Proinflammatory/profibrotic effects of aldosterone in Gitelman's syndrome, a human model opposite to hypertension.

PURPOSE: Aldosterone proinflammatory/profibrotic effects are mediated by the induction of mononuclear leucocytes (MNL) to express oxidative stress (OxSt)-related proteins, such as p22phox, and by the activation of RhoA/Rho kinase pathway. Gitelman's syndrome (GS), an autosomal recessive tubulopathy, is an interesting opposite model to hypertension, being characterized by hypokalemia, activation of renin-angiotensin-aldosterone system yet normo/hypotension and lack of cardiovascular-renal remodeling. We aimed to evaluate the proinflammatory/profibrotic effect of aldosterone in MNL of 6 GS patients compared with 6 healthy subjects (HS). METHODS: p22phox expression and MYPT-1 phosphorylation status, a marker of RhoA/Rho kinase pathway activation, were evaluated in MNL of GS patients and HS at baseline and after incubation with aldosterone (1 × 10-8 M) alone or with canrenone (1 × 10-6 M). RESULTS: At basal condition, p22phox expression was significantly higher in HS than in GS patients (1.02 ± 0.05 densitometric unit (du) vs 0.40 ± 0.1 du, respectively). Aldosterone significantly increased p22phox expression in HS and this effect was reversed by coincubation with canrenone (1.4 ± 0.05 du and 1.09 ± 0.03 du, respectively). No significant change was reported in GS after incubation of MNL with aldosterone and/or canrenone compared with basaline. Even MYPT-1 phosphorylation was significantly higher in HS compared with GS patients at basal condition (1.16 ± 0.1 du vs 0.69 ± 0.07, respectively). Aldosterone significantly increased MYPT-1 phosphorylation only in HS (1.37 ± 0.1 du vs 0.83 ± 0.12 du in GS). CONCLUSIONS: GS patients seem to be protected by the OxSt status induced by aldosterone and revealed in HS. This human model could provide additional clues to highlight the proinflammatory/cardiovascular remodeling effects of aldosterone.

Gαq/p63RhoGEF interaction in RhoA/Rho kinase signaling: investigation in Gitelman's syndrome and implications with hypertension.

PURPOSE: Gitelman's syndrome (GS) presents normo-hypotension and absence of cardiovascular-renal remodeling despite high angiotensin II (Ang II), activation of renin-angiotensin-aldosterone system and is a human model of endogenous antagonism of Ang II signaling, opposite to hypertension. GS's clinical presentation leads to questions regarding what features might be responsible. One area of investigation involves Ang II signaling. In hypertensive patients, RhoA/Rho kinase (RhoA/ROCK) pathway activation by Ang II is involved in hypertension development/maintenance and induction of long-term consequences (cardiovascular-renal remodeling), while GS has reduced p63RhoGEF gene and protein levels and ROCK activity. Ang II signaling is mediated by Gαq, which interacts with p63RhoGEF via the α6-αN linker connecting p63RhoGEF's DH and PH domains acting as a conformational switch to activate RhoA/ROCK signaling. METHODS: We have investigated in GS patients, the presence of mutations in either p63RhoGEF's α6-αN linker domain and in Gαq's Ala253, Trp263, and Tyr356 residues, crucial for p63RhoGEF-Gαq interplay. RESULTS: No mutations have been found in specific aminoacids of p63RhoGEF α6-αN linker and Gαq, key for p63RhoGEF/Gαq interplay. CONCLUSIONS: Gitelman's syndrome normo/hypotension and lack of cardiovascular-renal remodeling are not due to mutations of p63RhoGEF α6-αN linker and Gαq interactions. This opens the way for investigations on different coding and no-coding regions (p63RhoGEF and Gαq promoters) and on altered transcriptional/post-transcriptional regulation. Clarification of how these biochemical/molecular mechanisms work/interact would provide insights into mechanisms involved in the GS's Ang II signaling fine tuning, in human physiology/pathophysiology in general and could also identify significant targets for intervention in the treatments of hypertension.

Young athletes with ventricular premature beats: Continuing or not intense training and competition?

