OBJECTIVETo investigate the effects of perindopril and spirolactone on plasma aldosterone (Ald) and left atrial remodeling and function in a canine model of atrial fibrillation (AF).

METHODSAdult dogs were randomly assigned to receive normal diet (group A), perindopril (group B, 1 mgxkg(-1)xd(-1)) and spironolactone (group C, 10 mgxkg(-1)xd(-1), n = 6 each) and rapid paced (500 beats/min) for 8 weeks. Plasma Ald levels as well as atrial dimension and function at baseline and at 4 and 8 weeks after pacing were measured by RIA and echocardiography, respectively. Incidence of maintained AF and AF duration were recorded when pacing was stopped after 8 weeks of pacing. Left and right atrial tissues were collected for measurements of tissue Ald levels and fibrosis.

RESULTSPlasma Ald was similar among groups at baseline (P > 0.05) and significantly increased post 4 and 8 weeks pacing in group A (P < 0.05) while remained unchanged post pacing in group B and C (P > 0.05) compared to respective baseline level. Atrial Ald was significantly lower in group B and C compared that in group A post 8 weeks pacing (P < 0.05). Left atrial dimension, end-systolic and end-diastolic volume were significantly increased while left atrial ejection fraction (LAEF) was significantly reduced post pacing in group A (all P < 0.05 vs. baseline) and thses changes were significantly attenuated in group B and C (P < 0.05 vs. group A). Incidence of maintained AF and AF duration post pacing as well as interstitial collagen volume fraction were significantly lower in group B and C compared those in group A (P < 0.05).

CONCLUSIONIncreased Ald might be an important pathogenesis for AF formation and progression, spironolactone and perindopril could attenuate atrial remodeling and improve atrial function by reducing plasma and tissue Ald levels in this model.

Aldosterone ; metabolism ; Animals ; Atrial Fibrillation ; metabolism ; pathology ; physiopathology ; Atrial Function ; Disease Models, Animal ; Dogs ; Male ; Mineralocorticoid Receptor Antagonists ; pharmacology ; Perindopril ; pharmacology ; Spironolactone ; pharmacology

BACKGROUND/AIMS: JX-594 is an oncolytic virus derived from the Wyeth vaccinia strain that causes replication-dependent cytolysis and antitumor immunity. Starting with a cross-examination of clinical-trial samples from advanced hepatocellular carcinoma patients having high levels of aldosterone and virus amplification in JX-594 treatment, we investigated the association between virus amplification and aldosterone in human cancer cell lines. METHODS: Cell proliferation was determined by a cell-counting-kit-based colorimetric assay, and vaccinia virus quantitation was performed by quantitative polymerase chain reaction (qPCR) and a viral plaque assay. Also, the intracellular pH was measured using a pH-sensitive dye. RESULTS: Simultaneous treatment with JX-594 and aldosterone significantly increased viral replication in A2780, PC-3, and HepG2 cell lines, but not in U2OS cell lines. Furthermore, the aldosterone treatment time altered the JX-594 replication according to the cell line. The JX-594 replication peaked after 48 and 24 hours of treatment in PC-3 and HepG2 cells, respectively. qPCR showed that JX-594 entry across the plasma membrane was increased, however, the changes are not significant by the treatment. This was inhibited by treatment with spironolactone (an aldosterone-receptor inhibitor). JX-594 entry was significantly decreased by treatment with EIPA [5-(N-ethyl-N-isopropyl)amiloride; a Na+/H+-exchange inhibitor], but aldosterone significantly restored JX-594 entry even in the presence of EIPA. Intracellular alkalization was observed after aldosterone treatment but was acidified by EIPA treatment. CONCLUSIONS: Aldosterone stimulates JX-594 amplification via increased virus entry by affecting the H+ gradient.
Aldosterone/*pharmacology ; Aldosterone Antagonists/pharmacology ; Amiloride/analogs & derivatives/pharmacology ; Animals ; Carcinoma, Hepatocellular/blood/virology ; Cell Line, Tumor ; Humans ; Hydrocortisone/blood ; Hydrogen-Ion Concentration ; Liver Neoplasms/blood/virology ; Neuroprotective Agents/pharmacology ; Oncolytic Virotherapy ; Rabbits ; Spironolactone/pharmacology ; Vaccinia virus/*drug effects/genetics/metabolism/*physiology ; Virus Replication/*drug effects

