Mitochondrial Volume Regulation and Swelling Mechanisms in Cardiomyocytes.

Mitochondrion, known as the "powerhouse" of the cell, regulates ion homeostasis, redox state, cell proliferation and differentiation, and lipid synthesis. The inner mitochondrial membrane (IMM) controls mitochondrial metabolism and function. It possesses high levels of proteins that account for ~70% of the membrane mass and are involved in the electron transport chain, oxidative phosphorylation, energy transfer, and ion transport, among others.

Mitochondrial angiotensin receptors and cardioprotective pathways.

A growing body of data provides strong evidence that intracellular angiotensin II (ANG II) plays an important role in mammalian cell function and is involved in the pathogenesis of human diseases such as hypertension, diabetes, inflammation, fibrosis, arrhythmias, and kidney disease, among others. Recent studies also suggest that intracellular ANG II exerts protective effects in cells during high extracellular levels of the hormone or during chronic stimulation of the local tissue renin-angiotensin system (RAS). Notably, the intracellular RAS (iRAS) described in neurons, fibroblasts, renal cells, and cardiomyocytes provided new insights into regulatory mechanisms mediated by intracellular ANG II type 1 (ATRs) and 2 (ATRs) receptors, particularly, in mitochondria and nucleus.

Critical role of angiotensin II type 2 receptors in the control of mitochondrial and cardiac function in angiotensin II-preconditioned rat hearts.

Angiotensin II preconditioning (APC) involves an angiotensin II type 1 receptor (AT1-R)-dependent translocation of PKCε and survival kinases to the mitochondria leading to cardioprotection after ischemia-reperfusion (IR). However, the role that mitochondrial AT1-Rs and angiotensin II type 2 receptors (AT2-Rs) play in APC is unknown. We investigated whether pretreatment of Langendorff-perfused rat hearts with losartan (L, AT1-R blocker), PD 123,319 (PD, AT2-R blocker), or their combination (L + PD) affects mitochondrial AT1-R, AT2-R, PKCε, PKCδ, Akt, PKG-1, MAPKs (ERK1/2, JNK, p38), mitochondrial respiration, cardiac function, and infarct size (IS).

Angiotensin II-preconditioning is associated with increased PKCε/PKCδ ratio and prosurvival kinases in mitochondria.

Angiotensin II-preconditioning (APC) has been shown to reproduce the cardioprotective effects of ischaemic preconditioning (IPC), however, the molecular mechanisms mediating the effects of APC remain unknown. In this study, Langendorff-perfused rat hearts were subjected to IPC, APC or both (IPC/APC) followed by ischaemia-reperfusion (IR), to determine translocation of PKCε, PKCδ, Akt, Erk1/2, JNK, p38 MAPK and GSK-3β to mitochondria as an indicator of activation of the protein kinases. In agreement with previous observations, IPC, APC and IPC/APC increased the recovery of left ventricular developed pressure (LVDP), reduced infarct size (IS) and lactate dehydrogenase (LDH) release, compared to controls.

Metabolic Changes After Roux-N-Y Bariatric Surgery In Hispanics.

The objective was to describe the metabolic outcomes 12 months after bariatric surgery (Roux-N-Y) in morbidly obese Hispanic patients, and evaluate the correlation between weight loss and the observed changes. Medical records from a hundred-and-two Hispanic obese patients who underwent bariatric surgery were identified at the University of Puerto Rico (UPR) Hospital. The following variables were obtained before and 12 months after surgery: Body Mass Index (BMI), body weight, total cholesterol (TC), triglycerides, high density lipoprotein (HDL), low density lipoprotein (LDL), and fasting blood sugar (FBS).

The Role of SIRT3 in Mediating Cardioprotective Effects of RAS Inhibition on Cardiac Ischemia-Reperfusion.

Cardiac ischemia-reperfusion stimulates the renin-angiotensin system (RAS) associated with elevated levels of circulating angiotensin II. Numerous studies demonstrate that the antagonist for the angiotensin II type 1 receptor, losartan improves cardiac function in animal models of ischemia-reperfusion. Molecular mechanisms of the cardioprotective effects of RAS inhibitors on cardiac ischemia-reperfusion remain poorly understood, and are not associated with the anti-hypertensive action of these drugs.

Celiac trunk and branches dissection due to energy drink consumption and heavy resistance exercise: case report and review of literature.

