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Symptom
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Target Concepts:
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Query: EC:3.1.4.1 (
phosphodiesterase
)
18,767
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
SCH351591, a novel
phosphodiesterase
-4 inhibitor under investigation as a potential therapeutic for asthma and
chronic obstructive pulmonary disease
(
COPD
), was evaluated in a 3-month rising-dose study in Cynomolgus monkeys. Four groups, containing four monkeys/sex, received vehicle control or rising doses up to 12, 24, or 48 mg/kg of SCH351591 daily. Although initial exposure produced clinical signs of emesis, reduced food intake, and reduced body weight, tachyphylaxis to the emesis allowed dose escalation up to 48 mg/kg/day. Two monkeys died and 3 were sacrificed in moribund condition over the course of the study. Early mortality, involving monkeys dosed with 12 or 24 mg/kg, was attributed to sepsis (2 monkeys) or colon inflammation (3 monkeys). Leukocyte function assays on low- and mid-dose group survivors revealed an inhibition of T lymphocyte proliferation for 12 mg/kg group males and 24 mg/kg group monkeys of both sexes. Necropsy findings, unassociated with early mortality, included reduced size and weight of the thymus, depletion of body fat, red discoloration of the gastric mucosa, and perivascular hemorrhage of the stomach and heart. Stomach and heart gross findings were present in the high-dose group only. Histopathologic lesions, in addition to those attributed to concurrent bacterial infection, included thymic atrophy, serous atrophy of fat, myocardial degeneration and acute to chronic inflammation of small to medium-sized arteries in various organs and tissues including the heart, kidneys, stomach, salivary glands, pancreas, esophagus, gallbladder, and mesentery. The findings of this study demonstrate the potential of a PDE4 inhibitor to alter immunologic response as well as to produce arteriopathy in nonhuman primates.
...
PMID:The toxicity of SCH 351591, a novel phosphodiesterase-4 inhibitor, in Cynomolgus monkeys. 1520 71
The presence of acute reversibility to bronchodilators does not distinguish asthma from
COPD
. Patients with either condition can benefit from bronchodilators, and should be given a trial to assess their response. Some respond with a change in lung volume with less hyperinflation; others improve their forced inspiratory flow and become much more comfortable. The combination of long-acting beta-agonists (LABAs) and inhaled steroids is useful in both conditions. While anticholinergics seem to yield the best results in
COPD
, some patients with asthma benefit from their use. Tiotropium may be the most effective agent as monotherapy in
COPD
, but the combination of an inhaled steroid and a LABA may produce similar results in improving lung function. Long-acting bronchodilators are effective agents as monotherapy in
COPD
, but in asthma should be combined with a controller medication. Short-acting beta-agonists should be used intermittently in asthma, but may be used regularly or combined with an anticholinergic in
COPD
. The roles of stereoisomers, leukotriene receptor antagonists, and type 4
phosphodiesterase
inhibitors in asthma and
COPD
remain uncertain at this time.
...
PMID:Therapeutic responses in asthma and COPD. Bronchodilators. 1530 73
No currently available treatments have been shown to slow the progression of
chronic obstructive pulmonary disease
(
COPD
) or suppress the inflammation in small airways and lung parenchyma. However, several new treatments are in clinical development; some target the inflammatory process and others are directed against structural cells. A group of specific therapies are directed against the influx of inflammatory cells into the airways and lung parenchyma that occurs in
COPD
; these include agents directed against adhesion molecules and chemokines, as well as therapies to oppose tumour necrosis factor alpha and increase interleukin 10. Broad-range anti-inflammatory drugs are now in phase III development for
COPD
; they include inhibitors of
phosphodiesterase
4. Other drugs that inhibit cell signalling include inhibitors of p38 mitogen-activated protein kinase, nuclear factor kappaB, and phosphoinositide-3-kinase gamma. More specific approaches are to give antioxidants, inhibitors of inducible nitric oxide synthase, and antagonists of leukotriene B4 receptor. Inhibitors of epidermal-growth-factor-receptor kinase and calcium-activated chloride channels have the potential to prevent overproduction of mucus. Therapy to inhibit fibrosis is being developed against transforming growth factor beta1 and protease-activated receptor 2. There is also a search for inhibitors of serine proteinases and matrix metalloproteinases to prevent lung destruction and the development of emphysema, as well as drugs such as retinoids that might even reverse this process. Effective delivery of drugs to the sites of disease in the peripheral lung is an important consideration, and there is a need for validated biomarkers and monitoring techniques in early clinical studies with new therapies for
COPD
.
