Canadian journal of physiology and pharmacology最新文献

Postmenopausal cardiovascular health is a critical determinant of longevity. Consumption of beetroot juice (BR) and other nitrate-rich foods is a safe, effective non-pharmaceutical intervention to increase systemic bioavailability of the vasoprotective molecule, nitric oxide, through the exogenous nitrate (NO₃ ^-)-nitrite (NO₂ ^-)-nitric oxide (NO) pathway. We hypothesized that a single dose of nitrate-rich beetroot juice (BR_nitrate 600 mg NO₃ ^-/140 mL, BR_placebo ∼ 0 mg/140 mL) would improve resting endothelial function and resistance to ischemia-reperfusion (IR) injury to a greater extent in early-postmenopausal (1-6 years following their final menstrual period (FMP), n = 12) compared to late-postmenopausal (6+ years after FMP, n = 12) women. Analyses with general linear models revealed a significant (p < 0.05) time^*treatment interaction effect for brachial artery adjusted flow-mediated dilation (FMD). Pairwise comparisons revealed that adjusted FMD was significantly lower following IR-injury in comparison to all other time points with BR_placebo (early FMD 2.51 ± 1.18%, late FMD 1.30 ± 1.10, p < 0.001) and was lower than post-IR with BR_nitrate (early FMD 3.84 ± 1.21%, late FMD 3.21 ± 1.13%, p = 0.014). A single dose of BR_nitrate significantly increased resting macrovascular function in the late postmenopausal group only (p = 0.005). Considering the postmenopausal stage-dependent variations in endothelial responsiveness to dietary nitrate, we predict differing mechanisms underpin macrovascular protection against IR injury.

This study aimed to assess the utility of echocardiography-measured epicardial adipose tissue (EAT) thickness (EATT) as an independent predictor for coronary artery disease (CAD), examining its correlation with oxidative stress levels in epicardial tissue and the complexity of the disease in patients undergoing open-heart surgery. This study included a total of 25 patients referred for cardiac surgery with 14 in the CAD group and 11 in the non-CAD group. Epicardial fat was sampled from patients subjected to open-heart surgery. EATT was higher in the CAD group compared to the non-CAD group (8.15 ± 2.09 mm vs. 5.12 ± 1.8 mm, p = 0.001). The epicardial reactive oxygen species level was higher in the CAD group compared to the non-CAD group (21.4 ± 2.47 nmol H₂O₂/g tisssue/h vs. 15.7 ± 1.55 nmol H₂O₂/g tisssue/h, p < 0.001). EATT greater than 6.05 mm was associated with CAD, with a sensitivity of 86% and specificity of 73%. Echocardiographically measured EATT is a significant, independent predictor of CAD. Its relationship with increased EAT oxidative stress levels suggests a potential mechanistic link between EATT and CAD pathogenesis. These findings highlight the importance of EATT as a diagnostic tool in assessing the complexity of CAD in patients undergoing cardiac surgery.

Retinoic acid-related orphan receptors (RORs) serve as transcription factors that play a pivotal role in a myriad of physiological processes within the body. Their involvement extends to critical biological processes that confer protective effects in the heart, immune system, and nervous system, as well as contributing to the mitigation of several aggressive cancer types. These protective functions are attributed to ROR's regulation of key proteins and the management of various cellular processes, including autophagy, mitophagy, inflammation, oxidative stress, and glucose metabolism, highlighting the emerging need for pharmacological approaches to modulate ROR expression. Thus, the modulation of RORs is a rapidly growing area of research aimed not only at comprehending these receptors, but also at manipulating them to attain the desired physiological response. Despite the presence of natural ROR ligands, the development of synthetic agonists with high selectivity for these receptors holds substantial therapeutic potential. The exploration and advancement of such compounds can effectively target diseases associated with ROR dysregulation, thereby providing avenues for therapeutic interventions. Herein, we provide a comprehensive examination of the multifaceted role of ROR in diverse physiological and pathophysiological conditions, accompanied by an in-depth exploration of a spectrum of ROR agonists, inverse agonists, and antagonists.

