The negative chronotropic effects of (±)-propranolol and (±)-4-NO2-propranolol in the rat isolated right atrium are due to blockade of the 6-nitrodopamine receptor.

The positive chronotropic action induced by 6-nitrodopamine (6-ND) is selectively blocked by ß1-adrenoceptor antagonists at concentrations that do not affect the positive chronotropic effect induced by dopamine, noradrenaline, and adrenaline. Here, the effects of ( ±)-propranolol, ( ±)-4-NO2-propranolol, and ( ±)-7-NO2-propranolol were investigated in the rat isolated right atrium. The atrium was mounted in glass chambers containing gassed (95%O2:5%CO2) and warmed (37 °C) Krebs-Henseleit's solution, and the isometric tension registered (PowerLab system). ( ±)-Propranolol, ( ±)-4-NO2-propranolol, and ( ±)-7-NO2-propranolol caused concentration-dependent falls in the spontaneous atrial frequency (pIC50: 4.80 ± 0.10, 4.64 ± 0.10, and 4.95 ± 0.10, respectively). The calculated pA2 values for ( ±)-propranolol, ( ±)-4-NO2-propranolol, and ( ±)-7-NO2-propranol on noradrenaline-induced positive chronotropism were 8.44 ± 0.08, 6.41 ± 0.07, and 9.21 ± 0.29, respectively. The positive chronotropism induced by 6-ND (10 pM) was blocked by ( ±)-propranolol (1 µM) and ( ±)-4-NO2-propranolol (30 nM), whereas ( ±)-7-NO2-propranolol (1 µM) had no effect on 6-ND-induced responses. The pIC50 of ( ±)-propranolol, ( ±)-4-NO2-propranolol, and ( ±)-7-NO2-propranolol were significantly shifted to the right in L-NAME-treated atria. The discrepancy between pA2 values of ( ±)-propranolol and its respective pIC50 indicates that the falls in atrial rate induced by ( ±)-propranolol should not be attributed to b-adrenergic antagonism. The reduced chronotropism by ( ±)-propranolol was unaffected by the sodium channel inhibitors tetrodotoxin and lidocaine but that was abolished in atria pre-treated with ( ±)-4-NO2-propranolol. The finding that ( ±)-propranolol reduces spontaneous atrial rate only in concentrations that affect 6-ND-induced positive chronotropism confirms the role of this catecholamine as an endogenous modulator of heart chronotropism. ( ±)-4-NO2-Propranolol behaves as a selective antagonist of 6-ND in the rat isolated atrium.

Effects of Selective and Nonselective Beta Blockers on Bone Mineral Density in Mexican Patients with Breast Cancer.

Breast cancer (BCa) is related to chronic stress and can reduce the bone mineral density (BMD) through neurochemicals related to beta-adrenergic receptor (ADRB) 1 and 2. Selective beta blockers (sBBs) and nonselective beta blockers (nsBBs) are used to treat systemic arterial hypertension (SAH) and may have osteoprotective effects, as they inhibit ADRBs. To evaluate the effects of sBBs and nsBBs on the BMD of Mexican patients with BCa. A retrospective study was conducted. We included 191 Mexican women with BCa without SAH and with SAH treated with nsBBs, sBBs, and diuretics. BMD was evaluated using a bone density scan (DEX scan). A greater average BMD (p < 0.05) was observed in patients with prior treatment with both nsBBs and sBBs (0.54 ± 0.94 and -0.44 ± 1.22, respectively) compared to patients treated with diuretics or without SAH (-1.73 ± 0.83 and -1.22 ± 0.98, respectively). Regarding the diagnosis of osteoporosis/osteopenia, no cases were observed in patients treated with nsBBs, whereas 5.6% of the patients treated with sBBs presented osteopenia. A total of 23.1% and 10.6% patients managed with diuretics or without treatment presented with osteoporosis and 61.5% and 48% patients managed with loop diuretics and without treatment presented with osteopenia, respectively (p < 0.05). Treatment with nsBBs is a promising option for the prevention and management of osteoporosis/osteopenia in Mexican patients with BCa; however, further prospective studies are needed.

Probiotics and the reduction of SARS-CoV-2 infection through regulation of host cell calcium dynamics.

