The pathophysiological implications of aldosterone and adrenomedullin in the cardiac ventricular hypertrophy were examined. Male Sprague-Dawley rats were treated with deoxycorticosterone acetate (DOCA)-salt and monocrotaline (MCT) to selectively elicit left and right ventricular (LV, RV) hypertrophy, respectively. The mRNA expression of aldosterone synthase and adrenomedullin in LV and RV was determined by reverse transcription-polymerase chain reaction. The expression of aldosterone synthase and adrenomedullin was increased in LV, while not altered significantly in RV of DOCA-salt-treated rats. On the contrary, the expression was not significantly altered in LV, but increased in RV of MCT-treated rats. The enhanced expression of aldosterone synthase may be causally related with the development of ventricular hypertrophy, and the increased expression of adrenomedullin may act as a counter-regulatory mechanism.
Adrenomedullin* ; Aldosterone Synthase* ; Aldosterone* ; Animals ; Desoxycorticosterone ; Humans ; Hypertrophy ; Hypertrophy, Right Ventricular* ; Male ; Monocrotaline ; Rats* ; Rats, Sprague-Dawley ; RNA, Messenger

BACKGROUND: Evidence is accumulating that aldosterone secretion can be regulated in a paracrine and/or an autocrine manner by several neuropeptides locally released within the adrenal gland. Among neuropeptides, pituitary adenylate cyclase-activating polypeptide (PACAP) is present in high concentration in the human adrenal gland. The purpose of this study was to investigate the action of PACAP and the interaction between PACAP and angiotensin II (AII), the main physiologic aldosterone secretagogue, in aldosterone production in human H295R adrenocortical cells. METHODS: H295R cells were incubated with increasing concentrations of PACAP (10(-11)M~10(-7)M) in the absence or presence of 10(-7)M AII. Aldosterone concentration in the supernatant was determined by RIA. Intracellular cAMP content was measured by RIA and total inositol phosphate (IP) production by anion exchange chromatography. Gene expression of CYP11B2 was studied by RT-PCR. RESULTS: In H295R cells, PACAP stimulated aldosterone production in a dose-dependent manner. Incubation of H295R cells with PACAP in the presence of AII significantly increased aldosterone production, compared with that of PACAP alone. PACAP dose-dependently increased cAMP production, but 10(-7)M AII had no effect on either basal or PACAP-stimulated cAMP production. Total IP production was not affected by PACAP, but was increased by 10(-7)M AII; an increase that was not further increased by addition of PACAP. RT-PCR analysis of H295R cells which were exposed to 10-7M PACAP or 10(-7)M AII showed an increase in CYP11B2 transcript signal. Induction of CYP11B2 mRNA expression in response to treatment with both PACAP and AII was significantly more than that resulting from using PACAP alone. CONCLUSION: The present study demonstrates that PACAP exerts a direct stimulatory effect on aldosterone production through induction of CYP11B2 mRNA expression by adenylate cyclase activation as the main intracellular signal pathway in H295R cells. Furthermore, there may be some additive effects between PACAP and AII on aldosterone production.
Adenylyl Cyclases ; Adrenal Glands ; Aldosterone Synthase ; Aldosterone* ; Angiotensin II* ; Angiotensins* ; Chromatography ; Gene Expression ; Humans* ; Inositol ; Neuropeptides ; Pituitary Adenylate Cyclase-Activating Polypeptide* ; RNA, Messenger ; Signal Transduction

BACKGROUND AND OBJECTIVES: Several polymorphisms of the renin-angiotensin-aldosterone system have been found to have pleiotropic effects on cardiovascular diseases. Polymorphism of the aldosterone synthase gene (CYP11B2), which may influence plasma aldosterone levels, has been reported to cause systemic hypertension, influence the left ventricular diameter and mass, and decrease baroreflex sensitivity of the cardiovascular system. Through these mechanisms, it is thought to increase the risk of myocardial infarction (MI). Our study was designed to elucidate whether polymorphism of CYP11B2 increased the risk of MI. SUBJECTS AND METHODS: We analyzed the genotypes of CYP11B2 and the classic risk factors of MI in 188 MI patients and 320 control subjects without history of MI. RESULTS: There was no significant difference in the distribution of genotypes between the patient and control groups. Adjusting for the classical risk factors, multiple logistic regression analysis showed no significant effect of CYP11B2 gene polymorphism on the development of MI. However, the presence of the -344C allele is associated with a markedly increased MI risk conferred by classic risk factors including hypertension, smoking, and male sex. In particular, hypertension was not a significant risk factor as compared with non-hypertensive patients in subjects without -344C, but the relative risk was increased to 2.40 (95% CI:1.05-5.51, p<0.05) with - 344C. The relative risks of smoking and male sex were also increased with the presence of the - 344C allele. CONCLUSION: CYP11B2 polymorphism is not an independent risk factor of MI, although hypertension, smoking, and male sex are more potent risk factors for MI in Koreans who possess the - 344C allele.
Aldosterone Synthase* ; Aldosterone* ; Alleles ; Baroreflex ; Cardiovascular Diseases ; Cardiovascular System ; Genotype ; Humans ; Hypertension ; Logistic Models ; Male ; Myocardial Infarction* ; Plasma ; Polymorphism, Genetic ; Renin-Angiotensin System ; Risk Factors ; Smoke ; Smoking

