Sample records for tyrosyl-dna phosphodiesterase tdp1

  1. The Human Tyrosyl-DNA Phosphodiesterase 1 (hTdp1) Inhibitor NSC120686 as an Exploratory Tool to Investigate Plant Tdp1 Genes. (United States)

    Macovei, Anca; Pagano, Andrea; Sabatini, Maria Elisa; Grandi, Sofia; Balestrazzi, Alma


    The hTdp1 (human tyrosyl-DNA phosphodiesterase 1) inhibitor NSC120686 has been used, along with topoisomerase inhibitors, as a pharmacophoric model to restrain the Tdp1 activity as part of a synergistic treatment for cancer. While this compound has an end-point application in medical research, in plants, its application has not been considered so far. The originality of our study consists in the use of hTdp1 inhibitor in Medicago truncatula cells, which, unlike human cells, contain two Tdp1 genes. Hence, the purpose of this study was to test the hTdp1 inhibitor NSC120686 as an exploratory tool to investigate the plant Tdp1 genes, since their characterization is still in incipient phases. To do so, M. truncatula calli were exposed to increasing (75, 150, 300 μM) concentrations of NSC120686. The levels of cell mortality and DNA damage, measured via diffusion assay and comet assay, respectively, were significantly increased when the highest doses were used, indicative of a cytotoxic and genotoxic threshold. In addition, the NSC120686-treated calli and untreated MtTdp1α -depleted calli shared a similar response in terms of programmed cell death (PCD)/necrosis and DNA damage. Interestingly, the expression profiles of MtTdp1α and MtTdp1β genes were differently affected by the NSC120686 treatment, as MtTdp1α was upregulated while MtTdp1β was downregulated. The NSC120686 treatment affected not only the MtTdp1 genes but also other genes with roles in alternative DNA repair pathways. Since the expression patterns of these genes were different than what was observed in the MtTdp1α -depleted plants, it could be hypothesized that the NSC120686 treatment exerts a different influence compared to that resulting from the lack of the MtTdp1α gene function.

  2. Combining a nanosensor and ELISA for measurement of tyrosyl-dna phosphodiesterase 1 (tdp1) activity and protein amount in cell and tissue extract

    DEFF Research Database (Denmark)

    Jakobsen, Ann-Katrine; Stougaard, Magnus


    radiation and free radical-based genotoxins. TDP1 has been reported to be posttranslational regulated, and in nonsmall cell lung cancer (NSCLC) it has been reported that the enzyme activity of TDP1 can be upregulated without detectable upregulation in protein amount. Activity and protein analyses...... are normally performed sequentially using radioactively labeled DNA substrates analyzed using gel-electrophoresis for the activity measurement and western blot or ELISA for protein measurement. We demonstrate here that our previously developed TDP1 nanosensor due to the optical real-time readout can...

  3. Analysis of the Active-Site Mechanism of Tyrosyl-DNA Phosphodiesterase I: A Member of the Phospholipase D Superfamily

    Energy Technology Data Exchange (ETDEWEB)

    Gajewski, Stefan; Comeaux, Evan Q.; Jafari, Nauzanene; Bharatham, Nagakumar; Bashford, Donald; White, Stephen W.; van Waardenburg, Robert C.A.M. (UAB); (SJCH)


    Tyrosyl-DNA phosphodiesterase I (Tdp1) is a member of the phospholipase D superfamily that hydrolyzes 3'-phospho-DNA adducts via two conserved catalytic histidines - one acting as the lead nucleophile and the second acting as a general acid/base. Substitution of the second histidine specifically to arginine contributes to the neurodegenerative disease spinocerebellar ataxia with axonal neuropathy (SCAN1). We investigated the catalytic role of this histidine in the yeast protein (His432) using a combination of X-ray crystallography, biochemistry, yeast genetics, and theoretical chemistry. The structures of wild-type Tdp1 and His432Arg both show a phosphorylated form of the nucleophilic histidine that is not observed in the structure of His432Asn. The phosphohistidine is stabilized in the His432Arg structure by the guanidinium group that also restricts the access of nucleophilic water molecule to the Tdp1-DNA intermediate. Biochemical analyses confirm that His432Arg forms an observable and unique Tdp1-DNA adduct during catalysis. Substitution of His432 by Lys does not affect catalytic activity or yeast phenotype, but substitutions with Asn, Gln, Leu, Ala, Ser, and Thr all result in severely compromised enzymes and DNA topoisomerase I-camptothecin dependent lethality. Surprisingly, His432Asn did not show a stable covalent Tdp1-DNA intermediate that suggests another catalytic defect. Theoretical calculations revealed that the defect resides in the nucleophilic histidine and that the pK{sub a} of this histidine is crucially dependent on the second histidine and on the incoming phosphate of the substrate. This represents a unique example of substrate-activated catalysis that applies to the entire phospholipase D superfamily.

  4. Correlation between topoisomerase I and tyrosyl-DNA phosphodiesterase 1 activities in non-small cell lung cancer tissue

    DEFF Research Database (Denmark)

    Jakobsen, Ann-Katrine; Lauridsen, Kristina Lystlund; Samuel, Evelyn Benuja


    of the camptothecin family (CPT). TDP1 has in cell line based assays been shown to counteract the effect of CPT. We have quantified the enzymatic activities of TOP1 and TDP1 in paired (tumor and adjacent non-tumor) samples from non-small cell lung cancer (NSCLC) patients and show that in NSCLC TOP1 and TDP1...

  5. Real-time detection of TDP1 activity using a fluorophore-quencher coupled DNA-biosensor

    DEFF Research Database (Denmark)

    Jensen, Pia Wrensted; Falconi, Mattia; Kristoffersen, Emil Laust


    Real-time detection of enzyme activities may present the easiest and most reliable way of obtaining quantitative analyses in biological samples. We present a new DNA-biosensor capable of detecting the activity of the potential anticancer drug target tyrosyl-DNA phosphodiesterase 1 (TDP1) in a very...... simple, high throughput, and real-time format. The biosensor is specific for Tdp1 even in complex biological samples, such as human cell extracts, and may consequently find future use in fundamental studies as well as a cancer predictive tool allowing fast analyses of diagnostic cell samples...... activity in pure enzyme fractions as well as in crude cell extracts. In the present study we demonstrate the specificity of the biosensor, its ability to quantitatively detect up- or down-regulated TDP1 activity, and that it may be used for measuring and for analyzing the mechanism of TDP1 inhibition....

  6. Drosophila TDP1 Ortholog Important for Longevity and Nervous System Maintenance | Center for Cancer Research (United States)

    As the molecule responsible for encoding a cell’s hereditary information, DNA must maintain its integrity. However, nucleic acids are vulnerable to damage by a number of endogenous and exogenous insults, such as reactive oxygen species or enzymes that react with DNA. Thus, other enzymes are tasked with repairing damaged DNA, including tyrosyl-DNA phosphodiesterase 1 (TDP1), which frees the 3’ ends of DNA that are blocked by proteins and oxidized bases to allow the ligation of strand breaks. Yeast, mice, and humans that express mutants of TDP1 have a reduced capacity to repair oxidative or topoisomerase-induced damage. A Drosophila TDP1 ortholog, glaikit (gkt), has been reported, but its function in DNA repair has not been evaluated because, surprisingly, gkt knockout flies were not viable.

  7. Phosphodiesterase 4 inhibitors. (United States)

    Zebda, Rema; Paller, Amy S


    Historically, drugs available for treating atopic dermatitis (AD) have been limited to topical corticosteroids and topical calcineurin inhibitors, with systemic immunosuppressants and phototherapy reserved for severe AD. Despite their efficacy and infrequent adverse events, phobia about the use of topical steroids and calcineurin inhibitors has limited their use. More targeted options with fewer systemic and cutaneous side effects are needed for treating AD. Phosphodiesterase 4 (PDE4) is involved in the regulation of proinflammatory cytokines via the degradation of cyclic adenosine monophosphate. PDE4 activity is increased in the inflammatory cells of patients with AD, leading to increased production of proinflammatory cytokines and chemokines. Targeting PDE4 reduces the production of these proinflammatory mediators in AD. Both topical and oral PDE4 inhibitors have a favorable safety profile. Crisaborole 2% ointment, a topical PDE4, is now US Food and Drug Administration-approved for children older than 2 years and adults in the treatment of AD. Crisaborole 2% ointment shows early and sustained improvement in disease severity and pruritus and other AD symptoms, with burning and/or stinging upon application as the only related adverse event. Other PDE4 inhibitors are currently in trials with promising efficacy and safety. Copyright © 2017. Published by Elsevier Inc.

  8. Bronchodilatory and anti-inflammatory properties of inhaled selective phosphodiesterase inhibitors in a guinea pig model of allergic asthma

    NARCIS (Netherlands)

    Santing, R.E; de Boer, J; Rohof, A.A B; van der Zee, N.M; Zaagsma, Hans


    In a guinea pig model of allergic asthma, we investigated the effects of the selective phosphodiesterase inhibitors rolipram (phosphodiesterase 4-selective), Org 9935 (phosphodiesterase 3-selective) and Org 20241 (dual phosphodiesterase 4/phosphodiesterase 3-selective), administered by aerosol

  9. Two phosphodiesterases from Ustilago maydis share structural and biochemical properties with non-fungal phosphodiesterases

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    Charu eAgarwal


    Full Text Available The dependence of Protein Kinase A (PKA activity on cAMP levels is an important facet of the dimorphic switch between budding and filamentous growth as well as for pathogenicity in some fungi. To better understand these processes in the pathogenic fungus Ustilago maydis, we characterized the structure and biochemical functions of two phosphodiesterase (PDE genes. Phosphodiesterases are enzymes involved in cAMP turnover and thus, contribute to the regulation of the cAMP-PKA signaling pathway. Two predicted homologues of PDEs were identified in the genome of U. maydis and hypothesized to be involved in cAMP turnover, thus regulating activity of the PKA catalytic subunit. Both umpde1 and umpde2 genes contain domains associated with phosphodiesterase activity predicted by InterPro analysis. Biochemical characterization of recombinantly produced UmPde1 (U. maydis Phosphodiesterase I and UmPde2 demonstrated that both enzymes have phosphodiesterase activity in vitro, yet neither was inhibited by the phosphodiesterase inhibitor IBMX. Moreover, UmPde1 is specific for cAMP, while UmPde2 has broader substrate specificity, utilizing cAMP and cGMP as substrates. In addition, UmPde2 was also found to have nucleotide phosphatase activity that was higher with GMP compared to AMP. These results demonstrate that UmPde1 is a bona fide phosphodiesterase, while UmPde2 has more general activity as a cyclic nucleotide phosphodiesterase and/or GMP/AMP phosphatase. Thus, UmPde1 and UmPde2 likely have important roles in cell morphology and development and share some characteristics with a variety of non-fungal phosphodiesterases.

  10. Effect of phosphodiesterase inhibitors in the bladder

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    Bilal Chughtai


    Full Text Available Many aging men will experience lower urinary tract symptoms (LUTS. Phosphodiesterase type 5 (PDE5 inhibitors have shown promise in treating LUTS in these patients. PDE5 inhibitors mediate their effects through several pathways including cAMP, NO/cGMP, K-channel modulated pathways, and the l-cysteine/H2S pathway. PDE5 inhibitors exert their effect in muscle cells, nerve fibers, and interstitial cells (ICs. The use of PDE5 inhibitors led to improvement in LUTS. This included urodynamic parameters. PDE5 inhibitors may play a significant role in LUTS due to their effect on the bladder rather than the prostate.

  11. Phosphodiesterases in endocrine physiology and disease. (United States)

    Vezzosi, Delphine; Bertherat, Jérôme


    The cAMP-protein kinase A pathway plays a central role in the development and physiology of endocrine tissues. cAMP mediates the intracellular effects of numerous peptide hormones. Various cellular and molecular alterations of the cAMP-signaling pathway have been observed in endocrine diseases. Phosphodiesterases (PDEs) are key regulatory enzymes of intracellular cAMP levels. Indeed, PDEs are the only known mechanism for inactivation of cAMP by catalysis to 5'-AMP. It has been suggested that disruption of PDEs could also have a role in the pathogenesis of many endocrine diseases. This review summarizes the most recent advances concerning the role of the PDEs in the physiopathology of endocrine diseases. The potential significance of this knowledge can be easily envisaged by the development of drugs targeting specific PDEs.

  12. Effectiveness of Phosphodiesterase-5 Inhibitor Therapy for Portopulmonary Hypertension

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    Jolene H Fisher


    Full Text Available BACKGROUND: Portopulmonary hypertension is associated with significant morbidity and mortality. Phosphodiesterase-5 inhibitor therapy is efficacious in other causes of WHO group I pulmonary arterial hypertension.

  13. Assay of cyclic nucleotide phosphodiesterase using radiolabeled and fluorescent substrates

    International Nuclear Information System (INIS)

    Kincaid, R.L.; Manganiello, V.C.


    There are four major classes of phosphodiesterase with different specificities for cAMP and cGMP and different allosteric regulators. Type I phosphodiesterase is activated by calmodulin plus Ca/sup 2+/ and has a higher affinity for cGMP than cAMP. Type II phosphodiesterase likewise has a higher affinity for cGMP than cAMP, but the activity toward one substrate is markedly stimulated by low (micromolar) concentrations of the other nucleotide. Type III phosphodiesterase has a higher affinity for cAMP than cGMP; its activity is increased in responsive cells by certain hormones, e.g., insulin, isoproterenol. Type IV phosphodiesterase is the cGMP-specific enzyme, which also has an allosteric binding site for cGMP. An example of this class of enzyme is the one from retinal rod outer segments, which is activated by light via rhodopsin and the guanine nucleotide-binding protein transducin. There appears to be little structural relatedness among these enzymes based on immunologic analysis, consistent with the possibility that divergent forms evolved from an ancestral enzyme. Determination of the amount of a specific form of phosphodiesterase in crude material is often difficult. Modification of assay conditions by judicious choice of substrate and/or inhibitor concentrations may selectively favor (or reduce) the activity of a particular form; in many instances, however, some fractionation of enzymes may be necessary. This is discussed more fully in the final section of this chapter

  14. Phosphodiesterase-5 inhibitors: Raynaud's and beyond

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    Sanat Phatak


    Full Text Available Phosphodiesterases (PDE are a group of ubiquitously present enzymes involved in regulation of various cellular pathways. PDE5 acts to metabolize cyclic guanosine monophosphate (GMP. The various PDE5 inhibitors available are sildenafil, tadalafil, vardenafil, and mirodenafil. We shall discuss the roles of various PDE5 inhibitors in rheumatic diseases. PDE5 inhibitors prevent degradation of cyclic GMP; hence, they have vasodilatory properties which render them useful in the management of secondary Raynaud's phenomenon. They have also demonstrated efficacy in the healing of digital ulcers in systemic sclerosis and potentially prevent the formation of new digital ulcers. Their vasodilatory property has also been utilized in the management of pulmonary arterial hypertension, wherein their ability to favorably affect hemodynamics of a pressure-overloaded right heart is beneficial. Recent evidences have suggested a potential antifibrotic role of these agents, and studies in idiopathic pulmonary fibrosis and systemic sclerosis-associated interstitial lung disease hold promise for future exploration of these agents for these indications.

  15. Cyclic nucleotide specific phosphodiesterases of Leishmania major

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    Linder Markus


    Full Text Available Abstract Background Leishmania represent a complex of important human pathogens that belong to the systematic order of the kinetoplastida. They are transmitted between their human and mammalian hosts by different bloodsucking sandfly vectors. In their hosts, the Leishmania undergo several differentiation steps, and their coordination and optimization crucially depend on numerous interactions between the parasites and the physiological environment presented by the fly and human hosts. Little is still known about the signalling networks involved in these functions. In an attempt to better understand the role of cyclic nucleotide signalling in Leishmania differentiation and host-parasite interaction, we here present an initial study on the cyclic nucleotide-specific phosphodiesterases of Leishmania major. Results This paper presents the identification of three class I cyclic-nucleotide-specific phosphodiesterases (PDEs from L. major, PDEs whose catalytic domains exhibit considerable sequence conservation with, among other, all eleven human PDE families. In contrast to other protozoa such as Dictyostelium, or fungi such as Saccharomyces cerevisiae, Candida ssp or Neurospora, no genes for class II PDEs were found in the Leishmania genomes. LmjPDEA contains a class I catalytic domain at the C-terminus of the polypeptide, with no other discernible functional domains elsewhere. LmjPDEB1 and LmjPDEB2 are coded for by closely related, tandemly linked genes on chromosome 15. Both PDEs contain two GAF domains in their N-terminal region, and their almost identical catalytic domains are located at the C-terminus of the polypeptide. LmjPDEA, LmjPDEB1 and LmjPDEB2 were further characterized by functional complementation in a PDE-deficient S. cerevisiae strain. All three enzymes conferred complementation, demonstrating that all three can hydrolyze cAMP. Recombinant LmjPDEB1 and LmjPDEB2 were shown to be cAMP-specific, with Km values in the low micromolar range

  16. Phosphodiesterase 5 inhibition as a therapeutic target for ischemic stroke

    DEFF Research Database (Denmark)

    Ölmestig, Joakim N E; Marlet, Ida R; Hainsworth, Atticus H


    Phosphodiesterase 5 inhibitors (PDE5i), such as sildenafil (Viagra®) are widely used for erectile dysfunction and pulmonary hypertension. Preclinical studies suggest that PDE5i may improve functional outcome following ischemic stroke. In this systematic review we aimed to evaluate the effects...

  17. In vitro pharmacology of R 80122, a novel phosphodiesterase inhibitor

    NARCIS (Netherlands)

    Wilhelm, D.; Wilffert, B.; Janssens, W.J.; Leidig, A.; Meuter, C.; Ebbert, M.; Peters, Thies


    The cardiac in vitro effects of R 80122, a novel phosphodiesterase (PDE) inhibitor, were investigated and compared with those of the reference compound milrinone and of the calcium-sensitizer adibendan. In guinea pig left atria, both milrinone and R 80122 increased contractile force; 10 μM milrinone

  18. Phosphodiesterase 4 cAMP phosphodiesterases as targets for novel anti-inflammatory therapeutics

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    Simon J MacKenzie


    Full Text Available Cyclic nucleotides are powerful signaling molecules and their sole means of removal is through the action of cyclic nucleotide phosphodiesterases (PDEs. Elevating levels of cAMP is beneficial in many diseases, including neurological conditions, cancers, viral infections and most inflammatory disorders. There are 11 known PDE families, with PDE4 being the most highly expressed. Evidence of the clinical usefulness of PDE4 inhibition has come from the use of specific chemical inhibitors and the generation of knock-out mice models. There exists an extensive range of PDE4 family members, because there are four subfamilies, each encoded by their own gene and each capable of generating multiple isoforms. Several members of the PDE4 family are found to be expressed in every cell and tissue studied and evidence is now being uncovered indicating unique functions for each. Their actions are controlled by their expression patterns, subcellular location and interaction with other signaling pathways. The first generation of PDE4 inhibitors, although potent anti-inflammatory agents, failed as pharmaceuticals owing to their emetic and gastric side-effects. A new generation of chemical inhibitors is now nearing the market, which display greatly reduced side-effects. In the future lies the generation of more specific inhibitors that will focus upon particular diseases. This will be achieved by targeting specific PDE4 family members. Because the current target of chemical inhibition (the catalytic site is virtually identical between isoforms, this specificity is likely to be achieved by blocking the enzyme's interaction with other signaling cascades.