Higher doses and consumption of energy drinks leads to cardiovascular effects and potential consequences. Principal components found in energy drinks such as caffeine, guarana and taurine has been related to dilatation, aneurysm formation, dissection and ruptures. There is no evidence showing an integration of these components and its effects in endothelium and aortic walls due to higher levels of pressure during exercises.

Coronary levels of angiotensin-II and endothelin-I in diabetic patients with and without coronary artery disease.

Two groups of patients were studied to find out the levels of angiotensin-II and endothelin-I in the coronary and peripheral circulation. Group A consisted of eight patients with diabetes mellitus type 2 and coronary artery disease; and Group B with diabetes mellitus without coronary artery disease. Significant differences were found between Group A and B in the levels of both peptides peripherally and intracoronary.

Mitochondria-targeted ROS scavenger improves post-ischemic recovery of cardiac function and attenuates mitochondrial abnormalities in aged rats.

Mitochondria-generated reactive oxygen species (ROS) play a crucial role in the pathogenesis of aging and age-associated diseases. In this study, we evaluated the effects of XJB-5-131 (XJB), a mitochondria-targeted ROS and electron scavenger, on cardiac resistance to ischemia-reperfusion (IR)-induced oxidative stress in aged rats. Male adult (5-month old, n=17) and aged (29-month old, n=19) Fischer Brown Norway (F344/BN) rats were randomly assigned to the following groups: adult (A), adult+XJB (AX), aged (O), and aged+XJB (OX).

Angiotensin II and ischemic preconditioning synergize to improve mitochondrial function while showing additive effects on ventricular postischemic recovery.

Recent studies indicate that the cardioprotective effects of ischemic preconditioning (IPC) against sustained ischemia/reperfusion can be replicated by angiotensin II (Ang II). However, it is not clear whether IPC and Ang II-induced preconditioning (APC) act through similar mechanisms or synergize to enhance cardioprotection. In this study, Langendorff-perfused rat hearts were subjected to IPC, APC, or their combination (IPC/APC) followed by ischemia/reperfusion.

Ethnicity and genetics are more important than diabetes mellitus and hypertension in producing cardiovascular events in patients with the metabolic syndrome: emphasis in the Puerto Rico population.

Metabolic syndrome is a cluster of risk factors for cardiovascular disease that affects an estimated 50 million Americans. The present article reviews the metabolic syndrome with respect to its definition, epidemiology, pathophysiology and management. A primary focus in research has been to elucidate the processes determined to cause insulin resistance, the fundamental mechanism underlying the metabolic syndrome.

Magnesium: the forgotten electrolyte.

Unlabelled: Magnesium (Mg++), Potassium (K+) and Calcium (CA++) are important electrolytes in keeping a stable electrical status. The purpose of this study was to measure them in critically ill patients.

Methods: We evaluated the electrolytes in 28 consecutive patients.

Heart tumors in Puerto Rico de novo atrial fibrillation as clinical presentation in a subgroup of patients.

Objective: Primary cardiac tumors are rare neoplasms in humans, of which the most common is the atrial Myxoma. The objective of this study was to find the incidence of these tumors at the Heart Center of Puerto Rico and the Caribbean.

Methods: This study was approved by the Institutional Review Board of the Medical Sciences Campus University of Puerto Rico to review the records at the Heart Center of patients with heart tumors in the last 14 years.

Higher incidence of atrial fibrillation in the metabolic syndrome: a Hispanic population study.

Unlabelled: The metabolic syndrome is probably one of the main medical problems in developing countries. Purpose of this investigation was to study the metabolic syndrome at the Puerto Rico and Caribbean Cardiovascular Center with emphasis on the cardiovascular complications.

Materials/methods: The medical charts in the last six years of the metabolic syndrome were evaluated at the PRCCC.

The Department of Physiology of the UPR-School of Medicine: history and contribution to the physiological sciences in Puerto Rico 1950-2010.

In 1949, the creation of the University of Puerto Rico-School of Medicine required the recruitment of a group of faculty with expertise in the physiological sciences. The assembled group established the foundation for the Department of Physiology in the fall of 1950. Since then, the Department has made important contributions to the School of Medicine, the Medical Sciences Campus, and the University of Puerto Rico.

Aliskiren improves left ventricular dysfunction and reduces cardiac dilation in Syrian cardiomyopathic hamsters.

Objective: Chronic activation of the renin-angiotensin-aldosterone system is a major contributing factor to the pathogenesis and progression of cardiovascular and renal diseases.

