sildenafil-citrate and Body-Weight

Leucine was previously demonstrated to allosterically activate mammalian sirtuin 1 and synergize with other sirtuin 1/AMP-activated protein kinase/nitric oxide pathway activators to modulate energy metabolism. The objective of this study was to evaluate the effects of a triple combination of leucine, metformin, and sildenafil (NS-0200) on body weight and obesity comorbidities in a phase 2 randomized trial.. A total of 91 subjects with obesity were randomized to placebo, low dose (1.1 g leucine/0.5 g metformin/0.5 mg sildenafil), or high dose (1.1 g leucine/0.5 g metformin/1.0 mg sildenafil) twice daily for 16 weeks. Seventy subjects completed the trial and met all a priori compliance criteria. Hypertensive (n = 35) and hypertriglyceridemic (n = 22) subcohorts were also analyzed.. NS-0200 dose-responsively reduced weight; high dose reduced weight by 2.4 and 5.0 kg in the full and high-triglyceride cohorts, respectively (P < 0.0001). High-dose NS-0200 treatment also decreased blood pressure (-5.5 mm Hg diastolic pressure; P = 0.011), with greater effects among hypertensive subjects. NS-0200 also significantly reduced triglycerides and hemoglobin A1c. Significant improvement in ≥ 2 comorbidities was exhibited by 54% of subjects in the high-dose arm versus 5% of placebo subjects (P = 0.0009). Treatment-emergent adverse events did not significantly differ among groups.. These data support further study of NS-0200 as a therapy for obesity and associated comorbidities.

Topics: Body Weight; Double-Blind Method; Female; Humans; Hypoglycemic Agents; Leucine; Male; Metformin; Middle Aged; Obesity; Phosphodiesterase 5 Inhibitors; Sildenafil Citrate

To evaluate the body mass index (BMI) and lower urinary tract symptom (LUTS) severity on treatment response to sildenafil in men with erectile dysfunction (ED) and moderate to severe LUTS associated with benign prostatic hyperplasia.. A post hoc analysis of data from a 12-week, double-blind, placebo-controlled study of sildenafil (50 mg once daily titrated to 100 mg once daily) was conducted. The BMI categories were obese (> or = 30 kg/m(2)), overweight (> or = 25 to < 30 kg/m(2)), and normal weight (< 25 kg/m(2)). ED was defined as a score of < or = 25 on the erectile function domain of the International Index of Erectile Function, and LUTS was defined by an International Prostate Symptom Score of > or = 12. The maximal urinary flow rate was determined by uroflowmetry.. Patients receiving sildenafil (n = 189) had a significant improvement in the erectile function domain scores of the International Index of Erectile Function (P < .0001 vs placebo, n = 180), which did not vary across BMI groups. A greater improvement in LUTS score was observed with sildenafil compared with placebo for men with severe LUTS (-8.6 vs -2.4, P < .0001) than in men with moderate LUTS (-3.6 vs -1.7, P = .06). Also, the improvement in LUTS scores was significant (P < or = .02) for men taking sildenafil independent of BMI (obese, -8.9 vs -5.4; overweight, -7.3 vs -3.2; normal weight, -7.1 vs -0.84). No difference was found among the treatment groups in the change from baseline maximal urinary flow rate across all LUTS and BMI categories (range 4.5 to -4.2 mL/s).. The results of our study have shown that daily dosing with sildenafil improved ED and LUTS independent of baseline LUTS severity or BMI.

Topics: Aged; Body Mass Index; Body Weight; Double-Blind Method; Erectile Dysfunction; Humans; Male; Middle Aged; Obesity; Overweight; Penile Erection; Piperazines; Placebos; Purines; Sildenafil Citrate; Sulfones; Urologic Diseases; Vasodilator Agents

Topics: Animals; Arginase; Body Weight; Catalase; Erectile Dysfunction; Humans; Hydrogen Peroxide; Male; Paroxetine; Plant Extracts; Rats; Rats, Wistar; Sildenafil Citrate; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances

Sildenafil is widely used off-label in pediatric patients with pulmonary arterial hypertension (PAH). This study was conducted to characterize the pharmacokinetics (PK) of sildenafil in term and preterm neonates with PAH, by developing a population PK model, and to suggest appropriate doses to achieve clinically effective concentrations. A population PK modelling analysis was performed using sildenafil and its metabolite N-desmethyl sildenafil (DMS) concentration data from 19 neonates with PAH, whose gestational ages ranged 24-41 weeks. They received sildenafil orally at a dose of 0.5-0.75 mg/kg, four times a day. To investigate the appropriate sildenafil dose, simulations were conducted according to body weight which was significant covariate for sildenafil clearance. A one-compartment model with first-order absorption adequately described the PKs of sildenafil and DMS. Sildenafil clearance was expected to increase rapidly with increasing body weight. In the simulation, sildenafil doses > 1 mg/kg was required to achieve and maintain target concentrations of sildenafil and to expect timely clinical effects in term and preterm infants. These results could be utilized for the safer and more effective use of sildenafil in term and preterm infants.

Topics: Body Weight; Child; Familial Primary Pulmonary Hypertension; Humans; Hypertension, Pulmonary; Infant; Infant, Newborn; Infant, Premature; Pulmonary Arterial Hypertension; Sildenafil Citrate

The current study aimed to determine the effects of sildenafil-associated aerobic exercise training (ET) on the physical performance, hemodynamic, autonomic and inflammatory parameters of rats. Male Wistar rats were randomly assigned to: sedentary rats placebo-treated (SP); sedentary rats sildenafil-treated (SS); trained rats placebo-treated (TP); and trained rats sildenafil-treated (TS). Sildenafil treatment consisted of 8 weeks of daily oral gavage (1.5 mg/kg), one hour before the session of ET (60-75% of maximal running speed, 5 days/week, for 8 weeks). After ET period, physical capacity, hemodynamic, autonomic and skeletal muscle inflammatory profile were assessed. Chronic sildenafil treatment causes an additional increase of physical capacity in aerobically trained rats. However, these beneficial effects were accompanied by unwanted alterations, as increased of arterial pressure and peripheral sympathetic modulation, as well as exacerbated inflammatory status on skeletal muscle of rats. Taken together, these data suggest the positive and negative effects of sildenafil chronic administration, associated to aerobic ET, at doses used in clinical practice. This report stresses the importance of paying greater attention to the indiscriminate use of this substance in high-performance sports.