  19. Phosphodiesterase isoenzyme families in human osteoarthritis chondrocytes – functional importance of phosphodiesterase 4 (United States)

    Tenor, Hermann; Hedbom, Erik; Häuselmann, Hans-Jörg; Schudt, Christian; Hatzelmann, Armin


    We studied whether selective inhibitors of cyclic nucleotide hydrolysing phosphodiesterase (PDE) isoenzymes influence IL-1β-induced nitric oxide (NO) release from human articular chondrocytes. In addition, the pattern of PDE isoenzymes contributing to cyclic nucleotide hydrolysis in human chondrocytes was characterized.Chondrocytes were isolated from human osteoarthritic cartilage and cultured in alginate beads. IL-1β-induced chondrocyte products (nitric oxide and prostaglandin E2) were measured in culture supernatants after 48 h incubation time. PDE activities were assessed in chondrocyte lysates. Inducible nitric oxide synthase (iNOS) and PDE4A-D proteins were detected by immunoblotting.The selective PDE4 inhibitors Piclamilast and Roflumilast partially attenuated IL-1β-induced NO production whereas selective inhibitors of PDE2 (EHNA), PDE3 (Motapizone) or PDE5 (Sildenafil) were inactive. Indomethacin reversed the reduction of IL-1β-induced NO by PDE4 inhibitors. It was shown that autocrine prostaglandin E2 (PGE2) enabled PDE4 inhibitors to reduce IL-1β-induced NO in this experimental setting.Major PDE4 and PDE1 activities were identified in chondrocyte lysates whereas only minor activities of PDE2, 3 and 5 were found. IL-1β and cyclic AMP-mimetics upregulated PDE4 activity and this was associated with an augmentation of PDE4B2 protein.Based on the view that nitric oxide contributes to cartilage degradation in osteoarthritis our study suggests that PDE4 inhibitors may have chondroprotective effects. PMID:11834608

  20. Counterfeit phosphodiesterase type 5 inhibitors pose significant safety risks


    Jackson, G; Arver, S; Banks, I; Stecher, V J


    Counterfeit drugs are inherently dangerous and a growing problem; counterfeiters are becoming increasingly sophisticated. Growth of the counterfeit medication market is attributable in part to phosphodiesterase type 5 inhibitor (PDE5i) medications for erectile dysfunction (ED). Millions of counterfeit PDE5is are seized yearly and account for the bulk of all counterfeit pharmaceutical product seizures. It has been estimated that up to 2.5 million men in Europe are exposed to illicit sildenafil...

  1. Phosphodiesterase 10A upregulation contributes to pulmonary arterial hypertension


    Tian, Xia


    Pulmonary arterial hypertension (PAH) is a progressive disease defined by an elevation of pulmonary vascular resistance due to sustained vessel contraction and enhanced vascular remodeling. The abnormal tone and remodeling in the pulmonary vasculature are believed to be related, at least in part, to the decrease of cyclic nucleotide levels that are controlled by cyclic nucleotide phosphodiesterases (PDEs). PDEs, of which 11 families have been identified, maintain homeostasis...

  2. The role of cGMP hydrolysing phosphodiesterases 1 and 5 in cerebral artery dilatation

    DEFF Research Database (Denmark)

    Kruuse, Christina; Rybalkin, S D; Khurana, T S


    The aim was to investigate the presence and activity of cGMP hydrolysing phosphodiesterases in guinea pig basilar arteries and the effect of selective and non-selective phosphodiesterase inhibitors on cerebral artery dilatation involving the nitric oxide (NO)-guanosine cyclic 3'5-monophosphate (c......GMP) pathway. Immunoreactivity to phosphodiesterases 1A, 1B and 5, but not phosphodiesterase 1C was found in fractions of homogenised cerebral arteries eluted by high-pressure liquid chromatography (HPLC). Both the phosphodiesterase 1 inhibitor 8-methoxymethyl-1-methyl-3-(2methylpropyl)-xanthine (8-MM......-IBMX) and the phosphodiesterase 5 inhibitors zaprinast and dipyridamole induced dilatation of cerebral arteries. The dilatory response to 8-MM-IBMX was reduced by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) (10 microM) and endothelial removal and restored by sodium nitroprusside (0.1 microM) pretreatment, indicating...

  3. Analysis of the effects of phosphodiesterase type 3 and 4 inhibitors in cerebral arteries

    DEFF Research Database (Denmark)

    Birk, Steffen; Edvinsson, Lars; Olesen, Jes


    Inhibitors of phosphodiesterases 3 and 4, the main cyclic AMP (cAMP) degrading enzymes in arteries, may have therapeutic potential in cerebrovascular disorders. We analysed the effects of such phosphodiesterases in guinea pig cerebral arteries with organ bath technique and cyclic nucleotide assays...... the major contributors to total cAMP hydrolysis in the arteries examined. The phosphodiesterase 3 inhibitors additionally attenuated cyclic GMP (cGMP) hydrolysis, but relaxant responses were not dependent on an intact endothelium or on the nitric oxide-cGMP pathway. Conversely, the phosphodiesterase 4...

  4. Phosphodiesterase 4 Inhibitor Therapies for Atopic Dermatitis: Progress and Outlook. (United States)

    Ahluwalia, Jusleen; Udkoff, Jeremy; Waldman, Andrea; Borok, Jenna; Eichenfield, Lawrence F


    Phosphodiesterase 4 (PDE4) is a cyclic AMP degrading enzyme in leukocytes. Several decades ago, increased PDE activity was demonstrated in patients with atopic dermatitis (AD). Currently, several PDE4 inhibitors in both topical and oral formulation have been developed to target the inflammatory cascade of AD. This review shows the pathogenic rationale behind these inhibitors, and discusses multiple PDE4 inhibitors that are under evaluation or in the market. PDE4 inhibitors may be considered as favorable agents in the repertoire of current interventions for AD.

  5. Assay of covalent intermediate of 5'-nucleotide phosphodiesterase

    International Nuclear Information System (INIS)

    Blytt, H.J.; Brotherton, J.E.; Butler, L.


    A new procedure is reported for isolating a covalent phosphoryl enzyme (diester) intermediate of bovine intestinal 5'-nucleotide phosphodiesterase. The convenience of the procedure makes it possible to determine effects of reaction conditions on the yield of covalent intermediate. Under optimum conditions, using [methyl- 3 H]deoxythymidine 5'-triphosphate as substrate, more than 50% of the enzyme is recovered as thymidylyl enzyme, a 10-fold increase in yield over the previous procedure. Yields of thymidylyl enzyme were maximal at pH 4, whereas optimum catalytic activity is observed at pH greater than 9

  6. Therapeutic utility of Phosphodiesterase type I inhibitors in neurological conditions.

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    Alexandre Esteves Medina


    Full Text Available Neuronal plasticity is an essential property of the brain that is impaired in different neurological conditions. Phosphodiesterase type 1 (PDE1 inhibitors can enhance levels of the second messengers cAMP/cGMP leading to the expression of neuronal plasticity-related genes, neurotrophic factors and neuroprotective molecules. These neuronal plasticity enhancement properties make PDE1 inhibitors good candidates as therapeutic agents in many neurological conditions. However, the lack of specificity of the drugs currently available poses a challenge to the systematic evaluation of the beneficial effect of these agents. The development of more specific drugs may pave the way for the use of PDE1 inhibitors as therapeutic agents in cases of neurodevelopmental conditions such as fetal alcohol spectrum disorders and in degenerative disorders such as Alzheimer’s and Parkinson’s.

  7. Oral phosphodiesterase type 5 inhibitors alleviate recurrent priapism complicating thalassemia intermedia: a case report

    NARCIS (Netherlands)

    Tzortzis, Vassilios; Mitrakas, Lampros; Gravas, Stavros; Mamoulakis, Charalampos; Meissner, Andreas; Kyriakou, Despina; Melekos, Michael D.


    Recurrent ischemic priapism still remains a serious and difficult to treat complication of certain hematological disorders. Elucidation of the underlying pathophysiologic mechanisms and application of new effective prophylactic treatments are needed. To present the efficacy of phosphodiesterase type

  8. Ciprofloxacin-Induced Antibacterial Activity Is Attenuated by Phosphodiesterase Inhibitors. (United States)

    Masadeh, Majed M; Alzoubi, Karem H; Khabour, Omar F; Al-Azzam, Sayer I


    Ciprofloxacin is a commonly used antibiotic for urinary tract infection that interacts with bacterial topoisomerases leading to oxidative radicals generation and bacterial cell death. Phosphodiesterase inhibitors (PDEis), on the other hand, are commonly used drugs for the management of erectile dysfunction. The group includes agents such as sildenafil, vardenafil, and tadalafil. We investigated whether PDEi could interfere with the antibacterial activity of ciprofloxacin. PDEis were tested in several reference bacteria, including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Staphylococcus epidermidis, Acinetobacter baumannii, Proteus mirabilis, and Klebsiella pneumoniae utilizing a standard disc diffusion method and measuring both zones of inhibition and MIC. Results from both assays indicated that ciprofloxacin demonstrates potent activity against the tested reference bacteria. Additionally, when bacteria were treated with a combination of ciprofloxacin and sildenafil, tadalafil, or vardenafil, the zones of the combination inhibition were significantly reduced, whereas the MIC values were significantly greater than those of ciprofloxacin alone for all tested bacterial strains. In an attempt to examine the mechanism by which PDEis interfere with the action of ciprofloxacin, we utilized the in vitro E coli DNA gyrase cleavage assay. The results showed that PDEi drugs had no effect on ciprofloxacin's inhibition of E coli gyrase activity. Pretreatment of various reference bacterial cells with PDEis largely inhibited the antibacterial activity of ciprofloxacin.

  9. Purin-6-One Derivatives as Phosphodiesterase-2 Inhibitors

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    Wei Yuan


    Full Text Available A series of purin-6-one derivatives were synthesized, and their in vitro inhibitory activity against phosphodiesterase-2 (PDE2 was evaluated by using a fluorescence polarization assay. Three compounds, that are, 2j, 2p, and 2q, showed significant inhibitory activity against PDE2 with IC50 values of 1.73, 0.18, and 3.43 μM, respectively. Structure-activity relationship (SAR analysis was performed to explore the relationship between the chemical structures of these compounds and their inhibitory activity. Compounds 2j, 2p, and 2q were further selected for molecular docking study. The docking results suggested that these ligands bind with hydrophobic pockets of the catalytic active site of PDE2, where a Tyr655 residue was found to be important in binding with compound 2p, the most potent inhibitor identified in this study. Our present study provides useful information for the future design of novel PDE2 inhibitors.

  10. Interaction of 125I-labeled Ca2+-dependent regulator protein with cyclic nucleotide phosphodiesterase and its inhibitory protein

    International Nuclear Information System (INIS)

    Richman, P.G.; Klee, C.B.


    The Ca 2+ -dependent regulator protein of cyclic nucleotide phosphodiesterase was labeled with 125 I to the extent of 1 mol of monoiodotyrosine per mol. The iodinated protein showed a small decrease in affinity for phosphodiesterase but gave the same maximal level of activation of the enzyme as did the unmodified regulator protein. Iodinated regulator protein formed complexes with both highly purified cyclic nucleotide phosphodiesterase and phosphodiesterase inhibitory protein in the presence but not in the absence of Ca 2+ as demonstrated by ultracentrifugation in glycerol gradients. Cross-linking experiments indicate that the Ca 2+ -dependent regulator protein interacts with the large subunit of the inhibitory protein

  11. Phosphodiesterase 4D gene polymorphisms in sudden sensorineural hearing loss. (United States)

    Chien, Chen-Yu; Tai, Shu-Yu; Wang, Ling-Feng; Hsi, Edward; Chang, Ning-Chia; Wang, Hsun-Mo; Wu, Ming-Tsang; Ho, Kuen-Yao


    The phosphodiesterase 4D (PDE4D) gene has been reported as a risk gene for ischemic stroke. The vascular factors are between the hypothesized etiologies of sudden sensorineural hearing loss (SSNHL), and this genetic effect might be attributed for its role in SSNHL. We hypothesized that genetic variants of the PDE4D gene are associated with susceptibility to SSNHL. We conducted a case-control study with 362 SSNHL cases and 209 controls. Three single nucleotide polymorphisms (SNPs) were selected. The genotypes were determined using TaqMan technology. Hardy-Weinberg equilibrium (HWE) was tested for each SNP, and genetic effects were evaluated according to three inheritance modes. We carried out sex-specific analysis to analyze the overall data. All three SNPs were in HWE. When subjects were stratified by sex, the genetic effect was only evident in females but not in males. The TT genotype of rs702553 exhibited an adjusted odds ratio (OR) of 3.83 (95 % confidence interval = 1.46-11.18) (p = 0.006) in female SSNHL. The TT genotype of SNP rs702553 was associated with female SSNHL under the recessive model (p = 0.004, OR 3.70). In multivariate logistic regression analysis, TT genotype of rs702553 was significantly associated with female SSNHL (p = 0.0043, OR 3.70). These results suggest that PDE4D gene polymorphisms influence the susceptibility for the development of SSNHL in the southern Taiwanese female population.

  12. Counterfeit phosphodiesterase type 5 inhibitors pose significant safety risks. (United States)

    Jackson, G; Arver, S; Banks, I; Stecher, V J


    Counterfeit drugs are inherently dangerous and a growing problem; counterfeiters are becoming increasingly sophisticated. Growth of the counterfeit medication market is attributable in part to phosphodiesterase type 5 inhibitor (PDE5i) medications for erectile dysfunction (ED). Millions of counterfeit PDE5is are seized yearly and account for the bulk of all counterfeit pharmaceutical product seizures. It has been estimated that up to 2.5 million men in Europe are exposed to illicit sildenafil, suggesting that there may be as many illegal as legal users of sildenafil. Analysis of the contents of counterfeit PDE5is shows inconsistent doses of active pharmaceutical ingredients (from 0% to > 200% of labelled dose), contaminants (including talcum powder, commercial paint and printer ink) and alternative ingredients that are potentially hazardous. In one analysis, only 10.1% of samples were within 10% of the labelled tablet strength. Estimates place the proportion of counterfeit medications sold over the Internet from 44% to 90%. Of men who purchase prescription-only medication for ED without a prescription, 67% do so using the Internet. Counterfeit PDE5is pose direct and indirect risks to health, including circumvention of the healthcare system. More than 30% of men reported no healthcare interaction when purchasing ED medications. Because > 65% actually had ED, these men missed an opportunity for evaluation of comorbidities (e.g. diabetes and hypertension). Globally, increased obstacles for counterfeiters are necessary to combat pharmaceutical counterfeiting, including fines and penalties. The worldwide nature of the counterfeit problem requires proper coordination between countries to ensure adequate enforcement. Locally, physicians who treat ED need to inform patients of the dangers of ordering PDE5is via the Internet.

  13. Phosphodiesterase 5 inhibitors in the treatment of premature ejaculation. (United States)

    Wang, W F; Minhas, S; Ralph, D J


    To date, there is no FDA-approved therapy for premature ejaculation (PE). Recently, phosphodiesterase 5 inhibitors (PDE5-Is) have been demonstrated to have encouraging results in the treatment of PE by a few studies. The aim of this review was to assess the updated manuscripts and thereafter present the practical recommendations and possible mechanisms concerning PDE5-Is for treating PE. Using MEDLINE, we searched and assessed the peer manuscripts published from 1 January 1996 to 1 September 2005 about PDE5-Is for treating PE. The results show that the number of patients in all the reports is very few and most of the studies do not employ double-blinded and placebo-controlled tests, though they are prospective and randomized. Therefore, the results and conclusions might be biased. PDE5-Is are suggested to be used in PE with old age or associated with erectile dysfunction (ED), or to be employed alone or in combination with selective-serotonin reuptake inhibitors (SSRIs) when SSRIs fail to treat PE; behavioural therapy is proposed to be used for preventing the recurrence of PE following withdrawal of PDE5-Is. In addition, for the PE patient with a definite aetiological cause, the aetiology should be cured first, if PE still exists, followed by PDE-Is prescription. Possible mechanisms that are involved include relaxing the smooth muscles of vas deferens, seminal vesicle, prostate and urethra; decreasing the central sympathetic output; inducing peripheral analgesia; prolonging the duration of erection; and increasing confidence, the perception of ejaculatory control, overall sexual satisfaction, and decreasing the post-orgasmic refractory time to achieve a second erection after ejaculation. Well-designed multicentre studies are urgently warranted to further elucidate the efficacies and safety as well as mechanisms of PDE5-Is in the treatment of PE.

  14. Papaverine-sensitive phosphodiesterase activity is measured in bovine spermatozoa. (United States)

    Bergeron, A; Hébert, A; Guillemette, C; Laroche, A; Poulin, M-P; Aragon, J P; Leclerc, P; Sullivan, R; Blondin, P; Vigneault, C; Richard, F J


    Cyclic adenosine monophosphate (cAMP) plays a crucial role as a signaling molecule for capacitation, motility, and acrosome reaction in mammalian spermatozoa. It is well-known that cAMP degradation by phosphodiesterase (PDE) enzyme has a major impact on sperm functions. This study was undertaken to characterize cAMP-PDE activity in bovine spermatozoa. Total cAMP-PDE activity in cauda epididymal and ejaculated spermatozoa was 543.2 ± 49.5 and 1252.6 ± 86.5 fmoles/min/10 6 spermatozoa, respectively. Using different family-specific PDE inhibitors, we showed that in cauda epididymal and ejaculated spermatozoa, the major cAMP-PDE activity was papaverine-sensitive (44.5% and 57.5%, respectively, at 400 nm, papaverine is a specific inhibitor of the PDE10 family). These data are supporting the functional presence of PDE10 in bovine spermatozoa and were further confirmed by western blot to be PDE10A. Using immunocytochemistry, we showed immunoreactive signal for PDE10A present on the post-acrosomal region of the head and on the flagella of ejaculated spermatozoa. Using papaverine, we showed that it promotes tyrosine phosphorylation of sperm proteins, phosphorylation of Erk1 and Erk2, and Ca 2+ release from Ca 2+ store. These results suggest that PDE10 is functionally present in bovine spermatozoa and is affecting different molecular events involved in capacitation, most probably by cAMP local regulation. © 2016 American Society of Andrology and European Academy of Andrology.

  15. Role of phosphodiesterase-4 on ethanol elicited locomotion and narcosis. (United States)

    Baliño, Pablo; Ledesma, Juan Carlos; Aragon, Carlos M G


    The cAMP signaling pathway has emerged as an important modulator of the pharmacological effects of ethanol. In this respect, the cAMP-dependent protein kinase has been shown to play an important role in the modulation of several ethanol-induced behavioral actions. Cellular levels of cAMP are maintained by the activity of adenylyl cyclases and phosphodiesterases. In the present work we have focused on ascertaining the role of PDE4 in mediating the neurobehavioral effects of ethanol. For this purpose, we have used the selective PDE4 inhibitor Ro 20-1724. This compound has been proven to enhance cellular cAMP response by PDE4 blockade and can be administered systemically. Swiss mice were injected intraperitoneally (i.p.) with Ro 20-1724 (0-5 mg/kg; i.p.) at different time intervals before ethanol (0-4 g/kg; i.p.) administration. Immediately after the ethanol injection, locomotor activity, loss of righting reflex, PKA footprint and enzymatic activity were assessed. Pretreatment with Ro 20-1724 increased ethanol-induced locomotor stimulation in a dose-dependent manner. Doses that increased locomotor stimulation did not modify basal locomotion or the suppression of motor activity produced by high doses of this alcohol. Ro 20-1724 did not alter the locomotor activation produced by amphetamine or cocaine. The time of loss of righting reflex evoked by ethanol was increased after pretreatment with Ro 20-1724. This effect was selective for the narcotic effects of ethanol since Ro 20-1724 did not affect pentobarbital-induced narcotic effects. Moreover, Ro 20-1724 administration increased the PKA footprint and enzymatic activity response elicited by ethanol. These data provide further evidence of the key role of the cAMP signaling pathway in the central effects of ethanol. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. The effect of phosphodiesterase-5 inhibitors on cerebral blood flow in humans

    DEFF Research Database (Denmark)

    Pauls, Mathilde Mh; Moynihan, Barry; Barrick, Thomas R


    Agents that augment cerebral blood flow (CBF) could be potential treatments for vascular cognitive impairment. Phosphodiesterase-5 inhibitors are vasodilating drugs established in the treatment of erectile dysfunction (ED) and pulmonary hypertension. We reviewed published data on the effects......, ED, type 2 diabetes, stroke, pulmonary hypertension, Becker muscular dystrophy and subarachnoid haemorrhage. Most studies used middle cerebral artery flow velocity to estimate CBF. Few studies employed direct measurements of tissue perfusion. Resting CBF velocity was unaffected by phosphodiesterase-5...... inhibitors, but cerebrovascular regulation was improved in ED, pulmonary hypertension, diabetes, Becker's and a group of healthy volunteers. This evidence suggests that phosphodiesterase-5 inhibitors improve responsiveness of the cerebral vasculature, particularly in disease states associated...

  17. Coronary vasodilatory, spasmolytic and cAMP-phosphodiesterase inhibitory properties of dihydropyranocoumarins and dihydrofuranocoumarins

    DEFF Research Database (Denmark)

    Thastrup, Ole; Fjalland, B; Lemmich, J


    Twenty-three dihydropyrano- and dihydrofuranocoumarins, most of plant origin, were examined for their effects on the coronary flow of isolated perfused guinea-pig heart, on the Ba2+-induced spasms in isolated guinea-pig ileum, on the cAMP level in guinea-pig heart homogenate and on the cAMP metab...... between the coronary vasodilatory and the cAMP-phosphodiesterase inhibitory activity. The results indicate involvement of cAMP-phosphodiesterase inhibition in coronary vasodilatory effects of acyloxydihydropyrano- and acyloxydihydrofurano-coumarins....