Aldosterone synthase gene (CYP11B2) -344C/T polymorphism has been reported to be associated with serum aldosterone level, urinary aldosterone excretion, blood pressure, and left ventricular size and mass. The aim of this study was to evaluate the relation between CYP11B2 polymorphism and end-stage renal disease (ESRD) in the Korean population and the association with CYP11B2 polymorphism and cardiovascular morbidity in ESRD patients on hemodialysis. Genotyping was performed in 134 control subjects and 271 ESRD patients for CYP11B2 polymorphism using polymerase chain reaction through subsequent cleavage with restriction enzyme. Also current blood pressure, demographic, anthropometric and biochemical variables were investigated. The genotype distribution did not differ between ESRD patients and controls and there were no significant differences in blood pressure, use of antihypertensive medication, left ventricular hypertrophy and cardiovascular disease among the three genotypes in ESRD patients on hemodialysis. Our findings do not support the hypothesis that CYP11B2 polymorphism may be associated with prevalence of ESRD and suggest that CYP11B2 polymorphism may not be a genetic marker for cardiovascular morbidity in Korean ESRD patients.
Aldosterone ; Aldosterone Synthase ; Blood Pressure ; Cardiovascular Diseases ; Genetic Markers ; Genotype ; Humans ; Hypertrophy, Left Ventricular ; Kidney Failure, Chronic ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Prevalence ; Renal Dialysis

BACKGROUND/AIMS: This study investigated the role of Na,K-ATPase, the local renin-angiotensin-aldosterone system (RAAS), and atrial natriuretic peptide (ANP) system in the pathogenesis of renal tubular dysfunction and hypertension in rats with two-kidney, one-clip (2K1C) hypertension. METHODS: Adult male Sprague-Dawley rats were made 2K1C hypertensive for 4 weeks. The renal expression of Na,K-ATPase was determined by immunoblotting. The mRNA expression of renin, angiotensin-converting enzyme (ACE), aldosterone synthase (CYP11B2), mineralocorticoid receptor (MR), and the ANP system were determined in the kidney using real-time polymerase chain reaction. RESULTS: The blood pressure was increased in the 2K1C rats, compared with controls. The plasma renin activity and serum aldosterone concentrations were increased, as were the urine output and fractional excretion of sodium. The expression of Na,K-ATPase protein was decreased in the clipped kidney, as compared with the control kidney, while it remained unchanged in the contralateral kidney. The mRNA expression of renin, ACE1, CYP11B2, and MR was increased in the clipped kidney, but unchanged in the non-clipped kidney. The mRNA expression of ACE2 did not differ between the groups. The expression of ANP mRNA was increased in both clipped and non-clipped kidneys, as compared with control kidneys. CONCLUSIONS: The enhanced activity of the local RAAS may result in to ischemic tubular injury and the development of hypertension in 2K1C rats. The downregulation of Na,K-ATPase associated with tubular injury in the clipped kidney may account for the impaired tubular sodium reabsorption in 2K1C hypertension.
Adult ; Aldosterone ; Aldosterone Synthase ; Animals ; Atrial Natriuretic Factor ; Blood Pressure ; Down-Regulation ; Humans ; Hypertension ; Hypertension, Renovascular ; Immunoblotting ; Kidney ; Male ; Plasma ; Rats ; Rats, Sprague-Dawley ; Receptors, Mineralocorticoid ; Renin ; Renin-Angiotensin System ; RNA, Messenger ; Sodium