Isolated ventricular premature beats (VPBs) are commonly found during pre-participation screening in athletes. Currently, the debate about the role of detraining in reducing the number of VPBs is still open. This study evaluated the arrhythmic risk in a population of young competitive athletes who showed VPBs during eligibility evaluation and that did not undergo detraining but continued practicing competitive sports. 3746 consecutive subjects underwent pre-participation screening. Athletes who showed VPBs were selected and underwent second level evaluation (Echocardiogram, 24 hour Holter ECG and Exercise test). Athletes were re-evaluated after a follow-up period (6-48 months) while they continued practicing competitive sports. 5.3% of the whole population showed ventricular arrhythmias. 73% of the subjects showed isolated VPBs. 88% of the subjects showed monomorphic VPBs, and 12% of athletes showed polymorphic VPBs. At echocardiogram, there was not any pathology which contraindicated competitive sport activity. At 24 hour Holter ECG recording, mean number of daily VPBs was 1592±3217 (range 0-16678). At holter ECG follow-up (16±12 months), the median number of VPBs decreased from 93 (IQR 20-3065) to a new value of 72 (IQR 2-1299). Continuing competitive sport in subjects with ventricular arrhythmias even though frequent but with a low grade of complexity and without structural cardiomyopathy does not increase sudden death risk.

Biofilm in voice prosthesis: A prospective cohort study and laboratory tests using sonication and SEM analysis.

OBJECTIVE: The objective of the study was to compare the biofilm growing pattern and its morphological extent on silicone and a teflon-like material using a sonication process and a Scanning Electron Microscope (SEM). DESIGN: A prospective cohort study and a laboratory study. SETTING: Otolaryngology -Head and Neck surgery Department and the Microbiology Institute. PARTICIPANTS: The participants included fifteen laryngectomised patients with phonatory prostheses, which were removed because of device failure, and two different kinds of phonatory prostheses from the laboratory (Provox 2 and ActiValve) that were artificially colonised by Candida albicans. MAIN OUTCOME MEASURES: Tracheo-oesophageal puncture (TEP) is currently considered the gold standard for post-laryngectomy voice rehabilitation. "Leakage" represents the most common cause of substitution and is generated by biofilm colonisation of the prosthesis by mixed mycotic and bacterial agents. New biomaterials have been developed that are deemed to be more resistant to the colonisation of micro-organisms and material deformation. RESULTS: The devices showed colonisation by mixed bacterial flora (Staphylococci 13%, Streptococci 9%, and Haemophilus influenzae 5%) and by yeasts (Candida albicans 12%). Moreover, we observed a different distribution of biofilm layers in Provox ActiValve (22.56%) compared to Provox 2 (56.82%) after experimental colonisation by the previously isolated Candida strain. CONCLUSION: Resident microbiological species from the upper airways unavoidably colonise the polymer surfaces, and no strategies have been effective except for the manipulation of the chemical-physical properties of the device's polymer. Our study confirms that Provox ActiValve, which is made with a fluoroplastic material (teflon-like), is less subject to in vitro colonisation by Candida, and thus showed a higher clinical resistance to biofilm and a longer lifespan. The sonication seems to significantly improve the knowledge of bacterial and mycotic flora in biofilm colonisation. The design of a device for the daily cleaning capable to reach and brush the oesophageal flange of the prosthesis preserving the valve mechanism could represent a practical and simple help in this still unsolved problem.

Mechanistic approach to the pathophysiology of target organ damage in hypertension from studies in a human model with characteristics opposite to hypertension: Bartter's and Gitelman's syndromes.

INTRODUCTION: Extensive studies using Bartter's/Gitelman's syndrome patients have provided insights into the angiotensin II (Ang II) signaling pathways involved in the regulation of vascular tone and cardiovascular-renal remodeling. The renin-angiotensin-aldosterone system is activated in these syndromes, however, patients do not develop hypertension and cardiovascular remodeling and clinically manifest conditions opposite to hypertension. The short- and the long-term signaling of Ang II remains an important matter of investigation to shed light on mechanisms responsible for the pathophysiology of hypertension and its long-term complications. The long-term signaling of Ang II is involved in the pathophysiology of cardiovascular-renal remodeling and inflammatory responses in which the balance between RhoA/Rho kinase pathway and NO system plays a crucial role. METHODS AND RESULTS: In this brief review, the results of our studies in Bartter's and Gitelman's syndromes are reported on these processes. CONCLUSIONS: The information obtained from these studies can clarify, confirm or be used to extend the biochemical mechanisms responsible for the pathophysiology of hypertension and its long-term complications and could offer further chances to identify additional potential significant targets of therapy.

