Medroxyprogesterone acetate but not drospirenone ablates the protective function of 17 beta-estradiol in aldosterone salt-treated rats

Medroxyprogesterone opposes estradiol-induced renal damage in midlife ovariectomized Long Evans rats

OBJECTIVE

Our laboratory previously published that long-term administration of estradiol (E2) was detrimental to the kidneys of midlife ovariectomized Long Evans rats, contrasting clinical studies in showing that menopausal hormone therapy is associated with decreased albuminuria. However, it is unknown whether this renal benefit was due to estrogen and/or the combination with progestogen. Therefore, the objective of the current study was to determine the impact of medroxyprogesterone (MPA) on E2-mediated renal damage using a rodent model.

METHODS

Female Long Evans retired breeders underwent ovariectomy at 11 months of age and were treated for 40 days with subcutaneous E2, E2+MPA or vehicle at doses mimicking that of menopausal hormone therapy (N = 5-7 per group). Systolic blood pressure was measured along with indices of renal damage and function to investigate the impact of MPA on E2-mediated renal outcomes. Renal estrogen receptor alpha and G protein-coupled estrogen receptor transcript copy numbers were measured in all treatment groups through droplet digital PCR.

RESULTS

Middle-aged female Long Evans rats displayed spontaneous hypertension with similar systolic blood pressures and heart weights between groups. Even though blood pressure was comparable, E2 reduced glomerular filtration rate and increased proteinuria indicating pressure-independent renal damage. Coadministration with MPA prevented E2-induced glomerular filtration rate impairment and proteinuria by promoting renal hypertrophy and preventing renal interstitial fibrosis. Both E2 and E2+MPA reduced renal estrogen receptor alpha (ERα) and increased renal G protein-coupled estrogen receptor mRNA, but neither ERα nor ERß protein was different between groups.

CONCLUSION

MPA was protective against E2-induced renal damage and dysfunction in middle-aged female Long Evans rats. Assessing the impact of hormone therapy on renal outcomes may be an important clinical factor when considering treatment options for postmenopausal women.

Cardiac dysfunction after preeclampsia; an overview of pro- and anti-fibrotic circulating effector molecules

Preeclampsia (PE) is strongly associated with heart failure (HF) later in life. The aberrant cardiac remodelling is likely initiated or amplified during preeclamptic pregnancy. Aberrant remodelling often persists after delivery and is known to relate strongly to cardiac fibrosis. This review provides an overview of pro- and anti- fibrotic circulating effector molecules that are involved in cardiac fibrosis and their association with PE. Women with PE complicated pregnancies show increased ANG-II sensitivity and elevated levels of the pro-fibrotic factors IL-6, TNF-α, TGs and FFAs compared to uncomplicated pregnancies. In the postpartum period, PE pregnancies compared to uncomplicated pregnancies have increased ANG-II sensitivity, elevated levels of the pro-fibrotic factors IL-6, TNF-α, LDL cholesterol and leptin, as well as decreased levels of the anti-fibrotic factor adiponectin. The review revealed several profibrotic molecules that associate to cardiac fibrosis during and after PE. The role that these fibrotic factors have on the heart during and after PE may improve the understanding of the link between PE and HF. Furthermore they may provide insight into the pathways in which the relation between both diseases can be understood as potential mechanisms which interfere in the process of cardiovascular disease (CVD). Unravelling the molecular mechanism and pathways involved might bring the diagnostic and therapeutic abilities of those factors a step closer.

Levonorgestrel correlates with less weight gain than other progestins during hormonal replacement therapy in Turner Syndrome patients

Turner Syndrome (TS) is associated with an increased risk of cardiovascular and metabolic complications. Furthermore, TS women need hormone replacement therapy (HRT), of which progestins can influence body weight. We aimed to analyze the metabolic and weight profile in a cohort of 111 TS women. They started receiving estrogen at 15.8 (±3.6) years old, with no change in hypertension, dysglycemia, and dyslipidemia incidence but with a tendency to increase overweight (p = 0.054). As the first used type of progestin, most had received cycles of 10 days per month of medroxyprogesterone (MPA) or levonorgestrel (LNG), then shifted to micronized progesterone (MP), which has currently become the most used one. By multiple linear regression analysis, we found that the prolonged use of MPA, LNG, or MP showed no metabolic change except for weight gain. The percentage of annual BMI increment was positive for all progestins used in TS women (MPA 2.2 ± 2.2; LNG 0.2 ± 1.2; and MP 2.2 ± 2.6 kg/m2), but LNG seemed to best prevent on weight gain over time (p < 0.05). In conclusion, metabolic comorbidities are prevalent in TS even before the HRT regimen, and LNG performed better on less weight gain than MPA and MP in our cohort of the TS population.

