Coumarins are a large family of compounds derived from a wide range of plants, fungi, and bacteria, and coumarin derivatives can have extremely variable structures and consequently diverse biological properties including antitumor activity. Compounds that bear a benzimidazole moiety are known to possess antitumor activity and a variety of other biological activities. High-throughput screening of a compound library identified a coumarin-containing and a benzimidazole-containing compound [#32, 7-(diethylamino)-3-(1-methyl-1H-benzimidazol-2-yl)-2H-chromen-2-one] that has potent anticancer activity. Evaluation of 17 additional analogs further identified three compounds with anticancer activity in 14 different human cancer cell lines. Fluorescence-activated cell sorting and western blotting analyses suggested that these compounds can induce caspase-dependent apoptosis. Real-time reverse transcriptase PCR analyses of 26 cancer-related genes revealed that seven genes (NPPB, ATF3, DDIT4, CDH10, TSPAN14, TXNIP, and AXL) were significantly upregulated and nine genes (PAGE4, LRP8, SNCAIP, IGFBP5, SLCO2A1, CLDN2, ESRRG, D2HGDH, and PDGFRA) were significantly downregulated. The most upregulated gene is natriuretic peptide precursor B (NPPB) or brain natriuretic peptide, which is increased by 7-, 27-, and 197-fold at 12, 24, and 48 h, respectively. The second most upregulated gene is ATF3, which is increased by 23-fold at the 48 h timepoint. PAGE4 and IGFBP5 are the two most downregulated genes, with a 17-fold reduction in both genes. The expression of several genes (DDIT4, PDGFRA, LRP8, IGFBP5) and western blotting data on key signaling proteins indicate that compound #32 significantly inhibits the PI3K-AKT-mTOR pathway, an intracellular signaling pathway critical in cell proliferation and apoptosis.

A newly assay, up-converting phosphor technology-based lateral flow (UPT-LF) assay, was developed for rapid and quantitative detection of N-terminal fragment of B-type natriuretic peptide precursor (NT-proBNP), one of the most important serum molecular maker of heat failure, in plasma samples as a point of care testing (POCT) method for diagnosis of acute heart failure. Human plasma from 197 patients with acute heart failure and 200 healthy controls was assessed using the UPT-LF assay, in a comparison with a Roche Elecsys assay. The limit of detection of the UPT-LF assay, with a coefficient of variation (CV) of less than 15%, was 116 ng/L, which is lower than the clinical diagnosis cutoff (150 ng/mL). The linear range was 50-35,000 ng/L. The CVs were less than 10% for both UPT-LF and Roche Elecsys assays for plasma samples under different storages, demonstrating the good stability and reproducibility. There are certain linear correlations between the results of UPT-LF and Roche Elecsys assay for EDTA-K2 and heparin-anticoagulated plasma, as well as for serum samples. For UPT-LF assay, there is a significant correlation between the values derived from analysis of EDTA-K2 and heparin-anticoagulated plasma samples (R = 0.995). No statistically significant difference was found between serum and plasma samples for UPT-LF assay. Our results demonstrate that NT-proBNP levels in healthy adults are elevated with age and had a relationship with sex, and with the age increase the NT-proBNP levels of females are significantly higher than those of males (p<0.01). The UPT-LF assay has a high reproducibility, stability, sensitivity, specificity, and is consistent with Roche Elecsys assay, and therefore it could be used as a POCT method for the quantitative detection of NT-proBNP in blood for clinical diagnosis and research of acute heart failure.

Asymptomatic left ventricular dysfunction (ASLVD), a known precursor phase of heart failure, fulfills the essential criteria that should be met before screening for a disease. It is common and associated with reduced longevity and quality of life. Left untreated, it progresses to heart failure, which incurs a mortality greater than most cancers as well as significant morbidity rates. In addition, we now have several population-based studies that demonstrate that both B-type natriuretic peptide (BNP) and N-terminal prohormone brain natriuretic peptide (NTproBNP) can accurately exclude left ventricular systolic dysfunction. More recent work shows that this can be done cost-effectively. There is also a wealth of evidence from randomized controlled trials indicating that the treatment of ASLVD can reduce both morbidity and mortality and slow progression to the heart failure state. The main stumbling block to implementation of screening, in addition to the perceived cost, may well be the lack of a randomized study showing that screening the population for ASLVD really does alter the natural history of the condition, something that other screening strategies have so far failed to do.

