Acute effects of 17beta-estradiol on ventricular and vascular hemodynamics in postmenopausal women

Aortic hemodynamics in postmenopausal women following cessation of hormone therapy

Central (aortic) blood pressure and aortic pulse wave characteristics are measures of cardiovascular health, predictive of cardiovascular mortality. Previous studies have compared aortic hemodynamics in women who do and do not take menopausal hormone therapy, but characteristics of these parameters following cessation of treatment have not been defined. Therefore, the purpose of this study was to define aortic pulse wave characteristics in postmenopausal women with and without a history of menopausal hormone therapy use. Pulse wave analysis was conducted on 67 women who had participated in the randomized, double‐blind, placebo‐controlled Kronos Early Estrogen Prevention Study (KEEPS), 3 years subsequent to the four‐year treatment period. Treatment was oral conjugated equine estrogen (0.45 mg/day; n = 18); transdermal 17β‐estradiol (50 μg/day; n = 23) each with oral micronized progesterone (Prometrium 200 mg); and placebo pills and patch (n = 26). At post‐treatment, median age (60 years) and body mass index (27 kg/m²) did not differ across prior treatment assignment. Aortic blood pressures (median systolic 115 mm Hg and diastolic 76 mm Hg) and augmentation index (median 33%) did not differ among women across prior treatment assignment. These results suggest that these doses and formulations of menopausal hormone therapy had no long‐term effects on central vascular function 3 years after cessation of treatment.

Back to your heart: ubiquitin proteasome system-regulated signal transduction

Awareness of the regulation of cell signaling by post-translational ubiquitination has emerged over the past 2 decades. Like phosphorylation, post-translational modification of proteins with ubiquitin can result in the regulation of numerous cellular functions, for example, the DNA damage response, apoptosis, cell growth, and the innate immune response. In this review, we discuss recently published mechanisms by which the ubiquitin proteasome system regulates key signal transduction pathways in the heart, including MAPK JNK, calcineurin, FOXO, p53, and estrogen receptors α and β. We then explore how ubiquitin proteasome system-specific regulation of these signal transduction pathways plays a role in the pathophysiology of common cardiac diseases, such as cardiac hypertrophy, heart failure, ischemia reperfusion injury, and diabetes. This article is part of a Special Section entitled "Post-translational Modification."

Myocardial contractility is preserved early but reduced late after ovariectomy in young female rats

BACKGROUND

Ovarian sex hormones (OSHs) are implicated in cardiovascular function. It has been shown that OSHs play an important role in the long term regulation of cardiac sarcoplasmic reticulum (SR) function and contractility, although early effects of OSHs deprivation on myocardial contractility have not yet been determined. This study evaluated the early and late effects of OSHs deficiency on left ventricular contractility in rats after ovariectomy.

METHODS

Young female Wistar rats were divided into 3 groups (n=9-15): sham operated (Sham), ovariectomized (Ovx) and Ovx treated with estradiol (1 mg/kg, i.m., once a week) (Ovx+E2). After 7, 15, 30 and 60 days post Ovx, left ventricle papillary muscle was mounted for isometric tension recordings. The inotropic response to Ca2+ (0.62 to 3.75 mM) and isoproterenol (Iso 10-8 to 10-2 M) and contractility changes in response to rate changes (0.25 to 3 Hz) were assessed. Protein expression of SR Ca2+-ATPase (SERCA2a) and phospholamban (PLB) in the heart was also examined.

RESULTS

The positive inotropic response to Ca2+ and Iso at 7, 15, and 30 days after Ovx was preserved. However, at 60 days, the Ovx group had decreased myocardial contractility which was subsequently restored with E2 replacement. The reduction in SERCA2a and increase in PLB expression observed at 60 days after Ovx were restored with E2 replacement.

CONCLUSION

This study demonstrated that myocardial contractility and expression of key Ca2+ handling proteins were preserved in the early phase and reduced at long-term during OSHs deprivation.

Does hormone treatment alter arterial properties in postmenopausal women?