Hormonal therapy with estradiol and drospirenone improves endothelium-dependent vasodilation in the coronary bed of ovariectomized spontaneously hypertensive rats

Drospirenone (DRSP) is a progestin with anti-aldosterone properties and it reduces blood pressure in hypertensive women. However, the effects of DRSP on endothelium-dependent coronary vasodilation have not been evaluated. This study investigated the effects of combined therapy with estrogen (E2) and DRSP on endothelium-dependent vasodilation of the coronary bed of ovariectomized (OVX) spontaneously hypertensive rats. Female spontaneously hypertensive rats (n=87) at 12 weeks of age were randomly divided into sham operated (Sham), OVX, OVX treated with E2 (E2), and OVX treated with E2 and DRSP (E2+DRSP) groups. Hemodynamic parameters were directly evaluated by catheter insertion into the femoral artery. Endothelium-dependent vasodilation in response to bradykinin in the coronary arterial bed was assessed using isolated hearts according to a modified Langendorff method. Coronary protein expression of endothelial nitric oxide synthase and estrogen receptor alpha (ER-α) was assessed by Western blotting. Histological slices of coronary arteries were stained with hematoxylin and eosin, and morphometric parameters were analyzed. Oxidative stress was assessed in situ by dihydroethidium fluorescence. Ovariectomy increased systolic blood pressure, which was only prevented by E2+DRSP treatment. Estrogen deficiency caused endothelial dysfunction, which was prevented by both treatments. However, the vasodilator response in the E2+DRSP group was significantly higher at the three highest concentrations compared with the OVX group. Reduced ER-α expression in OVX rats was restored by both treatments. Morphometric parameters and oxidative stress were augmented by OVX and reduced by E2 and E2+DRSP treatments. Hormonal therapy with E2 and DRSP may be an important therapeutic option in the prevention of coronary heart disease in hypertensive post-menopausal women.

Effects of a contraceptive containing drospirenone and ethinyl estradiol on blood pressure and autonomic tone: a prospective controlled clinical trial

BACKGROUND

The use of combined oral contraceptives has been associated with an increased risk of adverse cardiovascular events. Whether these drugs alter cardiac autonomic nervous system control is not completely determined.

OBJECTIVE

To evaluate the effect of a contraceptive containing 20mcg of ethinyl estradiol and 3mg of drospirenone on the heart rate variability, baroreflex sensitivity and blood pressure of healthy women.

STUDY DESIGN

Prospective controlled trial with 69 healthy women allocated in two groups: 36 volunteers under oral combined contraceptive use and 33 volunteers using of non-hormonal contraceptive methods. Subjects were tested before the introduction of the contraceptive method and 6 months after its use. For data acquisition, we used continuous non-invasive beat-to-beat blood pressure curve recordings. Multiple ANOVA was used to determine differences between groups and moments and p< 0.05 was considered statistically significant.

RESULTS

At baseline, there were no differences in demographic and autonomic parameters between groups. Comparing cardiac sympatho-vagal modulation, baroreceptor sensitivity and blood pressure measurements between baseline and after 6 months, no significant difference was detected in each group or between groups.

CONCLUSION

A contraceptive containing 20mcg of ethinyl estradiol and 3mg of drospirenone causes no significant changes in clinical, hemodynamic and autonomic parameters of normal women.