Allisartan isoproxil is a new nonpeptide angiotensin II receptor blocker (ARB) precursor drug that is used to treat hypertension and reduce the risk of heart disease. The present study explored the effects of allisartan isoproxil on diabetic cardiomyopathy (DCM) and revealed the roles of hyperglycaemia‑induced oxidative stress and inflammation. A rat DCM model was established by high‑fat diet feeding in combination with intraperitoneal injection of streptozocin. Echocardiographs showed that diabetic rats exhibited significantly decreased cardiac function. Troponin T (cTnT) and B‑type natriuretic peptide (BNP) were significantly increased in DCM rats as obtained by ELISA. Allisartan isoproxil significantly improved the EF% and E'/A' ratio. Histopathologic staining showed that allisartan isoproxil prevented histological alterations, attenuated the accumulation of collagen, and ameliorated cTnT and BNP levels. Western blot and immunohistochemical results indicated that the expression levels of silent information regulator 2 homologue 1 (SIRT1) and nuclear factor erythroid 2‑related factor 2 (Nrf2) were decreased in the hearts of diabetic rats, and antioxidant defences were also decreased. In addition, allisartan isoproxil decreased the expression of NF‑κB p65 and the inflammatory cytokines TNF‑α and IL‑1β which were determined by reverse transcription‑quantitative PCR in the diabetic heart. Western blotting and TUNEL staining results also showed that cardiac Bax and cleaved caspase‑3 and the number of apoptotic myocardial cells were increased in the diabetic heart and decreased following treatment with allisartan isoproxil. In conclusion, the present results indicated that allisartan isoproxil alleviated DCM by attenuating diabetes‑induced oxidative stress and inflammation through the SIRT1/Nrf2/NF‑κB signalling pathway.

BACKGROUND

Cardiac-derived natriuretic peptides are sensitive plasma markers of cardiac dysfunction. Recent reports have disclosed a more complex molecular heterogeneity of B-type natriuretic peptide precursor (proBNP)-derived peptides than previously suggested. In this study, we examined the impact of epitope specificity and precursor maturation on plasma measurement of proBNP-derived peptides.

METHODS

We compared 2 assays, N-terminal proBNP and proBNP 1-76, in a randomly collected set of human plasma specimens (n = 370). Additionally, we evaluated the clinical performance of 4 assays with different epitope specificities in a cohort of elderly patients presenting with symptoms associated with heart failure (n = 415).

RESULTS

Comparison of N-terminal proBNP with proBNP 1-76 measurement in plasma revealed a high correlation on regression analysis (r(2) = 0.91, P < 0.0001). Nevertheless, the proBNP 1-76 assay measured lower concentrations in the high range than the N-terminal proBNP assay. Correlations between assay measurements in a clinical setting were comparable for all the assays (r(2) approximately 0.57-0.83), and ROC analyses revealed area-under-the-curve values ranging between 0.77 and 0.81 for identifying reduced left ventricular ejection fraction. In parallel, all assays displayed comparable abilities in predicting long-term mortality.

CONCLUSIONS

Our results reveal marked assay differences in analytical assay comparison, contrasting the overall comparable clinical performance in cardiovascular diagnostics or prognosis in the elderly.

Natriuretic peptide (NPs) levels have achieved worldwide acceptance. They are excellent rule-in and rule-out biomarkers for patients presenting with dyspnea. In the hospital, NP levels may represent altered forms of B-type natriuretic peptide (BNP), including the inactive precursor molecule, pro-BNP. NP levels drop during hospitalization as the patient is decongested. In the future, NP levels may be used as a surrogate to titrate outpatient therapy.

Proteomic analysis of human plasma and serum for identifying and validating disease-specific marker proteins and peptides has one major drawback besides its unique advantage as a readily available sample source for diagnostic assays. This disadvantage is represented by the predominance of several high- and middle-abundant proteins, which clearly hamper identification and quantification approaches of potential and validated protein and peptide biomarkers, which are often of very low abundance. During the last decades, a significant number of depletion and enrichment techniques evolved to address these two issues. We present here a cost-effective and easy-to-use strategy for protein depletion comprising a thermal precipitation protocol followed by a two-step liquid/liquid precipitation as well as using an immunoaffinity chromatography method for the specific enrichment and isolation of the low-abundance polypeptide N-terminal pro-B-type natriuretic peptide and its precursor proBNP clinically used as biomarkers for the detection of severe human heart failure and related diseases. The applicability of this approach is shown by SDS -CGE, SDS-PAGE, electrochemiluminescence immunoassay and nano-LC ESI-MS/MS. Our thermal precipitation protocol followed by a two-step liquid/liquid precipitation could also serve as a potential depletion technique for the characterization of other low-abundance peptides and proteins.