PURPOSE: Nitric oxide (NO) is known as the free radical which acts on the relaxation of the vascular smooth muscle. We performed the artificial renal infarction on the ipsilateral renal artery, and investigated the change of expressions of nitric oxide synthase (NOS) isoforms on the contralateral kindey of the rats. MATERIALS AND METHODS: Spraque-Dawley rats (300-350gm) were divided into 2 groups as control group (n=10) and operation group (n=30). Control group was performed sham operation and operation group was ligated the left renal artery with 5-0 silk. At the 1 week after operation, right kidney was obtained and determined expression of nNOS, eNOS and iNOS using immunohistochemical staining and the intensities of expression of NOS isoforms were analyzed with image analyzer. We also checked the blood pressure by tail-cuff method before and 1 week after operation. RESULTS: Average systolic BP was elevated on the operation group significantly. While in the control group, which was 128.7 +/- 1.5mmHg initially, to 127.2 +/- 3.3mmHg 1 week later, in the operation group 123.8 +/- 3.2mmHg to 152.5 +/- 4.3mmHg. The intensities of NOS isoform, only the nNOS in the glomerular area was increased with significance statistically, but eNOS and iNOS were not increased. In tubular area, there were no evidences of increment of the intensities. CONCLUSIONS: These results suggested that when the renal infarction was developed, nNOS which located in the renal glomerular area may has relations with influence on the renal blood flow and renin-angiotensin aldosterone on contralateral kidney. We were convinced that nNOS play a important role of the integral modulator of renovascular message system which result in the renovascular hypertension after all.
Aldosterone ; Animals ; Blood Pressure ; Hypertension, Renovascular ; Infarction* ; Kidney* ; Muscle, Smooth, Vascular ; Nitric Oxide Synthase* ; Nitric Oxide* ; Protein Isoforms* ; Rats* ; Relaxation ; Renal Artery ; Renal Circulation ; Silk

Intimal proliferation is a main cause of in-stent restenosis. Over-excretion of angiotensin I converting enzyme (ACE) and aldosterone is reported to stimulate intimal hyperplasia and the genetic effect of these molecules may alter the process of in-stent restenosis. We hypothesized that the genetic polymorphisms that alter the expression of genes such as ACE I/D, CYP11B2-344C/T, and AGT M235T can affect in-stent restenosis. We analyzed the angiographic and clinical data of 238 patients (272 stents) who underwent coronary stenting and follow-up angiography, and analyzed the genotypes of ACE I/D, CYP11B2-344T/C, and AGT M235T. There was no significant difference in age, sex, or lipid profiles between the patent and restenosis groups. Diabetes mellitus was more frequent in the binary restenosis group. Quantitative computer-assisted angiographic (QCA) analysis revealed that the risk of in-stent restenosis increased with lesion length and was inversely proportional to post- stenting minimal luminal diameter (MLD) and reference diameter. There was no difference in the frequency of binary restenosis between genotypes in each of the three genes. However, follow-up MLD was significantly smaller in the ACE DD genotype than in the ACE II or ID genotypes. Defining restenosis as MLD 2 mm, the restenosis rate was significantly higher in the ACE DD genotype than in the ACE II or ID genotypes. There was no significant synergistic effect between the three gene polymorphisms. In conclusion, while the ACE I/D polymor phism promoted the progress of in-stent restenosis and was of clinical significance, the other potential variables examined did not correlate with in-stent restenosis.
Adult ; Aged ; Aldosterone Synthase/*genetics ; Angiotensinogen/*genetics ; Coronary Restenosis/*etiology/genetics ; Female ; Genotype ; Human ; Logistic Models ; Male ; Middle Age ; Peptidyl-Dipeptidase A/*genetics ; *Polymorphism (Genetics) ; Risk Factors ; *Stents

OBJECTIVETo evaluate the effect and related mechanisms of aldosterone (ALD) on inducible nitric oxide synthase (iNOS) activity and nitric oxide (NO) production in aortic adventitia.

METHODSAortic adventitias from SD rats were incubated for 6 hours with various protocols: buffer alone (control), ALD (10(-8) mol/L - 10(-6) mol/L), ALD + spironolactone (10(-5) mol/L, ALD + SP), ALD + RU486 (10(-5) mol/L), LPS 10 ng/ml (LPS), ALD + LPS (10 ng/ml), ALD + LPS + SP (10(-5) mol/L), and ALD + LPS + RU486. Nitrate/nitrite (NOx), an index of NO production, was measured by Greiss Reaction. iNOS activity was determined by isotope-labeled L-arginine convertion rate.

