities included health literacy education and research projects on the influence of environmental, societal, and lifestyle factors on community health disparities. The research project involved use of the Photovoice method and All of Us data. At project's end, students presented their research to the community. RESULTS: The project's success was measured by students' participation in the research poster session and comparison of pre- and post-project scores from the Health Literacy Assessment Scale for Adolescent. Data analysis suggests the project succeeded in meeting its goal of increasing students' health literacy. DISCUSSION AND CONCLUSION: Through education and research activities, students learned about community health issues and the importance of participation in medical research programs, like All of Us, to address issues.

3.
Eur J Appl Physiol ; 120(9): 2029-2036, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32596752

RESUMEN

PURPOSE: Decline in skeletal muscle mitochondrial oxidative capacity (MOC) is associated with reduced aerobic capacity and increased risk of cardiovascular and metabolic disease. Measuring skeletal muscle MOC may be an alternative method to assess aerobic capacity, especially for individuals unable to perform a whole-body maximum oxygen uptake protocol. In this study, linear regression analysis in two leg muscles was performed to determine whether MOC values could be used to predict whole-body peak oxygen uptake. METHODS: MOC was measured with near infrared spectroscopy (NIRS) in the medial gastrocnemius (MG) and vastus lateralis (VL) muscles of 26 participants (age, 27.1 ± 5.8 years old). Whole-body peak oxygen uptake (VO2 peak) was determined by indirect calorimetry during a continuous ramp protocol on a cycle ergometer. RESULTS: VO2 peak values were significantly correlated with the muscle recovery rate constant (k) of the MG (kMG, r = 0.59; p < 0.01) and VL (kVL, r = 0.63; p < 0.01) muscles. Summing recovery rate constants of both muscles together (kMG + kVL) improved the strength of the correlation with VO2 peak (r = 0.78; p < 0.0001) and could explain a majority of the variance (R2 = 0.61) between the two measurements. CONCLUSION: Data suggest that NIRS can provide reliable MOC measurements on two leg muscles that correlate well with whole-body peak oxygen uptake.


Asunto(s)
Ejercicio Físico/fisiología , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiología , Consumo de Oxígeno/fisiología , Oxígeno/metabolismo , Adulto , Calorimetría Indirecta/métodos , Prueba de Esfuerzo/métodos , Tolerancia al Ejercicio/fisiología , Femenino , Humanos , Pierna/fisiología , Masculino , Mitocondrias Musculares/metabolismo , Mitocondrias Musculares/fisiología , Aptitud Física/fisiología , Músculo Cuádriceps/fisiología , Espectroscopía Infrarroja Corta/métodos
4.
Eur J Pharmacol ; 744: 76-82, 2014 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-25281837

RESUMEN

(-)-Epicatechin (EPI) is cardioprotective in the setting of ischemia/reperfusion (IR) injury and doxycycline (DOX) is known to preserve cardiac structure/function after myocardial infarction (MI). The main objective of this study was to examine the effects of EPI and DOX co-administration on MI size after IR injury and to determine if cardioprotection may involve the mitigation of mitochondrial swelling. For this purpose, a rat model of IR was used. Animals were subjected to a temporary 45 min occlusion of the left anterior descending coronary artery. Treatment consisted of a single or double dose of EPI (10 mg/kg) combined with DOX (5 mg/kg). The first dose was given 15 min prior to reperfusion and the second 12 h post-MI. The effects of EPI +/- DOX on mitochondrial swelling (i.e. mPTP opening) were determined using isolated mitochondria exposed to calcium overload and data examined using isobolographic analysis. To ascertain for the specificity of EPI effects on mitochondrial swelling other flavonoids were also evaluated. Single dose treatment reduced MI size by ~46% at 48 h and 44% at three weeks. Double dosing evidenced a synergistic, 82% reduction at 3 weeks. EPI plus DOX also inhibited mitochondrial swelling in a synergic manner thus, possibly accounting for the cardioprotective effects whereas limited efficacy was observed with the other flavonoids. Given the apparent lack of toxicity in humans, the combination of EPI and DOX may have clinical potential for the treatment of myocardial IR injury.