OBJECTIVE

Increased plasma concentrations of B-type natriuretic peptide (BNP) and its precursor (proBNP) provide important prognostic information in patients presenting with acute coronary syndromes. Although a majority of these patients undergo early invasive assessment, the effects of coronary angiography per se on plasma BNP and proBNP concentrations are not known. We therefore sought to determine whether coronary angiography and ventriculography affect the cardiac secretion of these prognostic markers.

RESULTS

Blood samples were collected before and two minutes after coronary angiography and ventriculography in patients with or without coronary artery disease (CAD) and normal left ventricular ejection fraction. In patients with suspected CAD and normal left ventricular ejection fraction, the plasma proBNP concentration transiently increased from 11 pmol/l (range 1-67 pmol/l) to 19 pmol/l (range 5-102 pmol/l, n=29,P<0.0001) two minutes after coronary angiography and ventriculography. The increase was similar in patients with or without CAD, although patients with stable CAD displayed higher plasma BNP and proBNP concentrations at baseline. In contrast, plasma BNP concentrations did not change after coronary angiography and ventriculography.

CONCLUSIONS

Coronary angiography induces a transient increase in cardiac proBNP secretion. Blood sampling for plasma proBNP measurements in patient stratification and prognosis estimation should consequently be avoided immediately after coronary angiography.

BACKGROUND

The polymorphisms rs198358, rs5068 and rs632793 in the natriuretic peptide precursor A-B gene region [encoding atrial natriuretic peptides (ANP) and brain natriuretic peptides (BNP)] have been recently associated with ANP and BNP plasma concentrations and blood pressure (BP) in a large cohort study.

METHODS

We observed that GCG, the haplotype based on these polymorphisms and combining the three rare alleles associated with higher natriuretic peptides and lower BP in a recent report, was associated with BNP plasma levels and BP in a French study of 5212 middle-aged participants, Epidemiological Data on Insulin Resistance Syndrome study. With the 9-year follow-up of Epidemiological Data on Insulin Resistance Syndrome study, we were able to analyze the association of incident microalbuminuria (576 patients) and low estimated glomerular filtration rate (<60 ml/min; 246 incident patients) with the tested haplotypes.

RESULTS

No haplotype, including GCG, the one combining the three rare alleles, was associated with incident patients of either microalbuminuria [odds ratio 1.27 (0.91-1.78), P = 0.15] or low estimated glomerular filtration rate [odds ratio 0.88 (0.54-1.46), P = 0.63].

CONCLUSIONS

This was consistent with a lack of effect on clinical renal outcomes found in previous studies and showed that even replicated and biologically plausible genetic association studies based on surrogate markers do not easily translate into clinically meaningful prognosis.

Ventricular natriuretic peptide (VNP), a newly discovered type of cardiac natriuretic peptide identified in eels, has a unique amino acid sequence and biological activity compared with other members of the natriuretic peptide family. We have cloned a cDNA encoding the eel VNP precursor from a cDNA library of eel ventricles and determined its sequence. Sequence analysis showed that the preproVNP consists of 150 amino acid residues containing a signal sequence of 22 amino acid residues at its N terminus and mature VNP(1-36) at its C terminus. Comparison with two types of mammalian cardiac natriuretic peptides (A and B type natriuretic peptides; ANP and BNP) revealed that VNP showed greater overall sequence identity to ANP than to BNP at both the cDNA and amino acid sequence levels. Since VNP cDNA lacks the repetitive ATTTA sequence in the 3' non-coding region, which is a characteristic common to all BNP cDNAs sequenced to date, VNP may differ from BNP. While mRNA for eel ANP was detected only in the atrium, that for eel VNP was more abundant in the ventricle than in the atrium. Thus VNP is regarded as the first truly ventricular hormone in terms of synthesis and storage. Southern blot analysis indicated that VNP is also present in the quail, which belongs to a taxon where BNP has already been identified.

