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

OBJECTIVETo investigate the effects of spironolactone on the concentration of collagen type I, III in the myocardium of spontaneous hypertension rats (SHR).

METHODSTwenty 8-week male SHR were assigned randomly into spironolactone (SHR-SPIRO, n=10) and control groups (SHR-CON, n=10), sex-age matched Wistar Kyoto rats (WKY group, n=7) were also served as controls. The rats of SHR-SPIRO group were given 20 mg/(kg*d) of spironolactone, the rats of SHR-CON and WKY groups were given the same volume of distilled water. After 16 weeks, the concentration of collagen type I was analyzed with Western blot. The areas of collagen type I and III were observed under polarized light microscopy and the ratio of type I/III collagen was calculated through accumulation score.

RESULTSCompared with WKY group,the concentration of collagen type I in SHR-CON group was significantly higher (1.87 ±0.2 Compared with 1.21 ±0.7, P<0.05). After 16 weeks of treatment the concentration of collagen type I (1.42 ±0.05 Compared with 1.87 ±0.2, P<0.05) and I/III ratio in SHR-SPIRO group were significantly reduced (15.64 ±1.34 Compared with 20.8 ±3.04, P<0.05) compared with SHR-CON group; but there were no differences in accumulation area scores of collagen type III among three groups (368.3 ±30.2 Compared with 481.6 ±32.4 Compared with 406.2 ±45.3, P>0.05).

CONCLUSIONThe deposition of collagen type I in myocardium may be involved in myocardial fibrosis of SHR, and spironolactone can decrease the concentration of collagen type I, which may be one of the mechanisms for its therapeutic effects.

Animals ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Male ; Mineralocorticoid Receptor Antagonists ; pharmacology ; Myocardium ; metabolism ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY ; Spironolactone ; pharmacology

OBJECTIVETo investigate the inhibitory effects of spironolactone against hepatic sinusoid angiogenesis in rats with hepatic fibrosis.

METHODSTwenty-four male Wistar rats were randomly divided into sham-operated group, bile duct ligation (BDL) group, and BDL+SP group in which the rats received daily spironolactone injection (20 mg/kg) the day after BDL. Four weeks after the operation, the rats were sacrificed for examination of liver histology using Masson staining and the expression of vascular endothelial growth factor A (VEGF-A) mRNA in the liver using real-time quantitative PCR. Immunohistochemistry was used to detect the expression of von Willebrand factor (vWF) in the hepatic tissues.

RESULTSSpironolactone significantly inhibited liver fibrogenesis in rats after BDL (METAVIR liver fibrosis scores 2.84∓0.44 vs 19.73∓3.54, P=0.00). Real-time PCR and immunohistochemistry showed that compared with BDL group, spironolactone treatment significantly inhibited the expression of VEGF-A mRNA (0.71∓0.12 vs 1.75∓0.15, P=0.00) and vWF (1.15∓0.09 vs 3.08∓0.17, P=0.00) in the liver. The expression of VEGF-A mRNA was highly correlated with the expression of vWF (r=0.890, P=0.000).

CONCLUSIONSpironolactone can inhibit hepatic sinusoid angiogenesis in rats with BDL-induced hepatic fibrosis by inhibiting the expression of VEGF-A.

Animals ; Hepatic Veins ; pathology ; Liver Cirrhosis, Experimental ; metabolism ; pathology ; Male ; Neovascularization, Pathologic ; drug therapy ; RNA, Messenger ; genetics ; Rats ; Rats, Wistar ; Spironolactone ; pharmacology ; Vascular Endothelial Growth Factor A ; metabolism

AIMTo observe the effect of angiotensin-converting enzyme inhibitors (ACEI) and aldosterone receptor blockers on cardiac function to explore the mechanism of cardiac function descending and myocardial injury in calcium-overload rats.