Oral hormonal contraception (OHC) is a widely employed method in females for the prevention of unintended pregnancies, as well as for the treatment of menstrual disorders, endometriosis, and polycystic ovarian syndrome. However, it is believed that with OHCs use, some females may have higher risk of cardiovascular diseases, such as hypertension, diabetes, myocardial infarction, thrombosis, and heart failure. Although such risks are infrequently detected in healthy young females with the use of oral contraceptives, slightly elevated risks of cardiovascular diseases have been observed among reproductive-aged healthy females. However, prolonged use of OHC has also been claimed to have protective cardiac effects and may contribute to reduced risk of cardiovascular disease. In fact, the debate on whether OHC administration increases the risk of cardiovascular diseases has been ongoing with inconsistent and controversial viewpoints. Nevertheless, a great deal of work has been carried out to understand the relationship between OHC use and the occurrence of cardiovascular risk in females who use OHC for preventing the unwanted pregnancy or treatment of other disorders. Therefore, in this review we summarize the most recent available evidence regarding the association between the use of oral hormonal contraceptives and the risk for cardiovascular disease in females who are using OHC to prevent unintended pregnancy.

Valvular heart disease (VHD) is common, affecting >14% of individuals aged >75, and is associated with morbidity, including heart failure and arrhythmia, and risk of early mortality. Increasingly, important sex differences are being found between males and females with VHD. These sex differences can involve the epidemiology, pathophysiology, presentation, diagnosis, and outcomes of the disease. Females are often disadvantaged, and female sex has been shown to be associated with delayed diagnosis and inferior outcomes in various forms of VHD. In addition, the unique pathophysiologic state of pregnancy is associated with increased risk for maternal and fetal morbidity and mortality in many forms of VHD. Therefore, understanding and recognizing these sex differences, and familiarity with the attendant risks of pregnancy and management of pregnant females with VHD, is of great importance for any primary care or cardiovascular medicine practitioner caring for the female patient. This review will outline sex differences in aortic, mitral, pulmonic, and tricuspid VHD, with particular focus on differences in pathophysiology, clinical presentation, and outcomes. In addition, the pathophysiology and management implications of pregnancy will be discussed.

Cardiovascular disease is the leading indirect cause of maternal morbidity and mortality, accounting for nearly one third of maternal deaths during pregnancy. The burden of cardiovascular disease in pregnancy is increasing, as are the incidence of maternal morbidity and mortality. Normal physiologic adaptations to pregnancy, including increased cardiac output and plasma volume, may unmask cardiac conditions, exacerbate previously existing conditions, or create de novo complications. It is important for care providers to understand the normal physiologic changes of pregnancy and how they may impact the care of patients with cardiovascular disease. This review outlines the physiologic adaptions during pregnancy and their pathologic implications for some of the more common cardiovascular conditions in pregnancy.

Coronary microvascular dysfunction (CMD) involves functional or structural abnormalities of the coronary microvasculature resulting in dysregulation of coronary blood flow (CBF) in response to myocardial oxygen demand. This perfusion mismatch causes myocardial ischemia, which manifests in patients as microvascular angina (MVA). CMD can be diagnosed non-invasively via multiple imaging techniques or invasively using coronary function testing (CFT), which assists in determining the specific mechanisms involving endothelium-independent and dependent epicardial and microcirculation domains. Unlike traditional coronary artery disease (CAD), CMD can often occur in patients without obstructive atherosclerotic epicardial disease, which can make the diagnosis of CMD difficult. Moreover, MVA due to CMD is more prevalent in women and carries increased risk of future cardiovascular events. Successful treatment of symptomatic CMD is often patient-specific risk factor and endotype targeted. This article aims to review newly identified mechanisms and novel treatment strategies for managing CMD, and outline sex-specific differences in the presentation and pathophysiology of the disease.