Calcium is a secondary messenger that interacts with several cellular proteins, regulates various physiological processes, and plays a role in diseases such as viral infections. Next-generation probiotics and live biotherapeutic products are linked to the regulation of intracellular calcium levels. Some viruses can manipulate calcium channels, pumps, and membrane receptors to alter calcium influx and promote virion production and release. In this study, we examined the use of bacteria for the prevention and treatment of viral diseases, such as coronavirus of 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Vaccination programs have helped reduce disease severity; however, there is still a lack of well-recognized drug regimens for the clinical management of COVID-19. SARS-CoV-2 interacts with the host cell calcium (Ca2+), manipulates proteins, and disrupts Ca2+ homeostasis. This article explores how viruses exploit, create, or exacerbate calcium imbalances, and the potential role of probiotics in mitigating viral infections by modulating calcium signaling. Pharmacological strategies have been developed to prevent viral replication and block the calcium channels that serve as viral receptors. Alternatively, probiotics may interact with cellular calcium influx, such as Lactobacillus spp. The interaction between Akkermansia muciniphila and cellular calcium homeostasis is evident. A scientific basis for using probiotics to manipulate calcium channel activity needs to be established for the treatment and prevention of viral diseases while maintaining calcium homeostasis. In this review article, we discuss how intracellular calcium signaling can affect viral replication and explore the potential therapeutic benefits of probiotics.

Effects of Ivabradine on Myocardial Perfusion in Chronic Angina: A Prospective, Preliminary, Open-Label, Single-Arm Study.

INTRODUCTION: Ivabradine reduces heart rate (HR), episodes of angina, and nitrate consumption, and increases exercise capacity in patients with chronic angina (CA). In this exploratory study, myocardial perfusion scintigraphy (MPS) was used to evaluate changes in the percentage of myocardial ischemia after ivabradine therapy in patients with CA. METHODS: This prospective, open-label, single-arm study included patients with CA receiving maximum tolerated doses of beta blockers, who had a resting HR ≥ 70 bpm and had experienced ischemia according to MPS during an exercise test at baseline. Participants received ivabradine 5 mg twice daily (titrated according to HR) concomitant with beta blockers. A second MPS was performed after 3 months, without interruption of treatment with beta blockers or ivabradine. The primary outcome was change in the percentage of myocardial ischemia from baseline to 3 months. Time to ischemia during the exercise test, the proportion of patients presenting angina during the exercise test, and health status, assessed using the seven-item Seattle Angina Questionnaire-7 (SAQ-7), were also evaluated. RESULTS: Twenty patients (3 females) with a mean (± standard deviation [SD]) age of 62.2 ± 6.5 years were included in the study, of whom 55% had diabetes, 70% had previous myocardial revascularization, and 45% had previous myocardial infarction. The percentage of patients with myocardial ischemia significantly decreased from baseline to 3 months after initiation of treatment with ivabradine (- 2.9%; 95% confidence interval [CI] - 0.3 to - 5.5; p = 0.031). Mean time to appearance of ischemia increased from 403 ± 176 s at baseline to 466 ± 136 s at 3 months after initiation of ivabradine (Δ62 s; 95% CI 18-106 s; p = 0.008), and the proportion of patients experiencing angina during the exercise test decreased from 40% at baseline to 5% also at 3 months (p = 0.016). Mean resting HR decreased from 76 ± 7 bpm at baseline to 55 ± 8 bpm at 3 months (p < 0.001). The mean SAQ-7 summary score improved from 69 ± 21 at baseline to 83 ± 12 at 3 months (p = 0.001). No serious adverse effects were reported. CONCLUSION: Ivabradine added to beta blockers was associated with a reduction in detectable myocardial ischemia by MPS in patients with CA. Infographic available for this article. TRIAL REGISTRATION: The trial has been retrospectively registered with the Brazilian Registry of Clinical Trials (REBEC) under the following number RBR-5fysqrh (date of registration: 30 November 2023).

Isradipine, an L-type calcium channel blocker, attenuates cocaine effects in mice by reducing central glutamate release.

Substance abuse disorder is a chronic condition for which pharmacological treatment options remain limited. L-type calcium channels (LTCC) have been implicated in drug-related plasticity and behavior. Specifically, dopaminergic neurons in the mesocorticolimbic pathway express Cav1.2 and Cav1.3 channels, which may regulate dopaminergic activity associated with reward behavior. Therefore, this study aimed to investigate the hypothesis that pre-administration of the LTCC blocker, isradipine can mitigate the effects of cocaine by modulating central glutamatergic transmission. For that, we administered isradipine at varying concentrations (1, 7.5, and 15 µg/µL) via intracerebroventricular injection in male Swiss mice. This pretreatment was carried out prior to subjecting animals to behavioral assessments to evaluate cocaine-induced locomotor sensitization and conditioned place preference (CPP). The results revealed that isradipine administered at a concentration of 1 µg/µL effectively attenuated both the sensitization and CPP induced by cocaine (15 mg/kg, via i. p.). Moreover, mice treated with 1 µg/µL of isradipine showed decreased presynaptic levels of glutamate and calcium in the cortex and hippocampus as compared to control mice following cocaine exposure. Notably, the gene expression of ionotropic glutamate receptors, AMPA, and NMDA, remained unchanged, as did the expression of Cav1.2 and Cav1.3 channels. Importantly, these findings suggest that LTCC blockage may inhibit behavioral responses to cocaine, most likely by decreasing glutamatergic input in areas related to addiction.