RESULTS(1) NOx production and iNOS activity were similar between ALD and control groups (P > 0.05). NOx production was significantly reduced while iNOS activity remained unchanged in the ALD (10(-6) mol/L) + SP group compared to ALD (10(-6) mol/L) group. NOx production by 10(-7) mol/L and 10(-6) mol/L ALD increased by 50.0% and 58.7% respectively (P < 0.01) and iNOS activity was also significantly increased (P < 0.01) in ALD + RU486 group than that in ALD group. (2) LPS significantly increased the NOx production and iNOS activity (P < 0.01) and these effects were not augmented by adding ALD to LPS (P > 0.05) and SP significantly blocked and RU486 significantly enhanced the effects by LSP and ALD on NOx production and iNOS activity (P < 0.05).

CONCLUSIONAldosterone has a dual effect on iNOS/NO through mineralocorticoid receptor and glucocorticoid receptor pathway.

Aldosterone ; pharmacology ; Animals ; Aorta, Thoracic ; metabolism ; Cells, Cultured ; Connective Tissue ; metabolism ; Male ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; metabolism ; Rats ; Rats, Sprague-Dawley

Glucocorticoid-remediable aldosteronism (GRA) is an autosomal-dominant inheritable form of hyperaldosteronism with early onset hypertension. GRA is caused by unequal crossing-over of the steroid 11beta-hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2) genes. As a result of chimeric gene duplication, aldosterone is ectopically synthesized in the adrenal zona fasciculata under the control of adrenocorticotropin. Here, we describe three cases of GRA in a Korean family. The proband-a 21-yr-old female-was incidentally found to have high blood pressure (170/108 mmHg). Her 46-yr-old father had been treated twice for cerebral hemorrhage at the ages of 29 and 39 yr. Her 15-yr-old brother had a 2-yr history of hypertension; however, he was never treated. Their laboratory test results showed normokalemia, hyporeninemia, hyperaldosteronism, and a high plasma aldosterone concentration-to-plasma renin activity ratio. Normal saline loading failed to suppress aldosterone secretion. However, dexamethasone administration effectively suppressed their plasma aldosterone concentrations. Following genetic analyses with PCR and direct sequencing to document the chimeric gene and crossover site, respectively, we identified CYP11B1/CYP11B2 and determined the breakpoint of unequal crossover to be located between intron 2 of CYP11B1 and exon 3 of CYP11B2.
Adolescent ; Aldosterone/blood ; Aldosterone Synthase/*genetics ; Asian Continental Ancestry Group/*genetics ; Dexamethasone/therapeutic use ; Family ; Female ; Glucocorticoids/*therapeutic use ; Humans ; Hyperaldosteronism/diagnosis/drug therapy/*genetics ; Hypertension/etiology ; Magnetic Resonance Angiography ; Male ; Middle Aged ; Renin/blood/metabolism ; Republic of Korea ; Sequence Analysis, DNA ; Steroid 11-beta-Hydroxylase/*genetics ; Young Adult

Some biological effects of Red Liriope platyphylla (RLP) on various chronic diseases including Alzheimer's disease, diabetes and obesity were suggested after a report of the production from Liriope platyphylla (L. platyphylla, LP) roots using a steaming process. To examine the beneficial effects of ethanol extracts RLP (EEtRLP) on the vascular dysfunction of hypertension, alterations in key factors related to vascular regulation and antioxidant conditions were investigated in spontaneously hypertensive rats (SHR) after EEtRLP treatment for 2 weeks. High levels of 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity were detected in 500 or 1,000 mg/mL EEtRLP. Although no significant improvement of systolic blood pressure or aortic wall thickness were observed in the EEtRLP treated group, the expression level of angiotensin converting enzyme (ACE) and ACE2 increased significantly after EEtRLP treatment. Moreover, the concentration of aldosterone and K ion in serum rapidly recovered in the EEtRLP treated group relative to the vehicle treated group. Furthermore, the endothelial nitric oxide synthase (eNOS) expression and superoxide dismutase (SOD) activity were significantly increased in the EEtRLP treated group relative to the vehicle treated group, while the level of malondialdehyde (MDA) and NOx in the serum of the same group were recovered to the level of Wistar Kyoto (WKY) rats. Overall, the results presented herein provide novel evidence that EEtRLP treatment may improve vascular dysfunction in the aorta of the SHR through up regulation of the antioxidant state and down regulation of aldosterone and K ion concentration. These results also suggest that EEtRLP may be a potential candidate for treatment of various chronic diseases showing vascular dysfunction.
Aldosterone ; Alzheimer Disease ; Animals ; Aorta* ; Blood Pressure ; Chronic Disease ; Down-Regulation ; Ethanol* ; Hypertension ; Malondialdehyde ; Nitric Oxide Synthase Type III ; Obesity ; Peptidyl-Dipeptidase A ; Rats ; Rats, Inbred SHR* ; Steam ; Superoxide Dismutase ; Up-Regulation