Asunto(s)
Catequina/farmacología , Doxiciclina/farmacología , Flavonoides/farmacología , Dilatación Mitocondrial/efectos de los fármacos , Infarto del Miocardio/tratamiento farmacológico , Daño por Reperfusión/tratamiento farmacológico , Animales , Cardiotónicos/farmacología , Vasos Coronarios/efectos de los fármacos , Sinergismo Farmacológico , Masculino , Mitocondrias Cardíacas/efectos de los fármacos , Daño por Reperfusión Miocárdica/tratamiento farmacológico , Ratas , Ratas Sprague-Dawley
5.
Int J Cardiol ; 175(2): 297-306, 2014 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-24908200

RESUMEN

BACKGROUND: Targeting the mitochondria during ischemia/reperfusion (IR) can confer cardioprotection leading to improved clinical outcomes. The cardioprotective potential of (-)-epicatechin (EPI) during IR via modulation of mitochondrial function was evaluated. METHODS AND RESULTS: Ischemia was induced in rats via a 45 min occlusion of the left anterior descending coronary artery followed by 1 h, 48 h, or 3 week reperfusion. EPI (10 mg/kg) was administered IV 15 min prior to reperfusion for the single dose group and again 12 h later for the double dose group. Controls received water. Experiments also utilized cultured neonatal rat ventricular myocytes (NRVM) and myoblasts. A single dose of EPI reduced infarct size by 27% at 48 h and 28% at 3 week. Double dose treatment further decreased infarct size by 80% at 48 h, and 52% by 3 weeks. The protective effect of EPI on mitochondrial function was evident after 1h of reperfusion when mitochondria demonstrated less respiratory inhibition, lower mitochondrial Ca2+ load, and a preserved pool of NADH that correlated with higher tissue ATP levels. Mechanistic studies in NRVM revealed that EPI acutely stimulated maximal rates of respiration, an effect that was blocked by inhibitors of the mitochondrial pyruvate carrier, nitric oxide synthase, or soluble guanylyl cyclase. In myoblasts, knockdown of components of the mitochondrial pyruvate carrier blocked EPI-induced respiratory stimulation. CONCLUSIONS: IV EPI confers cardioprotection via preservation of mitochondrial function potentially through enhanced substrate provision. These provocative results document a novel mechanism of a natural product with potential clinical utility.


Asunto(s)
Cardiotónicos/administración & dosificación , Catequina/administración & dosificación , Mitocondrias Cardíacas/efectos de los fármacos , Mitocondrias Cardíacas/fisiología , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/prevención & control , Animales , Animales Recién Nacidos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Infusiones Intravenosas , Masculino , Daño por Reperfusión Miocárdica/fisiopatología , Ratas , Ratas Sprague-Dawley
6.
J Cardiovasc Transl Res ; 5(6): 805-13, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23054657

RESUMEN

Cardiac fibroblasts (CFs) are involved in maintaining extracellular matrix (ECM) homeostasis in the heart. CFs mediate responses to hormonal and mechanical stimuli and relay these to other local cell types through release of autocrine and/or paracrine factors. CFs also play important roles in the setting of injury, i.e., myocardial infarction, where ECM production is key to efficient scarring. However, conditions exist in which excess production of ECM by CFs can lead to cardiac fibrosis. Two important pathways known to be involved in development of cardiac fibrosis are renin-angiotensin system (RAS) and advanced glycation end products (AGE) receptor (RAGE) signaling cascades. This report summarizes actions of these two pathways on function of CFs. Because cardiac fibrosis is an important component of diabetic cardiomyopathy, we include new data that suggests a possible crosstalk between the RAS and AGE/RAGE pathway in order to activate CFs in diabetes.