  18. A selective phosphodiesterase 10A inhibitor reduces l-dopa-induced dyskinesias in parkinsonian monkeys. (United States)

    Beck, Goichi; Maehara, Shunsuke; Chang, Phat Ly; Papa, Stella M


    Phosphodiesterase 10A is a member of the phosphodiesterase family whose brain expression is restricted to the striatum. Phosphodiesterase 10A regulates cyclic adenosine monophosphate and cyclic guanosine monophosphate, which mediate responses to dopamine receptor activation, and the levels of these cyclic nucleotides are decreased in experimental models of l-dopa-induced dyskinesia. The elevation of cyclic adenosine monophosphate/cyclic guanosine monophosphate levels by phosphodiesterase 10A inhibition may thus be targeted to reduce l-dopa-induced dyskinesia. The present study was aimed at determining the potential antidyskinetic effects of phosphodiesterase 10A inhibitors in a primate model of Parkinson's disease (PD). The experiments performed in this model were also intended to provide translational data for the design of future clinical trials. Five MPTP-treated macaques with advanced parkinsonism and reproducible l-dopa-induced dyskinesia were used. MR1916, a selective phosphodiesterase 10A inhibitor, at doses 0.0015 to 0.05 mg/kg, subcutaneously, or its vehicle (control test) was coadministered with l-dopa methyl ester acutely (predetermined optimal and suboptimal subcutaneous doses) and oral l-dopa chronically as daily treatment for 5 weeks. Standardized scales were used to assess motor disability and l-dopa-induced dyskinesia by blinded examiners. Pharmacokinetics was also examined. MR1916 consistently reduced l-dopa-induced dyskinesia in acute tests of l-dopa optimal and suboptimal doses. Significant effects were present with every MR1916 dose tested, but the most effective was 0.015 mg/kg. None of the MR1916 doses tested affected the antiparkinsonian action of l-dopa at the optimal dose. The anti-l-dopa-induced dyskinesia effect of MR1916 (0.015 mg/kg, subcutaneously) was sustained with chronic administration, indicating that tolerance did not develop over the 5-week treatment. No adverse effects were observed after MR1916 administration acutely or

  19. Effects of phosphodiesterase 3A modulation on murine cerebral microhemorrhages. (United States)

    Sumbria, Rachita K; Vasilevko, Vitaly; Grigoryan, Mher Mahoney; Paganini-Hill, Annlia; Kim, Ronald; Cribbs, David H; Fisher, Mark J


    Cerebral microbleeds (CMB) are MRI-demonstrable cerebral microhemorrhages (CMH) which commonly coexist with ischemic stroke. This creates a challenging therapeutic milieu, and a strategy that simultaneously protects the vessel wall and provides anti-thrombotic activity is an attractive potential approach. Phosphodiesterase 3A (PDE3A) inhibition is known to provide cerebral vessel wall protection combined with anti-thrombotic effects. As an initial step in the development of a therapy that simultaneously treats CMB and ischemic stroke, we hypothesized that inhibition of the PDE3A pathway is protective against CMH development. The effect of PDE3A pathway inhibition was studied in the inflammation-induced and cerebral amyloid angiopathy (CAA)-associated mouse models of CMH. The PDE3A pathway was modulated using two approaches: genetic deletion of PDE3A and pharmacological inhibition of PDE3A by cilostazol. The effects of PDE3A pathway modulation on H&E- and Prussian blue (PB)-positive CMH development, BBB function (IgG, claudin-5, and fibrinogen), and neuroinflammation (ICAM-1, Iba-1, and GFAP) were investigated. Robust development of CMH in the inflammation-induced and CAA-associated spontaneous mouse models was observed. Inflammation-induced CMH were associated with markers of BBB dysfunction and inflammation, and CAA-associated spontaneous CMH were associated primarily with markers of neuroinflammation. Genetic deletion of the PDE3A gene did not alter BBB function, microglial activation, or CMH development, but significantly reduced endothelial and astrocyte activation in the inflammation-induced CMH mouse model. In the CAA-associated CMH mouse model, PDE3A modulation via pharmacological inhibition by cilostazol did not alter BBB function, neuroinflammation, or CMH development. Modulation of the PDE3A pathway, either by genetic deletion or pharmacological inhibition, does not alter CMH development in an inflammation-induced or in a CAA-associated mouse model of CMH

  20. Phosphodiesterase 5 and effects of sildenafil on cerebral arteries of man and guinea pig

    DEFF Research Database (Denmark)

    Kruuse, Christina; Khurana, Tejvir S; Rybalkin, Sergei D


    Sildenafil (Viagra), a selective inhibitor of phosphodiesterase 5 (PDE5), induces headache and migraine. Although previously supposed to be a "vascular" headache, no significant cerebral artery dilatation was found in vivo. Thus, we hypothesised that PDE5 may not be present or that sildenafil...

  1. Modulation of Polycystic Kidney Disease Severity by Phosphodiesterase 1 and 3 Subfamilies

    NARCIS (Netherlands)

    Ye, H.; Wang, X.; Sussman, C.R.; Hopp, K.; Irazabal, M.V.; Bakeberg, J.L.; LaRiviere, W.B.; Manganiello, V.C.; Vorhees, C.V.; Zhao, H.; Harris, P.C.; Deursen, J. van; Ward, C.J.; Torres, V.E.


    Aberrant intracellular calcium levels and increased cAMP signaling contribute to the development of polycystic kidney disease (PKD). cAMP can be hydrolyzed by various phosphodiesterases (PDEs). To examine the role of cAMP hydrolysis and the most relevant PDEs in the pathogenesis of PKD, we examined

  2. Carbon-14 labelled nitrogen heterocycles; the syntheses of three phosphodiesterase inhibitors

    International Nuclear Information System (INIS)

    Lawrie, K.W.M.; Novelli, C.E.A.; Saunders, David


    The syntheses of three heterocyclic phosphodiesterase inhibitors are described from a common radiolabelled precursor, namely 2-propoxybenzo[cyano- 14 C] nitrile. Conversion of the nitrile to the corresponding methyl ketone or amidine allows elaboration of the heterocycles radiolabelled within the ring systems. (Author)

  3. Inhibition of phosphodiesterase 2 increases neuronal cGMP, synaptic plasticity and memory performance

    NARCIS (Netherlands)

    Boess, F.G.; Hendrix, M.; Staay, van der F.J.; Erb, C.; Schreiber, R.; Staveren, W.C.G.; Vente, de J.; Prikaerts, J.; Blokland, A.; Koenig, G.


    An essential element of the signalling cascade leading to synaptic plasticity is the intracellular second messenger molecule guanosine 3¿,5¿-cyclic monophosphate (cGMP). Using the novel, potent, and selective inhibitor Bay 60-7550, we show that the enzyme 3¿,5¿-cyclic nucleotide phosphodiesterase

  4. Phosphodiesterase inhibitors: Effectiveness and new applications [Fosfodi�steraseremmers: effectiviteit en nieuwe toepassingen

    NARCIS (Netherlands)

    Van Driel, M.F.


    Three different phosphodiesterase 5 (PDE5) inhibitors are currently available for the treatment of erectile dysfunction: sildenafil, vardenafil and tadalafil. The differences between these 3 are limited: tadalafil has a long duration of action, while vardenafil has a rapid onset of action after

  5. Medium Optimization for 5’-Phosphodiesterase Production from Penicillium citrinum Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Lu-E Shi


    Full Text Available Medium optimization for 5’-phosphodiesterase production from Penicillium citrinum was studied by applying one-factor-at-a-time method, orthogonal array method and response surface methodology in this paper. The one-factor-at-a-time method was used to study the effects of carbon, nitrogen, phosphorus and metal ion sources on 5’-phosphodiesterase production. Among various carbon and nitrogen sources used, glucose and peptone were the most suitable substances for 5’-phosphodiesterase production, respectively. Subsequently, the concentrations of glucose, peptone, groundnut meal, Zn2+ and KH2PO4 were optimized using the orthogonal array method. Response surface methodology was also applied for medium optimization. Glucose concentration (X1, peptone concentration (X2 and groundnut meal (X3 were selected as the independent variables. Results showed that the regression models adequately explained the data variation and represented the actual relationships between the parameters and responses. The optimum conditions were glucose at a fraction of 6.5 %, peptone at a fraction of 0.45 % and groundnut meal at a fraction of 1.0 %. Maximum enzyme activity was 353 U/mL under the optimum conditions. Maximum 5’-phosphodiesterase activity in media optimized by orthogonal method and response surface methodology was about 1.286 and 1.456 times, respectively, greater than in the medium optimized by one-factor-at-a-time method.

  6. Inhibition of human platelet aggregation by dihydropyrano- and dihydrofuranocoumarins, a new class of cAMP-phosphodiesterase inhibitors

    DEFF Research Database (Denmark)

    Thastrup, Ole; Knudsen, J B; Lemmich, J


    Certain esters of dihydropyranocoumarin and dihydrofuranocoumarin alcohols have previously been shown to inhibit the cAMP-phosphodiesterase from bovine heart. We now report that these naturally occurring coumarins inhibit the high affinity (Km = 1.1 microM) cAMP-phosphodiesterase from human...... platelets with activities that closely correlate with those obtained using phosphodiesterase from bovine heart tissue. Additionally the coumarins inhibit the aggregation of human platelets induced with ADP, adrenaline and collagen with activities comparable to those of dipyridamole. A lack of significant...

  7. Phosphodiesterase 4 inhibitor and phosphodiesterase 5 inhibitor combination therapy has antifibrotic and anti-inflammatory effects in mdx mice with Duchenne muscular dystrophy. (United States)

    Nio, Yasunori; Tanaka, Masayuki; Hirozane, Yoshihiko; Muraki, Yo; Okawara, Mitsugi; Hazama, Masatoshi; Matsuo, Takanori


    Duchenne muscular dystrophy (DMD) is the most common inherited muscular dystrophy. Patients experience DMD in their 20s from cardiac or respiratory failure related to progressive muscle wasting. Currently, the only treatments for the symptoms of DMD are available. Muscle fibrosis, a DMD feature, leads to reduced muscle function and muscle mass, and hampers pharmaceutical therapeutic efficacy. Although antifibrotic agents may be useful, none is currently approved. Phosphodiesterase 4 (PDE4) inhibitors have exhibited antifibrotic effects in human and animal models. In this study, we showed beneficial effects of the PDE4 inhibitor piclamilast in the DMD mdx mouse. Piclamilast reduced the mRNA level of profibrotic genes, including collagen 1A1, in the gastrocnemius and diaphragm, in the mdx mouse, and significantly reduced the Sirius red staining area. The PDE5 inhibitors sildenafil and tadalafil ameliorated functional muscle ischemia in boys with DMD, and sildenafil reversed cardiac dysfunction in the mdx mouse. Single-treatment piclamilast or sildenafil showed similar antifibrotic effects on the gastrocnemius; combination therapy showed a potent antifibrotic effect, and piclamilast and combination therapy increased peroxisome proliferator-activated receptor γ coactivator-1α mRNA in mouse gastrocnemius. In summary, we confirmed that piclamilast has significant antifibrotic effects in mdx mouse muscle and is a potential treatment for muscle fibrosis in DMD.-Nio, Y., Tanaka, M., Hirozane, Y., Muraki, Y., Okawara, M., Hazama, M., Matsuo, T. Phosphodiesterase 4 inhibitor and phosphodiesterase 5 inhibitor combination therapy has antifibrotic and anti-inflammatory effects in mdx mice with Duchenne muscular dystrophy. © FASEB.

  8. Evaluation of arterial stiffness and cardiac function in patients with vascular erectile dysfunction : Acute effects of phosphodiesterase-5 inhibitor tadalafil

    NARCIS (Netherlands)

    Özdabakoglu, O.; Güllülü, S.; Sag, S.; Sentürk, T.; Kilicarslan, H.; Tütüncü, A.; Kecebas, M.; Baran, Ismet; Aydinlar, A.


    This study aimed to detect endothelial dysfunction in erectile dysfunction (ED) patients free from cardiovascular diseases or atherosclerotic risk factors and to evaluate acute effects of phosphodiesterase-5 inhibitor tadalafil on endothelial dysfunction and cardiac function. Thirty ED patients and

  9. Active site structure and catalytic mechanism of phosphodiesterase for degradation of intracellular second messengers (United States)

    Zhan, Chang-Guo


    Phosphodiesterases are clinical targets for a variety of biological disorders, because this superfamily of enzymes regulate intracellular concentration of cyclic nucleotides that serve as the second messengers playing a critical role in a variety of physiological processes. Understanding structure and mechanism of a phosphodiesterase will provide a solid basis for rational design of the more efficient therapeutics. Although a three-dimensional X-ray crystal structure of the catalytic domain of human phosphodiesterase 4B2B was recently reported, it was uncertain whether a critical bridging ligand in the active site is a water molecule or a hydroxide ion. The identity of this bridging ligand has been determined by performing first-principles quantum chemical calculations on models of the active site. All the results obtained indicate that this critical bridging ligand in the active site of the reported X-ray crystal structure is a hydroxide ion, rather than a water molecule, expected to serve as the nucleophile to initialize the catalytic degradation of the intracellular second messengers.

  10. Overexpression screens identify conserved dosage chromosome instability genes in yeast and human cancer (United States)

    Duffy, Supipi; Fam, Hok Khim; Wang, Yi Kan; Styles, Erin B.; Kim, Jung-Hyun; Ang, J. Sidney; Singh, Tejomayee; Larionov, Vladimir; Shah, Sohrab P.; Andrews, Brenda; Boerkoel, Cornelius F.; Hieter, Philip


    Somatic copy number amplification and gene overexpression are common features of many cancers. To determine the role of gene overexpression on chromosome instability (CIN), we performed genome-wide screens in the budding yeast for yeast genes that cause CIN when overexpressed, a phenotype we refer to as dosage CIN (dCIN), and identified 245 dCIN genes. This catalog of genes reveals human orthologs known to be recurrently overexpressed and/or amplified in tumors. We show that two genes, TDP1, a tyrosyl-DNA-phosphdiesterase, and TAF12, an RNA polymerase II TATA-box binding factor, cause CIN when overexpressed in human cells. Rhabdomyosarcoma lines with elevated human Tdp1 levels also exhibit CIN that can be partially rescued by siRNA-mediated knockdown of TDP1. Overexpression of dCIN genes represents a genetic vulnerability that could be leveraged for selective killing of cancer cells through targeting of an unlinked synthetic dosage lethal (SDL) partner. Using SDL screens in yeast, we identified a set of genes that when deleted specifically kill cells with high levels of Tdp1. One gene was the histone deacetylase RPD3, for which there are known inhibitors. Both HT1080 cells overexpressing hTDP1 and rhabdomyosarcoma cells with elevated levels of hTdp1 were more sensitive to histone deacetylase inhibitors valproic acid (VPA) and trichostatin A (TSA), recapitulating the SDL interaction in human cells and suggesting VPA and TSA as potential therapeutic agents for tumors with elevated levels of hTdp1. The catalog of dCIN genes presented here provides a candidate list to identify genes that cause CIN when overexpressed in cancer, which can then be leveraged through SDL to selectively target tumors. PMID:27551064

  11. Phosphodiesterase type 5 inhibition is a novel therapeutic option in Raynaud disease. (United States)

    Caglayan, Evren; Huntgeburth, Michael; Karasch, Thomas; Weihrauch, Julia; Hunzelmann, Nicolas; Krieg, Thomas; Erdmann, Erland; Rosenkranz, Stephan


    Raynaud disease (RD) is a common disorder affecting 3% to 5% of the healthy population, and occurs in more than 90% of patients with connective tissue diseases. The therapeutic options remain limited, particularly in patients with secondary RD due to connective tissue disease. Theoretical considerations lead to the expectation that phosphodiesterase type 5 inhibitors may improve clinical symptoms and digital blood flow in patients with RD. We conducted an open-label pilot study in 40 patients with RD, 33 (82%) of whom had secondary and 7 (18%) of whom had primary RD. Digital blood flow was measured by laser-Doppler flowmetry at room temperature and during the cold-exposure test before medical treatment, 1 hour after the initial intake, and after 2 weeks of continuous treatment (10 mg twice a day) with the novel phosphodiesterase type 5 inhibitor vardenafil. Clinical symptoms were recorded by a patient questionnaire and summarized as the Raynaud condition score. Laser-Doppler flowmetry revealed that vardenafil improved digital blood flow in 28 (70%) patients, whereas 12 (30%) did not respond. In individuals responding, digital blood flow significantly increased by a mean +/- SEM of 21.0% +/- 4.9% and 30.0% +/- 5.7% at 1 hour and 2 weeks of treatment at room temperature, respectively, and by 18.8% +/- 4.4% and 35.1% +/- 7.5% at 1 hour and 2 weeks during the cold-exposure test, respectively (P Raynaud condition score declined from a mean +/- SEM of 5.05 +/- 0.38 to 3.54 +/- 0.31 (P < .001). Our data indicate that phosphodiesterase type 5 inhibition significantly improves peripheral blood flow and clinical symptoms in a large subset of patients with RD and, thus, may provide a novel therapeutic approach in such individuals.

  12. Beta-adrenoceptor responsiveness in intact leukocytes from adults and newborn infants; effect of phosphodiesterase inhibitors

    DEFF Research Database (Denmark)

    Foged, N; Bertelsen, Niels Haldor; Johansen, Torben


    Intact mononuclear and polymorphonuclear leukocytes from adults and newborn infants were used to estimate the beta 2-adrenoceptor responsiveness in vitro. The accumulation of cAMP in response to receptor stimulation by isoprenaline was used as a measure of the receptor responsiveness. The relevance......-1 inhibits the phosphodiesterase activity almost completely. By use of this concentration no age-dependent changes in the isoprenaline-stimulated cAMP accumulation in mononuclear and polymorphonuclear leukocytes from adults and newborn infants could be demonstrated....

  13. Effects of sevoflurane on adenylate cyclase and phosphodiesterases activity in brain of rats

    International Nuclear Information System (INIS)

    Feng Changdong; Yang Jianping; Dai Tijun


    Objective: To investigate the effects of sevoflurane on c adenylate cyclase (AC) and phosphodiesterases (PDE) activity in the cerebrocortex, hippocampus and brain stem of rats, and to examine the role of cAMP in sevoflurane anesthesia. Methods: Fourty SD rats were delaminately designed and allocated randomly to 5 groups inhaling 1.5% sevoflurane i.e., no recovery (recovery group, n=8) and one hour after righting reflexrecovery (aware group, n=8). The brain tissues were rapidly dissected into cerebrocortex and hippocampus and brain stem.Then the adenylate cyclase and phosphodiesterases activity were assessed. Results: So far as the activity of AC is concerned, compared with the control group, the activity of AC in the cerebrocortex, hippocampus and brain stem brain stem of induction group and anesthesia group, the cerebrocortex, and hippocampus in the recovery group were significantly increased; compared with those in the anesthesia group, the activity of AC in the cerebrocortex, hippocampus and brain stem of aware group were significantly decreased (P<0.05); For the activity of PDE, compared with the control group, the activity of PDE in the cerebrocortex, hippocampus and brain stem in the induction group and anesthesia group was significantly decreased, compared with that in anesthesia group, the activity of PDE in the cerebrocortex, hippocampus and brain stem of recovery group and aware group was significantly increased (P<0.05). Conclusion: cAMP may play an important role in sevoflurane anesthesia. (authors)

  14. Pathophysiology of visual disorders induced by phosphodiesterase inhibitors in the treatment of erectile dysfunction

    Directory of Open Access Journals (Sweden)

    Moschos MM


    Full Text Available Marilita M Moschos, Eirini Nitoda 1st Department of Ophthalmology, Medical School, National & Kapodistrian University of Athens, Athens, Greece Aim: The aim of this review was to summarize the ocular action of the most common phosphodiesterase (PDE inhibitors used for the treatment of erectile dysfunction and the subsequent visual disorders.Method: This is a literature review of several important articles focusing on the pathophysiology of visual disorders induced by PDE inhibitors.Results: PDE inhibitors have been associated with ocular side effects, including changes in color vision and light perception, blurred vision, transient alterations in electroretinogram (ERG, conjunctival hyperemia, ocular pain, and photophobia. Sildenafil and tadalafil may induce reversible increase in intraocular pressure and be involved in the development of nonarteritic ischemic optic neuropathy. Reversible idiopathic serous macular detachment, central serous chorioretinopathy, and ERG disturbances have been related to the significant impact of sildenafil and tadalafil on retinal perfusion.Discussion: So far, PDE inhibitors do not seem to cause permanent toxic effects on chorioretinal tissue and photoreceptors. However, physicians should write down any visual symptom observed during PDE treatment and refer the patients to ophthalmologists. Keywords: erectile dysfunction, pathophysiological mechanisms, phosphodiesterase inhibitors, PDE5, visual disorders

  15. The c-di-GMP phosphodiesterase BifA regulates biofilm development in Pseudomonas putida. (United States)

    Jiménez-Fernández, Alicia; López-Sánchez, Aroa; Calero, Patricia; Govantes, Fernando


    We previously showed the isolation of biofilmpersistent Pseudomonas putida mutants that fail to undergo biofilm dispersal upon entry in stationary phase. Two such mutants were found to bear insertions in PP0914, encoding a GGDEF/EAL domain protein with high similarity to Pseudomon asaeruginosa BifA. Here we show the phenotypic characterization of a ΔbifA mutant in P. putida KT2442.This mutant displayed increased biofilm and pellicle formation, cell aggregation in liquid medium and decreased starvation-induced biofilm dispersal relative to the wild type. Unlike its P. aeruginosa counterpart, P. putida BifA did not affect swarming motility. The hyperadherent phenotype of the ΔbifA mutant correlates with a general increase in cyclic diguanylate (c-di-GMP) levels, Congo Red-binding exopolyaccharide production and transcription of the adhesin-encoding lapA gene. Integrity of the EAL motif and a modified GGDEF motif (altered to GGDQF)were crucial for BifA activity, and c-di-GMP depletion by overexpression of a heterologous c-di-GMP phosphodiesterase in the ΔbifA mutant restored wild-type biofilm dispersal and lapA expression.Our results indicate that BifA is a phosphodiesterase involved in the regulation of the c-di-GMP pool and required for the generation of the low c-di-GMP signal that triggers starvation-induced biofilm dispersal.

