la-419 and Disease-Models--Animal

LA-419, currently being developed by Lacer SA, is a thiol-containing analog of isosorbide mononitrate that is undergoing assessment in clinical trials for the treatment of chronic ischemic cardiovascular disorders. The compound was originally designed to have a reduced tendency toward tolerance sensitivity - a major limitation of established organic nitrate compounds. The rationale behind the drug design was to include an antioxidant moiety in the drug structure to combat the contribution of oxidative stress in tolerance induction. The compound is at an early stage of development, but has already provided some surprising data. First, LA-419 does not appear to require the nitroxy ester moiety for activity and its actions might not be mediated only by nitric oxide release. Second, unlike conventional nitrates, LA-419 is active in platelets, suggesting a potential role as an antithrombotic agent. Third, LA-419 has a profound impact on left ventricular hypertrophy, making the drug a plausible candidate for several additional potential therapeutic opportunities. In addition, LA-419 has demonstrated potential in the treatment of glaucoma and intestinal disorders. At the time of publication, LA-419 was in phase II clinical trials in patients with chronic ischemic cardiovascular disorders.

Topics: Animals; Antioxidants; Cardiovascular Agents; Cardiovascular Diseases; Disease Models, Animal; Drug Tolerance; Fibrinolytic Agents; Humans; Hypertrophy, Left Ventricular; Isosorbide Dinitrate; Myocardial Ischemia; Nitric Oxide Donors; Patents as Topic; Structure-Activity Relationship; Treatment Outcome

Indomethacin induces a chronic model of inflammatory bowel disease (IBD) characterized by spontaneous relapses of inflammation, bacterial translocation, and long-lasting motor disturbances derived from cyclical up-regulated inducible nitric-oxide synthase (iNOS) and sustained down-regulated neuronal NOS (nNOS). The aims of this study were to evaluate whether LA-419 [S-(6-nitro-oxi-hexahydro-furo[3,2-b]furan-3-1-il)thioacetate], a NO-donor drug, could re-establish the normal expression of NOS and, hence, prevent the development of intestinal dysmotility, bacterial translocation, and relapses of inflammation associated to this model. Enteritis was induced in rats by administration of indomethacin with and without treatment with a novel NO-donor: LA-419 (0.5 mg/ml in the drinking water). Inflammatory reaction was evaluated by measuring blood leukocytes, serum tumor necrosis factor, and tissue myeloperoxidase. Intestinal motor activity was evaluated using strain-gauges. Ileal expression of iNOS and nNOS mRNA was determined by reverse transcription-polymerase chain reaction. Bacterial translocation was evaluated in cultures from mesenteric lymph nodes. The indomethacin-induced acute inflammatory reaction was associated with a rise in blood leukocytes and tumor necrosis factor. In the chronic stage, blood leukocyte monitoring allowed the selection of animals in active and inactive phases. Active phase was associated with iNOS up-regulation, high myeloperoxidase levels, hypomotility, and bacterial translocation. In contrast, inactive phase was associated with hypermotility and absence of bacterial translocation. LA-419 treatment restored nitric-oxide synthase isoenzyme expression and prevented the oscillation of both inflammatory and motor parameters that could be cyclically observed in inflamed rats. LA-419 also prevented intestinal dysmotility, bacterial translocation, and relapses of intestinal inflammation. LA-419 might be a novel therapeutic approach to prevent acute inflammatory relapses in patients with IBD.

Topics: Animals; Bacterial Translocation; Disease Models, Animal; Enteritis; Gastrointestinal Motility; Inflammation; Intestinal Diseases; Isosorbide Dinitrate; Lymph Nodes; Male; Nitric Oxide Donors; Rats; Rats, Sprague-Dawley

Stroke represents a major clinical problem with limited available therapeutic treatments. Nitric oxide (NO) and the enzymes that produce it are involved in the pathogenesis of this disease. Here we investigated whether the novel NO donor LA 419 was able to ameliorate the consequences of stroke in an experimental model of global ischemia. We observed a sharp increase in the amounts of inducible NO synthase (iNOS) and nitrotyrosine in the cerebral cortex of experimental rats and a moderate increase of neuronal NO synthase (nNOS), as demonstrated by immunohistochemistry, Western blotting, and enzymatic activity assays. Treatment of these animals with LA 419 completely prevented ischemia-induced upregulation of nitrergic markers. Magnetic resonance imaging of the experimental brains showed a marked decrease in apparent diffusion coefficient (ADC) following ischemia-reperfusion, which was significantly corrected by pre-treatment with LA 419. These results clearly show that LA 419 is an efficient modulator of NO-related pathophysiological events and could eventually be used for the treatment of patients with cerebrovascular pathologies.

