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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cardiologists are seeing increasing numbers of patients with erectile dysfunction (ED), which frequently coexists with cardiovascular disease. The pharmacologic profile of the new class of phosphodiesterase (PDE) inhibitors-specifically PDE5 inhibitors-and their potential effects on hemodynamic variables have therefore become significant factors in therapeutic decision making. Most of the published data linking PDE5 inhibitor effects and cardiovascular disease relate to sildenafil, although >or=2 new agents are in various stages of development and clinical trials. Sildenafil and other PDE5 inhibitors act on vascular smooth muscle, predominantly in the corpus cavernosum. PDE5 is not found in cardiomyocytes, and no effect of PDE5 inhibition on cardiac contractility has been demonstrated. On the basis of a safety database comprising thousands of men with ED, sildenafil has demonstrated minimal adverse effects in men with stable ischemia, hypertension, and/or severe coronary artery disease. Sildenafil has modest effects on hemodynamic variables and has been shown to increase coronary artery flow reserve. Alone or combined with >or=1 antihypertensive medication, sildenafil did not increase the incidence of adverse events or hypotensive episodes. Sildenafil-associated decreases in systolic and diastolic blood pressure, the result of its vasodilator activity, have been modest. Sildenafil has decreased both elevated pulmonary vascular resistance and elevated pulmonary artery pressures in patients with pulmonary vascular disease. Beneficial changes in hemodynamics have been observed with the use of sildenafil in patients with congestive heart failure with underlying ischemic and other dilated cardiomyopathies. No association between sildenafil and increased cardiovascular morbidity or mortality has emerged in analyses of clinical trial data.
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PMID:Sildenafil in patients with cardiovascular disease. 1460 21

To evaluate the association between hypertension, male erectile function, Rho-kinase, and cyclic GMP pathways, we monitored neurogenic erectile response in spontaneously hypertensive (SHR) vs normotensive rats. We also evaluated SHR erectile function before and after intracavernosal injection of either the specific Rho-kinase inhibitor Y-27632 or a combination of Y-27632 and the PDE5 inhibitor zaprinast to prevent cGMP degradation. SHR had lower resting baseline corpus cavernosum pressure and a higher threshold for development of tumescence than normotensive rats. In SHR, Y-27632 administration reversed hypertension-related changes in male erectile function; Rho-kinase antagonism and PDE5 inhibition in combination had a synergistic effect in improving the neurogenic erectile response. Our data indicate that hypertension is associated with impairment in the SHR neurogenic erectile response that may involve a derangement in hemodynamic mechanisms in penile erectile tissue. Rho-kinase inhibition alone or combined with PDE5 inhibition may be of value in treating hypertension-related ED.
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PMID:Phosphodiesterase-5 inhibition synergizes rho-kinase antagonism and enhances erectile response in male hypertensive rats. 1507 8

Sildenafil, a potent type 5 nucleotide-dependent phosphodiesterase (PDE) inhibitor, has been recently proposed as a therapeutic tool to treat or prevent pulmonary artery hypertension (PAHT). We thus studied the effect of sildenafil on both the calcium signaling of isolated pulmonary artery smooth muscle cells (PASMCs) and the reactivity of pulmonary artery (PA) obtained from chronic hypoxia (CH)-induced pulmonary hypertensive rats compared with control (normoxic) rats. CH rats were maintained in an hypobaric chamber (50.5 kPa) for 3 wk leading to full development of PAHT. Intracellular calcium concentration ([Ca2+]i) was measured in PASMCs loaded with the calcium fluorophore indo 1. Unlike in control rats, sildenafil (10-100 nM) decreased the resting [Ca2+]i value in PASMCs obtained from CH rats. In PASMCs from both control and CH rats, sildenafil concentration dependently inhibited the [Ca2+]i response induced by G-coupled membrane receptor agonists such as angiotensin II and phenylephrine but had no effect on the amplitude of the [Ca2+]i response induced by caffeine. Sildenafil (0.1 nM-1 microM) concentration dependently reduced basal PA tone that is present in CH rats and relaxed PA rings precontracted with phenylephrine in both control and CH rats. These data show that sildenafil is a potent pulmonary artery relaxant in CH rats and that it normalizes CH-induced increases in resting [Ca2+]i and basal tone. Consequently, pharmacological inhibition of sildenafil-sensitive PDE5 downregulates the Ca2+ signaling pathway involved in this model of pulmonary hypertension.
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PMID:Sildenafil alters calcium signaling and vascular tone in pulmonary arteries from chronically hypoxic rats. 1515 72