...
PMID:Prospects for new drugs for chronic obstructive pulmonary disease. 1558 53
Although the prevalence of
chronic obstructive pulmonary disease
(
COPD
) is gradually increasing in all industrialized countries, there have been relatively few treatment advances. Recently, a better understanding of the cellular and molecular mechanisms involved in the inflammatory and destructive processes underlying
COPD
has identified new therapeutic targets. Several classes of drug are now in preclinical and clinical development:
phosphodiesterase
-4 inhibitors, protease inhibitors and remodelling agents such as retinoic acid will be available in the near future.
...
PMID:[Modern therapy of COPD]. 1536 26
The biochemical and pharmacological characteristics in human proinflammatory cells of BRL 50481 [3-(N,N-dimethylsulfonamido)-4-methyl-nitrobenzene], a novel and selective inhibitor of
phosphodiesterase
(
PDE
) 7, are described. BRL 50481 inhibited the activity of hrPDE7A1 expressed in baculovirus-infected Spodoptera frugiperda 9 cells in a competitive manner (Ki value of 180 nM) and was 416 and 1884 times less potent against PDE3 and 38 and 238 times less potent against PDE4 at a substrate concentration of 1 microM and 50 nM cAMP, respectively. Western blotting identified HSPDE7A1 but not HSPDE7A2 in three human cell types that are implicated in the pathogenesis of
chronic obstructive lung disease
, namely, CD8+ T-lymphocytes, monocytes, and lung macrophages. BRL 50481 had no effect on the proliferation of CD8+ T-lymphocytes and only marginally (approximately 2-11%) reduced the generation of tumor necrosis factor (TNF)alpha from blood monocytes and lung macrophages. However, in the presence of BRL 50481 the inhibitory effect of rolipram was enhanced on all three cell types. The expression of HSPDE7A1 was increased in a time-dependent manner in monocytes that were "aged" in culture medium. Under this condition, BRL 50481 now inhibited TNFalpha generation in a concentration-dependent manner. In aged monocytes, rolipram, Org 9935 (a PDE3 inhibitor), and prostaglandin E2 inhibited TNFalpha generation in a concentration-dependent manner and interacted additively with BRL 50481. BRL 50481 is the first fully documented PDE7 inhibitor that has acceptable selectivity for in vitro studies. Furthermore, although BRL 50481 had only a modest inhibitory effect per se on the proinflammatory cells studied, it acted at least additively with other cAMP-elevating drugs, especially when HSPDE7A1 was up-regulated.
...
PMID:Discovery of BRL 50481 [3-(N,N-dimethylsulfonamido)-4-methyl-nitrobenzene], a selective inhibitor of phosphodiesterase 7: in vitro studies in human monocytes, lung macrophages, and CD8+ T-lymphocytes. 1537 56
Glucocorticosteroids remain the gold standard therapy for the prophylactic treatment of asthma. Concerns regarding its long-term use particularly in young children has provided an impetus for discovering novel anti-inflammatory molecules with high tolerability and clinical efficacy. Whilst for
chronic obstructive pulmonary disease
(
COPD
), there exist no pharmacological treatment for the prevention of decline in lung function. Targeting
phosphodiesterase
(
PDE
)4 is one example of this approach and inhibitors of this enzyme are the most advanced drug class in the respiratory pipeline. A number of potent PDE4 inhibitors have undergone clinical trials with moderate success. Tolerability and clinical efficacy issues have dampened enthusiasm in this area. However, with the prospect of newer potent and side effect free inhibitors on the horizon give this area guarded optimism. This review will summarise the most recent information concerning the effectiveness of PDE4 inhibitors as novel anti-inflammatory agents for the treatment of respiratory diseases.
...
