Selective Vagal Denervation of the Sinus and Atrioventricular Nodes, Guided by Vagal Reflexes Induced by High Frequency Stimulation, to Treat Refractory Neurally Mediated Syncope

Vagal Denervation and Neurally Mediated Syncope. A 15-year-old female patient presented with frequent episodes of vasovagal syncope refractory to non-pharmacological and pharmacological measures. Two tilt-table tests performed before and after conventional therapy were positive and reproduced the patient`s clinical symptoms. Selective vagal denervation, guided by HFS, was performed. Six radiofrequency pulses were applied on the left and right sides of the interatrial septum, abolishing vagal responses at these locations. Basal sinus node and Wenckebach cycle lengths changed significantly following ablation. A tilt test performed after denervation was negative and revealed autonomic tone modification. The patient reported significant improvement in quality of life and remained asymptomatic for 9 months after denervation. After this period, three episodes of NMS occurred during a 4-month interval and a tilt test performed 11 months after the procedure demonstrated vagal activity recovery. (J Cardiovasc Electrophysiol, Vol. 20, pp. 558-563, May 2009).

Antinociception induced by epidural motor cortex stimulation in naive conscious rats is mediated by the opioid system

Epidural motor cortex stimulation (MCS) has been used for treating patients with neuropathic pain resistant to other therapeutic approaches. Experimental evidence suggests that the motor cortex is also involved in the modulation of normal nociceptive response, but the underlying mechanisms of pain control have not been clarified yet. The aim of this study was to investigate the effects of epidural electrical MCS on the nociceptive threshold of naive rats. Electrodes were placed on epidural motor cortex, over the hind paw area, according to the functional mapping accomplished in this study. Nociceptive threshold and general activity were evaluated under 15-min electrical stimulating sessions. When rats were evaluated by the paw pressure test, MCS induced selective antinociception in the paw contralateral to the stimulated cortex, but no changes were noticed in the ipsilateral paw. When the nociceptive test was repeated 15 min after cessation of electrical stimulation, the nociceptive threshold returned to basal levels. On the other hand, no changes in the nociceptive threshold were observed in rats evaluated by the tail-flick test. Additionally, no behavioral or motor impairment were noticed in the course of stimulation session at the open-field test. Stimulation of posterior parietal or somatosensory cortices did not elicit any changes in the general activity or nociceptive response. Opioid receptors blockade by naloxone abolished the increase in nociceptive threshold induced by MCS. Data shown herein demonstrate that epidural electrical MCS elicits a substantial and selective antinociceptive effect, which is mediated by opioids. (C) 2008 Elsevier B.V. All rights reserved.

Intermittent target inhibition with dasatinib 100 mg once daily preserves efficacy and improves tolerability in imatinib-resistant and -intolerant chronic-phase chronic myeloid leukemia

Purpose Dasatinib is a BCR-ABL inhibitor, 325-fold more potent than imatinib against unmutated BCR-ABL in vitro. Phase II studies have demonstrated efficacy and safety with dasatinib 70 mg twice daily in chronic-phase (CP) chronic myelogenous leukemia (CML) after imatinib treatment failure. In phase I, responses occurred with once-daily administration despite only intermittent BCR-ABL inhibition. Once-daily treatment resulted in less toxicity, suggesting that toxicity results from continuous inhibition of unintended targets. Here, a dose-and schedule-optimization study is reported. Patients and Methods In this open-label phase III trial, 670 patients with imatinib-resistant or -intolerant CP-CML were randomly assigned 1: 1: 1: 1 between four dasatinib treatment groups: 100 mg once daily, 50 mg twice daily, 140 mg once daily, or 70 mg twice daily. Results With minimum follow-up of 6 months (median treatment duration, 8 months; range, = 1 to 15 months), marked and comparable hematologic (complete, 86% to 92%) and cytogenetic (major, 54% to 59%; complete, 41% to 45%) response rates were observed across the four groups. Time to and duration of cytogenetic response were similar, as was progression-free survival (8% to 11% of patients experienced disease progression or died). Compared with the approved 70-mg twice-daily regimen, dasatinib 100 mg once daily resulted in significantly lower rates of pleural effusion (all grades, 7% v 16%; P = .024) and grade 3 to 4 thrombocytopenia (22% v 37%; P = .004), and fewer patients required dose interruption (51% v 68%), reduction (30% v 55%), or discontinuation (16% v 23%). Conclusion Dasatinib 100 mg once daily retains the efficacy of 70 mg twice daily with less toxicity. Intermittent target inhibition with tyrosine kinase inhibitors may preserve efficacy and reduce adverse events.