  16. Immunohistochemical distribution of cAMP- and cGMP-phosphodiesterase (PDE) isoenzymes in the human prostate

    NARCIS (Netherlands)

    Uckert, Stefan; Oelke, Matthias; Stief, Christian G.; Andersson, K.-E.; Jonas, Udo; Hedlund, Petter


    With the introduction of sildenafil citrate (Viagra), the concept of phosphodiesterase (PDE) inhibition has gained tremendous interest in the field of urology. Cyclic nucleotide second messengers cGMP and cAMP have been assumed to be involved in the control of the normal function of the prostate.

  17. Dissociable effects of acetylcholinesterase inhibitors and phosphodiesterase type 5 inhibitors on object recognition memory: acquisition versus consolidation

    NARCIS (Netherlands)

    Prickaerts, L.; Sik, A.; Staay, van der F.J.; Vente, de J.; Blokland, A.


    Rationale Phosphodiesterase enzyme type 5 (PDE5) inhibitors and acetylcholinesterase (AChE) inhibitors have cognition-enhancing properties. However, it is not known whether these drug classes affect the same memory processes. Objective We investigated the memory-enhancing effects of the PDE5

  18. Determination of phosphodiesterase type V inhibitors in wastewater by direct injection followed by liquid chromatography coupled to tandem mass spectrometry

    NARCIS (Netherlands)

    Causanilles, A.; Emke, E.; de Voogt, P.


    A simple, fast and reliable analytical method for the determination of phosphodiesterase type V inhibitors in wastewater was developed and validated. The method was based on direct injection followed by liquid chromatography coupled to tandem mass spectrometry with triple quadrupole as mass

  19. Specificity of cGMP binding to a purified cGMP-stimulated phosphodiesterase from bovine adrenal tissue

    NARCIS (Netherlands)

    Miot, Françoise; Haastert, Peter J.M. van; Erneux, Christophe


    The binding of [3H]cGMP (guanosine 3’,5’-monophosphate) to purified bovine adrenal cGMP-stimulated phosphodiesterase was measured by Millipore filtration on cellulose ester filter. [3H]cGMP-binding activity was enhanced when the assay was terminated in buffer containing 70% of saturated ammonium

  20. Catechol pyrazolinones as trypanocidals: fragment-based design, synthesis, and pharmacological evaluation of nanomolar inhibitors of trypanosomal phosphodiesterase b1

    NARCIS (Netherlands)

    Orrling, K.M.; Jansen, C.J.W.; Vu, X.L.; Balmer, V.; Bregy, P.; Shanmugham, A.; England, P.; Bailey, D.; Cos, P.; Maes, L.; Adams, E.; van den Bogaart, E.; Chatelain, E.; Ioset, J.R.; van de Stolpe, A.; Zorg, S.; Veerman, J.; Seebeck, T.; Sterk, G.J.; de Esch, I.J.P.; Leurs, R.


    Trypanosomal phosphodiesterases B1 and B2 (TbrPDEB1 and TbrPDEB2) play an important role in the life cycle of Trypanosoma brucei, the causative parasite of human African trypanosomiasis (HAT), also known as African sleeping sickness. We used homology modeling and docking studies to guide fragment

  1. BRCA1: a novel prognostic factor in resected non-small-cell lung cancer. (United States)

    Rosell, Rafael; Skrzypski, Marcin; Jassem, Ewa; Taron, Miquel; Bartolucci, Roberta; Sanchez, Jose Javier; Mendez, Pedro; Chaib, Imane; Perez-Roca, Laia; Szymanowska, Amelia; Rzyman, Witold; Puma, Francesco; Kobierska-Gulida, Grazyna; Farabi, Raffaele; Jassem, Jacek


    Although early-stage non-small-cell lung cancer (NSCLC) is considered a potentially curable disease following complete resection, patients have a wide spectrum of survival according to stage (IB, II, IIIA). Within each stage, gene expression profiles can identify patients with a higher risk of recurrence. We hypothesized that altered mRNA expression in nine genes could help to predict disease outcome: excision repair cross-complementing 1 (ERCC1), myeloid zinc finger 1 (MZF1) and Twist1 (which regulate N-cadherin expression), ribonucleotide reductase subunit M1 (RRM1), thioredoxin-1 (TRX1), tyrosyl-DNA phosphodiesterase (Tdp1), nuclear factor of activated T cells (NFAT), BRCA1, and the human homolog of yeast budding uninhibited by benzimidazole (BubR1). We performed real-time quantitative polymerase chain reaction (RT-QPCR) in frozen lung cancer tissue specimens from 126 chemonaive NSCLC patients who had undergone surgical resection and evaluated the association between gene expression levels and survival. For validation, we used paraffin-embedded specimens from 58 other NSCLC patients. A strong inter-gene correlation was observed between expression levels of all genes except NFAT. A Cox proportional hazards model indicated that along with disease stage, BRCA1 mRNA expression significantly correlated with overall survival (hazard ratio [HR], 1.98 [95% confidence interval (CI), 1.11-6]; P = 0.02). In the independent cohort of 58 patients, BRCA1 mRNA expression also significantly correlated with survival (HR, 2.4 [95%CI, 1.01-5.92]; P = 0.04). Overexpression of BRCA1 mRNA was strongly associated with poor survival in NSCLC patients, and the validation of this finding in an independent data set further strengthened this association. Since BRCA1 mRNA expression has previously been linked to differential sensitivity to cisplatin and antimicrotubule drugs, BRCA1 mRNA expression may provide additional information for customizing adjuvant antimicrotubule-based chemotherapy


    Directory of Open Access Journals (Sweden)

    M. N. Mamedov


    Full Text Available About 150 million men worldwide and about 50% of men aged 40-88 y.o. in outpatient practice suffer from erectile dysfunction (ED. There is a linear relation between the age and ED rate. The main reason of ED in the majority of men (about 80% of patients is cardiovascular diseases (atherosclerosis, hypertension, diabetes mellitus, as well as certain risk factors (smoking, alcohol abuse, physical inactivity etc.. The problem of ED in cardiac outpatients and modern pharmacotherapy is discussed. The phosphodiesterase-5 (PDE5 inhibitors increase the relaxing effect of nitric oxide and increase cyclic GMP levels during sexual arousal. It results in increase of cavernosum blood flow, contributing to the physiological erection. Three PDE5 inhibitors (sildenafil, tadalafil, vardenafil are used in clinical practice nowadays.

  3. Phosphodiesterases in non-neoplastic appearing colonic mucosa from patients with colorectal neoplasia

    DEFF Research Database (Denmark)

    Mahmood, Badar; Damm, Morten Matthiesen Bach; Jensen, Thorbjørn Søren Rønn


    BACKGROUND: Intracellular signaling through cyclic nucleotides, both cyclic AMP and cyclic GMP, is altered in colorectal cancer. Accordingly, it is hypothesized that an underlying mechanism for colorectal neoplasia involves altered function of phosphodiesterases (PDEs), which affects cyclic...... functionally by measurements of transepithelial ion transport and their expression and localization by employing real-time qPCR and immunohistochemistry. RESULTS: In functional studies PDE subtype-4 displayed lower activity in colorectal neoplasia patients (p = 0.006). Furthermore, real-time qPCR analysis...... showed overexpression of subtype PDE4B (p = 0.002) and subtype PDE5A (p = 0.02) in colorectal neoplasia patients. Finally, immunohistochemistry for 7 PDE isozymes demonstrated the presence of all 7 isozymes, albeit with weak reactions, and with no differences in localization between colorectal neoplasia...

  4. Multiple Conformations of Phosphodiesterase-5: Implications for Enzyme Function and Drug Developement

    Energy Technology Data Exchange (ETDEWEB)

    Wang,H.; Liu, Y.; Huai, Q.; Cai, J.; Zoraghi, R.; Francis, S.; Corbin, J.; Robinson, H.; Xin, Z.; et al.


    Phosphodiesterase-5 (PDE5) is the target for sildenafil, vardenafil, and tadalafil, which are drugs for treatment of erectile dysfunction and pulmonary hypertension. We report here the crystal structures of a fully active catalytic domain of unliganded PDE5A1 and its complexes with sildenafil or icarisid II. These structures together with the PDE5A1-isobutyl-1-methylxanthine complex show that the H-loop (residues 660-683) at the active site of PDE5A1 has four different conformations and migrates 7 to 35 Angstroms upon inhibitor binding. In addition, the conformation of sildenafil reported herein differs significantly from those in the previous structures of chimerically hybridized or almost inactive PDE5. Mutagenesis and kinetic analyses confirm that the H-loop is particularly important for substrate recognition and that invariant Gly659 which immediately precedes the H-loop is critical for optimal substrate affinity and catalytic activity.

  5. The inhibition of phosphodiesterase type 5 as a novel target for antidepressant action

    DEFF Research Database (Denmark)

    Liebenberg, Nico


    therapy of depression. A recent study from our laboratory reported an antidepressant-like response in the rat forced swim test (FST) following chronic (11 day) co-administration of the phosphodiesterase type 5 (PDE5) inhibitor sildenafil and the muscarinic acetylcholine (mACh) receptor antagonist atropine...... in Sprague Dawley rats. In the current study we explored the antidepressant-like properties of PDE5 inhibitors in Flinders Sensitive Line (FSL) rats, a genetic animal model of depression, and investigated the mechanism(s) that may be involved in the antidepressant-like activity of these drugs. We also......Major depression is one of the most debilitating diseases of our time, while current antidepressant treatments remain deficient in several ways. The nitric oxide (NO) / cyclic guanosine monophosphate (cGMP) / cGMP-dependent protein kinase (PK-G) pathway shows promise as a novel target for the drug...

  6. An alpha-glucose-1-phosphate phosphodiesterase is present in rat liver cytosol

    International Nuclear Information System (INIS)

    Srisomsap, C.; Richardson, K.L.; Jay, J.C.; Marchase, R.B.


    UDP-glucose:glycoprotein glucose-1-phosphotransferase (Glc-phosphotransferase) catalyzes the transfer of alpha-Glc-1-P from UDP-Glc to mannose residues on acceptor glycoproteins. The predominant acceptor for this transfer in both mammalian cells and Paramecium is a cytoplasmic glycoprotein of 62-63 kDa. When cytoplasmic proteins from rat liver were fractionated by preparative isoelectric focusing following incubation of a liver homogenate with the 35S-labeled phosphorothioate analogue of UDP-Glc ([beta-35S]UDP-Glc), the acceptor was found to have a pI of about 6.0. This fraction, when not labeled prior to the focusing, became very heavily labeled when mixed with [beta-35S]. UDP-Glc and intact liver microsomes, a rich source of the Glc-phosphotransferase. In addition, it was observed that the isoelectric fractions of the cytosol having pI values of 2-3.2 contained a degradative activity, alpha-Glc-1-P phosphodiesterase, that was capable of removing alpha-Glc-1-P, monitored through radioactive labeling both in the sugar and the phosphate, as an intact unit from the 62-kDa acceptor. Identification of the product of this cleavage was substantiated by its partial transformation to UDP-Glc in the presence of UTP and UDP-Glc pyrophosphorylase. The alpha-Glc-1-P phosphodiesterase had a pH optimum of 7.5 and was not effectively inhibited by any of the potential biochemical inhibitors that were tested. Specificity for the Glc-alpha-1-P-6-Man diester was suggested by the diesterase's inability to degrade UDP-Glc or glucosylphosphoryldolichol. This enzyme may be important in the regulation of secretion since the alpha-Glc-1-P present on the 62-kDa phosphoglycoprotein appears to be removed and then rapidly replaced in response to secretagogue

  7. An alpha-glucose-1-phosphate phosphodiesterase is present in rat liver cytosol

    Energy Technology Data Exchange (ETDEWEB)

    Srisomsap, C.; Richardson, K.L.; Jay, J.C.; Marchase, R.B. (Univ. of Alabama, Birmingham (USA))


    UDP-glucose:glycoprotein glucose-1-phosphotransferase (Glc-phosphotransferase) catalyzes the transfer of alpha-Glc-1-P from UDP-Glc to mannose residues on acceptor glycoproteins. The predominant acceptor for this transfer in both mammalian cells and Paramecium is a cytoplasmic glycoprotein of 62-63 kDa. When cytoplasmic proteins from rat liver were fractionated by preparative isoelectric focusing following incubation of a liver homogenate with the 35S-labeled phosphorothioate analogue of UDP-Glc ((beta-35S)UDP-Glc), the acceptor was found to have a pI of about 6.0. This fraction, when not labeled prior to the focusing, became very heavily labeled when mixed with (beta-35S). UDP-Glc and intact liver microsomes, a rich source of the Glc-phosphotransferase. In addition, it was observed that the isoelectric fractions of the cytosol having pI values of 2-3.2 contained a degradative activity, alpha-Glc-1-P phosphodiesterase, that was capable of removing alpha-Glc-1-P, monitored through radioactive labeling both in the sugar and the phosphate, as an intact unit from the 62-kDa acceptor. Identification of the product of this cleavage was substantiated by its partial transformation to UDP-Glc in the presence of UTP and UDP-Glc pyrophosphorylase. The alpha-Glc-1-P phosphodiesterase had a pH optimum of 7.5 and was not effectively inhibited by any of the potential biochemical inhibitors that were tested. Specificity for the Glc-alpha-1-P-6-Man diester was suggested by the diesterase's inability to degrade UDP-Glc or glucosylphosphoryldolichol. This enzyme may be important in the regulation of secretion since the alpha-Glc-1-P present on the 62-kDa phosphoglycoprotein appears to be removed and then rapidly replaced in response to secretagogue.

  8. Characterization of binding and inhibitory properties of TAK-063, a novel phosphodiesterase 10A inhibitor.

    Directory of Open Access Journals (Sweden)

    Akina Harada

    Full Text Available Phosphodiesterase 10A (PDE10A inhibition is a novel and promising approach for the treatment of central nervous system disorders such as schizophrenia and Huntington's disease. A novel PDE10A inhibitor, TAK-063 [1-[2-fluoro-4-(1H-pyrazol-1-ylphenyl]-5-methoxy-3-(1-phenyl-1H-pyrazol-5-yl-pyridazin-4(1H-one] has shown high inhibitory activity and selectivity for human recombinant PDE10A2 in vitro; the half-maximal inhibitory concentration was 0.30 nM, and selectivity over other phosphodiesterases (PDEs was more than 15000-fold. TAK-063 at 10 µM did not show more than 50% inhibition or stimulation of 91 enzymes or receptors except for PDEs. In vitro autoradiography (ARG studies using rat brain sections revealed that [3H]TAK-063 selectively accumulated in the caudate putamen (CPu, nucleus accumbens (NAc, globus pallidus, substantia nigra, and striatonigral projection, where PDE10A is highly expressed. This [3H]TAK-063 accumulation was almost entirely blocked by an excess amount of MP-10, a PDE10A selective inhibitor, and the accumulation was not observed in brain slices of Pde10a-knockout mice. In rat brain sections, [3H]TAK-063 bound to a single high-affinity site with mean ± SEM dissociation constants of 7.2 ± 1.2 and 2.6 ± 0.5 nM for the CPu and NAc shell, respectively. Orally administered [14C]TAK-063 selectively accumulated in PDE10A expressing brain regions in an in vivo ARG study in rats. Striatal PDE10A occupancy by TAK-063 in vivo was measured using T-773 as a tracer and a dose of 0.88 mg/kg (p.o. was calculated to produce 50% occupancy in rats. Translational studies with TAK-063 and other PDE10A inhibitors such as those presented here will help us better understand the pharmacological profile of this class of potential central nervous system drugs.

  9. Phosphodiesterase Type 5 Inhibitors and the Risk of Melanoma Skin Cancer. (United States)

    Lian, Yi; Yin, Hui; Pollak, Michael N; Carrier, Serge; Platt, Robert W; Suissa, Samy; Azoulay, Laurent


    The association between phosphodiesterase type 5 inhibitors (PDE5-Is), drugs used in the treatment of erectile dysfunction (ED), and melanoma skin cancer is controversial. To assess whether the use of PDE5-Is is associated with an increased risk of melanoma skin cancer. Using the UK Clinical Practice Research Datalink, we assembled a cohort of men newly diagnosed with ED between 1998 and 2014 and followed until 2015. PDE5-I exposure was considered as a time-varying variable lagged by 1 yr for latency purposes. Cox proportional hazards models were used to estimate adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) of incident melanoma associated with PDE5-I use overall and by number of prescriptions and pills received. Identical analyses were conducted for basal and squamous cell carcinoma, two cancers for which PDE5-related pathways are not thought to be involved. The cohort included 142 983 patients, of whom 440 were newly diagnosed with melanoma during follow-up (rate: 63.0 per 100 000 person-years). Compared with nonuse, PDE5-I use was not associated with an overall increased risk of melanoma (rates: 66.7 vs 54.1 per 100 000 person-years; HR: 1.18; 95% CI, 0.95-1.47). The risk was significantly increased among those who had received seven or more prescriptions and ≥25 pills (HR: 1.30 [95% CI, 1.01-1.69] and 1.34 [95% CI, 1.04-1.72], respectively). In contrast, there was no overall association with basal and squamous cell carcinoma, with an unclear association with numbers of prescriptions and pills received. The use of PDE5-Is was not associated with an overall increased risk of melanoma skin cancer. The increased risks observed in the highest prescription and pill categories require further validation. In this study, the use of phosphodiesterase type 5 inhibitors was not associated with an increased risk of melanoma skin cancer. Copyright © 2016. Published by Elsevier B.V.