PMID:The potential of PDE4 inhibitors in respiratory disease. 1537 90
The pathogenesis of preeclampsia stems from aberrant changes at the placental interface. The trophoblastic endovascular invasion of tonic spiral arteries that converts them to passive conduits falters. Uteroplacental insufficiency and fetoplacental hypoxemia result. Secondary maternal oxidative stress and an excessive inflammatory response to pregnancy generate the clinical syndrome of preeclampsia. Current treatment focuses on preventing seizures, controlling hypertension, preserving renal function and delivering the baby. We propose that the pathophysiological changes induced by preeclampsia in the placenta parallel those caused by persistent hypoxemia in the lungs at high altitude or with
chronic obstructive pulmonary disease
. Unrelenting pulmonary hypoxic vasoconstriction induces pulmonary hypertension and cor pulmonale. Inhalation of nitric oxide and
phosphodiesterase
-5 inhibitors opposes pulmonary hypoxic vasoconstriction, alleviates pulmonary hypertension and improves systemic oxygenation. Notably nitric oxide donor therapy also counters hypoxemic fetoplacental vasoconstriction, a biological response analogous to pulmonary hypoxic vasoconstriction. Fetal oxygenation and nutrition improve. Placental upstream resistance to umbilical arterial blood flow decreases. Fetal right ventricular impedance falls. Heart failure (cor placentale) is avoided. Emergency preterm delivery can be postponed. Other than low dose aspirin and antioxidants vitamins C and E no available therapy specifically targets the underlying disease profile. We hypothesize that, like nitric oxide donation, pharmacological inhibition of placental
phosphodiesterase
-5 will also protect the fetus but for a longer time. Biological availability of guanosine 3'5'-cyclic monophosphate is boosted due to slowed hydrolysis. Adenosine 3'5'-cyclic monphosphate levels increase in parallel. Cyclic nucleotide accumulation dilates intact tonic spiral arteries and counters hypoxemic fetoplacental vasoconstriction. Intervillous and intravillous perfusion pick up. Maternal to fetal placental circulatory matching improves. Enhanced placental oxygen uptake alleviates hypoxemic fetal stress. Appropriate fetal nutrition resumes. Cor placentale and severe intrauterine growth restriction are averted. Increased maternal cyclic nucleotide concentrations promote systemic vasodilatation so that blood pressures fall. Preemption of oxidative stress initiated by "consumptive" oxidation of nitric oxide stabilizes the vascular endothelium and corrects coagulopathy. Anti-inflammatory and immunosuppressant adenosine 3'5'-cyclic monphosphate offsets the extreme gestational inflammatory response. Cellular injury and multi-organ damage are prevented. One tablet a day of the new long acting
phosphodiesterase
-5 inhibitor, tadalafil (half life of 17.5 h) theoretically should allow a preterm pregnancy affected by preeclampsia to continue safely. Selective monitoring of vital organ functions guards against life-threatening maternal complications. Regular biophysical profiling warns the obstetrician of impending fetal compromise. Fetal growth and vital organ maturation can continue. As a result workloads imposed upon neonatal intensivists will lighten. Parental anxiety and concern will be allayed. The cost of treating preeclamptic mothers and their extremely low birth weight infants will decrease. Money saved by midwifery services in poorer states can be used to pay for better prenatal care. Severe preeclampsia/eclampsia will be less common. Maternal and perinatal morbidity and mortality will be reduced. Because the human immunodeficiency virus often infects individuals at a workforce eligible age, the global acquired immunodeficiency syndrome pandemic has already brought many nations to the brink of economic ruin. Potentially productive lives saved for the future will help restore them fiscally.
...
PMID:Hypothesis: selective phosphodiesterase-5 inhibition improves outcome in preeclampsia. 1550 76
Chronic obstructive pulmonary disease (COPD)
is a common, progressive respiratory disease that causes great morbidity and mortality despite treatment. Tumor necrosis factor alpha (TNF-alpha) plays a central role as a pro-inflammatory cytokine in
COPD
. TNF-alpha release is markedly inhibited by
phosphodiesterase
type 4 (PDE4) inhibitors that have proven efficacious in
COPD
clinical trials. The aim of this study was to compare the in vitro activities of the novel selective PDE4 inhibitors CI-1044 compared to well-known PDE4 inhibitors, rolipram and cilomilast, and to the glucocorticoid dexamethasone at reducing lipopolysaccharide (LPS)-induced TNF-alpha release in whole blood from
COPD
patients and healthy subjects. In the whole blood from
COPD
patients pre-incubation with PDE4 inhibitors or dexamethasone resulted in a dose-dependent inhibition of LPS-induced TNF-alpha release with IC(50) values of 1.3+/-0.7, 2.8+/-0.9 microM, higher to 10 microM and lesser than 0.03 microM for CI-1044, rolipram, cilomilast and dexamethasone, respectively. We observed a similar inhibition in the whole blood from healthy volunteers with, however, higher IC(50) values. These results indicate that CI-1044 inhibits in vitro LPS-induced TNF-alpha release in whole blood from
COPD
patients better than rolipram and cilomilast and suggested that it could be a useful anti-inflammatory therapy in
COPD
.