The cyclic nucleotide signalling pathway mediates the smooth-muscle relaxing effects of nitric oxide necessary for normal erectile function. Down-regulation of this pathway is central to the pathophysiology of many forms of erectile dysfunction (ED), which is often associated with other chronic diseases (e.g. hypertension, type 2 diabetes mellitus) and treatments (e.g. certain drugs, radical prostatectomy). Conversely, selective inhibition of the enzyme that catalyses the degradation of cGMP (phosphodiesterase type 5, PDE-5) promotes erectile responses to sexual stimulation. The successful launch and commercialization of the selective PDE5 inhibitor (PDE5I) sildenafil transformed the treatment of ED, not only by providing an effective, well tolerated oral ED therapy, but also by fostering greater candour about the problem among men. Sildenafil is highly effective in promoting erectile responses across a wide spectrum of severity and causes of ED, including patients with ED that is often refractory to treatment. The recent advent of vardenafil, which has the highest in vitro potency of all available PDE5Is, and tadalafil, which has a prolonged half-life that may enable couples to have sexual activity with less planning, represent further advances. Other PDE5Is offering further potential improvements are under active investigation.
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PMID:Phosphodiesterase type 5 inhibitors for erectile dysfunction. 1604 13

Primary pulmonary arterial hypertension (PPH) is a rare disease of undetermined origin and fatal prognosis. A better prognosis is associated with at least 20% reduction of either pulmonary artery pressure or pulmonary vascular resistance ("responders") in acute vasodilatory trials. Prostacycline (PGI2) or nitric oxide (NO) administration promises valuable results. NO is one of the most powerful vasodilating agents, endogenously produced by endothelial cells. It migrates from these cells to smooth muscle cells and stimulates production of cGMP, that induces smooth muscle relaxation. cGMP is hydrolyzed by 5-phopshodiesterase (PDE-5). Several papers documenting hypotensive effect in pulmonary circulation of specific PDE5 inhibitor--sildenafil (Viagra--Pfizer) have been published recently. We present a case report of a 26 year old female patient with PPH--"nonresponder" in a trial with NO--and NO responder after sildenafil administration. Initial values were: mean pulmonary artery pressure (mPAP) was 58 mmHg, pulmonary vascular resistance was 10.9 Wood's units. mPAP and PVR during NO inhalation (40 ppm) decrease from 62 to 54 mmHg and from 11.4 to 10.3 Wood's units, respectively. Measurements performed 60 minutes after 50 mg of sildenafil orally disclosed a 19% reduction of mPAP and 21% reduction of PVR. NO inhalation caused further decrease of both parameters: mPAP was decreased for additional 28% and PVR for additional 36% in comparison to initial results. Neither peripheral hypotension nor other side effects were observed. A month-long administration of sildenafil in a dose 2 x 25 mg daily reduced mPAP and PVR to values reported for the acute trial. Physical capability improved also. It was assessed as increased distance in a six-minute-walk test (280 vs. 400 m in the first week of treatment, and 330 m in a fourth week of treatment). Echocardiography showed moderate decrease of right ventricle and right atrium diameters, along with decrease of the degree of relative tricuspid regurgitation with unchanged maximal velocity of regurgitant wave. Specific PDE-5 inhibitors might be an attractive alternative in the treatment of pulmonary hypertension in case the above noted observations are confirmed.
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PMID:[Sildenafil reduces pressure and pulmonary resistance and increases susceptibility of pulmonary arteries to nitric oxide in primary pulmonary arterial hypertension]. 1609 62

Pulmonary hypertension is a devastating disorder, characterized by vascular proliferation, intimal hypertrophy and vasoconstriction. In this disorder, alterations in the nitric oxide pathway have borne out to be important in not only vascular proliferation, but also in the maintenance of vascular tone. After synthesis by soluble guanylate cyclase, cGMP effects vasodilation via protein kinase G and other mediators, and is hydrolyzed by phosphodiesterases (PDEs). PDE5 is abundantly expressed in the mammalian lung and its inhibition by sildenafil has been demonstrated to improve pulmonary vascular physiology in vitro and in vivo animal models of pulmonary hypertension. Recent human data has confirmed the efficacy of sildenafil in therapy for humans with pulmonary arterial hypertension. The following review will discuss the underlying basic science supporting the use of sildenafil, as well as human evidence supporting the critical role of this drug in therapy of patients with pulmonary hypertension.
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PMID:Sildenafil, a PDE5 inhibitor, in the treatment of pulmonary hypertension. 1671 91