Asunto(s)
Cardiomiopatías Diabéticas/metabolismo , Fibroblastos/metabolismo , Productos Finales de Glicación Avanzada/metabolismo , Miocardio/metabolismo , Receptor Cross-Talk , Receptores Inmunológicos/metabolismo , Sistema Renina-Angiotensina , Transducción de Señal , Animales , Cardiomiopatías Diabéticas/patología , Matriz Extracelular/metabolismo , Fibroblastos/patología , Fibrosis , Humanos , Miocardio/patología , Receptor para Productos Finales de Glicación Avanzada
7.
J Biol Chem ; 287(35): 29273-84, 2012 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-22778266

RESUMEN

Understanding mechanisms underlying titin regulation in cardiac muscle function is of critical importance given recent compelling evidence that highlight titin mutations as major determinants of human cardiomyopathy. We previously identified a cardiac biomechanical stress-regulated complex at the cardiac-specific N2B region of titin that includes four-and-a-half LIM domain protein-1 (Fhl1) and components of the mitogen-activated protein signaling cascade, which impacted muscle compliance in Fhl1 knock-out cardiac muscle. However, direct regulation of these molecular components in mediating titin N2B function remained unresolved. Here we identify Fhl1 as a novel negative regulator of titin N2B levels and phosphorylation-mediated mechanics. We specifically identify titin N2B as a novel substrate of extracellular signal regulated-kinase-2 (Erk2) and demonstrate that Fhl1 directly interferes with Erk2-mediated titin-N2B phosphorylation. We highlight the critical region in titin-N2B that interacts with Fhl1 and residues that are dependent on Erk2-mediated phosphorylation in situ. We also propose a potential mechanism for a known titin-N2B cardiomyopathy-causing mutation that involves this regulatory complex. These studies shed light on a novel mechanism regulating titin-N2B mechano-signaling as well as suggest that dysfunction of these pathways could be important in cardiac disease states affecting muscle compliance.


Asunto(s)
Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas con Dominio LIM/metabolismo , Mecanotransducción Celular , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteínas Musculares/metabolismo , Miocardio/metabolismo , Proteínas Quinasas/metabolismo , Animales , Cardiomiopatías/metabolismo , Cardiomiopatías/patología , Conectina , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Proteínas con Dominio LIM/genética , Ratones , Ratones Noqueados , Proteína Quinasa 1 Activada por Mitógenos/genética , Proteínas Musculares/genética , Mutación , Miocardio/patología , Fosforilación , Proteínas Quinasas/genética , Estructura Terciaria de Proteína
8.
Am J Physiol Heart Circ Physiol ; 302(7): H1387-93, 2012 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-22268115

RESUMEN

Poorly synchronized activation of the ventricles can lead to impairment of normal cardiac structure/function. We reported previously that short term (4 h) left ventricular (LV) pacing-induced ventricular dyskinesis led to an inflammatory response localized to the epicardium. Results from this study demonstrated that neutrophils may play a major role in this inflammatory process. Neutrophil recruitment to a site of injury is a process that is highly dependent on an upregulation of cell adhesion molecules (CAM). The dependence of ventricular dysynchrony-induced inflammatory responses on CAM upregulation has not been explored. To gain further insight, we used a mouse model of LV pacing to evaluate the role of CAM in mediating the inflammatory response associated with ventricular dyskinesis. We first examined the effects of LV pacing in wild-type mice. Results demonstrate that 40 min of LV pacing increases ICAM-1 immunostaining as well as myeloperoxidase activity and tissue oxidative stress by twofold in early-activated myocardium. Matrix metalloproteinase-9 activity also increased in the same region by ∼3.5-fold. To determine the role of CAM, mice null for ICAM-1 or p-selectin were subjected to 40 min LV pacing. Results demonstrate that the inflammatory response seen in the wild-type mice was significantly mitigated in the ICAM-1 and p-selectin null mice. In conclusion, results demonstrate that CAM expression plays a critical role in the triggering of LV pacing-induced inflammation, thus providing evidence of a vascular mechanism underlying this response. The mechanisms that trigger an upregulation of myocardial CAM expression and, therefore, inflammation await further investigation since they suggest a specific involvement of vascular events.