SERCA-1 conformational change exerted by the Ca2+-channel blocker diltiazem affects mammalian skeletal muscle function.

In skeletal muscle (SM), inward Ca2+-currents have no apparent role in excitation-contraction coupling (e-c coupling), however the Ca2+-channel blocker can affect twitch and tetanic muscle in mammalian SM. Experiments were conducted to study how diltiazem (DLZ) facilitates e-c coupling and inhibits contraction. 1) In complete Extensor Digitorum Longus (EDL) muscle and single intact fibres, 0.03 mM DLZ causes twitch potentiation and decreases force during tetanic activity, with increased fatigue. 2) In split open fibres isolated from EDL fibres, DLZ inhibits sarcoplasmic reticulum (SR) Ca2+-loading in a dose-dependent manner and has a potentiating effect on caffeine-induced SR Ca2+-release. 3) In isolated light SR (LSR) vesicles, SERCA1 hydrolytic activity is not affected by DLZ up to 0.2 mM. However, ATP-dependent Ca2+-uptake was inhibited in a dose-dependent manner at a concentration where e-c coupling is changed. 4) The passive Ca2+-efflux from LSR was reduced by half with 0.03 mM diltiazem, indicating that SR leaking does not account for the decreased Ca2+-uptake. 5) The denaturation profile of the SERCA Ca2+-binding domain has lower thermal stability in the presence of DLZ in a concentration-dependent manner, having no effect on the nucleotide-binding domain. We conclude that the effect of DLZ on SM is exerted by crossing the sarcolemma and interacting directly with the SERCA Ca2+-binding domain, affecting SR Ca2+-loading during relaxation, which has a consequence on SM contractility. Diltiazem effect on SM could be utilized as a tool to understand SM e-c coupling and muscle fatigue.

Antihypertensive treatment of end-stage renal disease patients on hemodialysis does not alter circulating ACE and ACE2 activity and angiotensin peptides.

Cardiovascular diseases (CVD) are the main causes of death in hemodialysis patients, representing a public health challenge. We investigated the effect of different antihypertensive treatments on circulating levels of renin-angiotensin system (RAS) components in end-stage renal disease (ESRD) patients on hemodialysis. ESRD patients were grouped following the prescribed antihypertensive drugs: ß-blocker, ß-blocker+ACEi and ß-blocker+AT1R blocker. ESDR patients under no antihypertensive drug treatment were used as controls. Blood samples were collected before hemodialysis sessions. Enzymatic activities of the angiotensin-converting enzymes ACE and ACE2 were measured through fluorescence assays and plasma concentrations of the peptides Angiotensin II (Ang II) and Angiotensin-(1-7) [Ang-(1-7)] were quantified using mass spectrometry (LC-MS/MS). ACE activity was decreased only in the ß-blocker+ACEi group compared to the ß-blocker+AT1R, while ACE2 activity did not change according to the antihypertensive treatment. Both Ang II and Ang-(1-7) levels also did not change according to the antihypertensive treatment. We concluded that the treatment of ESRD patients on hemodialysis with different antihypertensive drugs do not alter the circulating levels of RAS components.

El papel de la Ivabradina y la titulación de los betabloqueadores en la insuficiencia cardíaca: una serie de casos y revisión de la literatura / The role of Ivabradine and beta-blocker titration in heart failure: a case series and literature review

RESUMEN Introducción y objetivos : La insuficiencia cardíaca (IC) es una preocupación creciente de salud pública. Si bien los betabloqueantes (BB) son la base del tratamiento, lograr reducciones objetivo de frecuencia cardíaca puede ser difícil debido a los efectos secundarios y la tolerancia limitada. La ivabradina, un inhibidor único de la corriente If, ofrece un enfoque complementario para controlar la frecuencia cardíaca sin afectar la contractilidad. El objetivo de este estudio fue evaluar la eficacia de agregar ivabradina a la terapia BB en pacientes con IC. Métodos: Se realizó un estudio observacional retrospectivo en un hospital privado en San José, Costa Rica se analizaron 7 casos de pacientes tratados con BB a los cuales posteriormente se les adicionó ivabradina. Se recopilaron datos demo- gráficos, las características clínicas, la frecuencia cardíaca previa y posterior a la ivabradina, la clase funcional NYHA y los valores de laboratorio seleccionados. Resultados: La ivabradina redujo significativamente la frecuencia cardíaca en reposo en un promedio de 26,87 latidos por minuto. El 42,86% alcanzó la dosis meta de su BB inicial después de agregar ivabradina. La clase funcional NYHA se mantuvo estable o mejoró en todos los casos. Conclusiones: Estos resultados sugieren que agregar ivabradina a la terapia BB puede ser una estrategia eficaz para optimizar el control de la frecuencia cardíaca en pacientes con IC. Este enfoque puede mejorar la tolerabilidad de BB, lo que lleva a un mayor manejo de la dosis meta y posiblemente mejores resultados clínicos.