  10. Phosphodiesterase-5 Inhibition Alleviates Pulmonary Hypertension and Basal Lamina Thickening in Rats Challenged by Chronic Hypoxia

    Directory of Open Access Journals (Sweden)

    Coline Nydegger


    Full Text Available Background: Hypoxia represents both an outcome of cardiopulmonary diseases and a trigger for severe pulmonary complications as pulmonary hypertension. Because nitric oxide (NO is a critical mediator in the development of pulmonary hypertension, the modulators of its downstream function may become target of pharmacological interventions aimed at alleviating the impact of this condition. Here, we investigate the effects of an early administration of phosphodiesterase-5 inhibitor in rats where pulmonary artery hypertension was induced by chronic exposure to hypoxia.Methods: Rats were divided into three groups: normoxic control, hypoxic with no treatments (2 weeks breathing an atmosphere containing 10% oxygen, and hypoxic treated with sildenafil (1.4 mg/Kg per day in 0.3 mL i.p.. After sacrifice, hearts and lungs were removed and harvested for analyses.Results: Sildenafil reduced hypoxia-induced right ventricle hypertrophy without effects in lung hypertrophy, and blunted the increase in right ventricle pressure without effects on left ventricle pressure. Furthermore, the NO-producing systems (i.e., the phosphorylation of the endothelial isoforms of NO synthase that was measured in both myocardial and lung tissues, and the blood NO stores (i.e., the plasma level of nitrates and nitrites were up-regulated by sildenafil. We did not find significant effects of sildenafil on weight and hemoglobin concentration. Morphological analysis in lung biopsies revealed that 2-week hypoxia increased the frequency of small pulmonary vessels leaving large vessels unaffected. Finally, ultrastructural analysis showed that sildenafil down-regulated the hypoxia-induced increase in the thickness of the pulmonary basal lamina.Conclusions: In this model of pulmonary hypertension, sildenafil contrasts the negative effects of hypoxia on pulmonary vascular and right ventricle remodeling. This action does not only encompass the canonical vasomodulatory effect, but involves

  11. Phosphodiesterase-III inhibitor prevents hemorrhagic transformation induced by focal cerebral ischemia in mice treated with tPA.

    Directory of Open Access Journals (Sweden)

    Mitsunori Ishiguro

    Full Text Available The purpose of the present study was to investigate whether cilostazol, a phosphodiesterase-III inhibitor and antiplatelet drug, would prevent tPA-associated hemorrhagic transformation. Mice subjected to 6-h middle cerebral artery occlusion were treated with delayed tPA alone at 6 h, with combined tPA plus cilostazol at 6 h, or with vehicle at 6 h. We used multiple imaging (electron microscopy, spectroscopy, histological and neurobehavioral measures to assess the effects of the treatment at 18 h and 7 days after the reperfusion. To further investigate the mechanism of cilostazol to beneficial effect, we also performed an in vitro study with tPA and a phosphodiesterase-III inhibitor in human brain microvascular endothelial cells, pericytes, and astrocytes. Combination therapy with tPA plus cilostazol prevented development of hemorrhagic transformation, reduced brain edema, prevented endothelial injury via reduction MMP-9 activity, and prevented the blood-brain barrier opening by inhibiting decreased claudin-5 expression. These changes significantly reduced the morbidity and mortality at 18 h and 7 days after the reperfusion. Also, the administration of both drugs prevented injury to brain human endothelial cells and human brain pericytes. The present study indicates that a phosphodiesterase-III inhibitor prevents the hemorrhagic transformation induced by focal cerebral ischemia in mice treated with tPA.

  12. Calmodulin-activated cyclic nucleotide phosphodiesterase from brain. Relationship of subunit structure to activity assessed by radiation inactivation

    International Nuclear Information System (INIS)

    Kincaid, R.L.; Kemdner, E.; Manganiello, V.C.; Osborne, J.C.; Vaughan, M.


    The apparent target sizes of the basal and calmodulin-dependent activities of calmodulin-activated phosphodiesterase from bovine brain were estimated using target theory analysis of data from radiation inactivation experiments. Whether crude or highly purified samples were irradiated, the following results were obtained. Low doses of radiation caused a 10 to 15% increase in basal activity, which, with further irradiation, decayed with an apparent target size of approx.60,000 daltons. Calmodulin-dependent activity decayed with an apparent target size of approx.105,000 daltons. The percentage stimulation of enzyme activity by calmodulin decreased markedly as a function of radiation dosage. These observations are consistent with results predicted by computer-assisted modeling based on the assumptions that: 1) the calmodulin-activated phosphodiesterase exists as a mixture of monomers which are fully active in the absence of calmodulin and dimers which are inactive in the absence of calmodulin; 2) in the presence of calmodulin, a dimer exhibits activity equal to that of two monomers; 3) on radiation destruction of a dimer, an active monomer is generated. This monomer-dimer hypothesis provides a plausible explanation for and definition of basal and calmodulin-dependent phosphodiesterase activity

  13. Erektile Dysfunktion, Phosphodiesterase-5-Hemmer und KHK - die Sicht des Kardiologen

    Directory of Open Access Journals (Sweden)

    Schmid P


    Full Text Available Die erektile Dysfunktion (ED kommt vermehrt bei Patienten mit koronarer Herzkrankheit (KHK vor und wird üblicherweise mit Phosphodiesterase- 5-Hemmern (PDE-5-Hemmer wie Sildenafil, Vardenafil und Tadalafil behandelt. Dies geht mit einem systemischen Blutdruckabfall von bis zu 10 mmHg systolisch und bis 6 mmHg diastolisch einher. Die Herzfrequenz bleibt gleich oder steigt minimal an, das Doppelprodukt (RR sys x HF als Maß des myokardialen Sauerstoffverbrauches bleibt unverändert oder sinkt ab. Koronarangiographische Untersuchungen bei KHK-Patienten unter Sildenafil ergaben gegenüber Placebo keine Unterschiede in der Hämodynamik. Auch die Koronarreserve, die Blutflußgeschwindigkeit, der Durchmesser der Koronararterien, das Blutflußvolumen und der Koronargefäßwiderstand blieben unbeeinflußt. Die körperliche Leistungsfähigkeit wurde durch Sildenafil und Vardenafil nicht verändert. Eine kardiovaskuläre Exzeßmortalität liegt durch Einnahme von PDE-5-Hemmern nicht vor. Absolute Kontraindikation für eine Therapie mit PDE-5-Hemmern ist die gleichzeitige Gabe von NO-Donatoren (Nitrate, Molsidomin, Nitroprussid-Natrium, relative Kontraindikationen sind eine akute Koronarinsuffizienz, Herzinsuffizienz mit niedrigem Blutdruck, vorbestehende antihypertensive 3- bis 4-fach-Kombinationstherapie, Pharmaka, die den Abbau bzw. die Elimination von PDE-5-Hemmern reduzieren, sowie Antiarrhythmika der Klasse III.

  14. Overactive Bladder Syndrome and the Potential Role of Prostaglandins and Phosphodiesterases: An Introduction (United States)

    Rahnama'i, Mohammad Sajjad; Van Koeveringe, Gommert A.; Van Kerrebroeck, Philip E.


    In this paper, a general introduction is given, presenting the overactive bladder syndrome (OAB) and its impact on the quality of life and economical burden in patients affected. Moreover, the anatomy, physiology and histology of the lower urinary tract are discussed, followed by a brief overview on the possible role of prostaglandin (PG) and phosphodiesterase type 5 (PDE5) in the urinary bladder. The current literature on the role and distribution of PGE2 and its receptors in the urinary bladder is discussed. In both animal models and in human studies, high levels of signaling molecules such as PG and cGMP have been implicated, in decreased functional bladder capacity and micturition volume, as well as in increased voiding contraction amplitude. As a consequence, inhibition of prostanoid production, the use of prostanoid receptor antagonists, or PDE inhibitors might be a rational way to treat patients with detrusor overactivity. Similarly, prostanoid receptor agonists, or agents that stimulate their production, might have a function in treating bladder underactivity. PMID:24350100

  15. The phosphodiesterase inhibitor, ibudilast, attenuates neuroinflammation in the MPTP model of Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Joanna Schwenkgrub

    Full Text Available Since the degeneration of the nigrostriatal dopaminergic pathway in Parkinson's disease (PD is associated with the inflammation process and decreased levels of cyclic nucleotides, inhibition of up-regulated cyclic nucleotide phosphodiesterases (PDEs appears to be a promising therapeutic strategy. We used ibudilast (IBD, a non-selective PDE3,4,10,11 inhibitor, due to the abundant PDE 4 and 10 expression in the striatum. The present study for the first time examined the efficacy of IBD in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP mouse model of PD.IBD [0, 20, 30, 40, or 50 mg/kg] was injected b.i.d. subcutaneously for nine days to three-month-old male C57Bl/10Tar mice, beginning two days prior to MPTP (60 mg/kg intoxication. High-pressure liquid chromatography, Western blot analysis, and real time RT-PCR methods were applied.Our study demonstrated that chronic administration of IBD attenuated astroglial reactivity and increased glial cell-derived neurotrophic factor (GDNF production in the striatum. Moreover, IBD reduced TNF-α, IL-6, and IL-1β expression.IBD had a well-defined effect on astroglial activation in the mouse model of PD; however, there was no protective effect in the acute phase of injury. Diminished inflammation and an increased level of GDNF may provide a better outcome in the later stages of neurodegeneration.

  16. Phosphodiesterase 3 and 5 and cyclic nucleotide-gated ion channel expression in rat trigeminovascular system

    DEFF Research Database (Denmark)

    Kruse, Lars S; Sandholdt, Nicolai T H; Gammeltoft, Steen


    may be associated with mutations in ion channels. The aim of the present study was to describe the expression of phosphodiesterase 3 (PDE3) and 5 (PDE5) and cyclic nucleotide-gated ion channels (CNG) in cerebral arteries, meninges, and the trigeminal ganglion. mRNA for PDE and CNG was determined...... in the rat middle cerebral artery, basilar artery, trigeminal ganglion, and dura mater using real-time PCR. PDE and CNG proteins were identified using Western blot. For comparison, rat aorta and mesenteric artery were analysed. PDE3A, PDE3B, and PDE5A mRNA were detected in all tissues examined except for PDE......3A mRNA in dura mater and the trigeminal ganglion. PDE5A and PDE3A protein expression was present in both cerebral and peripheral arteries, whereas PDE3B protein was present only in the cerebral arteries. The CNGA4 and B1 subunit mRNAs were detected in cerebral arteries and CNGA2 also...

  17. Lung vasodilatory response to inhaled iloprost in experimental pulmonary hypertension: amplification by different type phosphodiesterase inhibitors

    Directory of Open Access Journals (Sweden)

    Weissmann Norbert


    Full Text Available Abstract Inhaled prostanoids and phosphodiesterase (PDE inhibitors have been suggested for treatment of severe pulmonary hypertension. In catheterized rabbits with acute pulmonary hypertension induced by continuous infusion of the stable thromboxane analogue U46619, we asked whether sildenafil (PDE1/5/6 inhibitor, motapizone (PDE3 inhibitor or 8-Methoxymethyl-IBMX (PDE1 inhibitor synergize with inhaled iloprost. Inhalation of iloprost caused a transient pulmonary artery pressure decline, levelling off within per se ineffective dose of each PDE inhibitor (200 μg/kg × min 8-Methoxymethyl-IBMX, 1 μg/kg × min sildenafil, 5 μg/kg × min motapizone with subsequent iloprost nebulization, marked amplification of the prostanoid induced pulmonary vasodilatory response was noted and the area under the curve of PPA reduction was nearly threefold increased with all approaches, as compared to sole iloprost administration. Further amplification was achieved with the combination of inhaled iloprost with sildenafil plus motapizone, but not with sildenafil plus 8MM-IBMX. Systemic hemodynamics and gas exchange were not altered for all combinations. We conclude that co-administration of minute systemic doses of selective PDE inhibitors with inhaled iloprost markedly enhances and prolongs the pulmonary vasodilatory response to inhaled iloprost, with maintenance of pulmonary selectivity and ventilation perfusion matching. The prominent effect of sildenafil may be operative via both PDE1 and PDE5, and is further enhanced by co-application of a PDE3 inhibitor.

  18. cGMP-Phosphodiesterase Inhibition Prevents Hypoxia-Induced Cell Death Activation in Porcine Retinal Explants.

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    Lorena Olivares-González

    Full Text Available Retinal hypoxia and oxidative stress are involved in several retinal degenerations including diabetic retinopathy, glaucoma, central retinal artery occlusion, or retinopathy of prematurity. The second messenger cyclic guanosine monophosphate (cGMP has been reported to be protective for neuronal cells under several pathological conditions including ischemia/hypoxia. The purpose of this study was to evaluate whether the accumulation of cGMP through the pharmacological inhibition of phosphodiesterase (PDE with Zaprinast prevented retinal degeneration induced by mild hypoxia in cultures of porcine retina. Exposure to mild hypoxia (5% O2 for 24h reduced cGMP content and induced retinal degeneration by caspase dependent and independent (PARP activation mechanisms. Hypoxia also produced a redox imbalance reducing antioxidant response (superoxide dismutase and catalase activities and increasing superoxide free radical release. Zaprinast reduced mild hypoxia-induced cell death through inhibition of caspase-3 or PARP activation depending on the cell layer. PDE inhibition also ameliorated the effects of mild hypoxia on antioxidant response and the release of superoxide radical in the photoreceptor layer. The use of a PKG inhibitor, KT5823, suggested that cGMP-PKG pathway is involved in cell survival and antioxidant response. The inhibition of PDE, therefore, could be useful for reducing retinal degeneration under hypoxic/ischemic conditions.

  19. Phosphodiesterase 5 inhibitors lower both portal and pulmonary pressure in portopulmonary hypertension: a case report

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    Bremer Hinrich C


    Full Text Available Abstract Background Portopulmonary hypertension (PPHTN is a severe complication in liver cirrhosis. PDE5 inhibitors lower pulmonary arterial pressure (PAP in PPHTN. However, their effect on portal hypertension has not yet been investigated. Case presentation A 55 year old male patient presented with PPHTN and alcoholic liver cirrhosis. 10 mg of Tadalafil, a PDE5 inhibitor with a long half-life, was administered orally under continuous monitoring of pulmonary and portal hemodynamics. For maintenance therapy the patient received Sildenafil 20 mg bid. Tadalafil lowered mean PAP from 45 to 39 mmHg within 60 minutes. Cardiac output (CO increased from 6.8 to 7.9 l/min. Central venous pressure (CVP remained stable at 3 mmHg. Systolic and diastolic blood pressure was lowered from 167/89 to 159/86 mmHg. Pulse rate increased from 75 to 87 per min. Wedged hepatic vein pressure (WHVP decreased from 21 to 18 mm Hg, hepatovenous pressure gradient (HVPG decreased from 10 to 7 mmHg. Hemodynamic monitoring after 6 months of Sildenafil therapy revealed a sustained lowering of mean PAP. HVPG remained constant at 10 mmHg. Cardiac and pulmonary performance had further improved. Conclusion This case report shows for the first time, that phosphodiesterase 5 inhibitors lower both portal and pulmonary pressure in portopulmonary hypertension.

  20. Daily use of phosphodiesterase type 5 inhibitors as prevention for recurrent priapism

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    Archimedes Nardozza Junior

    Full Text Available Summary Objective: The pathogenesis of recurrent priapism is currently being investigated based on the regulation of the phosphodiesterase 5 (PDE5 enzyme. We explored the daily use of PDE5 inhibitors to treat and prevent priapism recurrences. Method: We administered PDE5 inhibitors using a long-term therapeutic regimen in seven men with recurrent priapism, with a mean age of 29.2 years (range 21 to 35 years. Six men (85.7% had idiopathic priapism recurrences and one man (24.3% had sickle cell disease-associated priapism recurrences. Tadalafil 5 mg was administered daily. The mean follow-up was 6.6 months (range 3 to 12 months. Results: Daily long-term oral PDE5 inhibitor therapy alleviated priapism recurrences in all patients. Five (71.4% had no episodes of priapism and two (28.6% referred decrease in their episodes of priapism. All patients referred improvement in erectile function. Conclusion: These findings suggest the hypothesis that PDE5 dysregulation exerts a pathogenic role for both sickle cell disease-associated priapism and for idiopathic priapism, and that it offers a molecular target for the therapeutic management of priapism. These preliminary observations suggest that continuous long-term oral PDE5 inhibitor therapy may treat and prevent recurrent priapism.

  1. A phosphodiesterase 4-controlled switch between memory extinction and strengthening in the hippocampus. (United States)

    Roesler, Rafael; Reolon, Gustavo K; Maurmann, Natasha; Schwartsmann, Gilberto; Schröder, Nadja; Amaral, Olavo B; Valvassori, Samira; Quevedo, João


    Established fear-related memories can undergo phenomena such as extinction or reconsolidation when recalled. Extinction probably involves the creation of a new, competing memory trace that decreases fear expression, whereas reconsolidation can mediate memory maintenance, updating, or strengthening. The factors determining whether retrieval will initiate extinction, reconsolidation, or neither of these two processes include training intensity, duration of the retrieval session, and age of the memory. However, previous studies have not shown that the same behavioral protocol can be used to induce either extinction or reconsolidation and strengthening, depending on the pharmacological intervention used. Here we show that, within an experiment that leads to extinction in control rats, memory can be strengthened if rolipram, a selective inhibitor of phosphodiesterase type 4 (PDE4), is administered into the dorsal hippocampus immediately after retrieval. The memory-enhancing effect of rolipram lasted for at least 1 week, was blocked by the protein synthesis inhibitor anisomycin, and did not occur when drug administration was not paired with retrieval. These findings indicate that the behavioral outcome of memory retrieval can be pharmacologically switched from extinction to strengthening. The cAMP/protein kinase A (PKA) signaling pathway might be a crucial mechanism determining the fate of memories after recall.

  2. Reduced Airway Hyperresponsiveness by Phosphodiesterase 3 and 4 Inhibitors in Guinea-Pigs

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    Nöella Germain


    Full Text Available The aim of the present study was to compare the effects of selective phosphodiesterase (PDE 3, 4 and 5 inhibitors on antigen-induced airway hyperresponsiveness in sensitized guinea-pigs. When the sensitized guinea-pigs were orally pre-treated with the selective PDE4 inhibitor, Ro 20-1724 (30 mg/kg, and studied 48 h after OA, a significant reduction (p<0.01 of the leftward shift of the dose-response curve to ACh was noted, whereas it was ineffective at the lower dose (10 mg/kg. Administration of the selective PDE3 inhibitor, milrinone (30 mg/kg also elicited a significant reduction (p<0.01 of the airway hyperresponsiveness, whereas the PDE5 inhibitor zaprinast (30 mg/kg was ineffective. These results show that both PDE3 and PDE4 inhibitors are able to inhibit the antigen-induced airway hyperresponsiveness in sensitized guinea-pigs and support the potential utility of selective PDE inhibitors in the treatment of asthma.

  3. Phosphodiesterase 10A inhibition attenuates sleep deprivation-induced deficits in long-term fear memory. (United States)

    Guo, Lengqiu; Guo, Zhuangli; Luo, Xiaoqing; Liang, Rui; Yang, Shui; Ren, Haigang; Wang, Guanghui; Zhen, Xuechu


    Sleep, particularly rapid eye movement (REM) sleep, is implicated in the consolidation of emotional memories. In the present study, we investigated the protective effects of a phosphodiesterase 10A (PDE10A) inhibitor MP-10 on deficits in long-term fear memory induced by REM sleep deprivation (REM-SD). REM-SD caused deficits in long-term fear memory, however, MP-10 administration ameliorated the deleterious effects of REM-SD on long term fear memory. Brain-derived neurotropic factor (BDNF) and phosphorylated cAMP response element-binding protein (pCREB) were altered in specific brain regions associated with learning and memory in REM-SD rats. Accordingly, REM-SD caused a significant decrease of pCREB in hippocampus and striatum and a significant decrease of BDNF in the hippocampus, striatum and amygdala, however, MP-10 reversed the effects of REM-SD in a dose-dependent manner. Our findings suggest that REM-SD disrupts the consolidation of long-term fear memory and that administration of MP-10 protects the REM-SD-induced deficits in fear memory, which may be due to the MP-10-induced expression of BDNF in the hippocampus, striatum and amygdala, and phosphorylation of CREB in the hippocampus and striatum. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  4. An Insight into the Pharmacophores of Phosphodiesterase-5 Inhibitors from Synthetic and Crystal Structural Studies

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    Chen,G.; Wang, H.; Robinson, H.; Cai, J.; Wan, Y.; Ke, H.


    Selective inhibitors of cyclic nucleotide phosphodiesterase-5 (PDE5) have been used as drugs for treatment of male erectile dysfunction and pulmonary hypertension. An insight into the pharmacophores of PDE5 inhibitors is essential for development of second generation of PDE5 inhibitors, but has not been completely illustrated. Here we report the synthesis of a new class of the sildenafil derivatives and a crystal structure of the PDE5 catalytic domain in complex with 5-(2-ethoxy-5-(sulfamoyl)-3-thienyl)-1-methyl-3-propyl-1, 6-dihydro-7H-pyrazolo[4, 3-d]pyrimidin-7-one (12). Inhibitor 12 induces conformational change of the H-loop (residues 660-683), which is different from any of the known PDE5 structures. The pyrazolopyrimidinone groups of 12 and sildenafil are well superimposed, but their sulfonamide groups show a positional difference of as much as 1.5 Angstroms . The structure-activity analysis suggests that a small hydrophobic pocket and the H-loop of PDE5 are important for the inhibitor affinity, in addition to two common elements for binding of almost all the PDE inhibitors: the stack against the phenylalanine and the hydrogen bond with the invariant glutamine. However, the PDE5-12 structure does not provide a full explanation to affinity changes of the inhibitors. Thus alternatives such as conformational change of the M-loop are open and further structural study is required.