Asunto(s)
Estimulación Cardíaca Artificial/efectos adversos , Moléculas de Adhesión Celular/fisiología , Miocarditis/fisiopatología , Animales , Moléculas de Adhesión Celular/genética , Interpretación Estadística de Datos , Electrocardiografía , Electrodos Implantados , Glutatión/metabolismo , Inmunohistoquímica , Técnicas In Vitro , Molécula 1 de Adhesión Intercelular/genética , Molécula 1 de Adhesión Intercelular/fisiología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Selectina-P/genética , Selectina-P/fisiología , Peroxidasa/metabolismo , Función Ventricular Izquierda/fisiología
9.
Am J Physiol Heart Circ Physiol ; 300(4): H1282-90, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21297025

RESUMEN

Perturbations in the normal sequence of ventricular activation can create regions of early and late activation, leading to dysynchronous contraction and areas of dyskinesis. Dyskinesis occurs across the left ventricular (LV) wall, and its presence may have important consequences on cardiac structure and function in normal and failing hearts. Acutely, dyskinesis can trigger inflammation and, in the long term (6 wk and above), leads to LV remodeling. The mechanisms that trigger these changes are unknown. To gain further insight, we used a canine model to evaluate transumural changes in myocardial function and inflammation induced by epicardial LV pacing. The results indicate that 4 h of LV suprathreshold pacing resulted in a 30% local loss of endocardial thickening. Assessment of neutrophil infiltration showed a significant approximately fivefold increase in myeloperoxidase activity in the epicardium versus the midwall/endocardium. Matrix metalloproteinase-9 activity increased ∼2 fold in the epicardium and ROS generation increased ∼2.5-fold compared with the midwall/endocardium. To determine the effects that electrical current alone has on these end points, a group of animals was subjected to subthreshold pacing. Significant increases were observed only in epicardial myeloperoxidase levels. Thus, the results indicate that transmural dyskinesis induced by suprathreshold epicardial LV activation triggers a localized epicardial inflammatory response, whereas subthreshold stimulation appears to solely induce the trapping of leucocytes. Suprathreshold pacing also induces a loss of endocardial function. These results may have important implications as to the nature of the mechanisms that trigger the inflammatory response and possibly long-term remodeling in the setting of dysynchrony.


Asunto(s)
Estimulación Cardíaca Artificial/métodos , Contracción Miocárdica/fisiología , Pericarditis/enzimología , Animales , Perros , Masculino , Metaloproteinasa 9 de la Matriz/biosíntesis , Infiltración Neutrófila/fisiología , Peroxidasa/biosíntesis , Especies Reactivas de Oxígeno/metabolismo , Función Ventricular Izquierda/fisiología
10.
J Am Coll Cardiol ; 55(25): 2869-76, 2010 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-20579545

RESUMEN

OBJECTIVES: We examined the effects of the flavanol (-)-epicatechin on short- and long-term infarct size and left ventricular (LV) structure and function after permanent coronary occlusion (PCO) and the potential involvement of the protective protein kinase B (AKT)/extracellular signal-related kinase (ERK) signaling pathways. BACKGROUND: (-)-epicatechin reduces blood pressure in hypertensive patients and limits infarct size in animal models of myocardial ischemia-reperfusion injury. However, nothing is known about its effects on infarction after PCO. METHODS: (-)-epicatechin (1 mg/kg daily) treatment was administered via oral gavage to 250 g male rats for 10 days before PCO and was continued afterward. The PCO controls received water. Sham animals underwent thoracotomy and treatment in the absence of PCO. Immunoblots assessed AKT/ERK involvement 2 h after PCO. The LV morphometric features and function were measured 48 h and 3 weeks after PCO. RESULTS: In the 48-h group, treatment reduced infarct size by 52%. There were no differences in hemodynamics among the different groups (heart rate and aortic and LV pressures). Western blots revealed no differences in AKT or ERK phosphorylation levels. At 3 weeks, PCO control animals demonstrated significant increases in LV end-diastolic pressure, heart and body weight, and LV chamber diameter versus sham. The PCO plus (-)-epicatechin group values were comparable with those of the sham plus (-)-epicatechin group. Treatment resulted in a 33% decrease in myocardial infarction size. The LV pressure-volume curves demonstrated a right shift in control PCO animals, whereas the (-)-epicatechin curves were comparable with those of the sham group. The LV scar area strains were significantly improved with (-)-epicatechin. CONCLUSIONS: These results demonstrate the unique capacity of (-)-epicatechin to confer cardioprotection in the setting of a severe form of myocardial ischemic injury. Protection is sustained over time and preserves LV structure and function. The cardioprotective mechanism(s) of (-)-epicatechin seem to be unrelated to AKT or ERK activation. (-)-epicatechin warrants further investigation as a cardioprotectant.