Estradiol`s Salutary Effects on Keratinocytes Following Trauma-Hemorrhage Are Mediated by Estrogen Receptor (ER)-alpha and ER-beta

Although administration of 17 beta-estradiol (estrogen) following trauma-hemorrhage attenuates the elevation of cytokine production and mitogen-activated protein kinase (MAPK) activation in epidermal keratinocytes, whether the salutary effects of estrogen are mediated by estrogen receptor (ER)-alpha. or ER-beta is not known. To determine which estrogen receptor is the mediator, we subjected C3H/HeN male mice to trauma-hemorrhage (2-cm midline laparotomy and bleeding of the animals to a mean blood pressure of 35 mmHg and maintaining that pressure for 90 min) followed by resuscitation with Ringer`s lactate (four times the shed blood volume) At the middle of resuscitation we subcutaneously injected ER-alpha agonist propyl pyrazole trial (PPT; 5 mu g/kg), ER-beta agonist diarylpropionitrile (DPN; 5 mu g/kg), estrogen (50 mu g/kg), or ER antagonist ICI 182,780 (150 mu g/kg). Two hours after resuscitation, we isolated keratinocytes, stimulated them with lipopolysaccharide for 24 In (5 mu g/mL for maximum cytokine production), and measured the production of interleukin (IL)-6, IL-10, IL-12, and INF-alpha and the activation of MAPK. Keratinocyte cytokine production markedly increased and MAPK activation occurred following trauma-hemorrhage but were normalized by administration of estrogen, PPT and DPN. PPT and DPN administration were equally effective in normalizing the inflammatory response of keratinocytes, indicating that both ER-alpha. and ER-beta mediate the salutary effects of estrogen on kerotinocytes after trauma-hemorrhage.

Predictors of Bothrops jararaca venom allergy in snake handlers and snake venom handlers

Since allergic sensitization to snake venom has been reported, anaphylactic reactions to snake venom might be an underestimated factor contributing to fatal snakebites, independently from the toxicity of the venom itself. However, little information is available on the determinants of such reaction. Hence, we studied a group of workers exposed to Bothrops jararaca venom (BJV), in order to clarify the factors related with snake venom allergy. The aim of this work was to investigate the prevalence and predictors of venom allergy among workers exposed to BJV and to confirm the involvement of IgE-mediated mechanisms in this condition. Workers exposed to BJV were assessed for venom allergy using questionnaires and immunological tests. The presence of BJV sensitization was determined through quantification of specific IgE. Allergens were studied using the Western blots and inhibition assays. Of the 67 workers evaluated, 7 (10.4%) presented specific IgE antibodies to BJV. Of those, 6 presented typical symptoms of an IgE-mediated allergic reaction when exposed to BJV. Venom sensitization was associated with length of employment (P = 0.042), high levels of total IgE (P = 0.034), atopy (P = 0.051), and specific tasks, primarily the handling of dried venom (P = 0.014). Our observations suggest that exposure to BJV can result in allergic sensitization in snake handlers through IgE-mediated mechanisms. The prevalence rate of this condition appears to be high among these workers, and the handling of dried venom, total IgE level above 100 kU/L, length of employment, and probably history of atopy were predictors of its occurrence. (C) 2008 Elsevier Ltd. All rights reserved.

Platelet protease-activated receptor 1 and membrane expression of P-selectin in pulmonary arterial hypertension