METHODSCalcium-overload in rat was induced by administration of Vitamin D3 plus nicotine. To Estimate the extent of calcium-overload by calcium content. Angiotension II and aldosterone levels in the myocardia were measured by radioimmunoassay. Cardiac function (+/- LVdp/dt, LVESP and LVEDP) were measured by Powerlab. The malondialdehyde (MDA) content, activities of lactate dehydrogenase (LDH) and creatine kinase (CPK) were measured by biochemistry.

RESULTSCalcium content increased by 3.2-, 5.8 -fold in myocardial and artery, compared with controls. VDN-treated survivors showed lower + LVdp/dt(max) and -LVdp/dt(max) values, by 27% and 34%, respectively (both P < 0.01). Higher LVESP, and LVEDP by 42 % and 32% (P < 0.01); heart rate and mean arterial pressure were not significantly altered (P > 0.05). The lipid peroxidation products MDA and conjugated diene in myocardia were increased 22% (P < 0.01), 68% (P < 0.05) (P < 0.05), respectively. The plasma activity of CPK and LDH was greatly increased by 4.5-and 3.1-fold (P < 0.01), respectively. ACEI and spironolactone obviously relieved degree of calcium-overload and improved cardiac function and myocardial injury(P < 0.01). Calcium content in myocardia and artery was lower 44%, 39% and 57%, 34%. Lower MDA by 20%, 30%, lower conjugated diene by 44%, 35% than calcium-overload group. The plasma activity of CPK and LDH were obviously decreased 28%, 34% and 20%, 27%, compared with calcium-overload group.

CONCLUSIONCalcium-overload could lead to cardiac function descending and myocardial injury in calcium-overload rats by VDN. ACEI and spironolactone could reduce calcium-overload in myocardial and ameliorate cardiac function and decrease myocardial injury.

Angiotensin-Converting Enzyme Inhibitors ; pharmacology ; Animals ; Calcium ; adverse effects ; Creatine Kinase ; metabolism ; L-Lactate Dehydrogenase ; metabolism ; Lipid Peroxidation ; Male ; Malondialdehyde ; analysis ; Mineralocorticoid Receptor Antagonists ; Myocardium ; metabolism ; Nicotine ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Spironolactone ; pharmacology ; Vitamin D ; pharmacology

Hypokalemic periodic paralysis (HOPP) is a rare disease characterized by reversible attacks of muscle weakness accompanied by episodic hypokalemia. Recent molecular work has revealed that the majority of familial HOPP is due to mutations in a skeletal muscle voltage-dependent calcium-channel: the dihydropyridine receptor. We report a 13-yr old boy with HOPP from a family in which 6 members are affected in three generations. Genetic examination identified a nucleotide 3705 C to G mutation in exon 30 of the calcium channel gene, CACNA1S. This mutation predicts a codon change from arginine to glycine at the amino acid position #1239 (R1239G). Among the three known mutations of the CACNA1S gene, the R1239G mutation was rarely reported. This boy and the other family members who did not respond to acetazolamide, showed a marked improvement of the paralytic symptoms after spironolactone treatment.
Acetazolamide/pharmacology ; Adolescent ; Arginine/chemistry ; Calcium Channels/chemistry/*genetics ; Codon ; Exons ; Family Health ; Female ; Glycine/chemistry ; Humans ; Hypokalemia/metabolism ; Hypokalemic Periodic Paralysis/*diagnosis/*genetics ; Korea ; Male ; Muscle, Skeletal/metabolism ; Mutation ; Pedigree ; Protein Structure, Tertiary ; Sequence Analysis, DNA ; Spironolactone/pharmacology

OBJECTIVETo study the expression of Toll-like receptor 4 (TLR4) in renal tubular epithelial cells exposed to high glucose and the effect of spironolactone on the TLR4 expression.

METHODSIn vitro renal tubular epithelial cells (NRK-52E) were randomly exposed to DMEM culture solution with low glucose (5 mmol /L), high glucose (25 mmol/L) or 10(-7) mol/L spironolactone plus 25 mmol/L glucose. Immunohistochemistry, RT-PCR and Western blot were used to determine TLR4 protein and mRNA expression. The levels of IL-6 and TNF-alpha in the cell culture supernatant were determined using ELISA.