Topics: Animals; Brain Ischemia; Calcium; Disease Models, Animal; Immunohistochemistry; Isosorbide Dinitrate; Magnetic Resonance Imaging; Male; Neurons; Nitric Oxide Donors; Nitric Oxide Synthase Type I; Nitric Oxide Synthase Type II; Rats; Rats, Wistar; Tyrosine

Stroke affects a large number of people, especially in developed countries, but treatment options are limited. Over the years, it has become clear that nitric oxide (NO) plays a major role in this pathology and that treatments that either reduce or increase NO presence may provide an alternative route for reducing the sequelae of brain ischemia. The NO donor LA 419 previously has been shown to protect the brain tissue from ischemic damage in an experimental model of global brain ischemia. Here we study whether this holds true for focal ischemia, a condition closer to the more common form of human stroke. Ischemia was induced in rats by a stereotaxic injection of endothelin-1, a potent vasoconstrictor, in the striatum. Seven days after the injection, magnetic resonance imaging (MRI) found a significant elevation in apparent diffusion coefficient (ADC) in the injected striatum of untreated rats, due to ischemia-induced vascular edema. Animals that received LA 419 prior to injection with endothelin-1 showed an ADC undistinguishable from the contralateral striatum or from the striatum of rats not treated with LA 419. In addition, immunohistochemistry with antibodies against neuronal nitric oxide synthase (nNOS), inducible NOS (iNOS), and nitrotyrosine showed a marked increase in the expression of these markers of NO production following ischemic treatment that was dampened by treatment with LA 419. In summary, our results clearly show that the NO donor LA 419 may be a useful compound for the prevention and/or treatment of focal brain ischemia.

Topics: Animals; Brain Injuries; Corpus Striatum; Disease Models, Animal; Ischemia; Isosorbide Dinitrate; Magnetic Resonance Imaging; Male; Nitric Oxide Donors; Nitric Oxide Synthase Type I; Nitric Oxide Synthase Type II; Rats; Rats, Wistar; Time Factors; Tyrosine

Despite the proven efficacy of current antithrombotic therapy in preventing ischemic heart disease (IHD), vascular events still occur. Our aims were i) to evaluate if combined oral treatment of clopidogrel and LA419, a novel nitric oxide donor with anti-ischemic and antiplatelet properties, provides additional antiplatelet effects to those of the blockade of P2Y(12) receptor; and ii) to gain insight into the mechanism behind LA419 antiplatelet effects. Pigs (n = 16) were randomized into four groups: 1) placebo-control; 2) LA419; 3) clopidogrel; and 4) LA419+clopidogrel. Both compounds were administered orally: LA419 0.9 mg kg(-1) twice daily for 10 days; clopidogrel 10 mg kg(-1) day the three last days. Antithrombotic effects were assessed by measuring platelet deposition (PD) triggered by denuded and disrupted vessel wall placed on the Badimon chamber. LA419 effects on platelet aggregation, hemodynamic parameters, and platelet protein expression upon in vitro thrombin stimulation were also evaluated. Total PD on denuded vessels was similarly reduced by all treatments with respect to placebo (p < 0.05). However, combination of LA419+clopidogrel largely reduced PD triggered by disrupted vessel wall by 80% versus placebo (p < 0.005), 15% versus clopidogrel alone (p < 0.01), and 30% versus LA419 alone (p < 0.005). All treatments inhibited collagen- and ADP-induced platelet aggregation, and no variations were detected in hemodynamic parameters. Proteomic analysis revealed that LA419 was associated with an increase in membrane protein disulphide isomerase (protein implicated in nitric oxide release). Treatment with LA419 may result in additional antiplatelet effect to that of clopidogrel in addition to restoring impaired endothelial dependent vasodilation without hemodynamic side effects. Further studies in IHD patients seem warranted.

Topics: Administration, Oral; Animals; Blood Coagulation; Clopidogrel; Disease Models, Animal; Drug Therapy, Combination; Female; Fibrinolytic Agents; Isosorbide Dinitrate; Nitric Oxide; Nitric Oxide Donors; Platelet Adhesiveness; Platelet Aggregation; Platelet Aggregation Inhibitors; Protein Disulfide-Isomerases; Proteomics; Purinergic P2 Receptor Antagonists; Random Allocation; Receptors, Purinergic P2; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Swine; Thrombosis; Ticlopidine; Vasodilator Agents