Screening of hypercortisolism among patients with hypertension: an Italian nationwide survey.

PURPOSE: Screening of Cushing Syndrome (CS) and Mild Autonomous Cortisol Secretion (MACS) in hypertensive patients is crucial for proper treatment. The aim of the study was to investigate screening and management of hypercortisolism among patients with hypertension in Italy. METHODS: A 10 item-questionnaire was delivered to referral centres of European and Italian Society of Hypertension (ESH and SIIA) in a nationwide survey. Data were analyzed according to type of centre (excellence vs non-excellence), geographical area, and medical specialty. RESULTS: Within 14 Italian regions, 82 centres (30% excellence, 78.790 patients during the last year, average 600 patients/year) participated to the survey. Internal medicine (44%) and cardiology (31%) were the most prevalent medical specialty. CS and MACS were diagnosed in 313 and 490 patients during the previous 5 years. The highest number of diagnoses was reported by internal medicine and excellence centres. Screening for hypercortisolism was reported by 77% in the presence of specific features of CS, 61% in resistant hypertension, and 38% in patients with adrenal mass. Among screening tests, the 24 h urinary free cortisol was the most used (66%), followed by morning cortisol and ACTH (54%), 1 mg-dexamethasone suppression test (49%), adrenal CT or MRI scans (12%), and late night salivary cortisol (11%). Awareness of referral centres with expertise in management of CS was reported by 67% of the participants, which reduced to 44% among non-excellence centres. CONCLUSIONS: Current screening of hypercortisolism among hypertensive patients is unsatisfactory. Strategies tailored to different medical specialties and type of centres should be conceived.

Public health and clinical approach to proactive management of frailty in multidimensional arena.

Background: Demographic changes have forced communities and people themselves to reshape ageing concepts and approaches and try to develop actions towards active and healthy ageing. In this context, the European Commission launched different private-public partnerships to develop new solutions and answers on questions related to this topic. The European Innovation Partnership on Active and Healthy Ageing, including topic related action groups as well reference sites committed towards a common action to facilitate active and healthy ageing, has contributed key elements for interventions, scaled up best practices and evaluated impact of their action to drive innovation across many regions in Europe over the past years. Methods: This paper describes action taken by A3 action group in the European Innovation Partnership on Active and Healthy Ageing. This paper gives an overview of how the partnership combined the view on frailty coming from public health as well as the clinical management. Results: Within different European regions, to tackle frailty, EIPonAHA partners have conceptualized functional decline and frailty, making use of good practice models working well on community programs. The A3 Group of EIPonAHA has worked alongside a process of innovation, targeting all ageing citizens with the clear goal of involving communities in the preventive approach. Conclusion: Engagement needs of older people with a focus on functionally rather than disease management as primary objective is considered as an overarching concept, also embracing adherence, compliance, empowerment, health literacy, shared decision-making, and activation. Furthermore, training of staff working with ageing people across all sectors needs to be implemented and evaluated in future studies.

Opposite effects of ß2-adrenoceptor gene deletion on insulin signaling in liver and skeletal muscle.

BACKGROUND AND AIM: ß2-Adrenoceptors (ß2-ARs) are G protein-coupled receptors (GPCRs) expressed in the major insulin target tissues. The interplay between ß2-AR and insulin pathways is involved in the maintenance of glucose homeostasis. The aim of this study was to explore the consequences of ß2-ARs deletion on insulin sensitivity and insulin signaling cascade in metabolically active tissues. METHODS AND RESULTS: We evaluated glucose homeostasis in skeletal muscle and liver of ß2-AR-null mice (ß2-AR-/-) by performing in vivo (glucose tolerance test and insulin tolerance test) and ex vivo (glucose uptake and glycogen determination) experiments. ß2-AR gene deletion is associated with hepatic insulin resistance and preserved skeletal muscle insulin sensitivity. Importantly, we demonstrate that hepatic ß2-AR regulates insulin-induced AKT activation via Grb2-mediated SRC recruitment through a Gi-independent mechanism. CONCLUSIONS: ß-AR stimulation contributes to the development of early stages of insulin resistance progression in the liver. Our findings indicate that the cross-talk between ß2-AR and insulin signaling represents a fundamental target towards the development of novel therapeutic approaches to treat type 2 diabetes and metabolic syndrome.

A generalized multi-resolution expansion for uncertainty propagation with application to cardiovascular modeling.

