Search results for "Sildenafil Citrate"
showing 10 items of 18 documents
Relaxation and cyclic GMP levels in response to sildenafil in human pulmonary arteries from donors.
2005
We measured cyclic GMP formation and relaxation response to sildenafil given either alone or in combination with sodium nitroprusside (SNP) in pulmonary arteries obtained from 13 multi-organ donors. Sildenafil (10(-9)-10(-4) M) caused concentration-dependent relaxations and amplified the relaxation induced by SNP. Relaxation was unaffected by endothelium removal or by pre-treatment with the inhibitor of nitric oxide synthase L-NMMA (10(-4) M). SNP (10(-7) M) caused elevation of cyclic GMP levels that was potentiated by sildenafil (10(-6) M). Thus, the enhancement of SNP-induced relaxation by sildenafil is mainly due to an increase in cyclic GMP accumulation.
Effects of sildenafil on human penile blood vessels.
2000
Abstract Objectives. To investigate the effects of sildenafil on human penile blood vessels and evaluate the interaction of sildenafil with neurogenic-mediated responses. Sildenafil is currently used in the treatment of erectile dysfunction. Methods. Penile dorsal arteries and deep dorsal veins were obtained from 14 multiorgan donors. Vascular rings were suspended in organ bath chambers, and the isometric tension was recorded. We then studied the effects of sildenafil on precontracted vessels and the neurogenic (noradrenergic and nitrergic) responses. Results. Sildenafil (10 −9 to 3 × 10 −6 M) caused concentration-dependent relaxation and amplified the relaxation induced by sodium nitroprus…
Relaxation of the isolated human internal anal sphincter by sildenafil.
2007
Abstract Background Hypertonicity of the internal anal sphincter (IAS) appears to be involved in the pathogenesis of anal fissure. The relaxant effects of sildenafil, a selective phosphodiesterase 5 (PDE5) inhibitor, on isolated human IAS were investigated. Methods The efficacy (maximal effect, Emax) and potency (−log IC50, where IC50 is half-maximal inhibitory concentration) of the PDE5 inhibitors, sildenafil and zaprinast, and of nitric oxide donors, sodium nitroprusside and glyceryl trinitrate, as relaxants of histamine (0·1 mmol/l)-induced tone were examined in IAS strips under isometric contraction. The presence of PDE5 isoenzymes and changes in intracellular calcium and cyclic nucleot…
Riociguat versus sildenafil on hypoxic pulmonary vasoconstriction and ventilation/perfusion matching
2017
Introduction Current treatment with vasodilators for pulmonary hypertension associated with respiratory diseases is limited by their inhibitory effect on hypoxic pulmonary vasoconstriction (HPV) and uncoupling effects on ventilation-perfusion (V'/Q'). Hypoxia is also a well-known modulator of the nitric oxide (NO) pathway, and may therefore differentially affect the responses to phosphodiesterase 5 (PDE5) inhibitors and soluble guanylyl cyclase (sGC) stimulators. So far, the effects of the sGC stimulator riociguat on HPV have been poorly characterized. Materials and methods Contraction was recorded in pulmonary arteries (PA) in a wire myograph. Anesthetized rats were catheterized to record …
Pulmonary vascular resistance as a potential marker of reactive pulmonary hypertension reduction following sildenafil therapy in patients disqualifie…
2019
Purpose:We sought to determine the predictors of restoration of heart transplantation (HTx) candidacy in pa-tients with systolic heart failure (HF) and reactive fixed pulmonary hypertension (RFPH) defined as pulmonaryvascular resistance (PVR) > 2.5 Wood units (WU), transpulmonary gradient (TPG) > 12 mmHg or ≤2.5 WUwith systolic arterial pressure ≤85 mmHg during vasoreactivity test, following sildenafil therapy.Material and methods:Between2007and20181136patientswereevaluatedatourdepartmentascandidatesforHTx. Thirty-five of them, who presented with systolic HF and were not eligible for HTx due to RFPH, wereincluded in the study (31 men aged 55.1 ± 7.4 years). In all the patients sildenafil wa…