ABSTRACT Introduction and objectives: Heart failure (HF) is a growing public health concern. While beta-blockers (BBs) are the cornerstone of treatment, achieving target heart rate reductions can be difficult due to side effects and limited tolerance. Ivabradine, a unique inhibitor of the If current, offers a complementary approach to controlling heart rate without affecting contractility. This study aimed to evaluate the effectiveness of adding ivabradine to BB therapy in patients with HF. Methods : A retrospective observational study was conducted at a private hospital in San José, Costa Rica. Seven cases of patients treated with BBs who were subsequently added to ivabradine were analyzed. Demographic data, clinical characteristics, heart rate before and after ivabradine, NYHA functional class, and selected laboratory values were collected. Results : Ivabradine significantly reduced resting heart rate by an average of 26.87 beats per minute. Forty-two-point eight-six percent (42.86%) achieved the target dose of their initial BB after adding ivabradine. NYHA functional class remained stable or improved in all cases. Conclusions: These results suggest that adding ivabradine to BB therapy may be an effective strategy to optimize heart rate control in patients with HF. This approach may improve BB tolerability, leading to greater target dose management and possibly better clinical outcomes.

6-Nitrodopamine Is the Most Potent Endogenous Positive Inotropic Agent in the Isolated Rat Heart.

BACKGROUND: 6-nitrodopamine released from rat isolated atria exerts positive chronotropic action, being more potent than noradrenaline, adrenaline, and dopamine. Here, we determined whether 6-nitrodopamine is released from rat isolated ventricles (RIV) and modulates heart inotropism. METHODS: Catecholamines released from RIV were quantified by LC-MS/MS and their effects on heart inotropism were evaluated by measuring left ventricular developed pressure (LVDP) in Langendorff's preparation. RESULTS: 6-nitrodopamine was the major released catecholamine from RIV. Incubation with L-NAME (100 µM), but not with tetrodotoxin (1 µM), caused a significant reduction in 6-nitrodopamine basal release. 6-nitrodopamine release was significantly reduced in ventricles obtained from L-NAME chronically treated animals. 6-nitrodopamine (0.01 pmol) caused significant increases in LVDP and dP/dtmax, whereas dopamine and noradrenaline required 10 pmol, and adrenaline required 100 pmol, to induce similar increases in LVDP and dP/dtmax. The infusion of atenolol (10 nM) reduced basal LVDP and blocked the increases in LVDP induced by 6-ND (0.01 pmol), without affecting the increases in LVDP induced by 10 nmol of dopamine and noradrenaline and that induced by adrenaline (100 nmol). CONCLUSIONS: 6-nitrodopamine is the major catecholamine released from rat isolated ventricles. It is 1000 times more potent than dopamine and noradrenaline and is selectively blocked by atenolol, indicating that 6-ND is a main regulator of heart inotropism.

Skeletal Muscle Atrophy Induced by Diabetes Is Mediated by Non-Selective Channels and Prevented by Boldine.

Individuals with diabetes mellitus present a skeletal muscle myopathy characterized by atrophy. However, the mechanism underlying this muscular alteration remains elusive, which makes it difficult to design a rational treatment that could avoid the negative consequences in muscles due to diabetes. In the present work, the atrophy of skeletal myofibers from streptozotocin-induced diabetic rats was prevented with boldine, suggesting that non-selective channels inhibited by this alkaloid are involved in this process, as has previously shown for other muscular pathologies. Accordingly, we found a relevant increase in sarcolemma permeability of skeletal myofibers of diabetic animals in vivo and in vitro due to de novo expression of functional connexin hemichannels (Cx HCs) containing connexins (Cxs) 39, 43, and 45. These cells also expressed P2X7 receptors, and their inhibition in vitro drastically reduced sarcolemma permeability, suggesting their participation in the activation of Cx HCs. Notably, sarcolemma permeability of skeletal myofibers was prevented by boldine treatment that blocks Cx43 and Cx45 HCs, and now we demonstrated that it also blocks P2X7 receptors. In addition, the skeletal muscle alterations described above were not observed in diabetic mice with myofibers deficient in Cx43/Cx45 expression. Moreover, murine myofibers cultured for 24 h in high glucose presented a drastic increase in sarcolemma permeability and levels of NLRP3, a molecular member of the inflammasome, a response that was also prevented by boldine, suggesting that, in addition to the systemic inflammatory response found in diabetes, high glucose can promote the expression of functional Cx HCs and activation of the inflammasome in skeletal myofibers. Therefore, Cx43 and Cx45 HCs play a critical role in myofiber degeneration, and boldine could be considered a potential therapeutic agent to treat muscular complications due to diabetes.