Patients with heart failure (HF) due to left ventricular (LV) systolic dysfunction have abnormal endothelium-dependent, nitric oxide-cyclic guanosine monophosphate-mediated vasodilation in the pulmonary and skeletal muscle vasculature. Therefore, inhibition of type 5 phosphodiesterase (PDE5), the principle enzyme responsible for cyclic guanosine monophosphate catabolism in the lungs and skeletal muscle, has been targeted in an effort to counteract vasoconstriction that contributes to increased right and LV afterload in HF. The efficacy of PDE5 inhibition in the treatment of pulmonary arterial hypertension has led to the investigation of its potential utility in the treatment of HF patients with secondary pulmonary hypertension. Moreover, recent preclinical studies suggest direct myocardial effects of PDE5 inhibition that may counteract beta-adrenergic, hypertrophic, and pro-apoptotic signaling, three critical pathways in the development of LV dysfunction. This review outlines both the underlying rationale and the results of initial studies of the therapeutic effects of PDE5 inhibition in HF.
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PMID:The emerging role for type 5 phosphodiesterase inhibition in heart failure. 1691 4

Erectile dysfunction (ED) has multifactor pathogenesis, with neurological, vascular, endocrinological and psychogenic components described. However, about 50-85% of ED population report the presence of one or more comorbidities i.e. hypertension, diabetes, cardiovascular disease, dyslipidemia which all impair endothelial function and, erection is a basically vascular event that necessitates an intact endothelium to occur. Hence, ED may be mostly considered as the clinical manifestation of a disease affecting penile circulation as a part of a generalized vascular disorder due to atherosclerosis. Orally active drugs, i.e. phosphodiesterase type-5 inhibitors (PDE5-i), are a group of on-demand drugs licensed for ED treatment and appear to offer advantages over past therapies in terms of ease of administration and cost, and they are now widely advocated as first-line therapy. The recent discovery that chronic not on-demand administration of these drugs may improve erectile and endothelial response in men previously unresponding to on-demand regimes, opens a new scenario in the treatment of men with ED and comorbidities. Finally, the recent approval of PDE5-i sildenafil for the treatment of pulmonary arterial hypertension represents the new challenge for these class of drugs. Aim of this article will be to provide an update on the pathophysiology of ED and how to use of different available PDE5-i in approaching sexual dysfunctional men, pointing out on their characteristic of efficacy and safety and different indications in special sub-populations.
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PMID:Phosphodiesterase 5 inhibitors in the treatment of erectile dysfunction. 1701 40

Phosphodiesterase (PDE) 5 inhibitors reduce cyclic guanylate monophosphate breakdown, promoting vascular relaxation in the corpora cavernosa and penile erection during sexual stimulation. Sildenafil, vardenafil, and tadalafil were approved as effective treatments for male erectile dysfunction. Because PDE5 is present in artery and vein smooth muscle cells throughout the body, PDE5 inhibitors have mild systemic vasodilatory effects and thus the potential to impact the vascular system. The US Food and Drug Administration has approved PDE5 inhibitors for treating pulmonary hypertension. Moreover, their systemic vasodilating properties theoretically make these drugs suitable for treating hypertension. Studies indicate that PDE5 inhibition may be an option for reducing blood pressure in hypertensive patients. Additional benefits may be related to improved arterial stiffness and endothelial dysfunction, two early vascular abnormalities characterizing essential hypertension. More investigation is needed on PDE5 inhibitors as antihypertensive drugs, especially with slow-release formulations or compounds with long half-life. Studies on safety during long-term administration, interactions with antihypertensive and nonantihypertensive drugs, and effect on target organ damage are needed.
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PMID:Phosphodiesterase 5 inhibition in essential hypertension. 1836 27

The treatment algorithm that has recently been developed at the 4th World Conference on Pulmonary Hypertension (PH) in Dana Point will contain a number of important innovations for patients with pulmonary arterial hypertension (PAH), but also for those with other forms of PH. In PAH patients, a targeted therapy with ERA or PDE5 inhibitors is now recommended for patients in functional class II. Combination therapy (ERA and/or PDE5i and/or prostanoids) is proposed if the clinical response to monotherapy is not adequate. In addition, supervised training programs are recommended for patients with PAH. For other forms of PH such as PH due to left heart disease or chronic lung disease, it remains valid that the underlying disease should be treated as efficiently as possible. However, a targeted PAH therapy may be beneficial in selected patients with "out of proportion PH", but these treatments should exclusively be initiated in expert centers. Pulmonary endarterectomy (PEA) remains the treatment of choice for chronic thromboembolic pulmonary hypertension (CTEPH). If patients are inoperable and/or if surgical treatment is not an option, targeted PAH therapy may be considered, but these patients should at present be included into clinical trials. Since there is currently no cure for PH/PAH, further development and progress in medical treatment are highly desirable. A number of promising novel compounds are currently under investigation. These include sGC stimulators, tyrosine kinase inhibitors, and serotonin antagonists.
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PMID:[Dana Point: what is new in the treatment of pulmonary hypertension?]. 1881 94


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