Emerging evidence indicates that aldosterone and mineralocorticoid receptors (MRs) are associated with the pathogenesis of erectile dysfunction. However, the molecular mechanisms remain largely unknown. In this study, freshly isolated penile corpus cavernosum tissue from rats was treated with aldosterone, with or without MRs inhibitors. Nuclear factor (NF)-kappa B (NF-κB) activity was evaluated by real-time quantitative PCR, luciferase assay, and immunoblot. The results demonstrated that mRNA levels of the NF-κB target genes, including inhibitor of NF-κB alpha (IκB-α), NF-κB1, tumor necrosis factor-alpha (TNF-α), and interleukin 6 (IL-6), were higher after aldosterone treatment. Accordingly, phosphorylation of p65/RelA, IκB-α, and inhibitor of NF-κB kinase-β was markedly increased by aldosterone. Furthermore, knockdown of MRs prevented activation of the NF-κB canonical pathway by aldosterone. Consistent with this finding, ectopic overexpression of MRs enhanced the transcriptional activation of NF-κB by aldosterone. More importantly, the MRs antagonist, spironolactone blocked aldosterone-mediated activation of the canonical NF-κB pathway. In conclusion, aldosterone has an inflammatory effect in the corpus cavernosum penis, inducing NF-κB activation via an MRs-dependent pathway, which may be prevented by selective MRs antagonists. These data reveal the possible role of aldosterone in erectile dysfunction as well as its potential as a novel pharmacologic target for treatment.
Aldosterone/pharmacology* ; Animals ; Cytokines/biosynthesis* ; Gene Knockdown Techniques ; I-kappa B Kinase/antagonists & inhibitors* ; Interleukin-6/genetics* ; Male ; Mineralocorticoid Receptor Antagonists/pharmacology* ; NF-kappa B/genetics* ; Penis/metabolism* ; Protein Serine-Threonine Kinases/antagonists & inhibitors* ; RNA, Messenger/biosynthesis* ; Rats ; Rats, Inbred WKY ; Receptors, Mineralocorticoid/genetics* ; Signal Transduction/drug effects* ; Spironolactone/pharmacology* ; Transcriptional Activation ; Tumor Necrosis Factor-alpha/biosynthesis* ; NF-kappaB-Inducing Kinase

In the present study, we investigated whether and how the mineralocorticoid receptor antagonist spironolactone affects cardiac growth and development through apoptosis and cell proliferation in the neonatal rat heart. Newborn rat pups were treated with spironolactone (200 mg/kg/d) for 7 days. The cell proliferation was studied by PCNA immunostaining. The treatment with spironolactone decreased proliferating myocytes by 32% (P<0.05), and reduced myocytes apoptosis by 29% (P<0.05). Immunoblot and immunohistochemistry for the expression of p38, p53, clusterin, TGF-beta2, and extracellular signal-regulated kinase were performed. In the spironolactone group, p38, p53, clusterin, and TGF-beta2 protein expression was significantly decreased (P<0.05). These results indicate that aldosterone inhibition in the developing rat heart induces cardiac growth impairment by decreasing proliferation and apoptosis of myocytes.
Aldosterone Antagonists/*pharmacology ; Animals ; Animals, Newborn ; *Apoptosis ; Cell Proliferation ; Clusterin/genetics/metabolism ; Female ; Heart/*drug effects/growth & development ; Proliferating Cell Nuclear Antigen/metabolism ; Rats ; Rats, Sprague-Dawley ; Spironolactone/*pharmacology ; Transforming Growth Factor beta2/genetics/metabolism ; Tumor Suppressor Protein p53/genetics/metabolism ; p38 Mitogen-Activated Protein Kinases/genetics/metabolism