Angiotensin-converting enzymes as druggable features of psychiatric and neurodegenerative disorders.

The renin-angiotensin system (RAS) plays essential roles in maintaining peripheral cardiovascular homeostasis, with its potential roles in the brain only being recognized more recently. Angiotensin-I-converting enzyme (ACE) is the main component of the RAS, and it has been implicated in various disorders of the brain. ACE and other RAS components, including the related enzyme ACE2, angiotensin peptides and their respective receptors, can participate in the pathological state, as well as with potential to contribute to neuroprotection and/or to complement existing treatments for psychiatric illness. In this narrative review, we aimed to identify the main studies describing the functions of the RAS and ACEs in the brain and their association with brain disorders. These include neurodegenerative disorders such as Parkinson's and Alzheimer's diseases, psychiatric illnesses such as schizophrenia, bipolar disorder, and depression. We also discuss the possible association of a functional polymorphism of the ACE gene with these brain diseases and the relevance of the neuroprotective and anti-inflammatory properties of ACE inhibitors (ACEis) and angiotensin receptor blockers (ARBs). Based on this, we conclude that there is significant potential value to the inclusion of ACEis and/or ARBs as a novel integrated approach for the treatment of various disorders of the brain, and particularly for psychiatric illness.

High-throughput screening method for discovering CatSper inhibitors using membrane depolarization caused by external calcium chelation and fluorescent cell barcoding.

The exclusive expression of CatSper in sperm and its critical role in sperm function makes this channel an attractive target for contraception. The strategy of blocking CatSper as a male, non-hormonal contraceptive has not been fully explored due to the lack of robust screening methods to discover novel and specific inhibitors. The reason for this lack of appropriate methodology is the structural and functional complexity of this channel. We have developed a high-throughput method to screen drugs with the capacity to block CatSper in mammalian sperm. The assay is based on removing external free divalent cations by chelation, inducing CatSper to efficiently conduct monovalent cations. Since Na+ is highly concentrated in the extracellular milieu, a sudden influx depolarizes the cell. Using CatSper1 KO sperm we demonstrated that this depolarization depends on CatSper function. A membrane potential (Em) assay was combined with fluorescent cell barcoding (FCB), enabling higher throughput flow cytometry based on unique fluorescent signatures of different sperm samples. These differentially labeled samples incubated in distinct experimental conditions can be combined into one tube for simultaneous acquisition. In this way, acquisition times are highly reduced, which is essential to perform larger screening experiments for drug discovery using live cells. Altogether, a simple strategy for assessing CatSper was validated, and this assay was used to develop a high-throughput drug screening for new CatSper blockers.

Influence of carvedilol and thyroid hormones on inflammatory proteins and cardioprotective factor HIF-1α in the infarcted heart.

Inflammatory pathways of Toll-like receptor 4 (TLR4) and NLRP3 inflammasome contribute to acute myocardial infarction (AMI) pathophysiology. The hypoxia-inducible factor 1α (HIF-1α), however, is a key transcription factor related to cardioprotection. This study aimed to compare the influence of carvedilol and thyroid hormones (TH) on inflammatory and HIF-1α proteins and on cardiac haemodynamics in the infarcted heart. Male Wistar rats were allocated into five groups: sham-operated group (SHAM), infarcted group (MI), infarcted treated with the carvedilol group (MI + C), infarcted treated with the TH group (MI + TH), and infarcted co-treated with the carvedilol and TH group (MI + C + TH). Haemodynamic analysis was assessed 15 days post-AMI. The left ventricle (LV) was collected for morphometric and Western blot analysis. The MI group presented LV systolic pressure reduction, LV end-diastolic pressure elevation, and contractility index decrease compared to the SHAM group. The MI + C, MI + TH, and MI + C + TH groups did not reveal such alterations compared to the SHAM group. The MI + TH and MI + C + TH groups presented reduced MyD88 and NLRP3 and increased HIF-1α levels. In conclusion, all treatments preserve the cardiac haemodynamic, and only TH, as isolated treatment or in co-treatment with carvedilol, was able to reduce MyD88 and NLRP3 and increase HIF-1α in the infarcted heart.

Three Generation ß-Blockers for Atrial Fibrillation Treatment.