Topics: Animals; Autonomic Nervous System; Baroreflex; Body Weight; Hemodynamics; Inflammation; Male; Muscle, Skeletal; Performance-Enhancing Substances; Phosphodiesterase 5 Inhibitors; Physical Conditioning, Animal; Rats, Wistar; Sildenafil Citrate

The erectile dysfunction drug sildenafil has cardiopulmonary protective actions, and a nephroprotective action in cisplatin and ischemia-reperfusion-induced acute kidney injury. Here, we assessed its possible ameliorative action in a model of chronic kidney disease (CKD) using adenine feeding. Eight groups of rats were treated with saline (controls), adenine (0.25% w/w in feed daily for 5 weeks), and oral sildenafil (0.1, 0.5 or 2.5 mg/kg), either alone, or concomitantly with adenine. Urine was collected 24 h after the end of the treatments from all rats and blood pressure measured, followed by collection of blood and kidneys for the measurement of several functional, biochemical and histopathological parameters. Adenine treatment reduced body weight, creatinine renal clearance, and increased water intake and urine output, as well as the plasma concentrations of urea and creatinine, neutrophil gelatinase-associated lipocalin, and N-acetyl-β-D-glucosaminidase activity, and albumin in urine. Adenine also increased the concentrations of the uremic toxins indoxyl sulfate, uric acid and phosphate, and a number of proteins and inflammatory cytokines, and decreased that of several anti - oxidant indices. Renal histopathological markers of damage (inflammation and fibrosis) were significantly increased by adenine. Sildenafil, given simultaneously with adenine, induced a dose - dependent improvements in most of the above parameters, suggesting its possible use as adjunct treatment for CKD in humans.

Topics: Adenine; Animals; Biomarkers; Blood Pressure; Body Weight; Creatinine; Cytokines; Fibrosis; Inflammation; Rats; Rats, Sprague-Dawley; Renal Insufficiency, Chronic; Sildenafil Citrate; Urea

Diabetic nephropathy (DN) is a leading cause of end-stage renal disease in the world. Several signaling pathways are involved in the pathogenesis of DN including elevation in level of angiotensin II, formation of advanced glycation end products (AGE), activation of protein kinase c (PKC), and lipid accumulation. These pathways activate one another mutually leading to oxidative stress, increasing expression of transforming growth factor beta-1(TGF-β 1) and release of interleukins and adhesion molecules, so the aim of this study is to interrupt more than pathogenic pathway to ameliorate the progression of DN. In the present study, white male rats (N=48) were divided into six groups (8 rats each), the first two groups served as normal control and a control vehicle group while the remaining four groups were rendered diabetic by a single intraperitoneal injection of Streptozotocin (STZ) and being left for 4 weeks to develop DN. Thereafter, the rats were divided into DN group, DN group receiving Telmisartan or Sildenafil or Telmisartan Sildenafil combination. After the specified treatment period, urine samples were collected (using metabolic cages) to measure proteinuria, animals were then euthanized, blood and tissue samples were collected for measurement of Blood glucose,BUN, S.Cr, LDL, NO, TGF-β1, IL-1β, AGEPs, and SOD. The combination therapy showed significant decrease in BUN, S.Cr,LDL, TGF-β1, IL-1β, Proteinuria and AGEPs and significant increase in SOD and NO. The findings showed that combination therapy was able to ameliorate DN and that the effects were superior to the single drugs alone.

Topics: Animals; Benzimidazoles; Benzoates; Blood Glucose; Blood Urea Nitrogen; Body Weight; Cholesterol, LDL; Creatinine; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Disease Models, Animal; Disease Progression; Drug Therapy, Combination; Glycation End Products, Advanced; Interleukin-1beta; Kidney; Nitric Oxide; Proteinuria; Rats; Sildenafil Citrate; Streptozocin; Superoxide Dismutase; Telmisartan; Transforming Growth Factor beta1

Pulmonary hypoplasia and hypertension is a leading cause of morbidity and mortality in congenital diaphragmatic hernia (CDH). The etiologic insult occurs early in gestation highlighting the potential of prenatal interventions. We evaluated prenatal pharmacologic therapies in the nitrofen CDH model.. Olive oil or nitrofen were administered alone or with dexamethasone (DM), sildenafil, or DM+sildenafil to pregnant rats. Newborn pups were assessed for lung function, structure and pulmonary artery (PA) flow and resistance.. Prenatal DM treatment of CDH pups increased alveolar volume density (Vva), decreased interalveloar septal thickness, increased tidal volumes and improved ventilation without improving oxygenation or PA resistance. Sildenafil decreased PA resistance and improved oxygenation without improving ventilation or resulting in significant histologic changes. DM+sildenafil decreased PA resistance, improved oxygenation and ventilation while increasing Vva and decreasing interalveolar septal and pulmonary arteriole medial wall thickness. Lung and body weights were decreased in pups treated with DM and/or sildenafil.. Prenatal DM or sildenafil treatment increased pulmonary compliance and decreased pulmonary vascular resistance respectively, and was associated with improved neonatal gas exchange but had a detrimental effect on lung and fetal growth. This study highlights the potential of individual and combined prenatal pharmacologic therapies for CDH management.