Arterial elastic properties and wave reflections constitute left ventricular pulsatile afterload and are directly related to cardiovascular morbidity and mortality. During the aging process, elastic arteries stiffen and increase pulse wave velocity, causing the reflected pressure wave to arrive at the heart during systole, and augment systolic and pulse blood pressure, resulting in left ventricular hypertrophy. The incidence of cardiovascular disease is much greater in men aged 30-50 years compared with women of a similar age. Among women, the incidence of cardiovascular disease increases dramatically after menopause, which occurs at an average age of 52 years. This observation has lead to the belief that sex hormones produced premenopausally impede or delay the progression of cardiovascular disease. Therefore, it appears logical that the administration of female sex hormones, hormone treatment (HT), estrogen alone or with progesterone should provide some degree of cardiovascular protection. This idea was supported by experiments in animals and isolated arterial segments demonstrating that HT increases plasma nitric oxide, decreases endothelin-1 levels and causes smooth muscle relaxation. Also, 17β-estradiol administration decreases collagen and increases elastin in the aortic wall of rats. These experimental studies suggest an improvement in both elastic and muscular artery properties and favorabe modifications of arterial wave reflection characteristics. Furthermore, HT improves lipoprotein metabolism and reduces coronary artery plaque formation in animal models. Unfortunately, observational and interventional studies in postmenopausal women that have evaluated the impact of HT on cardiovascular changes have produced inconsistent and inconclusive results. Most studies agree that arterial stiffness increases after menopause, partly due to advancing age and reduced estrogen production. Results from most studies that were designed to investigate the effects of HT on arterial properties have shown a selective decrease in elastic artery stiffness with little effect on muscular arteries. This beneficial effect was observed only if estrogen alone was administered. The main objective of this review is to discuss the ill effects of arterial stiffness in general and attempt to translate information from previous experimental studies to those in postmenopausal women and explain the beneficial effects of HT on arterial stiffness and improvement in left ventricular afterload.

SEX HORMONES AND THE CARDIOVASCULAR SYSTEM: EFFECTS ON ARTERIAL FUNCTION IN WOMEN

1. It has long been hypothesized that oestrogen may be cardioprotective. This hypothesis is supported by diverse and comprehensive mechanistic studies in animals and humans. Consistently, in observational studies, oestrogen use in post-menopausal women significantly reduced cardiovascular disease. Contrastingly, large interventional trials focusing on chronic disease prevention in older post-menopausal women have suggested neutral (oestrogen alone) or adverse (combined oestrogen/progestin preparations) cardiovascular effects. 2. The negative initial interpretation and extrapolation of the early randomized, controlled interventional trials, primarily the Women's Health Initiative, has recently been theoretically reconciled with the positive mechanistic and observational studies. As a new interventional literature emerges, it has been suggested that if oestrogen is used from menopause onwards it is likely to be protective, but if instituted after endothelial damage has occurred in an oestrogen-deficient post-menopausal state, the beneficial vessel wall effects are not observed and the procoagulant effects result in overall increased cardiovascular risk. 3. The present article reviews the literature on arterial function and oestrogen use in the setting of the early endothelial protection theory. This theory is generally supported by the data on oestrogen effects on arterial function. In general, in studies of premenopausal women the effects of oestrogen were positive, with similar benefits noted if oestrogen was used early after menopause. However, where hormone therapy was commenced some years after menopause, the beneficial effects on arterial function were not observed. In clinical practice, hormone therapy is primarily used at menopause for the treatment of menopausal symptoms. The data on arterial function reviewed herein, along with emerging interventional human studies, suggest that the cardiovascular effects of this practice are not adverse.

Vasospastic angina and microvascular angina are differentially influenced by PON1 A632G polymorphism in the Japanese

BACKGROUND

Ethnicity and smoking are well-known risk factors for the pathogenesis of coronary vasospasm. Oxidative stress induced by smoking plays a crucial role in coronary vasospasm, but is not enough to account for the pathogenesis of coronary vasospasm, indicating that genetic factors are strongly involved.