[Synthetic indicator of compliance with standards for Quality Units of health centers and multicenter prospective pilot study]. / Indicador sintético de cumplimiento de estándares para Unidades de Calidad de centros sanitarios y estudio de pilotaje prospectivo multicéntrico.

BACKGROUND AND OBJECTIVE: In Spain, Quality Units play a key and unique role in advising healthcare centers on the methodology of healthcare quality. The objectives of the study were to develop computer algorithms to obtain a synthetic indicator of standard compliance for Quality Units and to pilot its functioning in these units. MATERIALS AND METHODS: The Excel program was used to establish evaluation algorithms, and quantitatively interrelate and weight various categories of standards, as a computer evaluation tool, to build a continuous improvement cycle system, and offer a global synthetic indicator of compliance. The tool was tested in a prospective multicenter pilot study, in which coordinators of Quality Units from different health centers and care settings participated, to evaluate the usefulness of the tool and compliance with the standards, in addition to analyzing the content validity of each standard. RESULTS: The formulas for the structured computer algorithms were developed, consecutively, in a «PLAN-DO-CHECK-ACT¼ improvement cycle for the 9 categories of standards, resulting in a single synthetic indicator of compliance. Twenty-one Quality Units participated in the piloting. The overall average compliance rate for the synthetic indicator was 55.63% with differences between centers (P=.002) and between categories (P<.0001), but not by autonomous communities (P=.86) or by areas (P=.97). Content validity was ensured through the variable of «understanding¼ of the standards (P<.001), and through their «justification¼ with documentary evidence (P<.001). CONCLUSIONS: The computer tool with the synthetic indicator have allowed for the evaluation of standard compliance in Quality Units of healthcare centers.

[Development and validation of standards for quality units of health centers]. / Desarrollo y validación de estándares para unidades de calidad de centros sanitarios.

OBJECTIVE: In Spain, the Quality Units advise health centres, services and professionals on the methodology of continuous improvement of the quality of care. A system based on good practice standards could provide these units with a tool to improve their results and value their work. The objective was to develop, agree on and validate standards, to properly guide and orient the functions, results and continuous improvement of the Quality Units in health centers. MATERIAL AND METHODS: A qualitative-quantitative, prospective and cross-sectional study was carried out, applying the Metaplan method, the e-Delphi technique and a simulation study. The participants were coordinators of these units, belonging to 14 Spanish Autonomous Communities and distributed in four experts' panels. They agreed on the standards to be used and evaluated the different types of validity. RESULTS: The 204 standards proposed by the scientific committee were reduced to 157 with Metaplan, to 110 with e-Delphi, and to 96 with the committee's final review (87.3% consensus, content validity). The construct validity showed a Cronbach's alpha >0.7 (P<.001); the validity of content was reaffirmed in the simulation workshop (80% "understood" each other, P<.001; and there was "documentary evidence" in 84%, P<.001); face validity was accepted (75% "related to quality dimensions", P<.001); and the validity of the criteria was verified with a sensitivity of 84.2%, a specificity of 98.3%, and a kappa index of 0.84. CONCLUSIONS: Valid standards have been developed for Quality Units in health centers.

Road traffic deaths: A retrospective analysis (2009-2019) in the north of the Italian region Emilia Romagna.

OBJECTIVE: International literature and several national studies demonstrate that alcohol and illicit drugs impair driving abilities, diminishing the level of attention, and cause traffic accidents. In Italy, driving under the influence of alcohol or drugs is regulated by Articles 186 and 187 of the National Street Code, which defines penalties and fines for the convicted. The aim of this study was the collection of all available data from 2009 to 2019 focusing on deaths related to road accidents in the Unit of Legal Medicine of Department of Medicine and Surgery at the University of Parma, in order to assess any consumption of alcohol, illicit drugs, and medicinal drugs among drivers. METHODS: Data were retrieved from autopsy reports found at the Unit of Legal Medicine of Parma University related to 327 subjects who died following road accidents in the Italian areas of Parma, Reggio-Emilia, and Piacenza. The population was divided into subgroups according to age, gender, crash time, and drug positivity. RESULTS: Those in the age group 46 to 65 years old were involved in the most accidents, whereas the category with fewest members included subjects under 26 years old. The majority of road accidents occurred during the daytime and on weekends. Among the toxicological investigations carried out (only for drivers), the highest prevalence was found for alcohol (43.1%), followed by illicit drugs (14.4%) and medicinal drugs (7.8%). The prevalence of alcohol and illicit drugs in combination was 11.8%. Regarding subjects positive for alcohol and illicit drugs in combination, 44.4% had a blood alcohol concentration (BAC) > 1.5 g/L and overall, in 61.1% of the total cases a BAC > 0.81 g/L was detected. CONCLUSIONS: Our results are in line with national and international studies highlighting the prevalence of high BAC levels in most of the cases. Confirmation analyses on blood collected from people who died following road accidents showed levels of BAC above 0.8 g/L (threshold for penal sanctions) in the majority of the subjects who tested positive for alcohol. They also revealed cocaine, cannabis, and benzodiazepines as the most common illicit drugs and medicinal drugs used, respectively, as demonstrated in several international studies.