Topics: Animals; Arterioles; Body Weight; Dexamethasone; Female; Hernias, Diaphragmatic, Congenital; Hypertension, Pulmonary; Lung; Olive Oil; Organ Size; Oxygen; Phenyl Ethers; Pregnancy; Pregnancy, Animal; Pulmonary Artery; Rats; Rats, Sprague-Dawley; Respiratory Function Tests; Respiratory Physiological Phenomena; Sildenafil Citrate; Stroke Volume; Trachea

Allometric scaling is regularly used for the prediction of human pharmacokinetic (PK) parameters from animal PK studies. The predicted human PK parameters can also be used for the prediction of plasma concentration-time profiles in humans.. The main objective of this work is to predict human concentration-time profiles of drugs (one-compartment model) following oral administration using animal oral pharmacokinetic parameters.. Six drugs from the literature were chosen that were described by one-compartment model in both humans and animals following oral administration. Pharmacokinetic parameters such as oral clearance, oral volume of distribution of the central compartment, time to reach maximum plasma concentration, absorption rate constant, and half-life in humans were predicted from animals using allometric scaling. These predicted human pharmacokinetic parameters were then used to predict human plasma concentrations-time profiles of drugs.. The results of this study indicate that the proposed method can be used to predict human plasma concentrations- time profiles of drugs with reasonable accuracy (≤50% prediction error).. Given the complexity in the pharmacokinetics of oral drugs there remains some uncertainty in this entire exercise. One can minimize the prediction error by experience in allometric scaling, scientific judgment, and unconventional or innovative thinking.

Topics: Administration, Oral; Animals; Body Weight; Enoxacin; Fluoroquinolones; Half-Life; Humans; Linezolid; Metabolic Clearance Rate; Models, Biological; Monosaccharides; Sildenafil Citrate; Triazoles; Venlafaxine Hydrochloride

Mitochondrial large-conductance Ca2+-sensitive potassium (mBKCa) channels are involved in myocardial ischemic preconditioning. Their role in sildenafil-induced cardioprotection is unknown. We investigated whether sildenafil-induced acute cardioprotection is mediated by activation of mBKCa channels in the rat heart in vitro.. Male Wistar rats (n = 8 per group) were randomized and anesthetized with pentobarbital (90 mg/kg). Hearts were isolated, mounted on a Langendorff system and perfused with Krebs-Henseleit buffer at a constant pressure of 80 mmHg. Hearts underwent 30 min of global ischemia followed by 60 min of reperfusion. At the end of the experiments infarct size was determined by TTC staining. In the control group rats were not further treated. Sildenafil (3 μM) was administered over 10 min before the beginning of ischemia. The mBKCa channel inhibitor paxilline (1 μM) was administered with and without sildenafil before the onset of ischemia. The pathway underlying sildenafil-induced cardioprotection was further investigated with the protein kinase G blocker KT5823 (1 μM). Myocardial cGMP concentration was measured by ELISA. Data (mean±SD) were analysed with a one and two-way analysis of variance as appropriate.. In control animals infarct size was 52±8%. Sildenafil increased cGMP concentration and reduced infarct size to 35±6% (P<0.05 vs. control). Paxilline and KT5823 completely blocked sildenafil-induced cardioprotection (paxilline+sildenafil: 50±8%, KT5823+sildenafil: 45±8%; both P<0.05 vs. sildenafil). Functional heart parameters and coronary flow were not different between the study groups.. This study shows that in male rats protein kinase G-dependent opening of mBKCa channels plays a pivotal role in sildenafil-induced cardioprotection.

Topics: Animals; Body Weight; Calcium; Carbazoles; Cardiotonic Agents; Cyclic GMP; Hemodynamics; Male; Mitochondria, Heart; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardium; Potassium Channel Blockers; Potassium Channels, Calcium-Activated; Rats, Wistar; Sildenafil Citrate

Oxidative stress and DNA damage have been implicated in the pathogenesis of renovascular hypertension induced by renal artery stenosis in the two-kidney, one-clip (2K1C) Goldblatt model. Considering our previous report indicating that the chronic blockade of phosphodiesterase 5 with sildenafil (Viagra) has marked beneficial effects on oxidative stress and DNA damage, we tested the hypothesis that sildenafil could also protect the stenotic kidneys of 2K1C hypertensive mice against oxidative stress and genotoxicity.. The experiments were performed with C57BL6 mice subjected to renovascular hypertension by left renal artery clipping. Two weeks after clipping, the mice were treated with sildenafil (40 mg/kg/day for 2 weeks, 2K1C-sildenafil group) or the vehicle (2K1C). These mice were compared with control mice not subjected to renal artery clipping (Sham). After hemodynamic measurements, the stenotic kidneys were assessed using flow cytometry to evaluate cell viability and the comet assay to evaluate DNA damage. Measurements of intracellular superoxide anions and hydrogen peroxide levels as well as nitric oxide bioavailability were also obtained.. Sildenafil treatment significantly reduced mean arterial pressure (15%), heart rate (8%), intrarenal angiotensin II (50%) and renal atrophy (36%). In addition, it caused a remarkable decrease of reactive oxygen species production. On the other hand, sildenafil increased nitric oxide levels relative to those in the nontreated 2K1C mice. Sildenafil treatment also significantly reduced the high level of kidney DNA damage that is a characteristic of renovascular hypertensive mice.. Our data reveal that sildenafil has a protective effect on the stenotic kidneys of 2K1C mice, suggesting a new use of phosphodiesterase 5 inhibitors for protection against the DNA damage observed in the hypoperfused kidneys of individuals with renovascular hypertension. Further translational research is necessary to delineate the mechanisms involved in the prevention of renal stenosis in the clinical setting.