METHODS AND RESULTS

The study group comprised 162 vasospastic angina patients (VSAs), 61 microvascular angina patients (MVAs) and 61 non-responders (NRs) diagnosed by acetylcholine provocation test. Four polymorphisms of the oxidative stress related genes, cytochrome b-245, alpha polypeptide gene (CYBA) C242T and A640G, paraoxonase 1 gene (PON1) A632G, phospholipase A2 group VII gene (PLA2G7) G994T were genotyped. Allele frequency of PON1 632-G was significantly higher in both the VSA with dominant fashion and the MVA with recessive fashion compared with NR. This association was strongly influenced by gender in the MVA only. There were no significant associations between the other polymorphisms and coronary vasospasm. In addition, the allele frequency of PON1 632-G in the Japanese was higher than in Caucasians.

CONCLUSIONS

There was a significant association between PON1 A632G polymorphism and MVA as well as VSA, but the impact of this on VSA and MVA is different in the Japanese.

Effect of hormone therapy on the elastic properties of the arteries in healthy postmenopausal women

The aim of the study was to assess the effect of continuous hormone therapy (HT) for 1 yr on pulse wave analysis and central aortic pressure in healthy postmenopausal women. Sixty-five healthy postmenopausal women were randomly allocated to receive either conjugated equine estrogens 0.625 mg plus medroxyprogesterone acetate 5 mg (CEE/MPA, Premelle 5, Wyeth-Ayerst Lab, Philadelphia, PA, no.=32) or no therapy (no.=33). Treatment was continuous, and the study period lasted 12 months. Central aortic pressure, augmentation and augmentation index (AI) were determined non-invasively using applanation tonometry. All measurements were performed at baseline and at the end of the study by the same person. Ns differences were found between baseline values and values at the end of the study in either the control or the CEE/MPA group in central systolic aortic pressure (107.0 +/- 13.1 vs 107.6 +/- 11.3 mmHg, p=0.80, and 110.8 +/- 10.8 vs 112.3 +/- 11.4 mmHg, p=0.23, respectively), augmentation (12.6 +/- 4.2 vs 11.9 +/- 4.8 mmHg, p=0.45 and 11.7 +/- 3.7 vs 12.6 +/- 4.2 mmHg, p=0.34, respectively), and percentage of AI (36.8 +/- 9.3 vs 36.3 +/- 10.3, p=0.81 and 34.1 +/- 8.9 vs 34.9 +/- 9.8, p=0.72, respectively). The results of this preliminary report suggest that HT for 1 yr does not have any significant effect on central aortic pressure and wave reflection in healthy postmenopausal women.

Neuroendocrine control of body fluid metabolism

Mammals control the volume and osmolality of their body fluids from stimuli that arise from both the intracellular and extracellular fluid compartments. These stimuli are sensed by two kinds of receptors: osmoreceptor-Na+ receptors and volume or pressure receptors. This information is conveyed to specific areas of the central nervous system responsible for an integrated response, which depends on the integrity of the anteroventral region of the third ventricle, e.g., organum vasculosum of the lamina terminalis, median preoptic nucleus, and subfornical organ. The hypothalamo-neurohypophysial system plays a fundamental role in the maintenance of body fluid homeostasis by secreting vasopressin and oxytocin in response to osmotic and nonosmotic stimuli. Since the discovery of the atrial natriuretic peptide (ANP), a large number of publications have demonstrated that this peptide provides a potent defense mechanism against volume overload in mammals, including humans. ANP is mostly localized in the heart, but ANP and its receptor are also found in hypothalamic and brain stem areas involved in body fluid volume and blood pressure regulation. Blood volume expansion acts not only directly on the heart, by stretch of atrial myocytes to increase the release of ANP, but also on the brain ANPergic neurons through afferent inputs from baroreceptors. Angiotensin II also plays an important role in the regulation of body fluids, being a potent inducer of thirst and, in general, antagonizes the actions of ANP. This review emphasizes the role played by brain ANP and its interaction with neurohypophysial hormones in the control of body fluid homeostasis.