Medroxyprogesterone acetate aggravates oxidative stress and left ventricular dysfunction in rats with chronic myocardial infarction

The role of estrogens during myocardial ischemia has been extensively studied. However, effects of a standard hormone replacement therapy including 17β-estradiol (E2) combined with medroxyprogesterone acetate (MPA) have not been assessed, and this combination could have contributed to the negative outcomes of the clinical studies on hormone replacement. We hypothesized that adding MPA to an E2 treatment would aggravate chronic heart failure after experimental myocardial infarction (MI). To address this issue, we evaluated clinical signs of heart failure as well as left ventricular (LV) dysfunction and remodeling in ovariectomized rats subjected to chronic MI receiving E2 or E2 plus MPA. After eight weeks MI E2 showed no effects. Adding MPA to E2 aggravated LV remodeling and dysfunction as judged by increased heart weight, elevated myocyte cross-sectional areas, increased elevated left ventricle end diastolic pressure, and decreased LV fractional shortening. Impaired LV function in rats receiving MPA plus E2 was associated with increased cardiac reactive oxygen species generation and myocardial expression levels of NADPH oxidase subunits. These results support the interpretation that adding MPA to an E2 treatment complicates cardiovascular injury damage post-MI and therefore contributes to explain the adverse outcome of prospective clinical studies.

Blood pressure effects of the oral contraceptive and postmenopausal hormone therapies

Oral contraceptives and postmenopausal hormone therapy may induce hypertension through multiple mechanisms, including sodium and volume retention. Numerous studies have shown significant increases in blood pressure (BP) with the chronic administration of oral contraceptives as well as reversibility with discontinuation. The effects of different classes of oral contraceptive agents and hormonal replacement therapy on BP and associated effects on other cardiovascular risk factors are covered in this article. Novel hormonal replacement therapy that lowers BP is also discussed.

Increased myocardial stiffness with maintenance of length-dependent calcium activation by female sex hormones in diabetic rats

A decrease in peak early diastolic filling velocity in postmenopausal women implies a sex hormone-related diastolic dysfunction. The regulatory effect of female sex hormones on cardiac distensibility therefore was evaluated in ovariectomized rats by determining the sarcomere length-passive tension relationship of ventricular skinned fiber preparations. Diabetes also was induced in the rat to assess the protective significance of female sex hormones on diastolic function. While ovariectomy had no effect on myocardial stiffness, collagen content, or titin ratio, a significant increase in myocardial stiffness was observed in diabetic rat only when female sex hormones were intact. The increased stiffness in diabetic-sham rats was accompanied by an elevated collagen content resulting from increases in the levels of procollagen and Smad2. Surprisingly, the increased myocardial stiffness in diabetic-sham rats was accompanied by a shift toward a more compliant N2BA of cardiac titin isoforms. The pCa-active tension relationship was analyzed at fixed sarcomere lengths of 2.0 and 2.3 μm to determine the magnitude of changes in myofilament Ca(2+) sensitivity between the two sarcomere lengths. Interestingly, high expression of N2BA titin was associated with a suppressed magnitude of changes in myofilament Ca(2+) sensitivity only in the diabetic-ovariectomized condition. Estrogen supplementation in diabetic-ovariectomized rats partially increased myocardial stiffness but completely reversed the change in myofilament Ca(2+) sensitivity. These results indicate a restrictive adaptation of myocardium governed by female sex hormones to maintain myofilament activity in compensation to the pathophysiological induction of cardiac dilatation by the diabetic condition.

A review of the cardiovascular and breast actions of drospirenone in preclinical studies

OBJECTIVE

Hormone therapy is effective for the relief of menopausal symptoms. For women with a uterus, addition of a progestogen is required to protect the endometrium. However, synthetic progestins differ in certain pharmacological characteristics that may have implications for clinical practice. This literature-based review explores differences in the preclinical and clinical profiles of the progestins used in hormone therapy, focusing on their effects on the cardiovascular system and breast.

DESIGN

Studies included are selected based on criteria of relevance, topicality, and subjective assessment of quality, following comprehensive searches of online databases.

RESULTS

The biological actions of progestins depend on their receptor binding affinity profiles as well as their specific effects on progesterone receptor signaling, which often differ based on the ligand. Observational studies indicate that hormone therapies which include medroxyprogesterone acetate and certain other progestins may attenuate the cardiovascular benefits of estrogen and add to risk of breast cancer. Appraisal of the evidence suggests these clinical effects correlate with the progestin's pharmacological profile. Among the newer progestins, drospirenone has been investigated extensively in preclinical studies. With a pharmacological profile similar to progesterone, drospirenone is devoid of estrogenic, androgenic and glucocorticoid activity and possesses potent antialdosterone and antiandrogenic activity. This profile of drospirenone contrasts with that of older progestins, conferring specific effects on cardiovascular and breast cells.