  5. Natural phosphodiesterase-4 inhibitors from the leaf skin of Aloe barbadensis Miller. (United States)

    Zhong, Jia-Sheng; Huang, Yi-You; Zhang, Tian-Hua; Liu, Yu-Peng; Ding, Wen-Jing; Wu, Xiao-Fang; Xie, Zhi-Yong; Luo, Hai-Bin; Wan, Jin-Zhi


    The ethanolic extract of Aloe barbadensis Miller leaf skin showed inhibitory activity against phosphodiesterase-4D (PDE4D), which is a therapeutic target of inflammatory disease. Subsequent bioassay-guided fractionation led to the isolation of two new anthrones, 6'-O-acetyl-aloin B (9) and 6'-O-acetyl-aloin A (11), one new chromone, aloeresin K (8), together with thirteen known compounds. Their chemical structures were elucidated by spectroscopic methods including UV, IR, 1D and 2D NMR, and HRMS. All of the isolates were screened for their inhibitory activity against PDE4D using tritium-labeled adenosine 3',5'-cyclic monophosphate ((3)H-cAMP) as substrate. Compounds 13 and 14 were identified as PDE4D inhibitors, with their IC50 values of 9.25 and 4.42 μM, respectively. These achievements can provide evidences for the use of A. barbadensis leaf skin as functional feed additives for anti-inflammatory purpose. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. A phosphodiesterase 4-controlled switch between memory extinction and strengthening in the hippocampus

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    Rafael eRoesler


    Full Text Available Established fear-related memories can undergo phenomena such as extinction or reconsolidation when recalled. Extinction probably involves the creation of a new, competing memory trace that decreases fear expression, whereas reconsolidation can mediate memory maintenance, updating, or strengthening. The factors determining whether retrieval will initiate extinction, reconsolidation, or neither of these two processes, include training intensity, duration of the retrieval session, and age of the memory. However, previous studies have not shown that the same behavioral protocol can be used to induce either extinction or reconsolidation and strengthening, depending on the pharmacological intervention used. Here we show that, within an experiment that leads to extinction in control rats, memory can be strengthened if rolipram, a selective inhibitor of phosphodiesterase type 4 (PDE4, is administered into the dorsal hippocampus immediately after retrieval. The memory-enhancing effect of rolipram lasted for at least one week, was blocked by the protein synthesis inhibitor anisomycin, and did not occur when drug administration was not paired with retrieval. These findings indicate that the behavioral outcome of memory retrieval can be pharmacologically switched from extinction to strengthening. The cAMP/protein kinase A (PKA signaling pathway might be a crucial mechanism determining the fate of memories after recall.

  7. Present and future treatment strategies for pulmonary arterial hypertension : focus on phosphodiesterase-5 inhibitors. (United States)

    Kane, Laura B; Klings, Elizabeth S


    Idiopathic pulmonary arterial hypertension (IPAH) is a rare progressive disorder historically associated with mortality in treatment modalities including vasodilator therapy have resulted in improved symptoms, hemodynamics, and survival in these patients. Vasodilators, including the calcium channel antagonists, prostanoids, and endothelin receptor antagonists, have been used to counteract potential imbalances in vasoactive mediators in PAH patients; all have produced improved long-term symptomatology and hemodynamics. Only the prostanoid epoprostenol has improved survival in IPAH patients. Although these medications have worked well in many patients with PAH, each of them has limitations. The phosphodiesterase-5 (PDE-5) inhibitors are a relatively new form of treatment for PAH. They are designed to potentiate the effects of cyclic guanosine monophosphate, thereby mimicking endogenous nitric oxide within the vasculature. PDE-5 inhibitors are selective pulmonary vasodilators effective in animal models of pulmonary hypertension. The published clinical studies evaluating their use have been small in size to date but appear to demonstrate benefit. The recently completed 12-week randomized placebo-controlled Sildenafil Use in Pulmonary Hypertension (SUPER-1) trial demonstrated improvement in 6-minute walk distance and hemodynamics in patients receiving sildenafil. These data suggest that the PDE-5 inhibitors are effective in treating PAH and that it is likely that their usage will increase over time. The purpose of this review is to present a current view of the pathogenesis and treatment of PAH, with an emphasis on the use of PDE-5 inhibitors in these patients.

  8. Roles of A-Kinase Anchoring Proteins and Phosphodiesterases in the Cardiovascular System (United States)

    Ercu, Maria; Klussmann, Enno


    A-kinase anchoring proteins (AKAPs) and cyclic nucleotide phosphodiesterases (PDEs) are essential enzymes in the cyclic adenosine 3′-5′ monophosphate (cAMP) signaling cascade. They establish local cAMP pools by controlling the intensity, duration and compartmentalization of cyclic nucleotide-dependent signaling. Various members of the AKAP and PDE families are expressed in the cardiovascular system and direct important processes maintaining homeostatic functioning of the heart and vasculature, e.g., the endothelial barrier function and excitation-contraction coupling. Dysregulation of AKAP and PDE function is associated with pathophysiological conditions in the cardiovascular system including heart failure, hypertension and atherosclerosis. A number of diseases, including autosomal dominant hypertension with brachydactyly (HTNB) and type I long-QT syndrome (LQT1), result from mutations in genes encoding for distinct members of the two classes of enzymes. This review provides an overview over the AKAPs and PDEs relevant for cAMP compartmentalization in the heart and vasculature and discusses their pathophysiological role as well as highlights the potential benefits of targeting these proteins and their protein-protein interactions for the treatment of cardiovascular diseases. PMID:29461511

  9. Sildenafil preserves diastolic relaxation after reduction by L-NAME and increases phosphodiesterase-5 in the intercalated discs of cardiac myocytes and arterioles

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    Silvia Elaine Ferreira-Melo


    Full Text Available OBJECTIVES: We investigated the influence of sildenafil on cardiac contractility and diastolic relaxation and examined the distribution of phosphodiesterase-5 in the hearts of hypertensive rats that were treated with by NG-nitro-L-arginine methyl ester (L-NAME. METHODS: Male Wistar rats were treated with L-NAME and/or sildenafil for eight weeks. The Langendorff method was used to examine the effects of sildenafil on cardiac contractility and diastolic relaxation. The presence and location of phosphodiesterase-5 and phosphodiesterase-3 were assessed by immunohistochemistry, and cGMP plasma levels were measured by ELISA. RESULTS: In isolated hearts, sildenafil prevented the reduction of diastolic relaxation (dP/dt that was induced by L-NAME. In addition, phosphodiesterase-5 immunoreactivity was localized in the intercalated discs between the myocardial cells. The staining intensity was reduced by L-NAME, and sildenafil treatment abolished this reduction. Consistent with these results, the plasma levels of cGMP were decreased in the L-NAME-treated rats but not in rats that were treated with L-NAME + sildenafil. CONCLUSION: The sildenafil-induced attenuation of the deleterious hemodynamic and cardiac morphological effects of L-NAME in cardiac myocytes is mediated (at least in part by the inhibition of phosphodiesterase-5.

  10. The Characterization of Escherichia coli CpdB as a Recombinant Protein Reveals that, besides Having the Expected 3´-Nucleotidase and 2´,3´-Cyclic Mononucleotide Phosphodiesterase Activities, It Is Also Active as Cyclic Dinucleotide Phosphodiesterase.

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    Iralis López-Villamizar

    Full Text Available Endogenous cyclic diadenylate phosphodiesterase activity was accidentally detected in lysates of Escherichia coli BL21. Since this kind of activity is uncommon in Gram-negative bacteria, its identification was undertaken. After partial purification and analysis by denaturing gel electrophoresis, renatured activity correlated with a protein identified by fingerprinting as CpdB (cpdB gene product, which is annotated as 3´-nucleotidase / 2´,3´-cyclic-mononucleotide phosphodiesterase, and it is synthesized as a precursor protein with a signal sequence removable upon export to the periplasm. It has never been studied as a recombinant protein. The coding sequence of mature CpdB was cloned and expressed as a GST fusion protein. The study of the purified recombinant protein, separated from GST, confirmed CpdB annotation. The assay of catalytic efficiencies (kcat/Km for a large substrate set revealed novel CpdB features, including very high efficiencies for 3´-AMP and 2´,3´-cyclic mononucleotides, and previously unknown activities on cyclic and linear dinucleotides. The catalytic efficiencies of the latter activities, though low in relative terms when compared to the major ones, are far from negligible. Actually, they are perfectly comparable to those of the 'average' enzyme and the known, bona fide cyclic dinucleotide phosphodiesterases. On the other hand, CpdB differs from these enzymes in its extracytoplasmic location and in the absence of EAL, HD and DHH domains. Instead, it contains the domains of the 5´-nucleotidase family pertaining to the metallophosphoesterase superfamily, although CpdB lacks 5´-nucleotidase activity. The possibility that the extracytoplasmic activity of CpdB on cyclic dinucleotides could have physiological meaning is discussed.

  11. Clinical and preclinical treatment of urologic diseases with phosphodiesterase isoenzymes 5 inhibitors: an update

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    Wen-Hao Zhang


    Full Text Available Phosphodiesterase isoenzymes 5 inhibitors (PDE5-Is are the first-line therapy for erectile dysfunction (ED. The constant discoveries of nitric oxide (NO/cyclic guanosine monophosphate (cGMP cell-signaling pathway for smooth muscle (SM control in other urogenital tracts (UGTs make PDE5-Is promising pharmacologic agents against other benign urological diseases. This article reviews the literature and contains some previously unpublished data about characterizations and activities of PDE5 and its inhibitors in treating urological disorders. Scientific discoveries have improved our understanding of cell-signaling pathway in NO/cGMP-mediated SM relaxation in UGTs. Moreover, the clinical applications of PDE5-Is have been widely recognized. On-demand PDE5-Is are efficacious for most cases of ED, while daily-dosing and combination with testosterone are recommended for refractory cases. Soluble guanylate cyclase (sGC stimulators also have promising role in the management of severe ED conditions. PDE5-Is are also the first rehabilitation strategy for postoperation or postradiotherapy ED for prostate cancer patients. PDE5-Is, especially combined with α-adrenoceptor antagonists, are very effective for benign prostatic hyperplasia (BPH except on maximum urinary flow rate (Q max with tadalafil recently proved for BPH with/without ED. Furthermore, PDE5-Is are currently under various phases of clinical or preclinical researches with promising potential for other urinary and genital illnesses, such as priapism, premature ejaculation, urinary tract calculi, overactive bladder, Peyronie′s disease, and female sexual dysfunction. Inhibition of PDE5 is expected to be an effective strategy in treating benign urological diseases. However, further clinical studies and basic researches investigating mechanisms of PDE5-Is in disorders of UGTs are required.

  12. Phosphodiesterase type 5 inhibitors and risk of melanoma: A meta-analysis. (United States)

    Tang, Huilin; Wu, Wenting; Fu, Shuangshuang; Zhai, Suodi; Song, Yiqing; Han, Jiali


    The association between phosphodiesterase type 5 (PDE5) inhibitors and melanoma risk is controversial. We quantify the association between use of PDE5 inhibitors and melanoma. We systematically searched PubMed, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, and for studies that were conducted up to July 13, 2016, and evaluated the association between PDE5 inhibitors and skin cancer. Random effects meta-analyses were used to calculate the adjusted odds ratio (OR) with the 95% confidence interval (CI). Five observational studies were included. Compared with PDE5 inhibitor nonuse, PDE5 inhibitor use was slightly but significantly associated with an increased risk for development of melanoma (OR, 1.12; 95% CI, 1.03-1.21) and basal cell carcinoma (OR, 1.14; 95% CI, 1.09-1.19) but not squamous cell carcinoma. For melanoma risk, none of the prespecified factors (dose of PDE5 inhibitor, study design, and study region) significantly affected the results (P > .05). Our sensitivity analysis confirmed the stability of the results. We included only observational studies, which had some heterogeneities and inconsistent controlling for potential confounders. Use of PDE5 inhibitors may be associated with a slightly increased risk for development of melanoma and basal cell carcinoma but not squamous cell carcinoma. However, further large well-conducted prospective studies with adequate adjustment for potential confounders are required for confirmation. Copyright © 2017 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  13. Phosphodiesterase-5 inhibitors in management of pulmonary hypertension: Safety, tolerability, and efficacy

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    Mitchell S Buckley


    Full Text Available Mitchell S Buckley1, Robin L Staib1, Laura M Wicks1, Jeremy P Feldman21Department of Pharmacy, Banner Good Samaritan Medical Center, and 2Arizona Pulmonary Specialists Ltd, Phoenix, Arizona, USAAbstract: Pulmonary arterial hypertension (PAH is a progressive disease that causes severe disability and has no cure. Over the past 20 years, a variety of treatment options have evolved for the management of PAH. With an expanded therapeutic armamentarium come more complex decisions regarding treatment options. Agent selection depends upon several factors including efficacy, side effect profile, and cost, as well as convenience of administration. We have undertaken a review of phosphodiesterase-5 (PDE-5 inhibitors in PAH with a focus on efficacy and safety. A literature search was conducted using the Medline and Cochrane Central Register of Controlled Trials databases (1966–February 2010 for relevant randomized clinical studies. Overall, 10 studies met our inclusion criteria. Sildenafil was the most commonly studied agent, followed by tadalafil and vardenafil. Most trials found that the PDE-5 inhibitors significantly improved exercise capacity and lowered pulmonary pressures. However, there were conflicting results regarding these agents’ impact on improving cardiac function and functional class. Overall, these medications were effective and well tolerated with a relatively benign side effect profile. The PDE-5 inhibitors are an important option in treating PAH. While most of the published clinical data involved sildenafil, the other PDE-5 inhibitors show promise as well. Further studies are needed to determine the optimal doses of this therapeutic drug class, as well as its effects as adjunctive therapy with other agents in PAH.Keywords: sildenafil, tadalafil, vardenafil, pulmonary hypertension

  14. The phosphodiesterase-5 inhibitor vardenafil is a potent inhibitor of ABCB1/P-glycoprotein transporter.

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    Pei-Rong Ding

    Full Text Available One of the major causes of chemotherapy failure in cancer treatment is multidrug resistance (MDR which is mediated by the ABCB1/P-glycoprotein. Previously, through the use of an extensive screening process, we found that vardenafil, a phosphodiesterase 5 (PDE-5 inhibitor significantly reverses MDR in ABCB1 overexpressing cancer cells, and its efficacy was greater than that of tadalafil, another PDE-5 inhibitor. The present study was designed to determine the reversal mechanisms of vardenafil and tadalafil on ABC transporters-mediated MDR. Vardenafil or tadalafil alone, at concentrations up to 20 µM, had no significant toxic effects on any of the cell lines used in this study, regardless of their membrane transporter status. However, vardenafil when used in combination with anticancer substrates of ABCB1, significantly potentiated their cytotoxicity in ABCB1 overexpressing cells in a concentration-dependent manner, and this effect was greater than that of tadalafil. The sensitivity of the parenteral cell lines to cytotoxic anticancer drugs was not significantly altered by vardenafil. The differential effects of vardenafil and tadalafil appear to be specific for the ABCB1 transporter as both vardenafil and tadalafil had no significant effect on the reversal of drug resistance conferred by ABCC1 (MRP1 and ABCG2 (BCRP transporters. Vardenafil significantly increased the intracellular accumulation of [(3H]-paclitaxel in the ABCB1 overexpressing KB-C2 cells. In addition, vardenafil significantly stimulated the ATPase activity of ABCB1 and inhibited the photolabeling of ABCB1 with [(125I]-IAAP. Furthermore, Western blot analysis indicated the incubation of cells with either vardenafil or tadalafil for 72 h did not alter ABCB1 protein expression. Overall, our results suggest that vardenafil reverses ABCB1-mediated MDR by directly blocking the drug efflux function of ABCB1.

  15. Phosphodiesterase type 5 inhibitors increase Herceptin transport and treatment efficacy in mouse metastatic brain tumor models.

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    Jinwei Hu


    Full Text Available Chemotherapeutic drugs and newly developed therapeutic monoclonal antibodies are adequately delivered to most solid and systemic tumors. However, drug delivery into primary brain tumors and metastases is impeded by the blood-brain tumor barrier (BTB, significantly limiting drug use in brain cancer treatment.We examined the effect of phosphodiesterase 5 (PDE5 inhibitors in nude mice on drug delivery to intracranially implanted human lung and breast tumors as the most common primary tumors forming brain metastases, and studied underlying mechanisms of drug transport. In vitro assays demonstrated that PDE5 inhibitors enhanced the uptake of [(14C]dextran and trastuzumab (Herceptin, a humanized monoclonal antibody against HER2/neu by cultured mouse brain endothelial cells (MBEC. The mechanism of drug delivery was examined using inhibitors for caveolae-mediated endocytosis, macropinocytosis and coated pit/clathrin endocytosis. Inhibitor analysis strongly implicated caveolae and macropinocytosis endocytic pathways involvement in the PDE5 inhibitor-enhanced Herceptin uptake by MBEC. Oral administration of PDE5 inhibitor, vardenafil, to mice with HER2-positive intracranial lung tumors led to an increased tumor permeability to high molecular weight [(14C]dextran (2.6-fold increase and to Herceptin (2-fold increase. Survival time of intracranial lung cancer-bearing mice treated with Herceptin in combination with vardenafil was significantly increased as compared to the untreated, vardenafil- or Herceptin-treated mice (p0.05.These findings suggest that PDE5 inhibitors may effectively modulate BTB permeability, and enhance delivery and therapeutic efficacy of monoclonal antibodies in hard-to-treat brain metastases from different primary tumors that had metastasized to the brain.

  16. Inhibition of chlorine-induced lung injury by the type 4 phosphodiesterase inhibitor rolipram

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    Chang, Weiyuan; Chen, Jing; Schlueter, Connie F.; Rando, Roy J.; Pathak, Yashwant V.; Hoyle, Gary W.


    Chlorine is a highly toxic respiratory irritant that when inhaled causes epithelial cell injury, alveolar-capillary barrier disruption, airway hyperreactivity, inflammation, and pulmonary edema. Chlorine is considered a chemical threat agent, and its release through accidental or intentional means has the potential to result in mass casualties from acute lung injury. The type 4 phosphodiesterase inhibitor rolipram was investigated as a rescue treatment for chlorine-induced lung injury. Rolipram inhibits degradation of the intracellular signaling molecule cyclic AMP. Potential beneficial effects of increased cyclic AMP levels include inhibition of pulmonary edema, inflammation, and airway hyperreactivity. Mice were exposed to chlorine (whole body exposure, 228–270 ppm for 1 h) and were treated with rolipram by intraperitoneal, intranasal, or intramuscular (either aqueous or nanoemulsion formulation) delivery starting 1 h after exposure. Rolipram administered intraperitoneally or intranasally inhibited chlorine-induced pulmonary edema. Minor or no effects were observed on lavage fluid IgM (indicative of plasma protein leakage), KC (Cxcl1, neutrophil chemoattractant), and neutrophils. All routes of administration inhibited chlorine-induced airway hyperreactivity assessed 1 day after exposure. The results of the study suggest that rolipram may be an effective rescue treatment for chlorine-induced lung injury and that both systemic and targeted administration to the respiratory tract were effective routes of delivery. -- Highlights: ► Chlorine causes lung injury when inhaled and is considered a chemical threat agent. ► Rolipram inhibited chlorine-induced pulmonary edema and airway hyperreactivity. ► Post-exposure rolipram treatments by both systemic and local delivery were effective. ► Rolipram shows promise as a rescue treatment for chlorine-induced lung injury.