Introduction: Pulmonary arterial hypertension (PAH) is frequently associated with thrombotic events, particularly involving the pulmonary microcirculation at sites of vascular injury. We therefore decided to analyse protease-activated receptor 1 (PAR1), a key element in the activation of human platelets by thrombin, in PAH patients in stable clinical condition. Methods: Using flow cytometry, we analyzed platelet PAR1 density, PAR1-mediated exposure of P-selectin and the formation of platelet-leukocyte aggregates in 30 PAH patients aged 11 to 78 years (median 50.5 years). The control group consisted of 25 healthy subjects with the same age range as patients. Results: In patients, total platelet PAR1 density and uncleaved PAR1 density correlated negatively with platelet count (r(2) = 0.33 and r(2) = 0.34 respectively, p < 0.0015). In patients with a low platelet count (<150 x 10(9) platelets/L), both densities were increased relative to controls (82% and 33% respectively, p < 0.05). Thrombin peptide-induced platelet exposure of P-selectin was directly related to total and uncleaved PAR1 density (respectively, r(2) = 0.33 and r(2) = 0.29, p < 0.0025) and increased in subjects with low platelet count (46% versus those with normal platelet count, p < 0.05). Patients with low platelet count had decreased in vitro thrombin-induced formation of platelet-leukocyte aggregates (57% decrease versus controls, p < 0.05). Conclusions: There seems to be a subpopulation of PAH patients with increased propensity to thrombotic events as suggested by increased platelet PAR1 expression and PAR-mediated surface exposure of P-selectin associated with decreased platelet count. (C) 2009 Elsevier Ltd. All rights reserved.

Ticagrelor vs. clopidogrel in patients with acute coronary syndromes and diabetes: a substudy from the PLATelet inhibition and patient Outcomes (PLATO) trial

Patients with diabetes mellitus (DM) have high platelet reactivity and are at increased risk of ischaemic events and bleeding post-acute coronary syndromes (ACS). In the PLATelet inhibition and patient Outcomes (PLATO) trial, ticagrelor reduced the primary composite endpoint of cardiovascular death, myocardial infarction, or stroke, but with similar rates of major bleeding compared with clopidogrel. We aimed to investigate the outcome with ticagrelor vs. clopidogrel in patients with DM or poor glycaemic control. We analysed patients with pre-existing DM (n = 4662), including 1036 patients on insulin, those without DM (n = 13 951), and subgroups based on admission levels of haemoglobin A1c (HbA1c; n = 15 150). In patients with DM, the reduction in the primary composite endpoint (HR: 0.88, 95% CI: 0.76-1.03), all-cause mortality (HR: 0.82, 95% CI: 0.66-1.01), and stent thrombosis (HR: 0.65, 95% CI: 0.36-1.17) with no increase in major bleeding (HR: 0.95, 95% CI: 0.81-1.12) with ticagrelor was consistent with the overall cohort and without significant diabetes status-by-treatment interactions. There was no heterogeneity between patients with or without ongoing insulin treatment. Ticagrelor reduced the primary endpoint, all-cause mortality, and stent thrombosis in patients with HbA1c above the median (HR: 0.80, 95% CI: 0.70-0.91; HR: 0.78, 95% CI: 0.65-0.93; and HR: 0.62, 95% CI: 0.39-1.00, respectively) with similar bleeding rates (HR: 0.98, 95% CI: 0.86-1.12). Ticagrelor, when compared with clopidogrel, reduced ischaemic events in ACS patients irrespective of diabetic status and glycaemic control, without an increase in major bleeding events.

Effect of the Novel Thienopyridine Prasugrel Compared With Clopidogrel on Spontaneous and Procedural Myocardial Infarction in the Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition With Prasugrel-Thrombolysis in Myocardial Infarction 38 An Application of the Classification System From the Universal Definition of Myocardial Infarction

Background-Prasugrel is a novel thienopyridine that reduces new or recurrent myocardial infarctions (MIs) compared with clopidogrel in patients with acute coronary syndrome undergoing percutaneous coronary intervention. This effect must be balanced against an increased bleeding risk. We aimed to characterize the effect of prasugrel with respect to the type, size, and timing of MI using the universal classification of MI. Methods and Results-We studied 13 608 patients with acute coronary syndrome undergoing percutaneous coronary intervention randomized to prasugrel or clopidogrel and treated for 6 to 15 months in the Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition With Prasugrel-Thrombolysis in Myocardial Infarction (TRITON-TIMI 38). Each MI underwent supplemental classification as spontaneous, secondary, or sudden cardiac death (types 1, 2, and 3) or procedure related (Types 4 and 5) and examined events occurring early and after 30 days. Prasugrel significantly reduced the overall risk of MI (7.4% versus 9.7%; hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.67 to 0.85; P < 0.0001). This benefit was present for procedure-related MIs (4.9% versus 6.4%; HR, 0.76; 95% CI, 0.66 to 0.88; P = 0.0002) and nonprocedural (type 1, 2, or 3) MIs (2.8% versus 3.7%; HR, 0.72; 95% CI, 0.59 to 0.88; P = 0.0013) and consistently across MI size, including MIs with a biomarker peak >= 5 times the reference limit (HR. 0.74; 95% CI, 0.64 to 0.86; P = 0.0001). In landmark analyses starting at 30 days, patients treated with prasugrel had a lower risk of any MI (2.9% versus 3.7%; HR, 0.77; P = 0.014), including nonprocedural MI (2.3% versus 3.1%; HR, 0.74; 95% CI, 0.60 to 0.92; P = 0.0069). Conclusion-Treatment with prasugrel compared with clopidogrel for up to 15 months in patients with acute coronary syndrome undergoing percutaneous coronary intervention significantly reduces the risk of MIs that are procedure related and spontaneous and those that are small and large, including new MIs occurring during maintenance therapy. (Circulation. 2009; 119: 2758-2764.)