CONCLUSIONS

The relative risks associated with hormone therapy vary with the combination of hormones included. Differences in pharmacological profile among progestins may translate to characteristic divergences in clinical profile, with potential implications for long-term health.

Differential effects of 17beta-estradiol and of synthetic progestins on aldosterone-salt-induced kidney disease

Elevated mineralocorticoid levels and female sex hormones have been shown to confer opposing effects on renal injury, but their combined effects are still unknown.

OBJECTIVE

Identify the function of estrogens and of different synthetic progestins on aldosterone salt-mediated renal disease.

METHODS

The role of 17beta-estradiol, medroxyprogesterone acetate (MPA), and drospirenone during renal injury was studied in Wistar rats subjected to uni-nephrectomy plus aldosterone salt treatment.

RESULTS

Aldo-salt treatment of intact, ovariectomized, and estradiol-treated female rats resulted in remnant kidney hypertrophy without structural damage. Co-treatment with MPA, but not with drospirenone, increased kidney hypertrophy, fluid turnover, sodium retention, and potassium excretion. Medroxyprogesterone acetate also caused glomerular, vascular, tubular, and interstitial lesions that were accompanied by increased blood pressure and enhanced NADPH oxidase (p67phox) and sodium channel (alpha-ENaC) expression. Drospirenone, a progestin with anti-mineralocorticoid function, and spironolactone prevented kidney hypertrophy, hypertension, and sodium retention. Drospirenone and spironolactone also increased renal angiotensin II type 2 receptor expression and relieved aldosterone-induced suppression of serum angiotensin II levels.

CONCLUSION

The choice of specific synthetic progestins has profound implications on the development of kidney injury and renal gene expression under conditions of elevated aldosterone serum levels and salt intake.

Ovariectomy increases the formation of prostanoids and modulates their role in acetylcholine-induced relaxation and nitric oxide release in the rat aorta

AIMS

This study examines the effect of ovarian function on thromboxane A(2) (TXA(2)), prostaglandin (PG) I(2), PGF(2alpha), and PGE(2) release as well as the role of these substances in nitric oxide (NO) release and acetylcholine (ACh)-mediated relaxation.

METHODS AND RESULTS

Aortic segments from ovariectomized and control female Sprague-Dawley rats were used. Cyclooxygenase (COX-1 and COX-2) expression was studied. ACh-induced relaxation was analysed in the absence and presence of the COX-2 inhibitor NS-398, the TXA(2) synthesis inhibitor furegrelate, the PGI(2) synthesis inhibitor tranylcypromine (TCP), or the thromboxane-prostanoid receptor antagonist SQ-29548. TXA(2), PGI(2), PGF(2alpha), and PGE(2) release was measured, and the vasomotor effect of exogenous TXA(2), PGI(2,) PGF(2alpha), and PGE(2) was assessed. Basal and ACh-induced NO release in the absence and presence of NS-398, furegrelate, TCP, or TCP plus furegrelate was studied. Ovariectomy did not alter or increased COX-1 or COX-2 expression, respectively. NS-398 decreased, and furegrelate did not change, the ACh-induced relaxation in arteries from both groups. SQ29,548 decreased the ACh-induced relaxation only in aortas from ovariectomized rats. TCP decreased the ACh-induced relaxation in both groups, and furegrelate or SQ29,548 totally restored that response only in aortas from control rats. Ovariectomy increased the ACh-induced TXA(2), PGI(2), and PGE(2) release and the contractile responses induced by exogenous TXA(2), PGF(2alpha), or PGE(2), while it decreased the PGI(2)-induced vasodilator response. In aortas from control rats, NS-398 did not alter the ACh-induced NO release, and furegrelate, TCP, or TCP plus furegrelate increased that release. In arteries from ovariectomized rats, NS-398, furegrelate, TCP, or TCP plus furegrelate decreased the ACh-induced NO release.

CONCLUSION

Despite the prevalence of vasoconstrictor prostanoids derived from COX-2 in aortas from ovariectomized rats, the ACh-induced relaxation is maintained, probably as consequence of the positive regulation that prostanoids exert on eNOS activity.