Computational models are used in a variety of fields to improve our understanding of complex physical phenomena. Recently, the realism of model predictions has been greatly enhanced by transitioning from deterministic to stochastic frameworks, where the effects of the intrinsic variability in parameters, loads, constitutive properties, model geometry and other quantities can be more naturally included. A general stochastic system may be characterized by a large number of arbitrarily distributed and correlated random inputs, and a limited support response with sharp gradients or event discontinuities. This motivates continued research into novel adaptive algorithms for uncertainty propagation, particularly those handling high dimensional, arbitrarily distributed random inputs and non-smooth stochastic responses. In this work, we generalize a previously proposed multi-resolution approach to uncertainty propagation to develop a method that improves computational efficiency, can handle arbitrarily distributed random inputs and non-smooth stochastic responses, and naturally facilitates adaptivity, i.e., the expansion coefficients encode information on solution refinement. Our approach relies on partitioning the stochastic space into elements that are subdivided along a single dimension, or, in other words, progressive refinements exhibiting a binary tree representation. We also show how these binary refinements are particularly effective in avoiding the exponential increase in the multi-resolution basis cardinality and significantly reduce the regression complexity for moderate to high dimensional random inputs. The performance of the approach is demonstrated through previously proposed uncertainty propagation benchmarks and stochastic multi-scale finite element simulations in cardiovascular flow.

New small molecules, ISA27 and SM13, inhibit tumour growth inducing mitochondrial effects of p53.

BACKGROUND: p53 is a transcription factor with tumour suppressor properties, which is able to induce mitochondrial apoptosis independently of its transcriptional activity. We recently synthesised two new compounds (ISA27 and SM13), which block p53-MDM2 interaction and induce apoptosis in p53 wild-type (WT) tumour cells. The aim of this study was to verify the effectiveness of these compounds in tumours carrying a mutated form of p53 gene with no transcriptional activity. METHODS: In vitro we evaluated the effectiveness of our compounds in cancer cell lines carrying WT, mutated and null p53 gene. In vivo study was performed in Balb/c nude mice and the mitochondrial-dependent apoptotic signalling was evaluated by western blot. RESULTS: Both ISA27 and SM13 reduced cell proliferation and induced apoptosis in vitro in cells carrying either p53 WT or mutated gene, suggesting that its effect is independent from p53 transcriptional activity. On the contrary, SM13 had no effect in a p53 null cell line. In vivo, ISA27 and SM13 induced cancer cell death in a dose-dependent manner through the activation of the mitochondrial-dependent death signalling in p53-mutated cells. In vivo, SM13 reduced tumour growth. CONCLUSIONS: Our study proposes SM13 as anticancer compound to use for the treatment of p53-dependent tumours, even in the absence of p53 transcriptional activity.

Overexpression of VEGFα as a biomarker of endothelial dysfunction in aortic tissue of α-GAL-Tg/KO mice and its upregulation in the serum of patients with Fabry's disease.

Introduction: Fabry's disease is an X-linked lysosomal storage disorder caused by reduced activity of α-galactosidase A (GAL), leading to premature death on account of renal, cardiac, and vascular organ failure. Accumulation of the GAL substrate globotriaosylceramide (Gb3) in endothelial and smooth muscle cells is associated with early vascular cell damage, suggesting endothelial dysfunction as a driver of cardiorenal organ failure. Here, we studied the vascular expression of the key angiogenic factors, VEGFα and its antagonist angiostatin, in Fabry α-GAL-Tg/KO mice and determined circulating VEGFα and angiostatin serum levels in patients with Fabry's disease and healthy controls. Methods: Cryopreserved aortic vessels from six α-GAL-Tg/KO and six wild-type (WT) mice were obtained and VEGFα and angiostatin levels were determined by performing Western blot analysis. VEGFα expression was visualized by an immunohistochemical staining of paraffin aortic rings. In addition, VEGFα and angiostatin serum levels were measured by using an enzyme-linked immunosorbent assay in 48 patients with genetically verified Fabry's disease (50% male) and 22 healthy controls and correlated with disease severity markers such as lyso-Gb3, albuminuria, NTproBNP, high-sensitive troponin T (hsTNT), and myocardial wall thickness. Results: It was found that there was a significant increase in VEGFα protein expression (1.66 ± 0.35 vs. 0.62 ± 0.16, p = 0.0009) and a decrease in angiostatin expression (0.024 ± 0.007 vs. 0.053 ± 0.02, p = 0.038) in aortic lysates from α-GAL-Tg/KO compared with that from WT mice. Immunohistochemical staining revealed an adventitial VEGFα signal in α-GAL-Tg/KO mice, whereas no VEGFα signal could be detected in WT mice aortas. No differences in aortic angiostatin expression between α-GAL-Tg/KO- and WT mice could be visualized. The serum levels of VEGFα were significantly upregulated in patients with Fabry's disease compared with that in healthy controls (708.5 ± 426.3 vs. 458.5 ± 181.5 pg/ml, p = 0.048) and positively associated with albuminuria (r = 0.82, p < 0.0001) and elevated NTproBNP (r = 0.87, p < 0.0001) and hsTNT values (r = 0.41, p = 0.048) in male patients with Fabry's disease. For angiostatin, no significant difference was found between patients with Fabry's disease and healthy controls (747.6 ± 390.3 vs. 858.8 ± 599.3 pg/ml). Discussion: In conclusion, an overexpression of VEGFα and downregulation of its counter player angiostatin in aortic tissue of α-GAL-Tg/KO mice support the hypothesis of an underlying vasculopathy in Fabry's disease. Elevated VEGFα serum levels were also observed in patients with Fabry's disease and were positively associated with elevated markers of organ manifestation in males. These findings suggest that angiogenetic markers, such as VEGFα, may be potentially useful biomarkers for the detection of endothelial dysfunction in classical Fabry's disease.