Author Correction: Impact of sacubitril/valsartan on implantable defibrillator eligibility in heart failure: a real-world experience.

Correction to: European Review for Medical and Pharmacological Sciences 2021; 25 (18): 5690-5700-DOI: 10.26355/eurrev_202109_26788-PMID: 34604961, published online on 30 September 2021. After publication, the authors applied to change the first two lines of Table II as the second column results were erroneously shifted in the first column. In this way, the results were quite difficult to understand. There are amendments to this paper. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/26788.

Verapamil: prevention and treatment of cardio-renal syndromes in diabetic hypertensive patients?

Patients with diabetes mellitus (DM) often present other chronic comorbidities including arterial hypertension (AH), chronic kidney disease (CKD), ischemic heart disease (IHD) and heart failure with preserved ejection fraction (HFpEF). The frequent association of the latter conditions is considered part of the spectrum of cardio-renal syndromes (CRS), a group of disorders of the heart and kidneys whereby acute or chronic dysfunction in one organ may induce acute or chronic dysfunction of the other. Verapamil is a non-dihydropyridine calcium channel blocker (CCB) widely used in the treatment of hypertension, chronic stable angina, secondary prevention of reinfarction, paroxysmal supra-ventricular tachycardia and for rate control in atrial fibrillation/flutter. In addition to its antihypertensive and anti-ischemic actions verapamil exerts favorable effects also on glycemic control, proteinuric diabetic nephropathy, left ventricular diastolic dysfunction and sympathetic nervous system overactivity which may potentially benefit patients with DM and CRS. In this narrative review, we summarize the current evidence on the potential role of verapamil in the prevention and treatment of CRS in diabetic hypertensive patients.

Vitamin K, bone fractures, and vascular calcifications in chronic kidney disease: an important but poorly studied relationship.

Vitamin K denotes a group of lipophilic vitamins determining post-translational modification of proteins. There are 2 main forms of vitamin K: vitamin K1 (phylloquinone, found in vegetables); vitamin K2 (menaquinone, produced by bacteria in the intestine and in fermented foods). Vitamin K stores are limited in humans, but it can be recycled. Vitamin K1 is principally transported to the liver, regulating the production of coagulation factors. Vitamin K2, instead, is also transported to extra-hepatic tissues, such as bone and arteries, regulating the activity of matrix Gla-protein (MGP) and osteocalcin [bone Gla-protein (BGP)]. In patients with chronic kidney disease (CKD), cardiovascular mortality is the first cause of death. Some pathogenetic mechanisms of vascular calcification (such as hyperparathyroidism, hyperphosphatemia, hypercalcemia, role of vitamin D) have been widely investigated, but the potential role of vitamin K is still uncertain. Vitamin K could play a key role, as it transforms glutamic acid residues into γ-carboxyglutamic acid, through a carboxylation process, makings both MGP (cMGP) and BGP (cBGP) biologically active. cMGP inhibits vascular calcifications (VC), while cBGP has an important role for a proper mineralization process. Uncarboxylated MGP and BGP (ucMGP and ucBGP) concentrations are indirect markers of vitamin K2 deficiency. The purpose of this review is to analyze the current literature to understand the relationship between vitamin K2 status, fragility fractures and VC in CKD patients. This analysis could be of help in planning investigations of Vitamin K status and its possible supplementation in CKD patients to avert fragility fractures and VC.