OBJECTIVE

B-type natriuretic peptide (BNP) and amino-terminal proBNP (Nt-proBNP) are derived from a common precursor, the proBNP(1-108) (proBNP), synthesized by cardiomyocytes. We determined proBNP concentrations in patients admitted to ED and suspected of CHF.

METHODS

One hundred fifty six consecutive patients admitted to ED were included. ProBNP, BNP and Nt-proBNP levels were determined at admission.

RESULTS

In this ED population, assays for proBNP, BNP and Nt-proBNP were positively and significantly correlated. Circulating levels of proBNP were higher in patients admitted to ED for CHF than in patients admitted to ED other reasons. Applying receiver operating characteristic curve (ROC) analysis for the diagnosis of CHF, the area under the curve (AUC) was 0.92 for proBNP.

CONCLUSIONS

Our study demonstrated that proBNP testing, the precursor of BNP and Nt-proBNP, appears as a relevant tool to assist the diagnosis of CHF in patients admitted to ED.

OBJECTIVE

The aim of this study was to determine if the atrial natriuretic peptide (ANP) precursor proANP is biologically active compared with ANP and B-type natriuretic peptide (BNP).

BACKGROUND

ProANP is produced in the atria and processed to ANP and activates the guanylyl cyclase receptor-A (GC-A) and its second messenger, cyclic guanosine monophosphate (cGMP). ProANP is found in the human circulation, but its bioavailability is undefined.

METHODS

The in vivo actions of proANP compared with ANP, BNP, and placebo were investigated in normal canines (667 pmol/kg, n = 5/group). cGMP activation in human embryonic kidney 293 cells expressing GC-A or guanylyl cyclase receptor-B was also determined. ProANP processing and degradation were observed in serum from normal subjects (n = 13) and patients with heart failure (n = 14) ex vivo.

RESULTS

ProANP had greater diuretic and natriuretic properties, with more sustained renal tubular actions, compared with ANP and BNP in vivo in normal canines, including marked renal vasodilation not observed with ANP or BNP. ProANP also resulted in greater and more prolonged cardiac unloading than ANP but much less hypotensive effects than BNP. ProANP stimulated cGMP generation by GC-A as much as ANP. ProANP was processed to ANP in serum from normal control subjects and patients with heart failure ex vivo.

CONCLUSIONS

ProANP represents a novel activator of GC-A with enhanced diuretic, natriuretic, and renal vasodilating properties, and it may represent a key circulating natriuretic peptide in cardiorenal and blood pressure homeostasis. These results support the concepts that proANP may be a potential innovative therapeutic beyond ANP or BNP for cardiorenal diseases, including heart failure.

BACKGROUND

Deterioration of left ventricular function during follow-up was reported in some patients with syndrome X and concomitant left bundle branch block. The patients with syndrome X and left bundle branch block has been frequently presented with elevated Endothelin-1 (ET-1) level while brain natriuretic peptide (BNP) (a sensitive marker of left ventricular dysfunction) has not been measured in patients with syndrome X.

METHODS

The purpose of the present study was to assess left ventricular diastolic function, levels of N-terminal Brain Natriuretic Peptide (NT-proBNP) precursor and biochemical parameters of endothelial function in patients with syndrome X complicated by left bundle branch block but preserved left ventricular systolic function (group A, n=8). The echocardiographic and neurohormonal measures in these patients were compared to those in patients with syndrome X without left bundle branch block (group B, n=13), and controls (group C, n=15).

RESULTS

At rest and after exercise the serum concentration of NT-proBNP was significantly higher in group A than in the controls (at rest: 232+/-96 vs. 133+/-23 fmol/ml, P=0.03; after exercise: 313+/-96 vs. 180+/-33 fmol/ml, P=0.02). The highest concentration of endothelin-1 was also found in group A, being significantly higher than in the controls (6.81 vs. 4.52 pg/ml, P<0.05). Mitral flow abnormalities were detected in left bundle branch block patients. Accordingly, the lowest E/A ratio was in group A and it differed significantly from that in group C (0.85 vs. 1.1, P<0.05). E/A ratio inversely correlated with plasma NT-proBNP concentration in patients with left bundle branch block (r=-0.48, P=0.02).