Asunto(s)
Catequina/farmacología , Oclusión Coronaria/tratamiento farmacológico , Hemodinámica/fisiología , Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/prevención & control , Remodelación Ventricular/efectos de los fármacos , Administración Oral , Análisis de Varianza , Animales , Circulación Coronaria , Oclusión Coronaria/diagnóstico por imagen , Oclusión Coronaria/mortalidad , Modelos Animales de Enfermedad , Masculino , Infarto del Miocardio/mortalidad , Infarto del Miocardio/patología , Daño por Reperfusión Miocárdica/prevención & control , Probabilidad , Radiografía , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Valores de Referencia , Tasa de Supervivencia , Resultado del Tratamiento , Remodelación Ventricular/fisiología
11.
Am J Physiol Cell Physiol ; 296(5): C1178-84, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19279233

RESUMEN

Rat cardiac fibroblasts (CF) express multiple adenosine (ADO) receptors. Pharmacological evidence suggests that activation of A(2) receptors may inhibit collagen synthesis via adenylyl cyclase-induced elevation of cellular cAMP. We have characterized the signaling pathways involved in ADO-mediated inhibition of collagen synthesis in primary cultures of adult rat CF. ANG II stimulates collagen production in these cells. Coincubation with agents that elevate cellular cAMP [the ADO agonist, 5'-N-ethylcarboxamidoadensoine (NECA), and forskolin] inhibited the stimulatory effects of ANG II. However, direct stimulators and inhibitors of protein kinase A (PKA) did not alter ANG II-induced collagen synthesis, indicating that PKA does not mediate the inhibitory effects of NECA. Inhibitors of AMP-kinase (AMPK) and extracellular signal-regulated kinase 1/2 (ERK1/2) do not alter NECA-inhibited collagen synthesis. However, activation of exchange factor directly activated by cAMP (Epac) mimicked the effects of NECA on ANG II-stimulated collagen synthesis. Inhibition of phosphoinositol-3 kinase (PI3K) reduced the inhibitory effects of NECA on ANG II-induced collagen synthesis, suggesting that NECA acts via PI3K. Furthermore, inhibition of PI3K also relieved the inhibitory effect of Epac activation on ANG II-stimulated collagen synthesis. Thus it appears that ADO activates the A(2)R-G(s)-adenylyl cyclase pathway and that the resultant cAMP reduces collagen synthesis via a PKA-independent, Epac-dependent pathway that feeds through PI3K.


Asunto(s)
Adenosina/metabolismo , Colágeno/biosíntesis , Fibroblastos/metabolismo , Factores de Intercambio de Guanina Nucleótido/metabolismo , Miocardio/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Adenosina-5'-(N-etilcarboxamida)/farmacología , Angiotensina II/farmacología , Animales , Células Cultivadas , AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/metabolismo , Masculino , Miocardio/citología , Ratas , Ratas Sprague-Dawley , Receptores Purinérgicos P1/metabolismo , Vasoconstrictores/farmacología , Vasodilatadores/farmacología
12.
Am J Physiol Heart Circ Physiol ; 295(2): H610-8, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18515651