Topics: Angiotensin II; Animals; Blood Pressure; Body Weight; Comet Assay; Constriction, Pathologic; DNA Damage; Heart Rate; Hypertension, Renovascular; Kidney; Kidney Function Tests; Mice; Mice, Inbred C57BL; Organ Size; Oxidative Stress; Piperazines; Purines; Reactive Oxygen Species; Renal Artery; Sildenafil Citrate; Sulfones

This study investigates whether endothelin-1 (ET-1) mediates monocrotaline (MCT)-induced pulmonary artery hypertension (PAH) and right ventricular hypertrophy (RVH), and if so, whether the G-protein coupled receptor antagonist KMUP-1 (7-{2-[4-(2-chlorobenzene)piperazinyl]ethyl}-1,3-dimethylxanthine) inhibits ET-1-mediated PA constriction and the aforementioned pathological changes. In a chronic rat model, intraperitoneal MCT (60 mg/kg) induced PAH and increased PA medial wall thickening and RV/left ventricle + septum weight ratio on Day 21 after MCT injection. Treatment with sublingual KMUP-1 (2.5 mg/kg/day) for 21 days prevented these changes and restored vascular endothelial nitric oxide synthase (eNOS) immunohistochemical staining of lung tissues. Western blotting analysis demonstrated that KMUP-1 enhanced eNOS, soluble guanylate cyclase, and protein kinase G levels, and reduced ET-1 expression and inactivated Rho kinase II (ROCKII) in MCT-treated lung tissue over long-term administration. In MCT-treated rats, KMUP-1 decreased plasma ET-1 on Day 21. KMUP-1 (3.6 mg/kg) maximally appeared at 0.25 hours in the plasma and declined to basal levels within 24 hours after sublingual administration. In isolated PA of MCT-treated rats, compared with control and pretreatment with l-NG-nitroarginine methyl ester (100 μM), KMUP-1 (0.1-100 μM) inhibited ET-1 (0.01 μM)-induced vasoconstriction. Endothelium-denuded PA sustained higher contractility in the presence of KMUP-1. In a 24-hour culture of smooth muscle cells (i.e., PA smooth muscle cells or PASMCs), KMUP-1 (0.1-10 μM) inhibited RhoA- and ET-1-induced RhoA activation. KMUP-1 prevented MCT-induced PAH, PA wall thickening, and RVH by enhancing eNOS and suppressing ET-1/ROCKII expression. In vitro, KMUP-1 inhibited ET-1-induced PA constriction and ET-1-dependent/independent RhoA activation of PASMCs. In summary, KMUP-1 attenuates ET-1-induced/ET-1-mediated PA constriction, and could thus aid in the treatment of PAH caused by MCT.

Topics: Animals; Blood Pressure; Body Weight; Cyclic GMP-Dependent Protein Kinases; Disease Models, Animal; Endothelin-1; Guanylate Cyclase; Heart Rate; Hypertension, Pulmonary; Hypertrophy, Right Ventricular; In Vitro Techniques; Male; Monocrotaline; Nitric Oxide Synthase Type III; Piperazines; Piperidines; Pulmonary Artery; Purines; Rats, Wistar; Receptors, Cytoplasmic and Nuclear; Receptors, G-Protein-Coupled; rho-Associated Kinases; rhoA GTP-Binding Protein; Signal Transduction; Sildenafil Citrate; Soluble Guanylyl Cyclase; Sulfonamides; Vasoconstriction; Xanthines

Phosphodiesterase inhibitors have been reported to be beneficial in cognitive and motor disorders. In the present study, we have investigated the effects of RO 20-1724 (PDE4 inhibitor) and sildenafil (PDE5 inhibitor) in 3-nitropropionic acid (3-NP) induced experimental Huntington's disease in rats. 3-Nitropropionic acid was administered for 14 days (10 mg/kg i.p.) 1h following 3-NP administration, the rats were treated with either vehicle, RO 20-1724 (0.25 and 0.5 mg/kg i.p.) or sildenafil (2 and 4 mg/kg i.p.) for 14 days. Cognitive functions were assessed by using Morris water maze whereas, motor functions were assessed by spontaneous locomotor activity, limb withdrawal and suspended wire test at different time points. Biochemically, markers of oxidative stress and cell damage, such as reduced glutathione, malondialdehyde, nitrite and lactate dehydrogenase levels were assessed terminally in the brain homogenate. Chronic administration of 3-NP produced significant decrease in body weight, showed marked abnormalities in cognitive and motor functions. Further, significant oxidative-nitrosative stress and cell damage was also observed. Chronic administration of RO 20-1724 and sildenafil in 3-NP treated rats significantly and dose dependently attenuated 3-NP induced behavioral and biochemical abnormalities in rats. Both these drugs were equally effective in attenuating 3-NP induced neurotoxicity. These results suggesting that the inhibition of PDE4 and PDE5 would be therapeutic in neurodegenerative disorders associated with cognitive and motor dysfunction.

Topics: 4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone; Animals; Behavior, Animal; Body Weight; Brain; Glutathione; L-Lactate Dehydrogenase; Malondialdehyde; Maze Learning; Memory; Neuroprotective Agents; Nitro Compounds; Phosphodiesterase 4 Inhibitors; Phosphodiesterase 5 Inhibitors; Piperazines; Propionates; Purines; Rats; Rats, Wistar; Sildenafil Citrate; Succinate Dehydrogenase; Sulfones