Sex differences and central protective effect of 17beta-estradiol in the development of aldosterone/NaCl-induced hypertension

The present study tested the hypotheses that male and female rats respond differently to subcutaneous infusions of aldosterone (Aldo; 1.8 microg.kg(-1).h(-1), 1% NaCl to drink; 28 days) and that central estrogen plays a protective role against the development of hypertension. In rats with blood pressure (BP) and heart rate (HR) measured by Data Sciences International telemetry, chronic Aldo/NaCl treatment induced a greater increase in BP in males (Delta25.4 +/- 2.4 mmHg) than in females (Delta7.1 +/- 2.2 mmHg). Gonadectomy augmented Aldo/NaCl-induced hypertension in females (Delta18.2 +/- 2.0 mmHg) but had no effect in males (Delta23.1 +/- 2.9 mmHg). Immunohistochemistry for Fra-like activity was higher in the paraventricular nucleus of intact males, castrated males, and ovariectomized (OVX) females compared with intact females after 28 days of Aldo/NaCl treatment. In intact males, central 17beta-estradiol (E(2)) inhibited the Aldo/NaCl increase in BP (Delta10.5 +/- 0.8) compared with that in central vehicle plus systemic Aldo/NaCl (Delta26.1 +/- 2.5 mmHg) rats. Combined administration of E(2) and estrogen receptor antagonist ICI182780 (ICI) blocked the protective effect of E(2) (Delta23.2 +/- 2.4 mmHg). In intact females central, but not peripheral, infusions of ICI augmented the Aldo/NaCl (Delta20.4 +/- 1.8 mmHg) BP increase. Finally, ganglionic blockade after Aldo infusions resulted in a smaller reduction in BP in intact females (-23.9 +/- 2.5 mmHg) and in central estrogen-treated males (-30.2 +/- 1.0 mmHg) compared with other groups (intact males, -39.3 +/- 3.4; castrated males, -41.8 +/- 1.9; intact males with central E(2) + ICI, -42.3 +/- 2.1; OVX females, -40.3 +/- 3.3; and intact females with central ICI, -39.1 +/- 1.3 mmHg). Chronic Aldo infusion produced increases in NaCl intake and decreases in HR that were both similar in all groups. Taken together, the results indicate that central estrogen plays a protective role in the development of Aldo/NaCl-induced hypertension and that this may result from reduced sympathetic outflow.

Oral contraceptive progestins and angiotensin-dependent control of the renal circulation in humans

Oral contraceptive (OC) use is associated with increased intra-renal renin-angiotensin-aldosterone system (RAA System) activity and risk of nephropathy, though the contribution of progestins contained in the OC in the regulation of angiotensin-dependent control of the renal circulation has not been elucidated. Eighteen OC users (8 non-diabetic, 10 Type 1 diabetic) were studied in high salt balance, a state of maximal RAA System suppression. Progestational and androgenic activity of the progestin in each OC was standardized to that of the reference progestin norethindrone. Renal plasma flow (RPF) was measured by paraaminohippurate clearance at baseline and in response to angiotensin converting enzyme (ACE)-inhibition. There was a positive correlation between OC progestational activity and the RPF response to ACE-inhibition (r=0.52, p=0.03). Similar results were noted with OC androgenic activity (r=0.54, p=0.02). On subgroup analysis, only non-diabetic subjects showed an association between progestational activity and angiotensin-dependent control of the renal circulation (r=0.71, p=0.05 non-diabetic; r=0.14, p=0.7 diabetic; p=0.07 between groups). Similar results were noted with respect to androgenic activity (r=0.88, p=0.005 non-diabetic; r=−0.33, p=0.3 diabetic; p=0.002 between groups). Our results suggest that the OC progestin component is a significant influence on the degree of angiotensin-dependent control of the renal circulation, though these findings may not apply to women with diabetes.

Comparative analysis of the uterine and mammary gland effects of drospirenone and medroxyprogesterone acetate