The efficiency of blood flowing from the heart depends on its electrical properties. Myocardial electrical activity is associated with generating cardiac action potentials in isolated myocardial cells and their coordinated propagation, which are mediated by gap junctions. Atrial fibrillation (AF) is a common cardiac arrhythmia which causes an aggressive disturbance in cardiac electromechanical function. Moreover, AF increases the risk of stroke and mortality and is a major cause of death. The mechanisms underlying AF involve electrophysiological changes in ion channel expression and function. ß-blockers may be useful in patients with chronic AF or in preventing postoperative AF in subjects undergoing coronary artery bypass grafting (CABG) or other types of surgery. The reduction in heart rate induced by ß1-adrenergic receptor antagonists may be associated with the beneficial effect of this drug class. Second generation beta-blockers may be considered superior to the first generation due to their selectivity to the ß1 receptor as well as avoiding pulmonary or metabolic adverse effects. Third generation beta-blockers may be considered a great option for their vasodilation and antioxidant properties. There is also a new ß-blocker, named landilol that also results on reduced risk of post operative AF without adverse effects and its use has been increasing in clinical trials.

Propranolol: A migraine prophylactic since the 1960s / Propranolol: um profilático para enxaqueca desde 1960

Introduction: Propranolol was the first non-selective beta-adrenergic blocker to be developed. Initially it was used in the treatment of cardiovascular diseases, but since the 60's it has been used in the prevention of migraine. Objective: The objective of this study was to know the history of propranolol and its use as a migraine prophylactic. Methods: This study was an integrative literature review using articles with historical data on propranolol, from its origin in cardiology to its indication in the preventive treatment of migraine. Results: Propranolol was described in 1962 for the treatment of cardiovascular diseases. In the same decade, it was prescribed for the preventive treatment of migraine and, recently, included in the consensus of the Brazilian Headache Society. Conclusion: Although propranolol was initially synthesized for the treatment of heart disease, it has proved to be an effective drug in preventing migraine attacks

Introdução: O propranolol foi o primeiro bloqueador beta-adrenérgico não seletivo a ser desenvolvido. Inicialmente era utilizado no tratamento de doenças cardiovasculares, mas desde a década de 60 tem sido utilizado na prevenção de enxaquecas. Objetivo: O objetivo deste estudo foi conhecer a história do propranolol e seu uso como profilático para enxaqueca. Métodos: Este estudo foi uma revisão integrativa da literatura utilizando artigos com dados históricos sobre o propranolol, desde sua origem na cardiologia até sua indicação no tratamento preventivo da enxaqueca. Resultados: O propranolol foi descrito em 1962 para o tratamento de doenças cardiovasculares. Na mesma década, foi prescrito para o tratamento preventivo da enxaqueca e, recentemente, incluído no consenso da Sociedade Brasileira de Cefaleia. Conclusão: Embora o propranolol tenha sido inicialmente sintetizado para o tratamento de doenças cardíacas, provou ser um medicamento eficaz na prevenção de crises de enxaqueca

Association between erectile dysfunction and the severity of obstruction to airflow in patients with chronic obstructive pulmonary disease / Asociación entre disfunción eréctil y la severidad de la obstrucción al flujo aéreo en pacientes con enfermedad pulmonar obstructiva crónica

Objectives: The objective of this study was to explore a possible association between ED and the severity of airflow obstruction in patients with COPD. Materials and methods: A cross-sectional study was conducted using the International Index Erectile Function (IIEF), a scale validated and translated to Spanish. Bivariate analyses between subgroups were made for quantitative variables using a t-test for means and Mann­Whitney U for medians; qualitative variables were compared using the χ2 test or Fisher's test, depending on distribution. Confusion bias in the association between ED and airflow obstruction was controlled using a logistic regression model. Results: The Spanish version of the IIEF-15 scale was valid and applicable to the Colombian population. The prevalence of ED in COPD patients living at high altitudes was similar to that found at sea level. Such prevalence is higher than in general population. Beta-blockers increased 7 times the risk of ED, but we found no association between the degree of airflow obstruction and ED. Conclusion: Although the severity of COPD is not associated with ED, the prevalence of ED in COPD is higher than in general population. Therefore, ED screening in COPD patients using the IIEF could be justified. The strong association between beta-blockers and ED had not been previously described in patients with COPD but must be considered in their clinical management.