Nitric oxide (NO)-derived metabolites including the anion nitrite can recycle back to NO and thus complement NO formation independent of NO synthases. While nitrite is as a major vascular storage pool and source of NO, little is known about drugs that increase tissue nitrite concentrations. This study examined the effects of atorvastatin or sildenafil, or the combination, on vascular nitrite concentrations and on endothelial dysfunction in the 2 kidney-1 clip (2K1C) hypertension model. Sham-operated or 2K1C hypertensive rats were treated with vehicle, atorvastatin (50 mg/Kg), sildenafil (45 mg/Kg), or both for 8 weeks. Systolic blood pressure (SBP) was monitored weekly. Nitrite concentrations were assessed in the aortas and in plasma samples by ozone-based reductive chemiluminescence assay. Aortic rings were isolated to assess endothelium-dependent and independent relaxation. Aortic NADPH activity and ROS production were evaluated by luminescence and dihydroethidium, respectively, and plasma TBARS levels were measured. Aortic nitrotyrosine staining was evaluated to assess peroxynitrite formation. Atorvastatin and sildenafil, alone or combined, significantly lowered SBP by approximately 40 mmHg. Atorvastatin significantly increased vascular nitrite levels by 70% in hypertensive rats, whereas sildenafil had no effects. Both drugs significantly improved the vascular function, and decreased vascular NADPH activity, ROS, and nitrotyrosine levels. Lower plasma TBARS concentrations were found with both treatments. The combination of drugs showed no improved responses compared to each drug alone. These findings show evidence that atorvastatin, but not sildenafil, increases vascular NO stores, although both drugs exert antioxidant effects, improve endothelial function, and lower blood pressure in 2K1C hypertension.

Topics: Animals; Aorta; Atorvastatin; Blood Pressure; Body Weight; Disease Models, Animal; Drug Therapy, Combination; Heptanoic Acids; Hypertension, Renovascular; Male; Nitric Oxide; Piperazines; Purines; Pyrroles; Rats; Rats, Wistar; Sildenafil Citrate; Sulfonamides

It is well established that the pathogenesis of diabetic nephropathy is associated with abnormalities of renal nitric oxide (NO) generation. Many of the biological actions of NO are mediated by cGMP, which is rapidly degraded by phosphodiesterases. In this study, we evaluated the renoprotective effects of sildenafil (SIL), an inhibitor of phosphodiesterase-5, in type 2 diabetic rats.. Male Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a non-insulin-dependent diabetes model, and Long-Evans Tokushima Otsuka rats, a non-diabetic control, were treated with either SIL (2.5 mg·kg(-1) in drinking water) or undosed water for 28 weeks, starting at 30 weeks of age.. Sildenafil treatment significantly decreased albuminuria, attenuated glomerular hyperfiltration and resulted in a decrease in glomerular hypertrophy, in addition to a reduced glomerulosclerosis score and a dramatic decrease in the number of glomerular and tubulointerstitial proliferating cell nuclear antigen-positive cells in OLETF rats. This was accompanied by a significant reduction in renal cortical mRNA levels of collagen types I and III. The increased mRNA levels of matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitors of MMPs (TIMP)-1 and TIMP-2 in the OLETF rats were significantly or partially attenuated by SIL treatment.. This study suggests that SIL attenuated diabetic nephropathy due to its potent antiproliferative effects and its regulatory effects on extracellular matrix. This latter effect is thought to be a result of its ability to affect the balance between MMPs and their inhibitors.

Topics: Albuminuria; Animals; Blood Glucose; Blood Pressure; Body Weight; Cell Proliferation; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Kidney; Kidney Function Tests; Male; Nitric Oxide; Phosphodiesterase 5 Inhibitors; Piperazines; Purines; Rats; Rats, Inbred OLETF; Sildenafil Citrate; Sulfones; Transforming Growth Factor beta1

We evaluated the pharmacokinetics of routinely administered bosentan in 46 Japanese pediatric patients with pulmonary arterial hypertension. Plasma samples were taken twice at times corresponding to the peak and trough concentrations following repetitive oral administration. The population pharmacokinetic parameters of bosentan were estimated by use of the NONMEM program, in which a one-compartment model with repetitive bolus dosing was parameterized in terms of the oral clearance (CL/F) and elimination rate constant (k). Polymorphisms of CYP3A5, SLCO1B1, SLCO1B3, and SLCO2B1 had no significant effect on the disposition of bosentan. In addition, the pharmacokinetics of bosentan was not altered by heart failure or coadministration of sildenafil. In contrast, weight (WT)-normalized values of CL/F were correlated negatively with age (AGE). The final population mean values of CL/F and k were estimated to be 0.409 · (1 - 0.0377 · (AGE - 3.81)) · WT L/h and 0.175 h(-1), respectively.

Topics: Adolescent; Age Factors; Aryl Hydrocarbon Hydroxylases; Asian People; Bayes Theorem; Body Weight; Bosentan; Child; Child, Preschool; Computer Simulation; Cytochrome P-450 CYP2C9; Cytochrome P-450 CYP3A; Drug Interactions; Familial Primary Pulmonary Hypertension; Female; Genotype; Heart Failure; Humans; Hypertension, Pulmonary; Infant; Infant, Newborn; Liver-Specific Organic Anion Transporter 1; Male; Models, Biological; Organic Anion Transporters; Organic Anion Transporters, Sodium-Independent; Piperazines; Polymorphism, Single Nucleotide; Purines; Sildenafil Citrate; Solute Carrier Organic Anion Transporter Family Member 1B3; Sulfonamides; Sulfones