Experimental validation of an innovative approach in biokinetics study for personalised dosimetry of molecular radiation therapy treatments.

One of today's main challenges in molecular radiation therapy is to assess an individual dosimetry that allows treatment to be tailored to the specific patient, in accordance with the current paradigm of 'personalized medicine'. The evaluation of the absorbed doses for tumor and organs at risk in molecular radiotherapy is typically based on MIRD schema acquiring few experimental points for the assessement of biokinetic parameters. WIDMApp, the wearable individual dose monitoring apparatus, is an innovative approach for internal dosimetry based on a wearable radiation detecting system for individual biokinetics sampling, a Monte Carlo simulation for particle interaction, and an unfolding algorithm for data analysis and integrated activity determination at organ level. A prototype of a WIDMApp detector element was used to record the photon emissions in a body phantom containing 3 spheres with liquid sources (18F,64Cu and99mTc) to simulate organs having different washout. Modelling the phantom geometry on the basis of a CT scan imaging, the Monte Carlo simulation computed the contribution of each emitting sphere to the signal detected in 3 positions on the phantoms surface. Combining the simulated results with the data acquired for 120 h, the unfolding algorithm deconvolved the detected signal and assessed the decay half-life (T1/2) and initial activity values (A(0)) that best reproduces the observed exponential decays. A 3%-18% level of agreement is found between the actualA(0) andT1/2values and those obtained by means of the minimization procedure based on the Monte Carlo simulation. That resulted in an estimation of the cumulated activity <15%. Moreover, WIDMApp data redundancy has been used to mitigate some experimental occurrences that happened during data taking. A first experimental test of the WIDMApp approach to internal radiation dosimetry is presented. Studies with patients are foreseen to validate the technique in a real environment.

Effects of tissue factor induced by oxygen free radicals on coronary flow during reperfusion.

Tissue factor is a transmembrane protein that activates the extrinsic coagulation pathway by binding factor VII. Endothelial cells, being in contact with circulating blood, do not normally express tissue factor. Here we provide evidence that oxygen free radicals induce tissue factor messenger RNA transcription and expression of tissue factor procoagulant activity in endothelial cells in culture. Isolated, perfused rabbit hearts exposed to exogenous oxygen free radicals also showed a marked increase in tissue factor activity within the coronary circulation. Furthermore, in ex vivo and in vivo hearts subjected to ischemia and reperfusion, a condition associated with a production of oxygen free radicals in large amounts, a marked increase in tissue factor activity occurred. This phenomenon could be abolished by oxygen radical scavengers. This increase in tissue factor activity during postischemic reperfusion was accompanied by a significant decrease in coronary flow, suggesting that increase in tissue factor activity with the consequent activation of the coagulation cascade might impair coronary flow during reperfusion and possibly contribute to the occurrence of reperfusion injury.

From the bench to practice - Field integration of community-based services for older citizens with different levels of functional limitation across European Regions.