RESUMEN

Although previous studies report a reduction in myocardial volume during systole, myocardial volume changes during the cardiac cycle have not been quantitatively analyzed with high spatiotemporal resolution. We studied the time course of myocardial volume in the anterior mid-left ventricular (LV) wall of normal canine heart in vivo (n = 14) during atrial or LV pacing using transmurally implanted markers and biplane cineradiography (8 ms/frame). During atrial pacing, there was a significant transmural gradient in maximum volume decrease (4.1, 6.8, and 10.3% at subepi, midwall, and subendo layer, respectively, P = 0.002). The rate of myocardial volume increase during diastole was 4.7 +/- 5.8, 6.8 +/- 6.1, and 10.8 +/- 7.7 ml.min(-1).g(-1), respectively, which is substantially larger than the average myocardial blood flow in the literature measured by the microsphere method (0.7-1.3 ml.min(-1).g(-1)). In the early activated region during LV pacing, myocardial volume began to decrease before the LV pressure upstroke. We conclude that the volume change is greater than would be estimated from the known average transmural blood flow. This implies the existence of blood-filled spaces within the myocardium, which could communicate with the ventricular lumen. Our data in the early activated region also suggest that myocardial volume change is caused not by the intramyocardial tissue pressure but by direct impingement of the contracting myocytes on the microvasculature.


Asunto(s)
Función Atrial , Circulación Coronaria , Contracción Miocárdica , Miocardio/citología , Función Ventricular Izquierda , Animales , Estimulación Cardíaca Artificial , Cinerradiografía , Diástole , Perros , Ventrículos Cardíacos/diagnóstico por imagen , Modelos Anatómicos , Modelos Cardiovasculares , Tamaño de los Órganos , Reproducibilidad de los Resultados , Sístole , Factores de Tiempo
13.
Am J Physiol Heart Circ Physiol ; 295(2): H761-7, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18567705

RESUMEN

Epidemiological studies have shown a correlation between flavonoid-rich diets and improved cardiovascular prognosis. Cocoa contains large amounts of flavonoids, in particular flavanols (mostly catechins and epicatechins). Flavonoids possess pleiotropic properties that may confer protective effects to tissues during injury. We examined the ability of epicatechin to reduce short-and long-term ischemia-reperfusion (I/R) myocardial injury. Epicatechin (1 mg.kg(-1).day(-1)) pretreatment (Tx) was administered daily via oral gavage to male rats for 2 or 10 days. Controls received water. Ischemia was induced via a 45-min coronary occlusion. Reperfusion was allowed until 48 h or 3 wk while Tx continued. We measured infarct (MI) size (%), hemodynamics, myeloperoxidase activity, tissue oxidative stress, and matrix metalloproteinase-9 (MMP-9) activity in 48-h groups. Cardiac morphometry was also evaluated in 3-wk groups. With 2 days of Tx, no reductions in MI size occurred. After 10 days, a significant approximately 50% reduction in MI size occurred. Epicatechin rats demonstrated no significant changes in hemodynamics. Tissue oxidative stress was reduced significantly in the epicatechin group vs. controls. MMP-9 activity demonstrated limited increases in the infarct region with epicatechin. By 3 wk, a significant 32% reduction in infarct size was observed with Tx, accompanied with sustained hemodynamics and preserved chamber morphometry. In conclusion, epicatechin Tx confers cardioprotection in the setting of I/R injury. The effects are independent of changes in hemodynamics, are sustained over time, and are accompanied by reduced levels of indicators of tissue injury. Results warrant the evaluation of cocoa flavanols as possible therapeutic agents to limit ischemic injury.


Asunto(s)
Fármacos Cardiovasculares/farmacología , Catequina/farmacología , Infarto del Miocardio/prevención & control , Daño por Reperfusión Miocárdica/prevención & control , Miocardio/patología , Administración Oral , Animales , Fármacos Cardiovasculares/administración & dosificación , Catequina/administración & dosificación , Modelos Animales de Enfermedad , Esquema de Medicación , Hemodinámica/efectos de los fármacos , Masculino , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Infarto del Miocardio/patología , Infarto del Miocardio/fisiopatología , Daño por Reperfusión Miocárdica/patología , Daño por Reperfusión Miocárdica/fisiopatología , Miocardio/enzimología , Estrés Oxidativo/efectos de los fármacos , Peroxidasa/metabolismo , Ratas , Ratas Sprague-Dawley , Factores de Tiempo
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