Lung hypoplasia and persistent pulmonary hypertension of the newborn limit survival in congenital diaphragmatic hernia (CDH). Unlike other diseases resulting in persistent pulmonary hypertension of the newborn, infants with CDH are refractory to inhaled nitric oxide (NO). Nitric oxide mediates pulmonary vasodilatation at birth in part via cyclic GMP production. Phosphodiesterase type 5 (PDE5) limits the effects of NO by inactivation of cyclic GMP. Because of the limited success in postnatal management of CDH, we hypothesized that antenatal PDE5 inhibition would attenuate pulmonary artery remodeling in experimental nitrofen-induced CDH.. Nitrofen administered at embryonic day 9.5 to pregnant rats resulted in a 60% incidence of CDH in the offspring and recapitulated features seen in human CDH, including structural abnormalities (lung hypoplasia, decreased pulmonary vascular density, pulmonary artery remodeling, right ventricular hypertrophy), and functional abnormalities (decreased pulmonary artery relaxation in response to the NO donor 2-(N,N-diethylamino)-diazenolate-2-oxide). Antenatal sildenafil administered to the pregnant rat from embryonic day 11.5 to embryonic day 20.5 crossed the placenta, increased fetal lung cyclic GMP and decreased active PDE5 expression. Antenatal sildenafil improved lung structure, increased pulmonary vessel density, reduced right ventricular hypertrophy, and improved postnatal NO donor 2-(N,N-diethylamino)-diazenolate-2-oxide-induced pulmonary artery relaxation. This was associated with increased lung endothelial NO synthase and vascular endothelial growth factor protein expression. Antenatal sildenafil had no adverse effect on retinal structure/function and brain development.. Antenatal sildenafil improves pathological features of persistent pulmonary hypertension of the newborn in experimental CDH and does not alter the development of other PDE5-expressing organs. Given the high mortality/morbidity of CDH, the potential benefit of prenatal PDE5 inhibition in improving the outcome for infants with CDH warrants further studies.

Topics: Animals; Body Weight; Brain; Cyclic GMP; Cyclic Nucleotide Phosphodiesterases, Type 5; Disease Models, Animal; Female; Hernia, Diaphragmatic; Hernias, Diaphragmatic, Congenital; Hypertension, Pulmonary; Lung; Nitric Oxide; Phenyl Ethers; Phosphodiesterase 5 Inhibitors; Piperazines; Pregnancy; Pulmonary Artery; Purines; Rats; Rats, Sprague-Dawley; Sildenafil Citrate; Sulfones

We investigated whether early combined autologous adipose-derived mesenchymal stem cell (ADMSC) and sildenafil therapy offers an additive benefit in preserving heart function in rat dilated cardiomyopathy (DCM).. Adult Lewis rats (n = 8 per group) were divided into group 1 (normal control), group 2 (saline-treated DCM rats), group 3 [2.0 × 106 ADMSC implanted into left ventricular (LV) myocardium of DCM rats], group 4 (DCM rats with sildenafil 30 mg/kg/day, orally), and group 5 (DCM rats with combined ADMSC-sildenafil). Treatment was started 1 week after DCM induction and the rats were sacrificed on day 90.. The results showed that mitochondrial protein expressions of connexin43 and cytochrome-C were lowest in group 2, and lower in groups 3 and 4 than in group 5 (p < 0.002). Conversely, oxidative index was highest in group 2, and also higher in groups 3 and 4 than in group 5 (p < 0.0003). The mRNA expressions of interleukin (IL)-10, Gro/IL-8, endothelial nitric oxide synthase, and Bcl-2 were lowest in group 2, and lower in groups 3 and 4 compared with group 5 (p < 0.0001). The mRNA expressions of matrix metalloproteinase-9, Bax, caspase 3, and stromal-cell derived factor-1α were highest in group 2, and higher in groups 3 and 4 than in group 5 (p < 0.0004). Apoptosis and fibrosis in LV myocardium were most prominent in group 2 and higher in groups 3 and 4 than in group 5, whereas angiogenesis and LV ejection fraction were lowest in group 2 and lower in groups 3 and 4 than in group 5 (p < 0.003).. Early combined ADMSC/sildenafil is superior to either treatment alone in preserving LV function.

Topics: Adipose Tissue; Animals; Apoptosis; Body Weight; Cardiomyopathy, Dilated; Connexin 43; Cytochromes c; Flow Cytometry; Immunohistochemistry; Male; Mesenchymal Stem Cells; Organ Size; Oxidative Stress; Phosphodiesterase Inhibitors; Piperazines; Purines; Rats; Rats, Inbred Lew; Reverse Transcriptase Polymerase Chain Reaction; Sildenafil Citrate; Sulfones; Ultrasonography

Rats submitted to high altitude (Cerro de Pasco, Perú, 4,340 m, Po(2) = 12.2 kPa) for up to 84 days showed a physiological adaptive response with decreased body weight gain (15%), increased right ventricle weight (100%), and increased hematocrit (40%) compared with sea level animals. These classical parameters of adaptation to high altitude were accompanied by an increase in heart mitochondrial enzymes: complexes I-III activity by 34% and mitochondrial nitric oxide synthase (mtNOS) activity and expression by >75%. The hyperbolic increase for mtNOS activity during adaptation to high altitude was similar to the observed pattern for hematocrit. Hematocrit and mtNOS activity mean values correlated linearly (r(2) = 0.75, P

Topics: Adaptation, Physiological; Altitude; Animals; Arginine; Body Weight; Electron Transport Complex I; Electron Transport Complex II; Electron Transport Complex III; Electron Transport Complex IV; Enzyme Inhibitors; Heart; Hematocrit; Hypertrophy, Right Ventricular; Male; Mitochondria; Myocardium; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase; Organ Size; Phosphodiesterase Inhibitors; Piperazines; Purines; Rats; Rats, Sprague-Dawley; Sildenafil Citrate; Sulfones