Impact of sacubitril/valsartan on implantable defibrillator eligibility in heart failure: a real-world experience.

OBJECTIVE: Current guidelines recommend an implantable cardiac defibrillator (ICD) in patients with symptomatic heart failure and reduced ejection fraction (HFrEF; left ventricular ejection fraction [LVEF] ≤35%) despite ≥3 months of optimal medical therapy. Recent observations demonstrated that sacubitril/valsartan induces beneficial reverse cardiac remodeling in eligible HFrEF patients. Given the pivotal role of LVEF in the selection of ICD candidates, we sought to assess the impact of sacubitril/valsartan on ICD eligibility and its predictors in HFrEF patients. PATIENTS AND METHODS: We retrospectively evaluated 48 chronic HFrEF patients receiving sacubitril/valsartan and previously implanted with an ICD in primary prevention. We assumed that ICD was no longer necessary if LVEF improved >35% (or >30% if asymptomatics) at follow-up. RESULTS: Over a median follow-up of 11 months, sacubitril/valsartan induced a significant drop in LV end-systolic volume (-16.7 ml/m2, p=0.023) and diameter (-6.8 mm, p=0.022), resulting in a significant increase in LVEF (+3.9%, p<0.001). As a consequence, 40% of previously implanted patients resulted no more eligible for ICD at follow-up. NYHA class improved in 50% of the population. A dose-dependent effect was noted, with higher doses associated to more reverse remodeling. Among patients deemed no more eligible for ICD, lower NYHA class (odds ratio (OR) 3.73 [95% CI 1.05; 13.24], p=0.041), better LVEF (OR 1.23 [95% CI 1.01; 1.48], p=0.032) and the treatment with the intermediate or high dose of sacubitril/valsartan (OR 5.60 [1.15; 27.1], p=0.032) were the most important predictors of status change. CONCLUSIONS: In symptomatic HFrEF patients, sacubitril/valsartan induced beneficial cardiac reverse remodeling and improved NYHA class. These effects resulted in a significant reduction of patients deemed eligible for ICD in primary prevention.

An enigmatic case of cardiac death in an 18-years old girl.

We report a case of unusual and unexplained cardiac death in an 18-years old female patient with congenital neurosensorial deafness. The fatal event was characterized by an initial syncopal episode, associated with a wide QRS tachycardia (around 110 bpm) but stable hemodynamic conditions. The patient, however, subsequently developed severe hypotension and progressive bradyarrhythmias until asystole and lack of cardiac response to resuscitation maneuvers and ventricular pacing.

Oxidative stress-related proteins in a Conn's adenoma tissue. Relevance for aldosterone's prooxidative and proinflammatory activity.

BACKGROUND AND AIM: Angiotensin II (Ang II) induces oxidative stress (OxSt), which is essential for cardiovascular remodeling. Aldosterone also induces fibrosis and remodeling through direct effect on non-classical mineralocorticoid (MR) target tissues. However, studies on the role of aldosterone on OxSt and related factors in humans are lacking. MATERIALS AND METHODS: We assessed gene and protein expression of p22phox (RT-PCR and Western blot), NAD(P)H oxidase subunit essential for superoxide production and gene expression of transforming growth fator (TGF) beta, plasminogen activator inhibitor (PAI)-1, and heme oxygenase (HO)-1, effectors of OxSt (RT-PCR), in a Conn's adenoma, removed from a patient with primary hyperaldosteronism. Ang II type 1 (AT1R) and MR receptors expression were also evaluated (RT-PCR). The normal adrenal tissue adjacent to the adenoma was used as control. RESULTS: p22phox gene and protein expression were higher (31% and 53%, respectively) in the adrenal adenoma. TGFbeta, PAI-1, and HO-1 gene expression were also higher (25%, 129%, and 25%, respectively) in the adrenal adenoma while AT1R gene expression was similar (8%). The expression of MR in the adenoma was documented. CONCLUSIONS: This report demonstrates in a human model that the increased aldosterone production has effects on enzyme systems related to OxSt, enhancing the systemic fibrogenic effects of aldosterone excess through TGFbeta and PAI-1 expression which was previously demonstrated only indirectly in vitro and in animal models. The presence of MR expression in the adenoma may link the hormone with the adenoma growth. Therefore, the results of this study derived from a single case might represent an important working hypothesis for further research in a larger number of cases to clarify the role of aldosterone overproduction on OxSt and its clinical relevance.