  17. Simultaneous quantification of endothelin receptor antagonists and phosphodiesterase 5 inhibitors currently used in pulmonary arterial hypertension. (United States)

    Enderle, Yeliz; Witt, Lukas; Wilkens, Heinrike; Grünig, Ekkehard; Haefeli, Walter E; Burhenne, Jürgen


    Combination treatment with endothelin receptor antagonists (ERA) and phosphodiesterase 5 inhibitors (PDE5I) improved efficacy of pulmonary arterial hypertension (PAH) therapy. However, drug-drug interactions, variable exposure, non-adherence can influence plasma levels. For these reasons, drug quantification may be advantageous particularly in patients with poor treatment responses. We developed, validated, and applied an assay for the simultaneous quantification of ambrisentan, bosentan, macitentan, sildenafil, and tadalafil as well as their main (and partly active) metabolites in human plasma. This method is based on LC-MS/MS separation for a rapid and sensitive quantification with stable isotopically labelled analogues as internal standards for each drug and metabolite. Sample preparation was carried out using a solid phase extraction protocol based on Oasis HLB material. The separation was achieved on a Kinetex C18 column and multiple reaction monitoring in negative ionization mode was used for sensitive detection. The calibrations were linear for all analytes with correlation coefficients >0.99 within the concentration range observed under a therapeutic PAH dosing scheme with lower limits of quantification between 0.34ng/mL (OH-ambrisentan) and 10ng/mL (despropyl-macitentan). Intra- and inter-day precision at LLOQ and QC levels ranged between 2.03% and 19.8%, and 0.65% and 14.0%, respectively. The sample turnover time was 12min. The applicability of this versatile LC/MS/MS assay was verified by the successful analysis of clinical routine samples of patients on PAH medication. This new method allows for the first time to assess trough drug and metabolite levels of the currently approved PDE5I and ERAs in PAH patients, thus enabling for measurement of samples in clinical routine. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Synthesis, Pharmacological Profile and Docking Studies of New Sulfonamides Designed as Phosphodiesterase-4 Inhibitors.

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    Isabelle Karine da Costa Nunes

    Full Text Available Prior investigations showed that increased levels of cyclic AMP down-regulate lung inflammatory changes, stimulating the interest in phosphodiesterase (PDE4 as therapeutic target. Here, we described the synthesis, pharmacological profile and docking properties of a novel sulfonamide series (5 and 6a-k designed as PDE4 inhibitors. Compounds were screened for their selectivity against the four isoforms of human PDE4 using an IMAP fluorescence polarized protocol. The effect on allergen- or LPS-induced lung inflammation and airway hyper-reactivity (AHR was studied in A/J mice, while the xylazine/ketamine-induced anesthesia test was employed as a behavioral correlate of emesis in rodents. As compared to rolipram, the most promising screened compound, 6a (LASSBio-448 presented a better inhibitory index concerning PDE4D/PDE4A or PDE4D/PDE4B. Accordingly, docking analyses of the putative interactions of LASSBio-448 revealed similar poses in the active site of PDE4A and PDE4C, but slight unlike orientations in PDE4B and PDE4D. LASSBio-448 (100 mg/kg, oral, 1 h before provocation, inhibited allergen-induced eosinophil accumulation in BAL fluid and lung tissue samples. Under an interventional approach, LASSBio-448 reversed ongoing lung eosinophilic infiltration, mucus exacerbation, peribronchiolar fibrosis and AHR by allergen provocation, in a mechanism clearly associated with blockade of pro-inflammatory mediators such as IL-4, IL-5, IL-13 and eotaxin-2. LASSBio-448 (2.5 and 10 mg/kg also prevented inflammation and AHR induced by LPS. Finally, the sulfonamide derivative was shown to be less pro-emetic than rolipram and cilomilast in the assay employed. These findings suggest that LASSBio-448 is a new PDE4 inhibitor with marked potential to prevent and reverse pivotal pathological features of diseases characterized by lung inflammation, such as asthma.

  19. Evolution of multiple phosphodiesterase isoforms in stickleback involved in cAMP signal transduction pathway. (United States)

    Sato, Yukuto; Hashiguchi, Yasuyuki; Nishida, Mutsumi


    Duplicate genes are considered to have evolved through the partitioning of ancestral functions among duplicates (subfunctionalization) and/or the acquisition of novel functions from a beneficial mutation (neofunctionalization). Additionally, an increase in gene dosage resulting from duplication may also confer an advantageous effect, as has been suggested for histone, tRNA, and rRNA genes. Currently, there is little understanding of the effect of increased gene dosage on subcellular networks like signal transduction pathways. Addressing this issue may provide further insights into the evolution by gene duplication. We analyzed the evolution of multiple stickleback phosphodiesterase (PDE, EC: 1C genes involved in the cyclic nucleotide signaling pathway. Stickleback has 8-9 copies of this gene, whereas only one or two loci exist in other model vertebrates. Our phylogenetic and synteny analyses suggested that the multiple PDE1C genes in stickleback were generated by repeated duplications of >100-kbp chromosome segments. Sequence evolution analysis did not provide strong evidence for neofunctionalization in the coding sequences of stickleback PDE1C isoforms. On the other hand, gene expression analysis suggested that the derived isoforms acquired expression in new organs, implying their neofunctionalization in terms of expression patterns. In addition, at least seven isoforms of the stickleback PDE1C were co-expressed with olfactory-type G-proteins in the nose, suggesting that PDE1C dosage is increased in the stickleback olfactory transduction (OT) pathway. In silico simulations of OT implied that the increased PDE1C dosage extends the longevity of the depolarization signals of the olfactory receptor neuron. The predicted effect of the increase in PDE1C products on the OT pathway may play an important role in stickleback behavior and ecology. However, this possibility should be empirically examined. Our analyses imply that an increase in gene product sometimes

  20. Evolution of multiple phosphodiesterase isoforms in stickleback involved in cAMP signal transduction pathway

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    Nishida Mutsumi


    Full Text Available Abstract Background Duplicate genes are considered to have evolved through the partitioning of ancestral functions among duplicates (subfunctionalization and/or the acquisition of novel functions from a beneficial mutation (neofunctionalization. Additionally, an increase in gene dosage resulting from duplication may also confer an advantageous effect, as has been suggested for histone, tRNA, and rRNA genes. Currently, there is little understanding of the effect of increased gene dosage on subcellular networks like signal transduction pathways. Addressing this issue may provide further insights into the evolution by gene duplication. Results We analyzed the evolution of multiple stickleback phosphodiesterase (PDE, EC: 1C genes involved in the cyclic nucleotide signaling pathway. Stickleback has 8–9 copies of this gene, whereas only one or two loci exist in other model vertebrates. Our phylogenetic and synteny analyses suggested that the multiple PDE1C genes in stickleback were generated by repeated duplications of >100-kbp chromosome segments. Sequence evolution analysis did not provide strong evidence for neofunctionalization in the coding sequences of stickleback PDE1C isoforms. On the other hand, gene expression analysis suggested that the derived isoforms acquired expression in new organs, implying their neofunctionalization in terms of expression patterns. In addition, at least seven isoforms of the stickleback PDE1C were co-expressed with olfactory-type G-proteins in the nose, suggesting that PDE1C dosage is increased in the stickleback olfactory transduction (OT pathway. In silico simulations of OT implied that the increased PDE1C dosage extends the longevity of the depolarization signals of the olfactory receptor neuron. Conclusion The predicted effect of the increase in PDE1C products on the OT pathway may play an important role in stickleback behavior and ecology. However, this possibility should be empirically examined. Our

  1. Cyclic nucleotide metabolism including nitric oxide and phosphodiesterase-related targets in the lower urinary tract. (United States)

    Uckert, Stefan; Kuczyk, Markus A


    The clinical data on the use of the orally active phosphodiesterase (PDE) type 5 inhibitors sildenafil (VIAGRA™), vardenafil (LEVITRA™), and tadalafil (CIALIS™) for the treatment of male erectile dysfunction have boosted research activities on the physiology and pharmacology of the organs of the lower urinary tract (LUT). This includes both intracellular signal transduction in the prostate, urinary bladder (detrusor), and urethra, as well as central brain and spinal cord pathways controlling the function of the LUT. Such efforts provided the basis for the development of new therapeutic modalities into the management of dysfunctions/ syndromes of the LUT, some of which are already offered to the patients. The pharmacological treatment of the overactive bladder and the so-called benign prostatic syndrome, including LUT symptomatology and bladder outlet obstruction secondary to benign prostatic enlargement, has primarily focused on selective, orally available drugs acting by influencing intracellular regulatory mechanisms. These agents are regarded efficacious, have a fast onset of drug action in the target tissue and an improved effect-to-side-effect ratio. Better understanding of the functional significance of proteins related to cyclic nucleotide-dependent pathways, such as nitric oxide synthase, cytosolic and membrane-bound guanylyl cyclases, PDE isoenzymes and cyclic AMP- and cyclic GMP-binding protein kinases, the relative distribution in tissues of the LUT, and the consequences for urogenital function, seems to be of particular interest in order to identify new or more selective pharmacological approaches to manage disorders of the LUT. The present review focuses on cyclic nucleotide-related targets involved in the control of the function of the bladder, prostate, and urethra and the significance of those proteins in the process of evolving new pharmacological options for the treatment of LUT symptoms secondary to benign prostatic hyperplasia as well as

  2. Inhibition of Uterine Contractility by Thalidomide Analogs via Phosphodiesterase-4 Inhibition and Calcium Entry Blockade

    Directory of Open Access Journals (Sweden)

    Eduardo Fernández-Martínez


    Full Text Available Uterine relaxation is crucial during preterm labor. Phosphodiesterase-4 (PDE-4 inhibitors have been proposed as tocolytics. Some thalidomide analogs are PDE-4 inhibitors. The aim of this study was to assess the uterus-relaxant properties of two thalidomide analogs, methyl 3-(4-nitrophthalimido-3-(3,4-dimethoxyphenyl-propanoate (4NO2PDPMe and methyl 3-(4-aminophthalimido-3-(3,4-dimethoxyphenyl-propanoate (4APDPMe and were compared to rolipram in functional studies of spontaneous phasic, K+-induced tonic, and Ca2+-induced contractions in isolated pregnant human myometrial tissues. The accumulation of cAMP was quantified in HeLa cells. The presence of PDE-4B2 and phosphorylated myosin light-chain (pMLC, in addition to the effect of thalidomide analogs on oxytocin-induced pMLC, were assessed in human uterine myometrial cells (UtSMCs. Thalidomide analogs had concentration-dependent inhibitory effects on spontaneous and tonic contractions and inhibited Ca2+-induced responses. Tonic contraction was equipotently inhibited by 4APDPMe and rolipram (IC50 = 125 ± 13.72 and 98.45 ± 8.86 µM, respectively. Rolipram and the thalidomide analogs inhibited spontaneous and tonic contractions equieffectively. Both analogs increased cAMP accumulation in a concentration-dependent manner (p < 0.05 and induced changes in the subcellular localization of oxytocin-induced pMLC in UtSMCs. The inhibitory effects of thalidomide analogs on the contractions of pregnant human myometrium tissue may be due to their PDE-4 inhibitory effect and novel mechanism as calcium-channel blockers.

  3. Stress history increases alcohol intake in relapse: relation to phosphodiesterase 10A. (United States)

    Logrip, Marian L; Zorrilla, Eric P


    Stressful experiences can result in elevated alcohol drinking, as exemplified in many individuals with post-traumatic stress disorder. However, how stress history, rather than acute stressors, influences alcohol intake remains uncertain. To model the protracted effects of past stress, male Wistar rats were subjected to light-cued footshock (stress history) or light cues alone (control) prior to acquisition of alcohol self-administration (1-hour sessions, fixed ratio 1-3, 100 µl of 10% v/v alcohol as reinforcer). Stress history did not alter mean alcohol intake during acquisition of self-administration, but it increased preference for the alcohol-paired lever over the inactive lever. Following an extinction period, rats with a history of stress exposure and low baseline alcohol intake showed a twofold elevation in alcohol self-administration, as compared with low-drinking rats with no stress history. Similar effects were not seen in rats self-administering 0.1% sucrose. Analysis of mRNA levels of phosphodiesterase 10A (PDE10A), a dual-specificity cyclic adenosine monophosphate and cyclic guanosine monophosphate hydrolyzing enzyme, showed that stress history increased Pde10a mRNA levels in the basolateral amygdala and, in low-drinking rats, the prelimbic prefrontal cortex (plPFC). Pde10a mRNA levels in the plPFC correlated directly with greater alcohol self-administration during the relapse-like phase, and greater BLA Pde10a mRNA levels correlated with increased ethanol preference after acquisition. The data demonstrate that stress history sensitizes otherwise low alcohol drinkers to consume more alcohol in a relapse-like situation and identify stress-induced neuroadaptations in amygdala and prefrontal cortical Pde10a expression as changes that may drive heightened alcohol intake and preference in susceptible individuals. © 2012 The Authors. Addiction Biology © 2012 Society for the Study of Addiction.

  4. Inhibition of chlorine-induced lung injury by the type 4 phosphodiesterase inhibitor rolipram

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Weiyuan; Chen, Jing; Schlueter, Connie F. [Department of Environmental and Occupational Health Sciences, School of Public Health and Information Sciences, University of Louisville, Louisville, KY (United States); Rando, Roy J. [Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University Health Sciences Center, New Orleans, LA (United States); Pathak, Yashwant V. [College of Pharmacy, University of South Florida, Tampa, FL (United States); Hoyle, Gary W., E-mail: [Department of Environmental and Occupational Health Sciences, School of Public Health and Information Sciences, University of Louisville, Louisville, KY (United States)


    Chlorine is a highly toxic respiratory irritant that when inhaled causes epithelial cell injury, alveolar-capillary barrier disruption, airway hyperreactivity, inflammation, and pulmonary edema. Chlorine is considered a chemical threat agent, and its release through accidental or intentional means has the potential to result in mass casualties from acute lung injury. The type 4 phosphodiesterase inhibitor rolipram was investigated as a rescue treatment for chlorine-induced lung injury. Rolipram inhibits degradation of the intracellular signaling molecule cyclic AMP. Potential beneficial effects of increased cyclic AMP levels include inhibition of pulmonary edema, inflammation, and airway hyperreactivity. Mice were exposed to chlorine (whole body exposure, 228–270 ppm for 1 h) and were treated with rolipram by intraperitoneal, intranasal, or intramuscular (either aqueous or nanoemulsion formulation) delivery starting 1 h after exposure. Rolipram administered intraperitoneally or intranasally inhibited chlorine-induced pulmonary edema. Minor or no effects were observed on lavage fluid IgM (indicative of plasma protein leakage), KC (Cxcl1, neutrophil chemoattractant), and neutrophils. All routes of administration inhibited chlorine-induced airway hyperreactivity assessed 1 day after exposure. The results of the study suggest that rolipram may be an effective rescue treatment for chlorine-induced lung injury and that both systemic and targeted administration to the respiratory tract were effective routes of delivery. -- Highlights: ► Chlorine causes lung injury when inhaled and is considered a chemical threat agent. ► Rolipram inhibited chlorine-induced pulmonary edema and airway hyperreactivity. ► Post-exposure rolipram treatments by both systemic and local delivery were effective. ► Rolipram shows promise as a rescue treatment for chlorine-induced lung injury.

  5. Computational identification and experimental characterization of substrate binding determinants of nucleotide pyrophosphatase/phosphodiesterase 7

    Directory of Open Access Journals (Sweden)

    Parrill Abby L


    Full Text Available Abstract Background Nucleotide pyrophosphatase/phosphodiesterase 7 (NPP7 is the only member of the mammalian NPP enzyme family that has been confirmed to act as a sphingomyelinase, hydrolyzing sphingomyelin (SM to form phosphocholine and ceramide. NPP7 additionally hydrolyzes lysophosphatidylcholine (LPC, a substrate preference shared with the NPP2/autotaxin(ATX and NPP6 mammalian family members. This study utilizes a synergistic combination of molecular modeling validated by experimental site-directed mutagenesis to explore the molecular basis for the unique ability of NPP7 to hydrolyze SM. Results The catalytic function of NPP7 against SM, LPC, platelet activating factor (PAF and para-nitrophenylphosphorylcholine (pNPPC is impaired in the F275A mutant relative to wild type NPP7, but different impacts are noted for mutations at other sites. These results are consistent with a previously described role of F275 to interact with the choline headgroup, where all substrates share a common functionality. The L107F mutation showed enhanced hydrolysis of LPC, PAF and pNPPC but reduced hydrolysis of SM. Modeling suggests this difference can be explained by the gain of cation-pi interactions with the choline headgroups of all four substrates, opposed by increased steric crowding against the sphingoid tail of SM. Modeling also revealed that the long and flexible hydrophobic tails of substrates exhibit considerable dynamic flexibility in the binding pocket, reducing the entropic penalty that might otherwise be incurred upon substrate binding. Conclusions Substrate recognition by NPP7 includes several important contributions, ranging from cation-pi interactions between F275 and the choline headgroup of all substrates, to tail-group binding pockets that accommodate the inherent flexibility of the lipid hydrophobic tails. Two contributions to the unique ability of NPP7 to hydrolyze SM were identified. First, the second hydrophobic tail of SM occupies a second

  6. Atrazine acts as an endocrine disrupter by inhibiting cAMP-specific phosphodiesterase-4

    Energy Technology Data Exchange (ETDEWEB)

    Kucka, Marek [Section on Cellular Signaling, Program in Developmental Neuroscience, NICHD, NIH, Bethesda, MD (United States); Pogrmic-Majkic, Kristina; Fa, Svetlana [Laboratory for Ecotoxicology, Department of Biology and Ecology, University of Novi Sad, Faculty of Sciences, 21000 Novi Sad (Serbia); Stojilkovic, Stanko S. [Section on Cellular Signaling, Program in Developmental Neuroscience, NICHD, NIH, Bethesda, MD (United States); Kovacevic, Radmila, E-mail: [Laboratory for Ecotoxicology, Department of Biology and Ecology, University of Novi Sad, Faculty of Sciences, 21000 Novi Sad (Serbia)


    Atrazine, one of the most commonly used herbicides worldwide, acts as an endocrine disruptor, but the mechanism of its action has not been characterized. In this study, we show that atrazine rapidly increases cAMP levels in cultured rat pituitary and testicular Leydig cells in a concentration-dependent manner, but less effectively than 3-isobutyl-1-methylxanthine, a competitive non-specific inhibitor of phosphodiesterases (PDEs). In forskolin (an activator of adenylyl cyclase)- and probenecid (an inhibitor of cyclic nucleotide transporters)-treated cells, but not in 3-isobutyl-1-methylxanthine-treated cells, atrazine further increased cAMP levels, indicating that inhibition of PDEs accounts for accumulation of cAMP. In contrast to cAMP, atrazine did not alter cGMP levels, further indicating that it inhibits cAMP-specific PDEs. Atrazine-induced changes in cAMP levels were sufficient to stimulate prolactin release in pituitary cells and androgen production in Leydig cells, indicating that it acts as an endocrine disrupter both in cells that secrete by exocytosis of prestored hormones and in cells that secrete by de novo hormone synthesis. Rolipram abolished the stimulatory effect of atrazine on cAMP release in both cell types, suggesting that it acts as an inhibitor of PDE4s, isoforms whose mRNA transcripts dominate in pituitary and Leydig cells together with mRNA for PDE8A. In contrast, immortalized lacto-somatotrophs showed low expression of these mRNA transcripts and several fold higher cAMP levels compared to normal pituitary cells, and atrazine was unable to further increase cAMP levels. These results indicate that atrazine acts as a general endocrine disrupter by inhibiting cAMP-specific PDE4s. -- Highlights: ► Atrazine stimulates cAMP accumulation in pituitary and Leydig cells. ► Atrazine also stimulates PRL and androgens secretion. ► Stimulatory effects of atrazine were abolished in cells with IBMX-inhibited PDEs. ► Atrazine specificity toward c

  7. Phosphodiesterase 5 inhibition at disease onset prevents experimental autoimmune encephalomyelitis progression through immunoregulatory and neuroprotective actions. (United States)

    Pifarré, Paula; Gutierrez-Mecinas, María; Prado, Judith; Usero, Lorena; Roura-Mir, Carme; Giralt, Mercedes; Hidalgo, Juan; García, Agustina


    In addition to detrimental inflammation, widespread axon degeneration is an important feature of multiple sclerosis (MS) pathology and a major correlate for permanent clinical deficits. Thus, treatments that combine immunomodulatory and neuroprotective effects are beneficial for MS. Using myelin oligodendrocyte glycoprotein peptide 35-55 (MOG)-induced experimental autoimmune encephalomyelitis (EAE) as a model of MS, we recently showed that daily treatment with the phosphodiesterase 5 (PDE5) inhibitor sildenafil at peak disease rapidly ameliorates clinical symptoms and neuropathology (Pifarre et al., 2011). We have now investigated the immunomodulatory and neuroprotective actions of sildenafil treatment from the onset of EAE when the immune response prevails and show that early administration of the drug prevents disease progression. Ultrastructural analysis of spinal cord evidenced that sildenafil treatment preserves axons and myelin and increases the number of remyelinating axons. Immunostaining of oligodendrocytes at different stages of differentiation showed that sildenafil protects immature and mature myelinating oligodendrocytes. Brain-derived neurotrophic factor (BDNF), a recognized neuroprotectant in EAE, was up-regulated by sildenafil in immune and neural cells suggesting its implication in the beneficial effects of the drug. RNA microarray analysis of spinal cord revealed that sildenafil up-regulates YM-1, a marker of the alternative macrophage/microglial M2 phenotype that has neuroprotective and regenerative properties. Immunostaining confirmed up-regulation of YM-1 while the classical macrophage/microglial activation marker Iba-1 was down-regulated. Microarray analysis also showed a notable up-regulation of several members of the granzyme B cluster (GrBs). Immunostaining revealed expression of GrBs in Foxp3+-T regulatory cells (Tregs) suggesting a role for these proteases in sildenafil-induced suppression of T effector cells (Teffs). In vitro analysis of

  8. Structural and Biophysical Analysis of the Soluble DHH/DHHA1-Type Phosphodiesterase TM1595 from Thermotoga maritima. (United States)

    Drexler, David Jan; Müller, Martina; Rojas-Cordova, Carlos Alberto; Bandera, Adrian Maurice; Witte, Gregor


    The concentration of messenger molecules in bacterial cells needs to be tightly regulated. This can be achieved by either controlling the synthesis rate, degradation, or export by specific transporters, respectively. The regulation of the essential second messenger c-di-AMP is achieved by modulation of the diadenylate cyclase activity as well as by specific phosphodiesterases that hydrolyze c-di-AMP in the cell. We provide here structural and biochemical data on the DHH-type phosphodiesterase TmPDE (TM1595) from Thermotoga maritima. Our analysis shows that TmPDE is preferentially degrading linear dinucleotides, such as 5'-pApA, 5'-pGpG, and 5'-pApG, compared with cyclic dinucleotide substrates. The high-resolution structural data provided here describe all steps of the PDE reaction: the ligand-free enzyme, two substrate-bound states, and three post-reaction states. We can furthermore show that Pde2 from Streptococcus pneumoniae shares both structural features and substrate specificity based on small-angle X-ray scattering data and biochemical assays. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Quantum measurements of signals from the Alphasat TDP1 laser communication terminal (United States)

    Elser, D.; Günthner, K.; Khan, I.; Stiller, B.; Bayraktar, Ö.; Müller, C. R.; Saucke, K.; Tröndle, D.; Heine, F.; Seel, S.; Greulich, P.; Zech, H.; Gütlich, B.; Richter, I.; Philipp-May, S.; Marquardt, Ch.; Leuchs, G.