The role of progestins in combined hormone therapy is the inhibition of uterine epithelial cell proliferation. The Women's Health Initiative study provided evidence for an increased risk of breast cancer in women treated with conjugated equine estrogens plus the synthetic progestin medroxyprogesterone acetate (MPA), compared with conjugated equine estrogens-only treatment. These findings continue to be discussed, and it remains to be clarified whether the results obtained for MPA in the Women's Health Initiative study are directly applicable to other progestins used in hormone therapy. In this study we compared in a mouse model the effects of the synthetic progestins, MPA, and drospirenone in two major target organs: the uterus and mammary gland. As quantitative measures of progestin activity, we analyzed maintenance of pregnancy, ductal side branching in the mammary gland, and proliferation of mammary and uterine epithelial cells as well as target gene induction in both organs. The outcome of this study is that not all synthetic progestins exhibit the same effects. MPA demonstrated uterine activity and mitogenic activity in the mammary gland at the same doses. In contrast, drospirenone behaved similarly to the natural hormone, progesterone, and exhibited uterine activity at doses lower than those leading to considerable proliferative effects in the mammary gland. We hypothesize that the safety of combined hormone therapy in postmenopausal women may be associated with a dissociation between the uterine and mammary gland activities of the progestin component.

Physiological concentration of 17beta-estradiol on sympathetic reinnervation in ovariectomized infarcted rats

17beta-Estradiol (E2) has been shown to exert antiarrhythmic effect after myocardial infarction; however, the mechanisms remain unclear. This study was performed to determine whether E2 exerts beneficial effects through attenuated sympathetic hyperreinnervation after infarction. Two weeks after ovariectomy, female Wistar rats were assigned to coronary artery ligation or sham operation. Twenty-four hours after coronary ligation, rats underwent one of five treatments: 1) sc vehicle treatment (control), 2) sc E2 treatment, 3) sc E2 treatment + tamoxifen (a potent estrogen receptor antagonist), 4) bosentan (an endothelin receptor blocker), or 5) sc E2 treatment + bosentan and followed for 4 wk. Myocardial endothelin-1 and norepinephrine levels at the remote zone revealed a significant elevation in control infarcted rats, compared with sham-operated rats, which is consistent with sympathetic hyperinnervation after infarction. Sympathetic hyperinnervation was blunted after giving the rats either E2 or bosentan, assessed by immunohistochemical analysis of tyrosine hydroxylase, growth-associated protein 43 and neurofilament, and Western blotting and real-time quantitative RT-PCR of nerve growth factor. Arrhythmic scores during programmed stimulation in E2-treated infarcted rats were significantly lower than in control-infarcted rats. Addition of bosentan did not have additional beneficial effects, compared with rats treated with E2 alone. The beneficial effect of E2 on sympathetic hyperinnervation was abolished by tamoxifen. Our data indicated that E2 has a role for sympathetic hyperinnervation after infarction, probably through an endothelin-1-depedent pathway. Chronic administration of E2 after infarction may attenuate the arrhythmogenic response to programmed electrical stimulation.

Hormonal replacement therapy (HRT) in postmenopause: a reappraisal

Hormone replacement therapy (HRT) is the most effective treatment currently available for vasomotor and urogenital symptoms and decreased libido. Because harmful effects were evidenced in some clinical trials, health authorities now consider that risk-benefit considerations do not favour the use of HRT for prevention of cardiovascular diseases and bone fractures in postmenopausal women. However, experimental and clinical studies indicate that adverse effects of HRT may largely depend on the estrogen and progesterone/progestin formulation, dosage, mode of administration, patient's age, associated diseases, and duration of treatment. All estrogen formulations and modes of administration have similar beneficial effects on vasomotor and urogenital symptoms and on bone structure. But cardiovascular and invasive breast cancer risks are higher with oral estrogen than with transdermal estradiol, and also higher with many progestin compounds than with micronized progesterone. The combination of transdermal estradiol+micronized progesterone appears to be effective and relatively safe if elementary precautions are taken, and seems to be presently the best choice for HRT in most postmenopausal women. In the author's--heterodox--opinion, HRT may also be a good therapeutic choice to prevent bone loss, since alternative medications, including raloxifene and bisphosphonates, may have dramatic harmful effects in some patients. It might also have beneficial effects on the development of coronary disease in young postmenopausal women. HRT requires careful adjustment to each individual patient and continuous monitoring of clinical evolution. In the future, this adjustment could benefit from genetic screening to maximize in each individual the ratio between positive and adverse effects.