Pulmonary arterial hypertension (PAH) is often treated with endothelin (ET) receptor blockade or phosphodiesterase-5 (PDE5) inhibition. Little is known about the specific effects on right ventricular (RV) function and metabolism. We determined the effects of single and combination treatment with Bosentan [an ET type A (ET(A))/type B (ET(B)) receptor blocker] and Sildenafil (a PDE5 inhibitor) on RV function and oxidative metabolism in monocrotaline (MCT)-induced PAH. Fourteen days after MCT injection, male Wistar rats were orally treated for 10 days with Bosentan, Sildenafil, or both. RV catheterization and echocardiography showed that MCT clearly induced PAH. This was evidenced by increased RV systolic pressure, reduced cardiac output, increased pulmonary vascular resistance (PVR), and reduced RV fractional shortening. Quantitative histochemistry showed marked RV hypertrophy and fibrosis. Monotreatment with Bosentan or Sildenafil had no effect on RV systolic pressure or cardiac function, but RV fibrosis was reduced and RV capillarization increased. Combination treatment did not reduce RV systolic pressure, but significantly lowered PVR, and normalized cardiac output, RV fractional shortening, and fibrosis. Only combination treatment increased the mitochondrial capacity of the RV, as reflected by increased succinate dehydrogenase and cytochrome c oxidase activities, associated with an activation of PKG, as indicated by increased VASP phosphorylation. Moreover, significant interactions were found between Bosentan and Sildenafil on PVR, cardiac output, RV contractility, PKG activity, and mitochondrial capacity. These data indicate that the combination of Bosentan and Sildenafil may beneficially contribute to RV adaptation in PAH, not only by reducing PVR but also by acting on the mitochondria in the heart.

Topics: Animals; Body Weight; Bosentan; Capillaries; Cyclic GMP-Dependent Protein Kinases; Diffusion; Endothelin Receptor Antagonists; Fibrosis; Hemodynamics; Hypertension, Pulmonary; In Vitro Techniques; Male; Mitochondria, Heart; Myocardial Contraction; Myocardium; Myocytes, Cardiac; Myoglobin; Organ Size; Oxygen Consumption; Phosphodiesterase 5 Inhibitors; Phosphodiesterase Inhibitors; Piperazines; Pulmonary Artery; Purines; Rats; Rats, Wistar; Sildenafil Citrate; Sulfonamides; Sulfones; Ultrasonography

The present study addressed whether combined treatment with a phosphodiesterase type 5 inhibitor, sildenafil, and a nitric oxide donor, molsidomine, prevents development of pulmonary hypertension in chronic hypoxic rats. Two weeks of hypoxia increased right ventricular systolic pressure, and right ventricular and lung weight. Treatment with either sildenafil (10 mg/kg/day) or molsidomine (15 mg/kg/day) in drinking water reduced right ventricular systolic pressure and weight, while lung weight was unchanged. Combining sildenafil and molsidomine did not have additional effects compared to molsidomine alone. The number of muscularized pulmonary arteries with diameters below 50 microm was increased in vehicle and sildenafil-treated, but not in molsidomine-treated hypoxic rats. Acetylcholine relaxation was blunted in arteries from vehicle and molsidomine-treated, but not in sildenafil-treated rats. In conclusion, both sildenafil and molsidomine blunts pulmonary hypertension and right ventricular hypertrophy in chronic hypoxic rats, but no synergistic effects were observed.

Topics: Acetylcholine; Actins; Animals; Atrial Natriuretic Factor; Body Weight; Dose-Response Relationship, Drug; Drug Synergism; Enzyme Inhibitors; Guanylate Cyclase; Heart Ventricles; Hypertension, Pulmonary; Hypoxia; Lung; Male; Molsidomine; Muscle, Smooth; Oxadiazoles; Piperazines; Pulmonary Artery; Purines; Quinoxalines; Rats; Rats, Wistar; Sildenafil Citrate; Sulfones; Systole; Vasodilation; Vasodilator Agents

A recent in vitro study showed that sildenafil, a type 5 phosphodiesterase inhibitor, dilated the constricted ductus arteriosus of neonatal rabbits. We studied the in vivo ductus-dilating effects of sildenafil in fetal and neonatal rats. Ductus diameters were measured with whole-body freezing and cutting on a freezing microtome. Indomethacin (10 mg/kg) constricted the fetal ductus severely at 4 and 8 h after orogastric administration to the dams. Sildenafil, administered orogastrically and simultaneously with indomethacin, dilated the near-term fetal [21 fetal days (FD)] ductus constricted by indomethacin completely with 1 mg/kg at 8 h after administration. The preterm fetal ductus was more sensitive to sildenafil at 19FD. The ductus constricted rapidly after birth, and the ductal diameter was only 10% of the fetal diameter at 1 h after birth. The ductus-dilating effect of sildenafil was studied by i.p. injection at 1 h after birth, and the ductus diameter was studied 30 and 60 min later. Sildenafil dilated the neonatal constricted ductus moderately with a massive dose (100 mg/kg) and only minimally with 1 mg/kg. In conclusion, sildenafil, a type 5 phosphodiesterase inhibitor, dilated the constricted fetal ductus completely at 8 h with 1 mg/kg in the near-term fetus and completely with a smaller dose (0.1 mg/kg) in the preterm fetus. However, sildenafil dilated the neonatal constricted ductus only moderately with large doses and minimally with 1 mg/kg. Probably, sildenafil is useful clinically for treating idiopathic and secondary fetal ductal constriction and not useful for dilation of the neonatal constricted ductus.

Topics: 3',5'-Cyclic-GMP Phosphodiesterases; Animals; Anti-Inflammatory Agents, Non-Steroidal; Body Weight; Cyclic GMP; Cyclic Nucleotide Phosphodiesterases, Type 5; Ductus Arteriosus; Freezing; Indomethacin; Phosphodiesterase Inhibitors; Phosphoric Diester Hydrolases; Piperazines; Prostaglandins E; Purines; Rats; Rats, Wistar; Sildenafil Citrate; Sulfones; Time Factors