Native LDL-Cholesterol Mediated Monocyte Adhesion Molecule Overexpression is Blocked by Simvastatin

Aim of the study This study sought to evaluate the effect of nLDL concentrations on monocyte adhesion molecule expression in hypercholesterolemic patients with stable corollary artery disease (CAD) and to determine whether lipid-lowering therapy with simvastatin Would change this effect. Methods Blood samples from patients with hypercholesterolemia (mean LDL 152 mg/dL) and CAD (HC, n = 23) were collected before and after a 12-week treatment with 40 mg of simvastatin. Healthy individuals (mean LDL 111 mg/dL) were used as controls (CT, n = 15). Isolated nLDL, at a fixed concentration of 100 mg/dL, was added to monocyte suspensions obtained before and after the simvastatin treatment. Monocyte activation was determined by changes in cellular adhesion molecule expression. Results In response to nLDL, CD11b and CD14 adhesion molecule expression was higher in HC patients than in CT patients before treatment (174.2+/-8.4 vs 102.2+/-6.3, P<0.03 and 140.4+/-5.0 vs 90.4+/-6.7, P<0.04). After simvastatin treatment, CD11b expression decreased to 116.9+/-12.5 (P< 0.03) and CD14 expression to 107.5+/-6.2 (P<0.04). Alternatively, L-selectin expression was lower in HC patients than in CT patients before therapy (46.0+/-3.5 vs 62.1+/-5.5, P<0.04), and it increased markedly after lipid reduction to 58.7+/-5.0 (P<0.04 vs baseline). After simvastatin treatment, LDL was reduced to mean 101.5 mg/dL. Conclusions These data demonstrate that monocytes from HC patients are more prone to marked nLDL-mediated changes of adhesion molecule expression than monocytes from controls. Simvastatin is capable of inhibiting such nLDL effects. This proinflammatory response to nLDL may have a role in the early onset of atherosclerosis.

Inhibition of angiotensin II receptor 1 limits tumor-associated angiogenesis and attenuates growth of murine melanoma

Purpose We evaluated the involvement of angiotensin II (AngII)-dependent pathways in melanoma growth, through the pharmacological blockage of AT1 receptor by the antihypertensive drug losartan (LOS). Results We showed immunolabeling for both AngII and the AT1 receptor within the human melanoma microenvironment. Like human melanomas, we showed that murine melanomas also express the AT1 receptor. Growth of murine melanoma, both locally and at distant sites, was limited in mice treated with LOS. The reduction in tumor growth was accompanied by a twofold decrease in tumorassociated microvessel density and by a decrease in CD31 mRNA levels. While no differences were found in the VEGF expression levels in tumors from treated animals, reduction in the expression of the VEGFR1 (Flt-1) at the mRNA and protein levels was observed. We also showed downregulation of mRNA levels of both Flt-4 and its ligand, VEGF-C. Conclusions Together, these results show that blockage of AT1 receptor signaling may be a promising anti-tumor strategy, interfering with angiogenesis by decreasing the expression of angiogenic factor receptors.