CONCLUSIONS

Elevated NT-proBNP and endothelin-1 plasma concentrations were demonstrated in patients with syndrome X complicated by left bundle branch block even when left ventricular systolic function was still preserved. In this subgroup the magnitude of left ventricular diastolic dysfunction correlated with the increase of BNP level which reflects neurohormonal activation.

BACKGROUND

The degree of fatty acid (FA) unsaturation as a determinant of lipid peroxidation has been inadequately studied.

METHODS

We examined associations of plasma free F2α-isoprostanes (F2-IsoPs), an indicator of in-vivo lipid peroxidation, with the levels/intake of FAs, adjusted for the risk factors of cardiovascular disease (CVD) in 1211 Finnish men and women, of whom 50% were hypertensive, aged 59.3 ± 8.3 years, mean ± SD.

RESULTS

Elevated age- and sex-adjusted plasma free levels of omega-6 and omega-3 polyunsaturated Fas (PUFAs), saturated FAs (SFAs), and the PUFA/SFA and the omega-6/omega-3 PUFA ratios were all associated with decreased F2-IsoPs. High dietary SFA intake was associated with elevated F2-IsoP concentrations. In a multivariable regression (with clinical, nutritional, and behavioral CVD risk factors), female gender, body mass index (BMI), serum apolipoprotein A1, and NT-proBNP (natriuretic peptide) were positively associated with the F2-IsoPs, whereas the dietary PUFA/SFA ratio, plasma β-carotene, the omega-6/omega-3 PUFA ratio, and protein intake showed inverse associations.

CONCLUSIONS

We propose that elevated lipid peroxidation is associated with several risk factors of CVD, such as a low PUFA/SFA ratio, whereas the FA precursors of lipid peroxidation, i.e. omega-3 and omega-6 PUFAs are associated with attenuated F2-IsoP levels. These findings provide mechanistic support for earlier observations linking PUFA to improved cardiovascular health.

BACKGROUND

Renovascular hypertension caused by renal artery stenosis (RAS) accounts for 3-5% of all cases of hypertension.

OBJECTIVE

The aim of the study was to determine the association between SNP rs198389 (T-381 C) polymorphism in the B-type natriuretic peptide promoter (BNP) gene and the degree of RAS in patients with atherosclerotic renovascular hypertension.

METHODS

Thirty-six patients scheduled for invasive diagnostic evaluation of atherosclerotic renovascular hypertension were enrolled in the study. Arteriography was performed through a femoral artery access. In order to identify SNP rs198389 (T-381 C) polymorphism in the BNP gene genotyping was performed using genomic DNA isolated from peripheral blood leukocytes. Amplified by polymerase chain reaction and purified product was used to minisequencing. Capillary electrophoresis was applied to separate and detect minisequencing products. The analysis enabled to discriminate TC heterozygotes, TT homozygotes, and CC homozygotes at position 381 of the BNP gene promoter.

RESULTS

Patients homozygous for C allele occurred more frequently in patients with high-grade RAS in comparison with the moderate and mild stenosis groups. TT homozygotes were observed more frequently in mild stenosis patients compared to the moderate and high-grade stenosis groups. None of the patients who had mild RAS was homozygous for C allele and none of the patients who had severe RAS was homozygous for T allele.

CONCLUSIONS

We demonstrated the association between SNP rs198389 (T-381 C) polymorphism in the BNP gene promoter and the degree of RAS in patients with atherosclerotic renovascular hypertension. It appears that subjects homozygous for C allele at position 381 of the BNP precursor gene promoter are more prone to develop atherosclerotic lesions in renal arteries.

Jumonji (JMJ, Jarid2), a prototypical member of the jumonji domain-containing protein family, plays a major role in embryonic cardiac development, but its role in the developed heart is unclear. Cardiomyocytes from neonatal mouse heart were treated in culture with NO donor SIN-1, 500 microM, for 2, 4, and 20 h. SIN-1 treatment was associated with a significant and 6.9 +/- 2.5 fold increase in jmj gene expression over all time points. The expression of jmj increased markedly and significantly 4.2 +/- 1.1 fold, 16.6 +/- 4.1 fold, and 2.7 +/- 0.3 fold, respectively, at time points 2 h, 4 h, and 20 h after treatment. The ability of the increase in gene expression to translate into an increase in cellular protein expression was ascertained by Western blotting, which showed an increase in the JMJ protein in whole-cell lysates. Because of the relationship of JMJ to Rb and ANP in the heart, gene expression of these proteins was also examined. SIN-1 produced a small but significant increase in Rb2, but not Rb1 or Rb-binding proteins 4, 6, or 7. In contrast, SIN-1 produced a marked and significant reduction in natriuretic peptide precursor type B but not type C to 0.24 +/- 0.09 fold of the control. These data suggest that JMJ may be a critical, previously unrecognized factor that mediates some of the cellular effects of NO, that NO may be able to increase JMJ in diseases associated with reduced JMJ expression.