The meeting of the European Innovation Partnership on Active and Healthy Ageing (EIPonAHA) action group A3 together with members of the Reference site collaborative network (RSCN) in December 2019 in Rome focused on integration of evidence-based approaches on health and care delivery for older citizens at different levels of needs with expertise coming from stakeholder across Europe. It was the final aim of the group to co-create culturally sensitive pathways and facilitate co-ownership for further implementation of the pathways in different care systems across Europe. The study design is a mixed method approach. Based on data analysis from a cohort of community-dwelling over-65 citizens in the framework of a longitudinal observational study in Rome, which included health, social and functional capacity data, three personas profiles were developed: the pre-frail, the frail and the very frail personas. Based on these data, experts were asked to co-create care pathways due to evidence and eminence during a workshop and included into a final report. All working groups agreed on a common understanding that integration of care means person-centered integration of health and social care, longitudinally provided across primary and secondary health care including citizens' individual social, economic and human resources. Elements for consideration during care for pre-frail people are loneliness and social isolation, which, lead to limitation of physical autonomy in the light of reduced access to social support. Frail people need adaption of environmental structures and, again, social resource allocation to maintain at home. Very frail are generally vulnerable patients with complex needs. Most of them remain at home because of a strong individual social support and integrated health care delivery. The approach described in this publication may represent a first approach to scaling-up care delivery in a person-centered approach.

Hyperuricemia and Risk of Cardiovascular Outcomes: The Experience of the URRAH (Uric Acid Right for Heart Health) Project.

The latest European Guidelines of Arterial Hypertension have officially introduced uric acid evaluation among the cardiovascular risk factors that should be evaluated in order to stratify patient's risk. In fact, it has been extensively evaluated and demonstrated to be an independent predictor not only of all-cause and cardiovascular mortality, but also of myocardial infraction, stroke and heart failure. Despite the large number of studies on this topic, an important open question that still need to be answered is the identification of a cardiovascular uric acid cut-off value. The actual hyperuricemia cut-off (> 6 mg/dL in women and 7 mg/dL in men) is principally based on the saturation point of uric acid but previous evidence suggests that the negative impact of cardiovascular system could occur also at lower levels. In this context, the Working Group on uric acid and CV risk of the Italian Society of Hypertension has designed the Uric acid Right for heArt Health project. The primary objective of this project is to define the level of uricemia above which the independent risk of CV disease may increase in a significantly manner. In this review we will summarize the first results obtained and describe the further planned analysis.

Overproduction of phosphoprotein enriched in diabetes (PED) induces mesangial expansion and upregulates protein kinase C-beta activity and TGF-beta1 expression.

AIMS/HYPOTHESIS: Overproduction of phosphoprotein enriched in diabetes (PED, also known as phosphoprotein enriched in astrocytes-15 [PEA-15]) is a common feature of type 2 diabetes and impairs insulin action in cultured cells and in mice. Nevertheless, the potential role of PED in diabetic complications is still unknown. METHODS: We studied the effect of PED overproduction and depletion on kidney function in animal and cellular models. RESULTS: Transgenic mice overexpressing PED (PEDTg) featured age-dependent increases of plasma creatinine levels and urinary volume, accompanied by expansion of the mesangial area, compared with wild-type littermates. Serum and kidney levels of TGF-beta1 were also higher in 6- and 9-month-old PEDTg. Overexpression of PED in human kidney 2 cells significantly increased TGF-beta1 levels, SMAD family members (SMAD)2/3 phosphorylation and fibronectin production. Opposite results were obtained following genetic silencing of PED in human kidney 2 cells by antisense oligonucleotides. Inhibition of phospholipase D and protein kinase C-beta by 2-butanol and LY373196 respectively reduced TGF-beta1, SMAD2/3 phosphorylation and fibronectin production. Moreover, inhibition of TGF-beta1 receptor activity and SMAD2/3 production by SB431542 and antisense oligonucleotides respectively reduced fibronectin secretion by about 50%. TGF-beta1 circulating levels were significantly reduced in Ped knockout mice and positively correlated with PED content in peripheral blood leucocytes of type 2 diabetic patients. CONCLUSIONS/INTERPRETATION: These data indicate that PED regulates fibronectin production via phospholipase D/protein kinase C-beta and TGF-beta1/SMAD pathways in kidney cells. Raised PED levels may therefore contribute to the abnormal accumulation of extracellular matrix and renal dysfunction in diabetes.