RESULTSThe expression of TLR4 mRNA in the high glucose group began to increase 6 hrs and remained at a higher level up to 24 hrs after exposure as compared with the low glucose group. The TLR4 mRNA expression in the spironolactone treatment group was significantly lower than that in the high glucose group, although it was higher than that in the low glucose group between 6 and 24 hrs after exposure. TLR4 protein expression increased significantly in the high glucose group 24 and 48 hrs after exposure compared with that in the low glucose group. The TLR4 protein expression in the spironolactone treatment group was lower than that in the high glucose group, but higher than that in the low glucose group. IL-6 and TNF-alpha expression in the supernatant from the NRK-52E cells in the high glucose groups increased significantly as compared with the low glucose group. The spironolactone treatment group had significantly reduced IL-6 and TNF-alpha expression compared with the high glucose group.

CONCLUSIONSHigh glucose triggers an increase in the expression of TLR4 and inflammatory factors in NRK-52E cells. TLR4 may participate in the progress of diabetic nephropathy. Spironolactone can reduce expression of TLR4 and inflammatory factors, which might be attributed to one of the mechanisms of protection by spironolactone against diabetic nephropathy.

Cells, Cultured ; Diabetic Nephropathies ; etiology ; Epithelial Cells ; metabolism ; Humans ; Hyperglycemia ; metabolism ; Immunohistochemistry ; Interleukin-6 ; analysis ; Kidney Tubules ; metabolism ; RNA, Messenger ; analysis ; Spironolactone ; pharmacology ; Toll-Like Receptor 4 ; analysis ; genetics ; physiology ; Tumor Necrosis Factor-alpha ; analysis

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

The effect of aldosterone on connective tissue growth factor (CTGF) was examined in rat embryonic ventricular myocytes. Upon aldosterone treatment, CTGF expression was significantly increased in a dose and time-dependent manner. To explore the molecular mechanism for this upregulation, we examined the role of mineralocorticoid receptor. Pre-treatment of an antagonist (spironolactone) at 5-fold excess of aldosterone blocked the CTGF induction by aldosterone, suggesting that the upregulation was mediated by mineralocorticoid receptor. Aldosterone treatment resulted in activation of ERK1/2, p38 MAPK, and JNK pathways with a more transient pat-tern in p38 MAPK. Blocking studies using pre-treatment of the inhibitor of each path-way revealed that p38 MAPK cascade may be important for aldosterone-mediated CTGF upregulation as evidenced by the blocking of CTGF induction by SB203580 (p38 MAPK inhibitor), but not by PD098059 (ERK1/2 inhibitor) and JNK inhibitor I. Interestingly, JNK inhibitor I and PD098059 decreased the basal level of CTGF expression. On the other hand, pre-treatment of spironolactone abrogated the p38 MAPK activation, indicating that mineralocorticoid receptor mechanism is linked to p38 MAPK pathway. Taken together, our findings suggest that aldosterone induces CTGF expression via both p38 MAPK cascade and mineralocorticoid receptor and that cross-talk exists between the two pathways.
Aldosterone/*pharmacology ; Animals ; Cells, Cultured ; Dose-Response Relationship, Drug ; Gene Expression Regulation/drug effects/physiology ; Heart Ventricles/drug effects/embryology/metabolism ; Immediate-Early Proteins/*metabolism ; Intercellular Signaling Peptides and Proteins/*metabolism ; Myocytes, Cardiac/*drug effects/*metabolism ; Rats ; Receptors, Mineralocorticoid/*metabolism ; Research Support, Non-U.S. Gov't ; Signal Transduction/drug effects/physiology ; Spironolactone/pharmacology ; Up-Regulation/drug effects/physiology ; p38 Mitogen-Activated Protein Kinases/*metabolism

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