Mephedrone and chemsex: a case report.

The chemsex or slamsex phenomenon has attracted attention worldwide, with concerns also expressed by health professionals for the spread of sexually transmitted diseases. Mephedrone or 4-methylmethcathinone, a substituted cathinone homolog of ephedrine, is one of the most popular substances used as a cheaper alternative to other traditional drugs. Fatal cases of chemsex are still rare. We present here the first case-report to the best of our knowledge of a mephedrone-related acute toxicity case in Parma (Italy) detected and quantitated in biological specimens (2.0 mg/L in urine sample, 1.1 mg/L in bile and 1.0 mg/L in central blood while 0.8 mg/L in peripheral blood). None of the other most common drugs of abuse could be detected. Autopsy findings such as facies edematosa, oedema and polyvisceral congestion, interstitial petechiae are compatible elements with a death from acute cardio-respiratory failure, with peri-mortem agony of few minutes in which the cardiac hypertrophy, the moderate aortocoronary sclerosis and mephedrone injection have played a substantial role in the evaluation of the final cause due to an accidental acute intoxication with mephedrone.

Gynaecological and obstetrical problems in women with different bleeding disorders.

The aim of this case-control study was to analyse the prevalence of gynaecological, obstetrical and other more general bleeding symptoms in 114 women affected by various inherited bleeding disorders, who were compared with 114 apparently healthy women. Retrospective information were collected by means of two specific questionnaires, one on gynaecological and obstetrical bleeding symptoms, with special focus on the presence of menorrhagia as defined by a pictorial blood loss assessment chart (PBAC); and the other on general bleeding symptoms, whose severity was graded by means of the bleeding score (BS). Compared to normal women, the whole group of women with inherited bleeding disorders had a higher prevalence of excessive bleeding at menarche (25% vs. 5%, P < 0.0001) and menorrhagia (59% vs. 46%, P = 0.06). Affected women also had a higher frequency than controls of general bleeding symptoms that scored as severe by a BS > or = 12 (49% vs. 0%, P < 0.0001). In affected women, the BS increased according to the severity of the haemostasis defect. In conclusions, the BS and the PBAC are simple tools to evaluate the severity of general bleeding symptoms and menorrhagia in women with inherited bleeding disorders. These instruments may help to identify those women for whom a therapeutic intervention is warranted.

Revisiting essential hypertension--a "mechanism-based" approach may argue for a better definition of hypertension.

Several major overarching themes have recently emerged in our understanding of the pathophysiology of hypertension which may allow to revisit essential hypertension with an eye towards the possibility of adopting a more rational "mechanistic-based" definition of hypertension and moving away from the unsatisfactory "essential" label for hypertension from unknown cause. As our understanding of the biochemical and physiological mechanisms that control blood pressure rapidly evolves, the "essential" label of hypertension is losing both value as well as utility as it will describe an increasingly small number of hypertensive patients. This paper uses some recently identified pathways central to hypertension and uses this understanding of pathophysiology to argue for a better definition of hypertension.

Effect of canrenone and amiloride on the prooxidative effect induced by aldosterone in human mononuclear leukocytes in vitro.

Clinical studies have demonstrated that aldosterone receptor antagonists do improve the survival of patients with chronic heart diseases and in vitro studies have shown that canrenone blocks the proinflammatory effect of aldosterone in mononucler leukocytes (MNL). The aim of the study was to compare, in the model of human MNL, the effect of potassium-sparing diuretics amiloride and canrenone, on the protein expression of p22phox, a NADPH-oxidase system subunit, that is a principal marker of production of superoxide anions. MNL were isolated from 10 informed healthy volunteers (5 males and 5 females, age range 24-36 yr) and the proteins extracted. p22phox protein expression was evaluated by Western blot and quantified using a densitometric semiquantitative analysis. The experiments showed that aldosterone (10(-8) M) enhances the protein expression of p22phox and that its effect is reversed by co-incubation with canrenone (10(-6) M), while incubation with amiloride (10(-6) M) reduced the prooxidative effect of aldosterone at a significantly lower extent than canrenone. Co-incubation with canrenone, amiloride, and aldosterone together produced the same effect as aldosterone plus canrenone. Incubation with cortisol (40(-8) M) was not effective. These data confirm the prooxidative effect of aldosterone in MNL. The addition of aldosterone-receptor antagonist canrenone produced a higher inhibition than sodium channel blocker amiloride on the effect of aldosterone on p22phox protein expression.