Hyperbaric oxygen preconditioning (HBO-PC) can protect the heart from injury during subsequent ischemia. The presence of high loads of venous gas emboli (VGE) induced by a rapid ambient pressure reduction on ascent from diving may cause ischemia and acute heart failure. The aim of this study was to investigate the effect of diving-induced VGE formation on cardiac stress marker levels and the cardioprotective effect of HBO-PC. To induce high loads of VGE, 63 female Sprague-Dawley rats were subjected to a rapid ambient pressure reduction from a simulated saturation dive (50 min at 709 kPa) in a pressure chamber. VGE loads were measured for 60 min in anesthetized animals by the use of ultrasonography. The animals were divided into five groups. Three groups were exposed to either diving or to HBO-PC (100% oxygen, 38 min at 303 kPa) with a 45 or 180 min interval between HBO-PC and diving. Two additional groups were used as baseline controls for the measurements; one group was exposed to equal handling except for HBO-PC and diving, and the other group was completely unexposed. Diving caused high loads of VGE, as well as elevated levels of the cardiac stress markers, cardiac troponin T (cTnT), natriuretic peptide precursor B (Nppb), and αB-crystallin, in blood and cardiac tissue. There were strong positive correlations between VGE loads and stress marker levels after diving, and HBO-PC appeared to have a cardioprotective effect, as indicated by the lower levels of stress marker expression after diving-induced VGE formation.

OBJECTIVE

We sought to test the prognostic performance of thrombus precursor protein (TpP) in patients presenting with an acute coronary syndrome (ACS).

BACKGROUND

Because thrombus formation is a critical step in the development of ACS, a measurement of activated coagulation could yield important information. Thrombus precursor protein is a biomarker that is used to measure soluble fibrin polymers, which are the penultimate products in fibrin formation.

METHODS

We measured the levels of TpP in 284 healthy volunteers and in 2,349 patients with ACS.

RESULTS

Median TpP concentrations were 3.6 mug/ml (interquartile range 2.6 to 5.5) in the volunteers and 8.9 mug/ml (interquartile range 4.9 to 15.9) in the ACS patients (p < 0.001). Patients with ACS who had elevated TpP were older, more likely to be women, and more likely to have diabetes and pre-existing CAD (p < 0.02 for each). Thrombus precursor protein levels greater than the median were associated with a significantly increased risk for the composite of death, myocardial infarction (MI), or recurrent ischemia leading to rehospitalization or urgent revascularization through 10 months (hazard ratio [HR] 1.45, p < 0.001), as well as death or MI (HR 1.42, p = 0.02). We found that TpP correlated only weakly with cardiac troponin I, B-type natriuretic peptide, and high-sensitivity C-reactive protein (|r| <0.15 for each). After adjusting for clinical characteristics, cardiac troponin I, high-sensitivity C-reactive protein, and B-type natriuretic peptide, we found that patients with TpP levels greater than the median remained at significantly increased risk for the composite outcome (adjusted HR 1.51, p = 0.001) and death or MI (adjusted HR 1.58, p = 0.02).

CONCLUSIONS

In patients with ACS, increased levels of TpP are associated with an increased risk of death or ischemic complications. The incorporation of a marker of activated coagulation, such as TpP, with established cardiovascular risk factors may offer valuable complementary insight into risk assessment in ACS.