Objetivos: Explorar una posible asociación entre DE y severidad de la obstrucción al flujo aéreo en pacientes con EPOC. Materiales y métodos: Estudio de corte transversal aplicando el Índice Internacional de Función Eréctil (IIFE), validado y traducido al español. Se realizó análisis bivariado para variables cuantitativas usando prueba-t para medias y U de Mann Whitney para medianas; las variables cualitativas fueron comparadas usando prueba de Chi2 o test de Fisher, según distribución. Los sesgos de confusión en la asociación entre DE y obstrucción al flujo aéreo fueron controlados usando un modelo de regresión logística. Resultados: La versión en español de la escala IIFE-15 fue aplicable en población colombiana. La prevalencia de DE en pacientes con EPOC viviendo a gran altura fue similar a lo encontrado a nivel del mar. Esta prevalencia es mayor que en población general. El uso de beta-bloqueadores aumentó hasta siete veces el riesgo de DE, pero no se encontró asociación entre el grado de obstrucción y la DE. Conclusiones: Aunque la severidad de la EPOC no está asociada con DE, la prevalencia de DE en EPOC es mayor que en población general. Está justificada la realización de tamizaje usando el IIFE. La asociación fuerte entre beta-bloqueadores y DE no se ha descrito previamente en pacientes con EPOC, pero debe considerarse en su manejo.

Short-Term Results of Ivabradine versus Metoprolol: The Effects on Atrial Fibrillation in Patients Undergoing Off-Pump Coronary Artery Bypass Grafting

ABSTRACT Introduction: Classic coronary artery bypass grafting (CABG) surgery involves diastolic cardiac arrest under cardiopulmonary bypass, while off-pump CABG (OPCABG) has become widespread in recent years. Methods: 174 patients who underwent OPCABG were included in the study. Patients were divided into two groups. Group I (n=90) received ivabradine and Group M (n=84) received metoprolol before surgery until postoperative day 10. Intraoperative arrhythmias and hypotension were recorded. Postoperative atrial fibrillation (AF) and arrhythmia, mortality and morbidity rates were assessed based on the 30-day postoperative follow-up. Results: There were no significant differences in the intraoperative amount of inotropic support and red blood cell transfusion between groups (P=0.87 and P=0.31). However, the rates of intraoperative arrhythmias and hypotension were not significantly higher in Group M (P=0.317 and P=0.47). Ventricular tachycardia/ventricular fibrillation (VT/VF) was observed in 2 patients in both groups. Postoperative AF occurred in 7 patients (7.7%) in Group I and in 10 patients (11.9%) in Group M. Although there was a trend towards a higher prevalence of AF in Group M patients, this did not reach statistical significance. In addition, mortality and morbidity rates were comparable between groups.

Safety of intravitreal metoprolol in eyes with central serous chorioretinopathy.

PURPOSE: To investigate ocular safety of intravitreal metoprolol in eyes with central serous chorioretinopathy. METHODS: Five eyes of five patients diagnosed with chronic central serous chorioretinopathy (cCSC) previously treated unsuccessfully with oral spironolactone, micropulse laser and intravitreal anti-vascular endothelial growth factor agents were enrolled and received off-label intravitreal metoprolol (50 µg/0.05 ml). Baseline and follow-up examinations included measurement of best-corrected visual acuity (BCVA), intraocular pressure, anterior chamber cellular/flare scores, vitritis classification, fluorescein and indocyanine green angiography, spectral domain optical coherence tomography and electroretinography (ERG), recorded by means of DTL electrodes and following the standard suggested by the International Society for Clinical Electrophysiology of Vision (ISCEV). The total follow-up period was 4 weeks. RESULTS: There were no significant differences between baseline and follow-up ERG parameters: scotopic or photopic, a- and b-wave amplitude and implicit time, nor oscillatory potentials amplitude, or whatsoever. No intraocular inflammation sign was observed. In addition, BCVA showed small improvement in 4 or kept baseline values in 1 patient. The subretinal and/or intraretinal fluid volume reduced in all patients at 1 month after treatment. CONCLUSION: Patients with refractory cCSC treated with intravitreal 50 µg/0.05 ml metoprolol showed no signs of acute ocular toxicity, along with intraretinal fluid reduction and slight BCVA improvement 1 month after injection. This data suggest that intravitreal metoprolol may be a safe alternative for cCSC.

Losartan Attenuates Radiation-Induced Damage on Testes and Accelerates Tubular Regeneration.