The mechanism of intrathecal antinociceptive action of the phosphodiesterase 5 inhibitor sildenafil was assessed in diabetic rats using the formalin test. Intrathecal administration of sildenafil (12.5-50 microg) produced a dose-related antinociception during both phases of the formalin test in non-diabetic and diabetic rats. Intrathecal pretreatment with N-L-nitro-arginine methyl ester (L-NAME, nitric oxide (NO) synthase inhibitor, 1-50 microg), 1H-(1,2,4)-oxadiazolo(4,2-a)quinoxalin-1-one (ODQ, guanylyl cyclase inhibitor, 1-10 microg), KT5823 (protein kinase G (PKG) inhibitor, 5-500 ng), charybdotoxin (large-conductance Ca2+-activated K+ channel blocker, 0.01-1 ng), apamin (small-conductance Ca2+-activated K+ channel blocker, 0.1-3 ng) and glibenclamide (ATP-sensitive K+ channel blocker, 12.5-50 microg), but not N-D-nitro-arginine methyl ester (D-NAME, 50 microg) or saline, significantly diminished sildenafil (50 microg)-induced antinociception in non-diabetic rats. Intrathecal administration of ODQ, KT5823, apamin and glibenclamide, but not L-NAME nor charybdotoxin, reversed intrathecal antinociception induced by sildenafil in diabetic rats. Results suggest that sildenafil produces its intrathecal antinociceptive effect via activation of NO-cyclic GMP-PKG-K+ channels pathway in non-diabetic rats. Data suggest that diabetes leads to a dysfunction in NO and large-conductance Ca2+-activated K+ channels. Sildenafil could have a role in the pharmacotherapy of diabetes-associated pain.

Topics: Analgesia; Animals; Blood Glucose; Body Weight; Carbazoles; Cyclic GMP-Dependent Protein Kinases; Diabetes Mellitus, Experimental; Dose-Response Relationship, Drug; Enzyme Inhibitors; Female; Formaldehyde; Guanylate Cyclase; Indoles; Injections, Spinal; NG-Nitroarginine Methyl Ester; Nitric Oxide Synthase; Oxadiazoles; Pain; Pain Measurement; Phosphodiesterase Inhibitors; Piperazines; Potassium Channel Blockers; Purines; Quinoxalines; Rats; Rats, Wistar; Sildenafil Citrate; Streptozocin; Sulfones; Time Factors

Erectile dysfunction is common in men with chronic renal failure. Previously nitrergic and endothelium-dependent relaxation responses have been shown to be reduced in chronic renal failure rabbits. We have therefore investigated the efficacy of phosphodiesterase inhibitors on the corpora cavernosa obtained from uremic rabbits. Uremia was induced with 5/6 nephrectomy and 4 weeks later cavernosal tissue strips were isolated. The relaxant effect of phosphodiesterase 5 inhibitors, zaprinast (1-300 microM) and sildenafil (0.01-300 microM), phosphodiesterase 3 inhibitor amrinone (1-100 microM) and non-specific phosphodiesterase inhibitor papaverine (1-300 microM) were investigated on phenylephrine (10 microM)-induced tone. We found a shift in the dose-response curve of only phosphodiesterase 5 inhibitors. These results suggest that the decreased production or availability of endogenous nitric oxide in chronic renal failure animals leads to decreased efficacy of phosphodiesterase 5 inhibitors to induce relaxation.

Topics: Amrinone; Animals; Body Weight; Calcium; Creatinine; Dose-Response Relationship, Drug; Electric Stimulation; In Vitro Techniques; Isoenzymes; Kidney Failure, Chronic; Male; Muscle Relaxation; Nephrectomy; Papaverine; Parathyroid Hormone; Penis; Phosphates; Phosphodiesterase Inhibitors; Phospholipases; Piperazines; Purines; Purinones; Rabbits; Sildenafil Citrate; Sulfones; Testosterone

Sildenafil, a type V phosphodiesterase inhibitor, enhances smooth muscle relaxation in normal human and rabbit corpus cavernosum. We investigated the in vitro effects of sildenafil on non-adrenergic, non-cholinergic and nitric oxide (NO)-mediated cavernosal smooth muscle relaxation in diabetic rabbits, since alterations in this pathway are recognised in diabetic erectile dysfunction. Diabetes mellitus was induced in male New Zealand White rabbits with alloxan. Cavernosal strips from age-matched control, 3- and 6-month diabetic animals were mounted in organ baths. Relaxation responses to electrical field stimulation (1-20 Hz) or sodium nitroprusside (10(-8)-10(-4) M) were assessed in the absence and presence of sildenafil (10(-8) and 10(-7) M). The effect of sildenafil on cGMP formation by the corpus cavernosum was also assessed following stimulation with sodium nitroprusside, A23187 and acetylcholine. Sodium nitroprusside-stimulated relaxations were significantly (P<0.03) impaired in the corpus cavernosum from both diabetic groups, (IC(50)=4.6 x 10(-6) M following 3 months of diabetes mellitus and 4.0 x 10(-6) M following 6 months of diabetes mellitus; compared to 7.5 x 10(-7) M for pooled age-matched controls). Sildenafil (10(-7) M) significantly enhanced sodium nitroprusside-stimulated relaxation in control (P<0.05) and diabetic groups (P<0.03). Electrical field stimulation-mediated relaxations of the corpus cavernosum were significantly impaired after 6-month diabetes mellitus and enhanced by sildenafil (10(-8) M). cGMP formation by the diabetic corpus cavernosum was impaired significantly, but restored towards normal by sildenafil. We suggest that the impairment of NO-mediated relaxation of the corpus cavernosum reflect, at least in part, a defect in guanylyl cyclase activity. These findings support the use of sildenafil as an effective, orally administered, treatment for diabetic erectile dysfunction.

Topics: Acetylcholine; Animals; Biomarkers; Body Weight; Calcimycin; Cyclic GMP; Diabetes Mellitus, Experimental; Dose-Response Relationship, Drug; Electric Stimulation; In Vitro Techniques; Male; Muscle Relaxation; Muscle, Smooth; Nitric Oxide Donors; Nitroprusside; Penis; Phosphodiesterase Inhibitors; Piperazines; Purines; Rabbits; Sildenafil Citrate; Sulfones; Time Factors; Vasodilator Agents