The diagnosis of primary aldosteronism (PA) is based on the finding of the combination of elevated urinary and/or plasma aldosterone and suppressed renin activity in patients with hypertension and hypokalemia. However, PA consists in a number of subsets, and diagnostic criteria for a correct identification of surgically remediable forms are of great interest. The methods and the results concerning our series of 113 patients with primary aldosteronism are presented in this review. Aldosterone producing adenoma (APA) and idiopathic hyperaldosteronism (IHA) were the most frequent forms, 51% and 44% respectively. They had similar BP levels, but hypokalemia was most frequently found in APA. Urinary and upright plasma aldosterone were similar, but supine plasma aldosterone was lower in IHA. Plasma aldosterone response to upright posture and angiotensin II infusion was absent in most cases of APA and present in IHA, but occasionally renin-responsive adenoma were found. Captopril failed to decrease plasma aldosterone in most patients with APA, and in a subgroup of patients with IHA. Patients with adenoma had also higher values of the aldosterone precursor 18-OH-B, and of atrial natriuretic peptide (ANP), probably as a consequence of a greater degree of volume expansion. Among morphological studies, CT scan and adrenal radio-cholesterol scintiscan provided similar results (85% accuracy): adrenal vein catheterization clarified almost all the remaining cases. Among the subsets of PA, 3 familiar cases of dex-suppressible hyperaldosteronism were recognized, with characteristically high levels of aldo, 18-OH-B, 18-OH-cortisol and 18-oxo-cortisol, due to the genetic abnormalities of the 11-18 hydroxylase system.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP), two distinct members of the natriuretic peptide family, share many features in common. However, differences in expression indicate that the processing mechanisms must be different. The leader sequence of rat BNP contains three potential phosphorylation sites for proline-directed kinases that are not present in the leader sequence of ANP. This study has examined how these sites are used by two somewhat different proline-directed kinases. A peptide containing these sites was phosphorylated in vitro by HeLa p34cdc2 kinase and by sea star p44mpk kinase at rates that were comparable to the rates with peptide substrates that are used to assay these enzymes. Sequence analysis of the phosphopeptide shows that both kinases phosphorylate only the two potential phosphorylation sites surrounding the cleavage site of the BNP precursor. The enzymatic potential for such a phosphorylation of BNP in cardiac tissue is demonstrated by immunoblots and kinase assays, showing that in fetal and in adult rat heart both the atria and the ventricles contain a mitogen-activated protein kinase homologue that can phosphorylate this preproBNP sequence.

BACKGROUND

Neurohormones play a key role in regulating hemodynamics in heart failure (HF) both at rest and during exercise. In contrast, little is known about the importance of neurohormonal regulation for exercise capacity in continuous-flow left ventricular assist device (CF-LVAD) patients. The aim of this study was to assess the relation between neurohormonal activation patterns in CF-LVAD patients and exercise capacity.

METHODS

Plasma concentrations of the C-terminal portion of pro-arginine vasopressin precursor (copeptin), pro-adrenomedullin (proADM), pro-B-type (proBNP) and pro-atrial (proANP) natriuretic peptides were measured in 25 CF-LVAD patients (HeartMate II) in the morning prior to maximal cardiopulmonary exercise testing determining peak oxygen uptake (peak VO2). Quality of life (QOL) was determined by questionnaires.

RESULTS

Peak VO2 was severely reduced averaging 13.0±5.3ml/kg/min and exhibited strong negative correlations with copeptin, r=-0.61 (p=0.001) and proADM, r=-0.56 (p=0.005). Additionally comparing patients with peak VO2<14 vs≥14ml/kg/min demonstrated significant differences in copeptin and proADM concentrations, 2.8±0.8 vs 2.1±0.7pmol/l (p=0.03) and 1.0±0.5 vs 0.7±0.2nmol/l (p=0.01), respectively. In contrast natriuretic peptides were not associated with maximal exercise capacity. Lower QOL correlated with increasing proBNP.

CONCLUSIONS

Resting plasma levels of proADM and copeptin are significantly correlated with peak VO2 in CF-LVAD patients. Future studies should address if interventions to lower the levels of these markers are associated with restoration of exercise tolerance.