Male germ cells are particularly susceptible to radiation; infertility being a common consequence after radiotherapy as it impairs spermatogenesis. This study aimed to test whether treatment with losartan (LOS), a selective antagonist of angiotensin II receptor subtype 1 (AT1R), can prevent or attenuate the acute and long-term radiation-induced damage to testes. Wistar rats were randomly distributed into six groups, three of which were studied on day 2 after irradiation: control (CTRL 2), irradiated non-treated (IR 2), and irradiated and treated with LOS (IRLOS 2); and three other groups that were studied on day 60 after irradiation: control (CTRL 60), irradiated non-treated (IR 60), and irradiated and treated with LOS (IRLOS 60). Seven consecutive days before and on the day of irradiation with 2.5 Gy directly administered in the scrotum, the animals were treated with LOS (34 mg/kg/two times/day). This treatment was continued 2 or 60 days after irradiation. The sperm quality was assessed from epididymis cauda. In addition, the testes were submitted to histopathological and morphometric-stereological analysis as well as the proliferating cell nuclear antigen (PCNA) quantification. Serum FSH and LH and plasma testosterone levels were also determined. The data obtained 2 days after the irradiation showed germ cell apoptosis, formation of vacuoles in the seminiferous epithelium, sloughing of germ cells into the lumen, and retention and phagocytosis of step-19 spermatids in Sertoli basal cytoplasm. The treatment with LOS in this period did not prevent or attenuate a radio-induced damage to the testes, illustrating that this drug does not protect against apoptosis derived from direct effects of radiation. On the other hand, 60 days after exposure, the data evidenced the deleterious effects of ionizing radiation on the testes as decreasing of testicular, epididymal, and seminal vesicle masses; tubular atrophy; reduction of cellular proliferation; and loss of germ cells. LOS was able to prevent some of those deleterious effects, promoting improvements in seminal vesicle mass, sperm vitality, plasma testosterone levels, vacuole number, and cell proliferation. In conclusion, inhibition of the AngII/AT1R axis by LOS is effective in protecting the indirect/delayed radiation damage resulting from oxidative stress established in the tissue.

Efficacy and safety of potassium-competitive acid blockers versus proton pump inhibitors as Helicobacter pylori eradication therapy: a meta-analysis of randomized clinical trials.

BACKGROUND AND AIMS: Potassium-Competitive Acid Blockers (P-CABs) have been used in Helicobacter pylori (H. pylori) eradication therapies in recent years. However, the efficacy and safety of P-CABs compared to Proton-Pump Inhibitors (PPIs) in this setting remain controversial. METHODS: The efficacy and safety of P-CABs and PPIs for H. pylori eradication were compared in a meta-analysis based on a systematic literature search of major electronic databases for relevant Randomized Controlled Trials (RCTs). RESULTS: Seven studies and 1,168 patients were included. The pooled eradication rate determined by Intention-To-Treat (ITT) analysis was 90.2% for P-CAB-based and 75.5% for PPI-based triple therapy (pooled RR [95% CI] = 1.17 [1.08-1.28], p < 0.001). The Per-Protocol (PP) analysis also demonstrated significant superiority of P-CABs (pooled eradication rate = 92.4% vs. 77.8%; pooled RR [95% CI] = 1.14 [1.03-1.26], p < 0.01). In a subgroup evaluation, P-CABs were significantly better than PPIs as a first-line eradication therapy, in both the ITT analysis (pooled eradication rate = 91.8% vs. 76.4%; pooled RR [95% CI] = 1.18 [1.10-1.28], p < 0.0001) and the PP analysis (pooled eradication rate = 93.0% vs. 78.6%; pooled RR [95% CI] = 1.13 [1.02-1.26], p < 0.05). However, P-CABs were not superior to PPIs when administered as salvage therapy, as determined in the ITT (75.0% vs. 66.0%, pooled RR [95% CI] = 1.11 [0.69-1.78], p = 0.66) and PP (85.7% vs. 70.0%, pooled RR [95% CI] = 1.20 [0.82-1.75], p = 0.34) analyses. In a subgroup analysis limited to Japanese patients, both the ITT analysis (pooled eradication rate = 89.6% vs. 73.9%; RR [95% CI] = 1.21 [1.14-1.29], p < 0.01) and the PP analysis (pooled eradication rate = 92.0% vs. 75.7%; RR [95% CI] = 1.18 [1.06-1.32], p < 0.01) showed that P-CABs were significantly superior compared to PPIs as triple eradication therapy. However, in the subgroup analysis of patients from other countries, there was no significant difference in either the ITT analysis (pooled eradication rate = 93.8% vs. 85.2%; RR [95% CI] = 1.10 [0.99-1.22], p = 0.07) or PP analysis (pooled eradication rate = 95.0% vs. 90.8%; RR [95% CI] = 1.05 [0.98-1.14], p = 0.17). The incidence of adverse events associated with the two regimens did not significantly differ (P-CABs vs. PPIs: 33.6% vs. 40.0%; RR [95% CI] = 0.84 [0.71‒1.00], p = 0.05). The incidence of serious adverse events and dropout rate due to adverse events also did not differ (p = 0.44 and p = 0.67, respectively). CONCLUSIONS: The efficacy of P-CAB-based triple therapy is superior to that of PPI-based triple therapy as a first-line approach to H. pylori eradication, particularly in Japanese patients. As salvage therapy, the efficacy of the two treatments did not significantly differ. The tolerability of P-CAB-based and PPI-based triple therapy was comparable, as was the incidence of adverse events.