ASPM gene expression in medulloblastoma

Medulloblastomas are the most common malignant tumors of the central nervous system in childhood. The incidence is about 19-20% between children younger than 16 years old with peak incidence between 4 and 7 years. Despite its sensibility to no specific therapeutic means like chemotherapy and radiotherapy, the treatment is very aggressive and frequently results in regression, growth deficit, and endocrine dysfunction. From this point of view, new treatment approaches are needed such as molecular targeted therapies. Studies in glioblastoma demonstrated that ASPM gene was overexpressed when compared to normal brain and ASPM inhibition by siRNA-mediated inhibits tumor cell proliferation and neural stem cell proliferation, supporting ASPM gene as a potential molecular target in glioblastoma. The aim of this work was to evaluate ASPM expression in medulloblastoma fragment samples, and to compare the results with the patient clinical features. Analysis of gene expression was performed by quantitative PCR real time using SYBR Green system in tumor samples from 37 children. The t test was used to analyze the gene expression, and Mann-Whitney test was performed to analyze the relationship between gene expressions and clinical characteristics. Kaplan-Meier test evaluated curve survival. All samples overexpressed ASPM gene more than 40-fold. However, we did not find any association between the overexpressed samples and the clinical parameters. ASPM overexpression may modify the ability of stem cells to differentiate during the development of the central nervous system, contributing to the development of medulloblastoma, a tumor of embryonic origin from cerebellar progenitor cells.

Involvement of Astroglial Fibroblast Growth Factor-2 and Microglia in the Nigral 6-OHDA Parkinsonism and a Possible Role of Glucocorticoid Hormone on the Glial Mediated Local Trophism and Wound Repair

We have observed in previous studies that 6-hydroxydopamine (6-OHDA)-induced lesions in the nigrostriatal dopamine (DA) system promote increases of the astroglial basic fibroblast growth factor (FGF-2, bFGF) synthesis in the ascending DA pathways, event that could be modified by adrenosteroid hormones. Here, we first evaluated the changes of microglial reactivity in relation to the FGF-2-mediated trophic responses in the lesioned nigrostriatal DA system. 6-OHDA was injected into the left side of the rat substantia nigra. The OX42 immunohistochemistry combined with stereology showed the time course of the microglial activation. The OX42 immunoreactivity (IR) was already increased in the pars compacta of the substantia nigra (SNc) and ventral tegmental area (VTA) 2 h after the 6-OHDA injection, peaked on day 7, and remained increased on the 14th day time-interval. In the neostriatum, OX42 immunoreactive (ir) microglial profiles increased at 24 h, peaked at 72 h, was still increased at 7 days but not 14 days after the 6-OHDA injection. Two-colour immunofluorescence analysis of the tyrosine hydroxylase (TH) and OX42 IRs revealed the presence of small patches of TH IR within the activated microglia. A decreased FGF-2 IR was seen in the cytoplasm of DA neurons of the SNc and VTA as soon as 2 h after 6-OHDA injection. The majority of the DA FGF-2 ir cells of these regions had disappeared 72 h after neurotoxin. The astroglial FGF-2 IR increased in the SNc and VTA, which peaked on day 7. Two-colour immunofluorescence and immunoperoxidase analyses of the FGF-2 and OX42 IRs revealed no FGF-2 IR within the reactive or resting microglia. Second, we have evaluated in a series of biochemical experiments whether adrenocortical manipulation can interfere with the nigral lesion and the state of local astroglial reaction, looking at the TH and GFAP levels respectively. Rats were adrenalectomized (ADX) and received a nigral 6-OHDA stereotaxical injection 2 days later and sacrificed up to 3 weeks after the DA lesion. Western blot analysis showed time-dependent decrease and elevation of TH and GFAP levels, respectively, in the lesioned versus contralateral midbrain sides, events potentiated by ADX and worsened by corticosterone replacement. ADX decreased the levels of FGF-2 protein (23 kDa isoform) in the lesioned side of the ventral midbrain compared contralaterally. The results indicate that reactive astroglia, but not reactive microglia, showed an increased FGF-2 IR in the process of DA cell degeneration induced by 6-OHDA. However, interactions between these glial cells may be relevant to the mechanisms which trigger the increased astroglial FGF-2 synthesis and thus may be related to the trophic state of DA neurons and the repair processes following DA lesion. The findings also gave further evidence that adrenocortical hormones may regulate astroglial-mediated trophic mechanisms and wound repair events in the lesioned DA system that may be relevant to the progression of Parkinson`s disease.