High angiotensin II state without cardiac remodeling (Bartter's and Gitelman's syndromes): are angiotensin II type 2 receptors involved?

BACKGROUND/AIMS: While Angiotensin II (Ang II) is a major factor in the development of cardiomyocyte hypertrophy and a pivotal role for Ang II signals via ERK1/2 has been identified, mechanism(s) responsible are still unclear. As Bartter's and Gitelman's syndrome patients (BS/GS) have increased Ang II, and yet normo/hypotension, hyporesponsiveness to pressors and blunted Ang II signaling via type 1 receptors (AT1R), this study assesses BS/GS's left ventricular (LV) mass and structure as well as Ang II induced ERK1/2 phosphorylation compared with essential hypertensive patients (EH) and normotensive healthy subjects (C) to gain insight into Ang II mediated processes. METHODS: Indices of cardiac hypertrophy were determined by M-mode, two-dimensional echo Doppler and ERK phosphorylation by Western blot. RESULTS: None of BS/GS exhibited LV remodelling; LV mass, LV end-diastolic volume and mass/volume ratio were unchanged vs C (60+/-14 g/m2 vs 64+/-12, 64+/-12 ml/m2 vs 60+/-8 and 0.95+/-0.2 vs 1.0+/-0.2, respectively) and reduced vs EH (119+/-15, p<0.001, 78+/-9, p<0.05 and 1.52+/-0.15, p<0.01). Despite BS/GS's higher plasma renin activity and aldosterone and unchanged level of AT1R, Ang II induced ERK1/2 phosphorylation was reduced vs both C and EH: 0.64 d.u.+/-0.08 vs 0.90+/-0.06 in C, p<0.006, and vs 1.45+/-0.07 in EH, p<0.001. CONCLUSION: The data point to a direct cardioremodeling role for Ang II and support a role of Ang II type 2 receptor (AT2R) signaling as involved in the lack of cardiovascular remodeling in BS/GS. However, further studies using more direct approaches to demonstrate the effects of AT2R signaling must be pursued.

Myocardial perfusion defects in Bartter and Gitelman syndromes.

BACKGROUND: Normotensive hypokalaemic tubulopathies (Bartter and Gitelman syndromes (BS/GS)) are genetic diseases that are considered benign. However, QT prolongation, left ventricular dysfunction and reduction of cardiac index upon exercise leading to arrhythmias and sudden cardiac death have been reported in these patients. Hence, we aimed to verifying whether an isometric exercise could represent a useful tool for the identification of patients at risk for future cardiac events. PATIENTS AND METHODS: Myocardial function (MF) and perfusion, evaluated as myocardial blood flow (MBF) of 10 BS/GS patients and 10 healthy controls, were investigated at rest and during isometric exercise. MF and MBF were evaluated using quantitative two-dimensional and myocardial contrast echocardiography. RESULTS: BS/GS patients had normal baseline MF and MBF. During exercise in BS/GS patients, corrected QT (QTc) was prolonged to peak value of 494 +/- 9.1 ms (P < 0.001). In controls, MF increased from resting to peak exercise (left ventricular ejection fraction: 65 +/- 4% to 78 +/- 5%, P < 0.003) while in seven BS/GS patients (Group 1) it declined (64 +/- 5% to 43 +/- 9%, P < 0.001). Myocardial perfusion increased upon exercise in controls as shown by changes of its markers: beta (a measure of myocardial flow velocity; 0.89 +/- 0.12 vs. 0.99 +/- 0.12, P < 0.001) and myocardial blood volume (14.4 +/- 2 vs. 20.2 +/- 0.25, P < 0.001), while in Group 1 BS/GS it decreased (0.87 +/- 0.15 vs. 0.67 +/- 0.15, P < 0.001; and 14.5 +/- 1.9 vs. 8.3 +/- 0.22, P < 0.001, respectively). CONCLUSIONS: Our results document for the first time that exercise induce coronary microvascular and myocardial defects in BS/GS patients. Therefore, this may challenge the idea that BS/GS are benign diseases. In addition, the diagnostic approach to these syndromes should include an in-depth cardiac assessment in order to identify patients at higher risk.