Both Estrogen Receptor Subtypes, α and β, Attenuate Cardiovascular Remodeling in Aldosterone Salt–Treated Rats

Experimental and population-based studies indicate that female gender and estrogens protect the cardiovascular system against aldosterone-induced injury. Understanding the function of estrogens in heart disease requires more precise information on the role of both estrogen receptor (ER) subtypes, ERalpha and ERbeta. Therefore, we determined whether selective activation of ERalpha or of ERbeta would confer redundant, specific, or opposing effects on cardiovascular remodeling in aldosterone salt-treated rats. The ERalpha agonist 16alpha-LE2, the ERbeta agonist 8beta-VE2, and the nonselective estrogen receptor agonist 17beta-estradiol lowered elevated blood pressure, cardiac mass, and cardiac myocyte cross-sectional areas, as well as increased perivascular collagen accumulation and vascular osteopontin expression in ovariectomized rats receiving chronic aldosterone infusion plus a high-salt diet for 8 weeks. Uterus atrophy was prevented by 16alpha-LE2 and 17beta-estradiol but not by 8beta-VE2. Cardiac proteome analyses by 2D gel electrophoresis, mass spectrometry, and peptide sequencing identified specific subsets of proteins involved in cardiac contractility, energy metabolism, cellular stress response and extracellular matrix formation that were regulated in opposite directions by aldosterone salt treatment and by different estrogen receptor agonists. We conclude that activation of either ERalpha or ERbeta protects the cardiovascular system against the detrimental effects of aldosterone salt treatment and confers redundant, as well as specific, effects on cardiac protein expression. Nonfeminizing ERbeta agonists such as 8beta-VE2 have a therapeutic potential in the treatment of hypertensive heart disease.

Drospirenone increases endothelial nitric oxide synthesis via a combined action on progesterone and mineralocorticoid receptors

BACKGROUND

Progestins have actions on the cardiovascular system, which depend on the structure as well as on receptor binding characteristics. Drospirenone (DRSP) is a progestin that uniquely interferes with the signaling of the mineralocorticoid receptor (MR). Hormone therapy containing DRSP results in blood pressure reduction in hypertensive post-menopausal women.

METHODS

We describe the effects of DRSP on endothelial nitric oxide (NO) synthesis and compare them with those of progesterone (P) and of medroxyprogesterone acetate (MPA). In addition, we herein tested the relevance of the anti-mineralocorticoid activity of DRSP for NO synthesis.

RESULTS

DRSP results in rapid activation of the endothelial NO synthase (eNOS) through mitogen-activated protein kinases and phosphatidylinositol 3-kinase as well as in enhanced eNOS expression. These actions depend on P receptor. When the cells are exposed to aldosterone, a reduction of eNOS expression is found that is antagonized by DRSP. This action is not shared by P or MPA. In addition, DRSP does not interfere with the induction or activation of eNOS induced by estradiol, as opposed to MPA.

CONCLUSIONS

DRSP acts on endothelial cells via a combined action through the P and MRs. These results help to interpret the anti-hypertensive effects of hormonal therapies containing DRSP.

Drospirenone, a New Progestogen, for Postmenopausal Women with Hypertension

The prevalence of hypertension increases in women after the menopause. Associated with the rise in postmenopausal blood pressure (BP) are increased salt sensitivity and imbalance between the renin-angiotensin-aldosterone system and nitric oxide pathways that lead to sodium and water retention. Drospirenone is the first synthetic progestogen with antialdosterone activity similar to natural progesterone. Drospirenone counteracts the salt- and water-retaining effects of estrogen and causes natriuresis, which leads to a reduction in BP. In preclinical studies as well as early efficacy studies (for menopausal symptoms), drospirenone exhibited antihypertensive and natriuretic effects. Subsequent clinical trials in postmenopausal women proved that drospirenone with 17beta-estradiol has a significant BP-lowering effect in untreated hypertension and has additive effects when coadministered with ACE inhibitors, angiotensin II type 1 receptor antagonists and thiazide diuretics. The lowest effective dose of drospirenone for reduction in BP is 2mg, a dose that is also protective of the uterus in women treated with estrogen therapy. Additionally, clinical trials have shown that drospirenone up to 3 mg/day has an acceptable safety profile with no clinically significant elevations in plasma potassium in patients with concomitant NSAID use, diabetes mellitus or mild to moderate renal insufficiency. In addition to effectively relieving menopausal symptoms and lowering BP, drospirenone reduces bodyweight and lipoprotein concentrations. Thus, drospirenone is a unique progestogen that confers the additional benefit of BP reduction, an effect that could lead to potential benefit with respect to some cardiovascular risk concerns in women taking hormone therapy.