Targeting the receptor-Gq interface to inhibit in vivo pressure overload myocardial hypertrophy.

Hormones and neurotransmitters may mediate common responses through receptors that couple to the same class of heterotrimeric guanine nucleotide-binding (G) protein. For example, several receptors that couple to Gq class proteins can induce cardiomyocyte hypertrophy. Class-specific inhibition of Gq-mediated signaling was produced in the hearts of transgenic mice by targeted expression of a carboxyl-terminal peptide of the alpha subunit Galphaq. When pressure overload was surgically induced, the transgenic mice developed significantly less ventricular hypertrophy than control animals. The data demonstrate the role of myocardial Gq in the initiation of myocardial hypertrophy and indicate a possible strategy for preventing pathophysiological signaling by simultaneously blocking multiple receptors coupled to Gq.

Public Prevention Plans to Manage Climate Change and Respiratory Allergic Diseases. Innovative Models Used in Campania Region (Italy): The Twinning Aria Implementation and the Allergy Safe Tree Decalogue.

In recent years, climate change has been influenced by air pollution, and this destructive combination has justifiably sounded an alarm for nations and many institutional bodies worldwide. Official reports state that the emission of greenhouse gases produced by human activity are growing, and consequently also the average temperature. The World Health Organization (WHO) believes that health effects expected in the future due to climate change will be dramatic, and has invited international groups to investigate potential remedies. A task force has been established by the Italian Society of Allergology, Asthma and Clinical Immunology (SIAAIC), with the aim to actively work on correlation between pollution and climate change. The Task Force provided prevention tools to suggest city leaders how to improve the health conditions of allergic people in public urban parks. The "Allergy Safe Tree Decalogue" suggests the preparation and maintenance of public low allergy-impact greenery. Through the Twinning ARIA project, the Division for the Promotion and Enhancement of Health Innovation Programs of Campania Region (Italy), sought to promote the implementation of the project in the regional Health System. The main objective will be to investigate the current use and usefulness of mobile phone Apps in the management of allergic respiratory disease, through Mobile Airways Sentinel networK (MASK), the Phase 3 of the ARIA initiative, based on the freely available MASK App (the Allergy Diary, Android and iOS platforms). The effects of these prevention activities will be registered and compared with monitoring efforts thanks to the Aerobiology Units, located throughout the Campania area. A joint effort between researchers and public administrations for the implementation of prevention plans coherently with the two models proposed in a specific area, i.e. the Decalogue for public administrations and the MASK Allergy Diary app for individual patients suffering from allergy, will be implemented as a pilot.

An Approach to Prevent Frailty in Community Dwelling Older Adults: a pilot study performed in Campania region in the framework of the PERSSILAA project.

We developed and tested an innovative physical training method in older adults that embeds the gym program into everyday life in the most conservative way possible. Physical training was included in the activities of local parishes where older women from Southern Italy spend most of their free time and was delivered by trained physical therapists with the support of an ICT tool known as CoCo. 113 older women (aged 72.0 [69.0-75.0] years) noncompliant to conventional exercise programs participated to the study. 57 of them underwent the final anthropometric assessment and 50 the final physical tests. In study completers handgrip strength and physical performance evaluated with the chair-stand, the two minutes step and the chair-sit and -reach tests significantly improved. Quality of life as evaluated with the EuroQol-5dimension (EQ-5D) questionnaire improved as well. In conclusion, a training program designed to minimally impact on life habits of older people is effective in improving fitness in patients noncompliant to other to physical exercise programs.

Innovative Approaches to Active and Healthy Ageing: Campania Experience to Improve the Adoption of Innovative Good Practices.

The demographic projections on the European population predict that people aged over 60 will increase by about two million/year in the next decades. Since 2012, the Campania Reference Site of the European Innovation Partnership on Active and Healthy Ageing supports the innovation of the Regional Health System, to face up demographic changes and sustainability. Campania Reference Site provides the opportunity to connect loco-regional stakeholders in social and health care services (universities, healthcare providers, social services, local communities and municipalities), with international organizations, in order to adopt and scale up innovative solutions and approaches. This paper describes the building process of Campania Reference Site and the main results achieved, that have been allowing it to become a hub for open innovation in the field of active and healthy aging at regional, national and international level.

Endothelial alpha1-adrenoceptors regulate neo-angiogenesis.