The Goto-Kakizaki (GK) rat, a non-obese model of type 2 diabetes mellitus (T2DM), was generated by the selective inbreeding of glucose-intolerant Wistar rats. This is a convenient model for studying diabetes-induced cardiomyopathy independently from the effects of the metabolic syndrome. We investigated the myocardial functional and structural changes and underlying molecular pathomechanisms of short-term and mild T2DM. The presence of DM was confirmed by an impaired oral glucose tolerance in the GK rats compared with the age-matched nondiabetic Wistar rats. Data from cardiac catheterization showed that in GK rats, although the systolic indexes were not altered, the diastolic stiffness was increased compared with nondiabetics (end-diastolic-pressure-volume-relationship: 0.12 ± 0.04 vs. 0.05 ± 0.01 mmHg/μl, P < 0.05). Additionally, DM was associated with left-ventricular hypertrophy and histological evidence of increased myocardial fibrosis. The plasma pro-B-type natriuretic peptide, the cardiac troponin-T, glucose, and the urinary glucose concentrations were significantly higher in GK rats. Among the 125 genes surveyed using PCR arrays, DM significantly altered the expression of five genes [upregulation of natriuretic peptide precursor-A and connective tissue growth factor, downregulation of c-reactive protein, interleukin-1β, and tumor necrosis factor (TNF)-α mRNA-level]. Of the altered genes, which were evaluated by Western blot, only TNF-α protein expression was significantly decreased. The ECG recordings revealed no significant differences. In conclusion, while systolic dysfunction, myocardial inflammation, and abnormal electrical conduction remain absent, short-term and mild T2DM induce the alteration of cardiac TNF-α at both the mRNA and protein levels. Further assessments are required to reveal if TNF-α plays a role in the early stage of diabetic cardiomyopathy development.

Left ventricular systolic dysfunction (LVSD) following acute myocardial infarction (AMI), by decreasing renal blood flow, may interfere with renal L-DOPA availability and, consequently, dopamine synthesis. Dopamine of renal origin exerts local natriuretic effects. We studied 17 post-AMI patients with asymptomatic LVSD (ejection fraction < 40%) and 14 without (ejection fraction>> or = 40%), measuring 24-h urinary excretions of L-DOPA, dopamine and its metabolites, and plasma levels of the amines, amine derivatives and type-B natriuretic peptide (BNP). Baseline characteristics were well balanced between the two groups. No differences were observed in urinary volume and sodium and creatinine excretions. The group with asymptomatic LVSD presented lower urinary excretion of L-DOPA (66.8 +/- 10.1 versus 115.3 +/- 21.9 nmol x day(-1), P = 0.04), whereas plasma levels of L-DOPA were identical in both groups. Urinary dopamine was similar in the two groups (1124.2 +/- 172.4 versus 1049.0 +/- 146.4 nmol x day(-1), P = 0.86), resulting in higher urinary dopamine/L-DOPA ratios in patients with asymptomatic LVSD (20.4 +/- 3.0 versus 9.9 +/- 0.8, P < 0.001). Plasma levels of BNP were higher in the asymptomatic LVSD group (348.5 +/- 47.3 versus 146.8 +/- 21.9 microg x ml(-1), P = 0.003). Ejection fraction was negatively correlated with both plasma levels of BNP and urinary dopamine/L-DOPA ratios. Renal dopamine production is well preserved in patients with asymptomatic LVSD and increased neurohumoral activation, despite reduced urinary excretion of its precursor. This suggests that renal uptake and/or decarboxylation of L-DOPA is enhanced in this condition, as a compensatory mechanism, contributing to preservation of urinary sodium excretion.

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a genetically heterogenous disease caused by mutations in genes that primarily encode sarcomeric proteins. No mutation is identified in up to 40% of HCM patients, suggesting other causative genes exist. Natriuretic peptide precursor B (NPPB; also known as "BNP") is a cardiac hormone involved in body fluid homeostasis and cardiac myocyte growth. NPPB concentrations are markedly increased in patients with ventricular hypertrophy, and it is therefore possible mutations in the NPPB gene could cause HCM.

METHODS

Genomic DNA was extracted from peripheral blood in 238 consecutive probands with HCM. The coding regions and intron/exon boundaries in the NPPB gene were amplified by PCR, and products were screened for sequence variants using high-performance liquid chromatography, followed by direct DNA sequencing.

RESULTS

Four sequence variants in the NPPB gene were identified in 9 of the 238 probands screened. Two of the variants were intronic, one was a synonymous variant at codon 79, and the final variant resulted in an amino acid substitution from arginine to histidine at codon 47 (Arg47His). The Arg47His variant was identified in a control population consisting of 204 chromosomes at an allelic frequency of 0.5%, and is therefore unlikely to cause disease.

CONCLUSIONS

No disease causing mutations were identified in the NPPB gene in this cohort, indicating that mutations in this gene are unlikely to be responsible for HCM.