Inhibition of phospholipase A(2) increases Tau phosphorylation at Ser214 in embryonic rat hippocampal neurons

Background: Arachidonic acid is released from cellular membranes by the action of phospholipase A(2) (PLA(2)) and is implicated in microtubule-associated protein Tau phosphorylation. Tau hyperphosphorylation affects its ability to stabilize microtubules. Objective: To determine the effect of PLA(2) inhibition on the phosphorylation state of Tau phosphoepitopes in primary cultures of hippocampal neurons. Methods: 4 DIC neurons were incubated at different concentrations of methyl-arachidonylfluorophosphonate (MAFP), an irreversible inhibitor of cPLA(2) and iPLA(2). Changes on Tau phosphorylation were determined by Western blotting with a panel of anti-Tau antibodies (C-terminal, Ser199/202, Ser202/205, Ser396 and Ser214). Results: The Ser214 site was hyperphosphorylated upon MAFP treatment. Significant differences were observed with 10 mu M (p = 0.01), 50 mu M (p = 0.01) and 100 mu M (p = 0.05) of MAFP. Less-intense changes were found in other phosphoepitopes. Conclusion: The present findings indicate that the phosphorylation of Ser214 is regulated by c- and/or iPLA(2), whereas other phosphoepitopes primarily regulated by GKS3b were not affected. (C) 2009 Elsevier Ltd. All rights reserved.

Inducible nitric oxide synthase inhibition attenuates lung tissue responsiveness and remodeling in a model of chronic pulmonary inflammation in guinea pigs

We evaluated the influence of iNOS-derived NO on the mechanics, inflammatory, and remodeling process in peripheral lung parenchyma of guinea pigs with chronic pulmonary allergic inflammation. Animals treated or not with 1400W were submitted to seven exposures of ovalbumin in increasing doses. Seventy-two hours after the 7th inhalation, lung strips were suspended in a Krebs organ bath, and tissue resistance and elastance measured at baseline and after ovalbumin challenge. The strips were submitted to histopathological measurements. The ovalbumin-exposed animals showed increased maximal responses of resistance and elastance (p < 0.05), eosinophils counting (p < 0.001), iNOS-positive cells (p < 0.001), collagen and elastic fiber deposition (p < 0.05), actin density (p < 0.05) and 8-iso-PGF2 alpha expression (p < 0.001) in alveolar septa compared to saline-exposed ones. Ovalbumin-exposed animals treated with 1400 W had a significant reduction in lung functional and histopathological findings (p < 0.05). We showed that iNOS-specific inhibition attenuates lung parenchyma constriction, inflammation, and remodeling, suggesting NO-participation in the modulation of the oxidative stress pathway. (C) 2008 Elsevier B.V. All rights reserved.

Effects of inducible nitric oxide synthase inhibition in bronchial vascular remodeling-induced by chronic allergic pulmonary inflammation

Vascular remodeling is an important feature in asthma pathophysiology. Although investigations suggested that nitric oxide (NO) is involved in lung remodeling, little evidence established the role of inducible NO synthase (iNOS) isoform in bronchial vascular remodeling. The authors investigated if iNOS contribute to bronchial vascular remodeling induced by chronic allergic pulmonary inflammation. Guinea pigs were submitted to ovalbumin exposures with increasing doses (1 similar to 5 mg/mL) for 4 weeks. Animals received 1400W (iNOS-specific inhibitor) treatment for 4 days beginning at 7th inhalation. Seventy-two hours after the 7th inhalation, animals were anesthetized, mechanical ventilated, exhaled NO was collected, and lungs were removed and submitted to picrosirius and resorcin-fuchsin stains and to immunohistochemistry for matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), and transforming growth factor-beta (TGF-beta). Collagen and elastic fiber deposition as well as MMP-9, TIMP-1, and TGF-beta expression were increase in bronchial vascular wall in ovalbumin-exposed animals. The iNOS inhibition reduced all parameters studied. In this model, iNOS inhibition reduced the bronchial vascular extracellular remodeling, particularly controlling the collagen and elastic fibers deposition in pulmonary vessels. This effect can be associated to a reduction on TGF-beta and on metalloproteinase-9/TIMP-1 vascular expression. It reveals new therapeutic strategies and some possible mechanism related to specific iNOS inhibition to control vascular remodeling.