BACKGROUND AND PURPOSE: Intact endothelium plays a pivotal role in post-ischaemic angiogenesis. It is a phenomenon finely tuned by activation and inhibition of several endothelial receptors. The presence of alpha(1)-adrenoceptors on the endothelium suggests that these receptors may participate in regenerative phenomena by regulating the responses of endothelial cells involved in neo-angiogenesis. EXPERIMENTAL APPROACH: We evaluated the expression of the subtypes of the alpha(1)-adrenoceptor in isolated endothelial cells harvested from Wistar-Kyoto (WKY) rats. We explored the possibility these alpha(1)-adrenoceptors may influence the pro-angiogenic phenotype of endothelial cells in vitro. In vivo, we used a model of hindlimb ischaemia in WKY rats, to assess the effects of alpha(1) adrenoceptor agonist or antagonist on angiogenesis in the ischaemic hindlimb by laser Doppler blood flow measurements, digital angiographies, hindlimb perfusion with dyed beads and histological evaluation. KEY RESULTS: In vitro, pharmacological antagonism of alpha(1)-adrenoceptors in endothelial cells from WKY rats by doxazosin enhanced, while stimulation of these adrenoceptors with phenylephrine, inhibited endothelial cell proliferation and DNA synthesis, ERK and retinoblastoma protein (Rb) phosphorylation, cell migration and tubule formation. In vivo, we found increased alpha(1)-adrenoceptor density in the ischaemic hindlimb, compared to non-ischaemic hindlimb, suggesting an enhanced alpha(1)-adrenoceptor tone in the ischaemic tissue. Treatment with doxazosin (0.06 mg kg(-1) day(-1) for 14 days) did not alter systemic blood pressure but enhanced neo-angiogenesis in the ischaemic hindlimb, as measured by all our assays. CONCLUSIONS: Our findings support the hypothesis that the alpha(1)-adrenoceptors in endothelial cells provide a negative regulation of angiogenesis.

Abnormal sympathetic overactivity evoked by insulin in the skeletal muscle of patients with essential hypertension.

The reason why hyperinsulinemia is associated with essential hypertension is not known. To test the hypothesis of a pathophysiologic link mediated by the sympathetic nervous system, we measured the changes in forearm norepinephrine release, by using the forearm perfusion technique in conjunction with the infusion of tritiated NE, in patients with essential hypertension and in normal subjects receiving insulin intravenously (1 mU/kg per min) while maintaining euglycemia. Hyperinsulinemia (50-60 microU/ml in the deep forearm vein) evoked a significant increase in forearm NE release in both groups of subjects. However, the response of hypertensives was threefold greater compared to that of normotensives (2.28 +/- 45 ng.liter-1.min-1 in hypertensives and 0.80 +/- 0.27 ng.liter-1 in normals; P less than 0.01). Forearm glucose uptake rose to 5.1 +/- .7 mg.liter-1.min-1 in response to insulin in hypertensives and to 7.9 +/- 1.3 mg.liter-1.min-1 in normotensives (P less than 0.05). To clarify whether insulin action was due to a direct effect on muscle NE metabolism, in another set of experiments insulin was infused locally into the brachial artery to expose only the forearm tissues to the same insulin levels as in the systemic studies. During local hyperinsulinemia, forearm NE release remained virtually unchanged both in hypertensive and in normal subjects. Furthermore, forearm glucose disposal was activated to a similar extent in both groups (5.0 +/- 0.6 and 5.2 +/- 1.1 mg.liter-1.min-1 in hypertensives and in normals, respectively). These data demonstrate that: (a) insulin evokes an abnormal muscle sympathetic overactivity in essential hypertension which is mediated by mechanisms involving the central nervous system; and (b) insulin resistance associated with hypertension is demonstrable in the skeletal muscle tissue only with systemic insulin administration which produces muscle sympathetic overactivity. The data fit the hypothesis that the sympathetic system mediates the pathophysiologic link between hyperinsulinemia and essential hypertension.

Insulin modulation of an endothelial nitric oxide component present in the alpha2- and beta-adrenergic responses in human forearm.