Blood pressure, arterial function, structure, and aging: the role of hormonal replacement therapy in postmenopausal women

The occurrence of natural menopause may indicate that a woman is entering a period of increased risk for cardiovascular disease, due to both chronologic aging and lower levels of estrogen. This brief review aims to demonstrate the relevance of changes in blood pressure and large artery structure and function occurring after menopause. These changes, i.e., thickening and stiffening of large arteries (which, in turn would also result in increased systolic and pulse pressures), were found to predict subsequent cardiovascular events, independently of other known cardiovascular risk. The benefits of early hormone replacement therapy on the life expectancy of women have dramatically lost consensus since publication of the Womens Health Initiative study results. However, the authors believe that those results should increase the attention paid by clinicians and public health researchers to the individualization of hormone replacement therapy prescription for postmenopausal women, and to a better characterization of those vascular parameters and profiles identifying postmenopausal women who are most likely to benefit from specific hormone replacement therapy in terms of cardiovascular protection.

Effects of oestrogen replacement on steady and pulsatile haemodynamics in ovariectomized rats

1. The effects of ovariectomy (Ovx), menopause and oestrogen replacement on the haemodynamics remain controversial. The present study employed the technique of arterial impedance analysis to measure and calculate the steady and pulsatile haemodynamics. The purpose was to determine the haemodynamic consequence of ovariectomy and oestrogen replacement. 2. Ovariectomy was carried out under anaesthesia on female Sprague Dawley rats aged 9 weeks. Oestrogen (17 beta-estradiol or E(2)) replacement started 1 week after ovariectomy for 4 weeks. Ovx increased the body weight (BW), while it greatly reduced the uterus weight. Left ventricular weight (LVW) was slightly increased, but LVW/BW ratio was slightly reduced. These changes were reversed after E(2) replacement. 3. Compared to sham group, Ovx with or without E(2) replacement did not significantly affect the systolic, mean and diastolic pressure. In Ovx, pulse pressure (PP) and heart rate were significantly increased, while stroke volume and cardiac output were slightly decreased. Total peripheral resistance (TPR) was largely elevated, indicating Ovx induced systemic vasoconstriction. These changes all returned to close normal values (sham group) after E(2) replacement, except PP. 4. Ovx increased the characteristic input impedance (Zc) and pulse wave reflection, while it decreased arterial compliance. E(2) treatment reversed these changes, except Zc. 5. These results demonstrate that Ovx influences both the resistance and Windkessel functions of the artery. E(2) treatment effectively reverses most the effects of Ovx both on the steady and pulsatile haemodynamics.

Effect of estrogen and progestin replacement on arterial stiffness indices in postmenopausal women

Our objectives were to investigate whether long-term estrogen replacement therapy (ERT) is associated with a reduction in age-associated increases in arterial stiffness and blood pressure (BP), and whether the addition of progestin modifies the effects of estrogen. ERT has been found to have beneficial effects on cardiovascular risk. There are few data, however, delineating the effects of ERT on BP and arterial stiffness, and their age-associated changes. BP and aorto-femoral pulse wave velocity (PWV) were measured in 134 postmenopausal volunteers, aged 51 to 90 years, from the Baltimore Longitudinal Study of Aging, screened to exclude clinical and occult cardiovascular disease, and classified as ERT non-users (N=57) or ERT users (N=77). The latter group was further substratified according to the use of estrogen alone (N=32) or a combination of estrogen and progestins (N=45). ERT users showed similar body habitus, physical activity, and plasma lipids compared to non-ERT users. ERT was associated with an average 9.8 mmHg lower systolic BP (p<0.001), and a 6.3 mmHg lower pulse pressure (p<0.01) than in non-users. Multiple regression analysis showed that ERT was an independent predictor of lower SBP and PP (p<0.05). By analysis of covariance, ERT predicted a reduced age-associated increase in SBP, PP, and PWV (p<0.05). When systolic BP was >130 mmHg, the combination of ERT and progestins predicted a higher PWV than ERT alone. In conclusion, ERT in postmenopausal women can beneficially affect the vascular system, by reducing BP and the age-associated increase in arterial stiffness. The addition of progestins to ERT may reduce these beneficial effects.