...
PMID:The novel phosphodiesterase 4 inhibitor, CI-1044, inhibits LPS-induced TNF-alpha production in whole blood from COPD patients. 1560 27
Inhibitors of
phosphodiesterase
type 4 (PDE4) act by increasing intracellular concentrations of cyclic AMP, which has a broad range of anti-inflammatory effects on various key effector cells involved in asthma and
chronic obstructive pulmonary disease
(
COPD
). The therapeutic ratio for PDE4 inhibitors is thought to be determined by selectivity on receptor subtypes for relative effects on PDE4B (anti-inflammatory) and PDE4D (emesis). The two main orally active PDE4 inhibitors in the late phase III of clinical development are cilomilast and roflumilast; the latter (and its active metabolite N-oxide) is more selective and potent with a superior therapeutic ratio. Studies on cilomilast in
COPD
based on bronchial biopsy material have shown a broad range of anti-inflammatory activity, and the available evidence on clinical outcomes for up to 6 months with cilomilast 15 mg twice daily and roflumilast 500 mug once daily have shown variable but significant effects on exacerbations and quality of life, with small improvements in measures of pulmonary function. Roflumilast has a better safety and tolerability profile than cilomilast, with the main adverse effects being nausea, diarrhoea, and abdominal pain. Roflumilast also has activity in asthma as assessed by its attenuation of allergen and exercise challenges, and it shows clinical efficacy equivalent to that of beclomethasone dipropionate 400 mug daily. The emerging results of clinical trials on PDE4 inhibitors in asthma and
COPD
should be interpreted with cautious optimism since much of the evidence has been published only in abstract form to date. The next few years should resolve important issues about the potential role of these drugs as oral non-steroidal anti-inflammatory therapy for asthma and
COPD
and their place in management guidelines. Ultimately, clinicians will want to know whether PDE4 inhibitors are anything more than expensive "designer" theophylline, the archetypal non-selective
phosphodiesterase
inhibitor.
...
PMID:Phosphodiesterase-4 inhibitors for asthma and chronic obstructive pulmonary disease. 1563
Neutrophil-derived proteases such as neutrophil elastase (NE) and matrix metalloproteinase (MMP) are implicated in the pathogenesis of
Chronic Obstructive Pulmonary Disease
(
COPD
). In this study, the effects of selective
phosphodiesterase
(
PDE
) inhibition on NE and MMP-9 release, as well as Myeloperoxidase (MPO) activity and integrin-mediated neutrophil adhesion to human umbilical vein endothelial cells (HUVECs), were investigated. Human neutrophils were treated with
PDE
inhibitors (10(-11)-10(-4)M) in the absence and presence of TNF-alpha (tumour necrosis factor) (100 U ml(-1)) for 30 min, prior to fMLP activation. After 45 min, the cells were removed and NE, MPO and MMP-9 release assessed. In the adhesion studies, the neutrophils were radio-labelled with 51Cr, stimulated and immediately transferred to cultured HUVEC monolayers for 30 min, prior to assessment of adhesion. TNF-alpha (100 U ml(-1)) acted synergistically with fMLP in stimulating azurophil degranulation with respect to both MPO activity (P<0.01) and NE release (P<0.01). In contrast, an additive effect was observed with TNF-alpha and fMLP with regard to MMP-9 release and neutrophil adhesion to HUVECs. The PDE4 inhibitors, roflumilast, roflumilast N-oxide, cilomilast and rolipram significantly suppressed MPO, NE and MMP-9 release in both the presence and absence of TNF-alpha (P<0.05; n=6-10) and also reduced neutrophil adhesion to HUVECs. In contrast, milrinone, a PDE3 inhibitor and the non-selective
PDE
inhibitor, theophylline did not inhibit azurophil degranulation under any of the experimental conditions. These data provide further evidence that selective PDE4 isoenzyme inhibitors can inhibit neutrophil degranulation, effects not shared by PDE3 inhibitors or theophylline.
...
PMID:The effect of selective phosphodiesterase isoenzyme inhibition on neutrophil function in vitro. 1564 51
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