We explored in 51 normal subjects, distributed in various series of experiments, whether endothelium nitric oxide may play a role in insulin modulation of alpha2- and beta-adrenergic- evoked vascular responses. In particular, we examined the forearm blood flow response (FBF, ml.min-1.dl-1) to intrabrachial infusion of BHT-933 (0.5, 1, and 2 microg.min-1.dl-1) or isoproterenol (1, 3, and 6 ng. min-1.dl-1) in control conditions, during intrabrachial infusion of insulin alone (0.05 mU.kg-1.min-1) and associated with l-N-monomethylarginine (L-NMMA) (0.05 microg.min-1.dl-1), a nitric oxide synthase inhibitor. In control conditions both BHT-933 and isoproterenol induced a dose-dependent vascular response. Local hyperinsulinemia (deep venous plasma insulin 68.5+/-4 microU/ml) did not change basal FBF whereas attenuated BHT-933 vasoconstriction and enhanced isoproterenol vasodilation. L-NMMA reduced basal FBF and abolished the insulin effect on BHT-933 and isoproterenol response. To clarify whether a nitric oxide component is included in alpha2- and beta-adrenergic response and may be responsible for insulin vascular effect, we further examined BHT-933 and isoproterenol responses during nitric oxide inhibition. Interestingly, L-NMMA potentiated the BHT-933 vasoconstriction and attenuated the isoproterenol vasodilation and, in these conditions, insulin was no more able to exhibit its vascular effects. Finally, to rule out the possibility that the conteracting effect of L-NMMA may not be specifically related to insulin action, dose-response curves to phenylephrine (0.5, 1, and 2 microg.min-1.dl-1) or sodium nitroprusside (1, 2, and 4 microg.min-1.dl-1) were also performed. Both insulin and L-NMMA were unable to alter the phenylephrine-induced vasoconstriction and the sodium nitroprusside vasodilation. In conclusion, our data demonstrate an endothelial nitric oxide component in the alpha2- and beta-adrenergic vascular responses which is the target of the insulin vascular action.

Association and cosegregation of stroke with impaired endothelium-dependent vasorelaxation in stroke prone, spontaneously hypertensive rats.

While hypertension is a major risk factor for stroke, it is not its sole determinant. Despite similar blood pressures, spontaneously hypertensive rats (SHR) do not share the predisposition to cerebrovascular disease typical of stroke-prone spontaneously hypertensive rats (SHRSP). We investigated vascular function in male SHR and SHRSP as well as in SHRSP/SHR-F2 hybrid animals. Animals were maintained on the appropriate dietary regimen necessary for the manifestation of stroke. Among the hybrid animals, a group of stroke-prone and a group of stroke-resistant rats were selected. Blood pressure was similar in all groups. Endothelium-independent vascular reactivity tested on isolated rings of thoracic aorta and basilar artery after death showed similar contractile and dilatory responses to serotonin and nitroglycerin, respectively, in all groups. In contrast, endothelium-dependent relaxation, in response to acetylcholine or substance P, was markedly reduced in SHRSP compared with SHR. Similarly, reduced vasodilatory responses were present in aortae of F2 rats that had suffered a stroke when compared with SHR or F2 rats resistant to stroke. The observed association and cosegregation of stroke with significant and specific impairment of endothelium-dependent vasorelaxation among SHRSP and stroke-prone F2 hybrids, respectively, suggest a potential causal role of altered endothelium-dependent vascular relaxation in the pathogenesis of stroke.

Alterations in cardiac adrenergic signaling and calcium cycling differentially affect the progression of cardiomyopathy.

The medical treatment of chronic heart failure has undergone a dramatic transition in the past decade. Short-term approaches for altering hemodynamics have given way to long-term, reparative strategies, including beta-adrenergic receptor (betaAR) blockade. This was once viewed as counterintuitive, because acute administration causes myocardial depression. Cardiac myocytes from failing hearts show changes in betaAR signaling and excitation-contraction coupling that can impair cardiac contractility, but the role of these abnormalities in the progression of heart failure is controversial. We therefore tested the impact of different manipulations that increase contractility on the progression of cardiac dysfunction in a mouse model of hypertrophic cardiomyopathy. High-level overexpression of the beta(2)AR caused rapidly progressive cardiac failure in this model. In contrast, phospholamban ablation prevented systolic dysfunction and exercise intolerance, but not hypertrophy, in hypertrophic cardiomyopathy mice. Cardiac expression of a peptide inhibitor of the betaAR kinase 1 not only prevented systolic dysfunction and exercise intolerance but also decreased cardiac remodeling and hypertrophic gene expression. These three manipulations of cardiac contractility had distinct effects on disease progression, suggesting that selective modulation of particular aspects of betaAR signaling or excitation-contraction coupling can provide therapeutic benefit.