eplerenone and Coronary-Disease

Topics: Adenosine; Angioplasty, Balloon, Coronary; Anti-Arrhythmia Agents; Antihypertensive Agents; Atherectomy, Coronary; Atrial Fibrillation; Azithromycin; Chlamydophila Infections; Coronary Disease; Defibrillators, Implantable; Double-Blind Method; Eplerenone; Heart Failure; Heart Transplantation; Heart-Assist Devices; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertrophy, Left Ventricular; Myocardial Reperfusion; Pyridines; Radiology, Interventional; Spironolactone; Stents; Thiazepines; Thrombolytic Therapy

In epithelial tissues such as kidney, mineralocorticoid receptors (MR) are protected against glucocorticoid occupancy by the enzyme 11 beta-hydroxysteroid dehydrogenase (11 beta HSD) type 2. If the enzyme is congenitally inactive, or blocked by carbenoxolone, physiologic glucocorticoids act as MR agonists in such tissues. In most nonepithelial tissues, including cardiomyocytes, 11 beta HSD2 is expressed at minimal levels; in these tissues physiologic glucocorticoids act as MR antagonists, with the basis for this tissue selectivity currently unknown. Vascular smooth muscle cells (VSMC) express MR and 11 beta HSD1/2, with 11 beta HSD1 reported to show uncharacteristic oxidase activity, so that VSMC thus constitute a potential physiologic aldosterone target tissue. Because mineralocorticoid/salt administration triggers marked inflammatory responses in coronary vasculature, we reasoned that VSMC (like epithelial) MR may be activated by glucocorticoids if the protective enzyme is blocked. We thus gave uninephrectomized rats 0.9% NaCl solution to drink, and deoxycorticosterone (DOC, as a single 20 mg sc dose) or carbenoxolone (CBX, 2.5 mg/d in the drinking solution). Both DOC and CBX increased systolic blood pressure, heart, and kidney weight, and expression of cyclooxygenase 2, ED-1-positive macrophages, and osteopontin, with effects of both DOC and CBX blocked by the selective MR antagonist eplerenone. These findings suggest that local glucocorticoid excess, reflecting lower VSMC 11 beta HSD1/2 activity may mimic systemic mineralocorticoid excess, and play a direct etiologic role in coronary vascular inflammatory responses under circumstances of a high salt intake.

Topics: 11-beta-Hydroxysteroid Dehydrogenases; Animals; Blood Pressure; Carbenoxolone; Cardiomegaly; Coronary Disease; Desoxycorticosterone; Enzyme Inhibitors; Eplerenone; Fibrosis; Heart; Hydroxysteroid Dehydrogenases; Kidney; Male; Mineralocorticoid Receptor Antagonists; Muscle, Smooth, Vascular; Myocardium; Nephrectomy; Organ Size; Rats; Rats, Sprague-Dawley; Sodium Chloride; Solutions; Spironolactone; Vasculitis

We studied the role of aldosterone (aldo) in myocardial injury in a model of angiotensin (Ang) II-hypertension. Wistar rats were given 1% NaCl (salt) to drink and randomized into one of the following groups (n = 10; treatment, 21 d): 1) vehicle control (VEH); 2) Ang II infusion (25 ng/min, sc); 3) Ang II infusion plus the selective aldo blocker, eplerenone (epl, 100 mg/kg.d, orally); 4) Ang II infusion in adrenalectomized (ADX) rats; and 5) Ang II infusion in ADX rats with aldo treatment (20 micro g/kg.d, sc). ADX rats received also dexamethasone (12 micro g/kg.d, sc). Systolic blood pressure increased with time in all treatment groups except the VEH group (VEH, 136 +/- 6; Ang II/NaCl, 203 +/- 12; Ang II/NaCl/epl, 196 +/- 10; Ang II/NaCl/ADX, 181 +/- 7; Ang II/NaCl/ADX/aldo, 236 +/- 8 mm Hg). Despite similar levels of hypertension, epl and ADX attenuated the increase in heart weight/body weight induced by Ang II. Histological examination of the hearts evidenced myocardial and vascular injury in the Ang II/salt (7 of 10 hearts with damage, P < 0.05 vs. VEH) and Ang II/salt/ADX/aldo groups (10 of 10 hearts with damage, P < 0.05). Injury included arterial fibrinoid necrosis, perivascular inflammation (primarily macrophages), and focal infarctions. Vascular lesions were associated with expression of the inflammatory mediators cyclooxygenase 2 (COX-2) and osteopontin in the media of coronary arteries. Myocardial injury, COX-2, and osteopontin expression were markedly attenuated by epl treatment (1 of 10 hearts with damage, P < 0.05 vs. Ang II/salt) and adrenalectomy (2 of 10 hearts with damage, P < 0.05 vs. Ang II/salt). Our data indicate that aldo plays a major role in Ang II-induced vascular inflammation in the heart and implicate COX-2 and osteopontin as potential mediators of the damage.

Topics: Adrenalectomy; Aldosterone; Angiotensin II; Animals; Body Weight; Coronary Disease; Coronary Vessels; Corticosterone; Cyclooxygenase 2; Diuresis; Drinking; Eating; Eplerenone; Heart; Hypertension; Isoenzymes; Macrophages; Male; Mineralocorticoid Receptor Antagonists; Myocardium; Necrosis; Organ Size; Osteopontin; Potassium; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Wistar; Renin; Sialoglycoproteins; Sodium; Sodium Chloride; Spironolactone; Vasculitis

Coronary artery angioplasty triggers healing that causes constrictive remodeling. Because collagen accumulation correlates with constrictive remodeling and aldosterone has been implicated in collagen accumulation, we examined how aldosterone and the mineralocorticoid receptor antagonists spironolactone and eplerenone affect remodeling and collagen in porcine coronary and iliac arteries after angioplasty.. Twenty-four pigs were allocated into 4 treatment groups: oral eplerenone (100 mg/d), oral spironolactone (200 mg/d), subcutaneous aldosterone (400 microgram/d), or no treatment. Twenty-eight days after angioplasty of the coronary arteries, eplerenone increased total vessel area by 30% (P<0.05) and luminal area by nearly 60% (P<0.05) compared with the no-treatment group, without affecting neointima size. These effects were accompanied by a 65% reduction in neointimal and medial collagen density (both P<0.05). Spironolactone was less effective, and aldosterone tended to exert opposite effects on coronary artery structure after angioplasty. These effects were not observed in angioplastied iliac arteries.. Eplerenone attenuates constrictive remodeling after coronary artery angioplasty by mechanisms involving reduction in collagen accumulation, which thus appears to be an important contributor to constrictive remodeling of angioplastied coronary arteries.

Topics: Aldosterone; Angioplasty, Balloon; Animals; Collagen; Constriction, Pathologic; Coronary Disease; Coronary Vessels; Elastin; Eplerenone; Iliac Artery; Male; Mineralocorticoid Receptor Antagonists; Spironolactone; Swine; Swine, Miniature; Tunica Intima