Methods: To evaluate the role of renin-angiotensin-aldosterone system blockade with aliskiren, a direct renin inhibitor, in the development and progression of dilated cardiomyopathy in the Syrian cardiomyopathic hamster (SCH) model, we treated 1-month-old SCH with aliskiren (10 mg·kg·d) over a 4-month period. For comparative purposes, we also evaluated the effects of the angiotensin receptor blocker valsartan (10 mg·kg·d) and the combination of both drugs.

Metabolic syndrome among Puerto Ricans and other Hispanic populations.

Metabolic syndrome is a cluster of risk factors for cardiovascular disease that affects an estimated 50 million Americans. The present article reviews this syndrome with respect to its definition, epidemiology, pathophysiology, and management. A primary focus in research has been to elucidate the processes that have been determined to cause insulin resistance, the fundamental mechanism underlying metabolic syndrome; these processes are reviewed here along with the interplay of the syndrome with the renin-angiotensin system, circadian rhythm, and atherosclerosis.

Chronic treatment with N-acetylcysteine improves cardiac function but does not prevent progression of cardiomyopathy in Syrian cardiomyopathic hamsters.

Oxidative stress has been postulated to contribute to the onset and development of heart failure (HF). The efficacy of antioxidant therapy in HF, however, remains controversial. This study evaluates the effect of the antioxidant N-acetylcysteine (NAC, 1 g/kg per day) on cardiovascular function in 2- and 6-month-old Bio-TO2 Syrian cardiomyopathic hamsters (SCH) after treatment for 1 month and 5 months with this drug.

Expression of mitochondrial fusion-fission proteins during post-infarction remodeling: the effect of NHE-1 inhibition.

Studies on the role of mitochondrial fission/fusion (MFF) proteins in the heart have been initiated recently due to their biological significance in cell metabolism. We hypothesized that the expression of MFF proteins is affected by post-infarction remodeling and in vitro cardiomyocyte hypertrophy, and serves as a target for the Na(+)/H(+) exchanger 1 (NHE-1) inhibition. Post-infarction remodeling was induced in Sprague-Dawley rats by coronary artery ligation (CAL) while in vitro hypertrophy was induced in cardiomyocytes by phenylephrine (PE).

Hemodynamic alterations in the coronary circulation of cardiomyopathic hamsters: age and Ang II-dependent mechanisms.

Background: Coronary vasospasms have been reported in the early stages of cardiomyopathy in the Syrian cardiomyopathic hamster (CM; BIO-TO2 strain). It has been proposed these alterations could lead to ischemic heart disease and heart failure. However, the cause of these coronary abnormalities has not been established.

Mitochondrial permeability transition pore opening as a promising therapeutic target in cardiac diseases.

In addition to their central role in ATP synthesis, mitochondria play a critical role in cell death. Oxidative stress accompanied by calcium overload, ATP depletion, and elevated phosphate levels induces mitochondrial permeability transition (MPT) with formation of nonspecific MPT pores (MPTP) in the inner mitochondrial membrane. Pore opening results in mitochondrial dysfunction with uncoupled oxidative phosphorylation and ATP hydrolysis, ultimately leading to cell death.

Early pathophysiological alterations in experimental cardiomyopathy: the Syrian cardiomyopathic hamster.

The Syrian cardiomyopathic hamster (SCH) is an established animal model for genetic cardiomyopathy. The disease in the hamster develops through similar stages to those observed in humans with this condition. The pathophysiological basis for this condition in the hamster resides in an inherited mutation in the gene encoding for delta-sarcoglycan, a component of the dystrophin complex.

Enalapril and losartan are more effective than carvedilol in preventing dilated cardiomyopathy in the Syrian cardiomyopathic hamster.

To assess the role of the renin-angiotensin (RAS) and adrenergic systems in the development and progression of dilated cardiomyopathy in the Syrian cardiomyopathic hamster (SCH), echocardiographic parameters were evaluated in 6-month-old animals after 5 months of treatment with enalapril (25 mg/kg/day) plus losartan (10 mg/kg/day), or with carvedilol (1 mg/kg/day). Cardiac output indexes (COI) increased by 53% after RAS blockade and by 20% after beta-blockade in SCH. Moreover, LVEDV and LVESV decreased 30% and 62%, respectively (P < .

Syncope in Puerto Rico.

Syncope is defined as a transient loss of consciousness with an inability to maintain postural tone that is followed by spontaneous recovery. Syncope is a prevalent disorder, accounting for 1-3% of emergency department visits and up to 6% of hospital admissions each year in the United States. The medical records of patients admitted at the Cardiovascular Center of Puerto Rico and the Caribbean after an episode of syncope were reviewed.