Vascular effects of sildenafil in patients with pulmonary fibrosis and pulmonary hypertension: an ex vivo/in vitro study
2015
Sildenafil improves the 6-min walking distance in patients with idiopathic pulmonary fibrosis (IPF) and right-sided ventricular systolic dysfunction.We analysed the previously unexplored role of sildenafil on vasoconstriction and remodelling of pulmonary arteries from patients with IPF and pulmonary hypertension (PH) ex vivo. Pulmonary arteries from 18 donors without lung disease, nine IPF, eight PH+IPF and four PH patients were isolated to measure vasodilator and anti-contractile effects of sildenafil in isometric organ bath. Ventilation/perfusion was explored in an animal model of bleomycin lung fibrosis.Sildenafil relaxed serotonin (5-HT) pre-contracted pulmonary arteries in healthy dono…
Role of K+ and Ca2+ fluxes in the cerebroarterial vasoactive effects of sildenafil
2007
The aim of this study was to assess the role of K(+) and Ca(2+) fluxes in the cerebroarterial vasoactive effects of the phosphodiesterase-5 inhibitor sildenafil. We used isolated rabbit basilar arteries to assess the effects of extracellular K(+) raising on sildenafil-induced vasodilatation, and studied the pharmacological interaction of sildenafil with selective modulators of membrane K(+) and Ca(2+) channels. Expression of Kv1 subunits of K(+) channels was assessed at messenger and protein levels. Parallel experiments were carried out with zaprinast for comparison. Sildenafil (10 nM-0.1 mM) induced concentration-dependent relaxation of endothelin-1 (10 nM)-precontracted arteries, which wa…
Sildenafil reduces neuroinflammation and restores spatial learning in rats with hepatic encephalopathy: underlying mechanisms
2015
Background: There are no specific treatments for the neurological alterations of cirrhotic patients with minimal hepatic encephalopathy (MHE). Rats with MHE due to portacaval shunt (PCS) show impaired spatial learning. The underlying mechanisms remain unknown. The aims of this work were to assess: (a) whether PCS rats show neuroinflammation in hippocampus, (b) whether treatment with sildenafil reduces neuroinflammation and restores spatial learning in PCS rats, and (c) analyze the underlying mechanisms. Methods: Neuroinflammation was assessed by determining inflammatory markers by Western blot. Phosphorylation of MAP-kinase p38 was assessed by immunohistochemistry. Membrane expression of GA…
Sildenafil orodispersible film in the treatment of erectile dysfunction after radical prostatectomy: A single‐centre open‐label uncontrolled trial
2020
Phosphodiesterase-5 inhibitors are the first-line therapy for erectile dysfunction (ED) after radical prostatectomy (RP). This single-centre open-label uncontrolled study evaluated the efficacy and safety of the new sildenafil orodispersible film (ODF) in ED treatment after RP. Sildenafil 100 mg ODF was administered twice a week for 3 months to patients under 75 years of age, with a Framingham cardiovascular risk score < 20% and a pre-operative International Index of Erectile Function (IIEF)-5 score ≥ 17, who had undergone open RP between 2016 and 2018. Erectile function was assessed pre-operatively, post-operatively and after treatment through the IIEF-5 score, the Sexual Encounter Prof…
Lower self-reported depression in patients with erectile dysfunction after treatment with sildenafil
2001
Abstract Background: Depressive symptoms in men with erectile dysfunction (ED) may improve under successful ED treatment. Self-reported depressive symptoms were compared in men with ED after sildenafil treatment to a group of untreated patients. Methods: In an open study, self-reported depressive symptoms of 54 men after successful treatment with sildenafil (>4 weeks) and 51 men awaiting ED treatment were investigated with the Center of Epidemiologic Studies–Depression Scale (CES–D). CES–D items were subjected to an exploratory factor analysis and group differences in CES–D items and factors were analyzed. Results: Groups were comparable with respect to demographic characteristics and illne…