    Quantum optics [1] can be harnessed to implement cryptographic protocols that are verifiably immune against any conceivable attack [2]. Even quantum computers, that will break most current public keys [3, 4], cannot harm quantum encryption. Based on these intriguing quantum features, metropolitan quantum networks have been implemented around the world [5-15]. However, the long-haul link between metropolitan networks is currently missing [16]. Existing fiber infrastructure is not suitable for this purpose since classical telecom repeaters cannot relay quantum states [2]. Therefore, optical satellite-to-ground communication [17-22] lends itself to bridge intercontinental distances for quantum communication [23-40].

  10. Administration of the Phosphodiesterase Type 4 Inhibitor Rolipram into the Amygdala at a Specific Time Interval after Learning Increases Recognition Memory Persistence (United States)

    Werenicz, Aline; Christoff, Raissa R.; Blank, Martina; Jobim, Paulo F. C.; Pedroso, Thiago R.; Reolon, Gustavo K.; Schroder, Nadja; Roesler, Rafael


    Here we show that administration of the phosphodiesterase type 4 (PDE4) inhibitor rolipram into the basolateral complex of the amygdala (BLA) at a specific time interval after training enhances memory consolidation and induces memory persistence for novel object recognition (NOR) in rats. Intra-BLA infusion of rolipram immediately, 1.5 h, or 6 h…

  11. Physiological Role of phnP-specified Phosphoribosyl Cyclic Phosphodiesterase in Catabolism of Organophosphonic Acids by the Carbon−Phosphorus Lyase Pathway

    DEFF Research Database (Denmark)

    Hove-Jensen, Bjarne; McSorley, Fern R.; Zechel, David L.


    In Escherichia coli , internalization and catabolism of organophosphonicacids are governed by the 14-cistron phnCDEFGHIJKLMNOP operon. The phnP gene product was previously shown to encode a phosphodiesterase with unusual specificity toward ribonucleoside 2',3'-cyclic phosphates. Furthermore, phnP...

  12. Catalytic enhancement of the heme-based oxygen-sensing phosphodiesterase EcDOS by hydrogen sulfide is caused by changes in heme coordination structure

    Czech Academy of Sciences Publication Activity Database

    Yang, F.; Fojtíková, V.; Man, Petr; Stráňava, M.; Martínková, M.; Du, Y.; Huang, D.; Shimizu, T.


    Roč. 28, č. 4 (2015), s. 637-652 ISSN 0966-0844 Grant - others:OPPC(XE) CZ.2.16/3.1.00/24023 Institutional support: RVO:61388971 Keywords : Heme * O-2 sensor * Phosphodiesterase Subject RIV: CE - Biochemistry Impact factor: 2.134, year: 2015

  13. Randomized comparison of the type 4 phosphodiesterase inhibitor cipamfylline cream, cream vehicle and hydrocortisone 17-butyrate cream for the treatment of atopic dermatitis

    NARCIS (Netherlands)

    Griffiths, C. E. M.; van Leent, E. J. M.; Gilbert, M.; Traulsen, J.


    Therapeutic options to treat atopic dermatitis are limited. Leukocytes from atopic patients have an abnormally high activity of cyclic adenosine monophosphate (AMP)-phosphodiesterase (PDE), which can be normalized in vitro by PDE inhibitors. Cipamfylline is a new potent and selective inhibitor of

  14. Discovery of novel Trypanosoma brucei phosphodiesterase B1 inhibitors by virtual screening against the unliganded TbrPDEB1 crystal structure

    NARCIS (Netherlands)

    Jansen, C.; Wang, H.; Kooistra, A.J.; de Graaf, C.; Orrling, K.M.; Tenor, H.; Seebeck, T.; de Esch, I.J.P.; Ke, H.; Leurs, R.


    Trypanosoma brucei cyclic nucleotide phosphodiesterase B1 (TbrPDEB1) and TbrPDEB2 have recently been validated as new therapeutic targets for human African trypanosomiasis by both genetic and pharmacological means. In this study we report the crystal structure of the catalytic domain of the

  15. Synthesis and evaluation of analogs of the phenylpyridazinone NPD-001 as potent trypanosomal TbrPDEB1 phosphodiesterase inhibitors and in vitro trypanocidals.

    NARCIS (Netherlands)

    Veerman, J.; van den Bergh, T.; Orrling, K.M.; Jansen, C.J.W.; Cos, P.; Maes, L.; Chatelain, E.; Ioset, J.R.; Edink, E.S.E.; Tenor, H.; Seebeck, T.; de Esch, I.J.P.; Leurs, R.; Sterk, G.J.


    Trypanosomal phosphodiesterases B1 and B2 (TbrPDEB1 and TbrPDEB2) play an important role in the life cycle of Trypanosoma brucei, the causative parasite of human African trypanosomiasis (HAT), also known as African sleeping sickness. Knock down of both enzymes leads to cell cycle arrest and is

  16. Time dependent involvement of cAMP and cGMP in consolidation of object memory: studies using selective phosphodiesterase type 2, 4 and 5 inhibitors

    NARCIS (Netherlands)

    Rutten, K.; Prickaerts, J.; Hendrix, M.; Staay, van der F.J.; Sik, A.; Blokland, A.


    The present study investigated the time-dependent memory enhancing properties of three selective phosphodiesterase inhibitors (PDE-I) vardenafil (PDE5-I), rolipram (PDE4-I) and BAY 60-7550 (PDE2-I) in the object recognition task. In particular, the time-dependent involvement of cAMP and cGMP in

  17. Novel Radioligands for Cyclic Nucleotide Phosphodiesterase Imaging with Positron Emission Tomography: An Update on Developments Since 2012

    Directory of Open Access Journals (Sweden)

    Susann Schröder


    Full Text Available Cyclic nucleotide phosphodiesterases (PDEs are a class of intracellular enzymes that inactivate the secondary messenger molecules, cyclic adenosine monophosphate (cAMP and cyclic guanosine monophosphate (cGMP. Thus, PDEs regulate the signaling cascades mediated by these cyclic nucleotides and affect fundamental intracellular processes. Pharmacological inhibition of PDE activity is a promising strategy for treatment of several diseases. However, the role of the different PDEs in related pathologies is not completely clarified yet. PDE-specific radioligands enable non-invasive visualization and quantification of these enzymes by positron emission tomography (PET in vivo and provide an important translational tool for elucidation of the relationship between altered expression of PDEs and pathophysiological effects as well as (pre-clinical evaluation of novel PDE inhibitors developed as therapeutics. Herein we present an overview of novel PDE radioligands for PET published since 2012.

  18. Synthesis of Quinoline Derivatives: Discovery of a Potent and Selective Phosphodiesterase 5 Inhibitor for the Treatment of Alzheimer's disease (United States)

    Fiorito, Jole; Saeed, Faisal; Zhang, Hong; Staniszewski, Agnieszka; Feng, Yan; Francis, Yitshak I.; Rao, Sudha; Thakkar, Devarshi M.; Deng, Shi-Xian; Landry, Donald W.; Arancio, Ottavio


    Phosphodiesterase type 5 (PDE5) mediates the degradation of cGMP in a variety of tissues including brain. Recent studies have demonstrated the importance of the nitric oxide/cGMP/cAMP-responsive element-binding protein (CREB) pathway to the process of learning and memory. Thus, PDE5 inhibitors (PDE5Is) are thought to be promising new therapeutic agents for the treatment of Alzheimer's disease (AD), a neurodegenerative disorder characterized by memory loss. To explore this possibility, a series of quinoline derivatives were synthesized and evaluated. We found that compound 7a selectively inhibits PDE5 with an IC50 of 0.27 nM and readily crosses the blood brain barrier. In an in vivo mouse model of AD, compound 7a rescues synaptic and memory defects. Quinoline-based, CNS-permeant PDE5Is have potential for AD therapeutic development. PMID:23313637

  19. Acute effect of phosphodiesterase type 5 inhibitor on serum oxidative status and prolidase activities in men with erectile dysfunction

    Directory of Open Access Journals (Sweden)

    Murat Savas


    Full Text Available OBJECTIVES: To investigate the acute effect of phosphodiesterase type 5 (PDE5 inhibitor on erectile dysfunction by evaluating serum oxidative status and prolidase activity. METHODS: Serum samples of 36 patients with erectile dysfunction and 30 control cases were analyzed for total antioxidant status, total oxidant status, and prolidase activity, before and after the administration of tadalafil citrate. RESULTS: Before and after tadalafil citrate administration, serum total antioxidant status, total oxidant status, and prolidase were 1.1+0.0 vs. 1.6 + 0.0 umol H2O2 Eq/L, 10.3+1.1 vs. 6.9 + 1.2 umol H2O2 Eq/L, and 236.4+19.5 vs. 228.2 + 19.2 U/L, respectively (p<0.0001 for all. CONCLUSIONS: Evaluation of serum oxidative status and prolidase activity confirmed the beneficial acute effects of PDE5 inhibitor in patients with erectile dysfunction.

  20. Psiguajadials A-K: Unusual Psidium Meroterpenoids as Phosphodiesterase-4 Inhibitors from the Leaves of Psidium guajava. (United States)

    Tang, Gui-Hua; Dong, Zhen; Guo, Yan-Qiong; Cheng, Zhong-Bin; Zhou, Chu-Jun; Yin, Sheng


    Bioassay-guided fractionation of the ethanolic extract of the leaves of Psidium guajava led to the isolation of 11 new Psidium meroterpenoids, psiguajadials A-K (1-11), along with 17 known ones (12-28). Their structures and absolute configurations were elucidated by spectroscopic methods and comparison of experimental and calculated ECD. Compounds 1 and 2 represent two unprecedented skeletons of 3,5-diformyl-benzyl phloroglucinol-coupled sesquiterpenoid, while 3 is the first example of Psidium meroterpenoids coupling via an oxepane ring. Putative biosynthetic pathways towards 1 and 2 are proposed. Compounds 1-13 and 16-26 exhibited moderate inhibitory activities against phosphodiesterase-4 (PDE4), a drug target for asthma and chronic obstructive pulmonary disease, with IC 50 values in the range of 1.34-7.26 μM.

  1. The phosphodiesterase 3 inhibitor cilostazol dilates large cerebral arteries in humans without affecting regional cerebral blood flow

    DEFF Research Database (Denmark)

    Birk, Steffen; Kruuse, Christina Rostrup; Petersen, Kenneth A


    Cilostazol, an inhibitor of phosphodiesterase (PDE) type 3, is used clinically in peripheral artery disease. PDE3 inhibitors may be clinically useful in the treatment of delayed cerebral vasospasm after subarachnoid hemorrhage. The authors present the first results on the effect of cilostazol...... on cerebral hemodynamics in normal participants. In this double-blind, randomized, crossover study, 200 mg cilostazol or placebo was administered orally to 12 healthy participants. Cerebral blood flow was measured using 133Xe inhalation and single photon emission computerized tomography. Mean flow velocity...... in the middle cerebral arteries (VMCA) was measured with transcranial Doppler, and the superficial temporal and radial arteries diameters were measured with ultrasonography. During the 4-hour observation period, there was no effect on systolic blood pressure (P = 0.28), but diastolic blood pressure decreased...

  2. Mechanistic insights into the role of prenyl-binding protein PrBP/δ in membrane dissociation of phosphodiesterase 6

    KAUST Repository

    Qureshi, Bilal M.


    Isoprenylated proteins are associated with membranes and their inter-compartmental distribution is regulated by solubilization factors, which incorporate lipid moieties in hydrophobic cavities and thereby facilitate free diffusion during trafficking. Here we report the crystal structure of a solubilization factor, the prenyl-binding protein (PrBP/δ), at 1.81 Å resolution in its ligand-free apo-form. Apo-PrBP/δ harbors a preshaped, deep hydrophobic cavity, capacitating apo-PrBP/δ to readily bind its prenylated cargo. To investigate the molecular mechanism of cargo solubilization we analyzed the PrBP/δ-induced membrane dissociation of rod photoreceptor phosphodiesterase (PDE6). The results suggest that PrBP/δ exclusively interacts with the soluble fraction of PDE6. Depletion of soluble species in turn leads to dissociation of membrane-bound PDE6, as both are in equilibrium. This

  3. Phosphodiesterase-Ialpha/autotaxin (PD-Ialpha/ATX): a multifunctional protein involved in central nervous system development and disease. (United States)

    Dennis, Jameel; Nogaroli, Luciana; Fuss, Babette


    Phosphodiesterase-Ialpha/autotaxin (PD-Ialpha/ATX) was originally identified as a cell-motility-stimulating factor secreted by a variety of tumor cells. Thus, studies related to its potential functional roles have traditionally focused on tumorigenesis. PD-Ialpha/ATX's catalytic activity, initially defined as nucleotide pyrophosphatase/phosphodiesterase, was soon recognized as being necessary for its tumor cell-motility-stimulating activity. However, only the discovery of PD-Ialpha/ATX's identity with lysophospholipase D, an extracellular enzyme that converts lysophosphatidylcholine into lysophosphatidic acid (LPA) and potentially sphingosylphosphoryl choline into sphingosine 1-phosphate (S1P), revealed the actual effectors responsible for PD-Ialpha/ATX's ascribed motogenic functions, i.e., its catalytic products. PD-Ialpha/ATX has also been detected during normal development in a number of tissues, in particular, the central nervous system (CNS), where expression levels are high. Similar to tumor cells, PD-Ialpha/ATX-expressing CNS cells secrete catalytically active PD-Ialpha/ATX into the extracellular environment. Thus, it appears reasonable to assume that PD-Ialpha/ATX's CNS-related functions are mediated via lysophospholipid, LPA and potentially S1P, signaling. However, recent studies identified PD-Ialpha/ATX as a matricellular protein involved in the modulation of oligodendrocyte-extracellular matrix interactions and oligodendrocyte remodeling. This property of PD-Ialpha/ATX was found to be independent of its catalytic activity and to be mediated by a novel functionally active domain. These findings, therefore, uncover PD-Ialpha/ATX, at least in the CNS, as a multifunctional protein able to induce complex signaling cascades via distinct structure-function domains. This Mini-Review describes PD-Ialpha/ATX's multifunctional roles in the CNS and discusses their potential contributions to CNS development and pathology.

  4. Selective phosphodiesterase-2A inhibitor alleviates radicular inflammation and mechanical allodynia in non-compressive lumbar disc herniation rats. (United States)

    Wang, Jun-Nan; Zhao, Xue-Jun; Liu, Zhi-Hua; Zhao, Xu-Li; Sun, Tao; Fu, Zhi-Jian


    Phosphodiesterase inhibitors possess anti-inflammatory properties. In addition, some studies report that phosphodiesterase 2A (PDE2A) are highly expressed in the dorsal horn of the spinal cord. The present study aimed to investigate whether intrathecal administration of Bay 60-7550, a specific PDE2A inhibitor, could alleviate mechanical allodynia in non-compressive lumbar disc herniation (NCLDH) rats. Rat NCLDH models by autologous nucleus pulposus implantation to dorsal root ganglion were established. Vehicle or Bay 60-7550 (0.1, 1.0 mg/kg) was injected by intrathecal catheter at day 1 post-operation. The ipsilateral mechanical withdrawal thresholds were analyzed from the day before surgery to day 7 after surgery. At day 7 post-operation, the ipsilateral lumbar (L4-L6) segments of the spinal dorsal horns were removed, and tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), cyclic adenosine monophosphate (cAMP), and cyclic guanosine monophosphate (cGMP) expressions were measured by ELISA. Furthermore, PDE2A mRNA and protein expressions in spinal cord were measured by Real-Time PCR and Western blot. Intrathecal administration of the PDE2A inhibitor Bay 60-7550, significantly attenuated mechanical allodynia, down-regulated spinal TNF-α, IL-1β and IL-6 over-expressions, increased the expression of spinal cAMP, as well as cGMP in a more remarkable manner, and decreased the spinal PDE2A expression in NCLDH rats in a dose-dependent manner. Bay 60-7550 alleviated mechanical allodynia and inflammation in NCLDH rats, which might be associated with increased cAMP and especially cGMP increase. Thus, spinal PDE2A inhibition might represent a potential analgesic strategy for radiculopathy treatment in non-compressive lumbar disc herniation.

  5. Cigarette Smoke-Induced Emphysema and Pulmonary Hypertension Can Be Prevented by Phosphodiesterase 4 and 5 Inhibition in Mice.

    Directory of Open Access Journals (Sweden)

    Michael Seimetz

    Full Text Available Chronic obstructive pulmonary disease (COPD is a widespread disease, with no curative therapies available. Recent findings suggest a key role of NO and sGC-cGMP signaling for the pathogenesis of the disease. Previous data suggest a downregulation/inactivation of the cGMP producing soluble guanylate cyclase, and sGC stimulation prevented cigarette smoke-induced emphysema and pulmonary hypertension (PH in mice. We thus aimed to investigate if the inhibition of the cGMP degrading phosphodiesterase (PDE5 has similar effects. Results were compared to the effects of a PDE 4 inhibitor (cAMP elevating and a combination of both.C57BL6/J mice were chronically exposed to cigarette smoke and in parallel either treated with Tadalafil (PDE5 inhibitor, Piclamilast (PDE4 inhibitor or both. Functional measurements (lung compliance, hemodynamics and structural investigations (alveolar and vascular morphometry as well as the heart ratio were determined after 6 months of tobacco smoke exposure. In addition, the number of alveolar macrophages in the respective lungs was counted.Preventive treatment with Tadalafil, Piclamilast or a combination of both almost completely prevented the development of emphysema, the increase in lung compliance, tidal volume, structural remodeling of the lung vasculature, right ventricular systolic pressure, and right ventricular hypertrophy induced by cigarette smoke exposure. Single, but not combination treatment prevented or reduced smoke-induced increase in alveolar macrophages.Cigarette smoke-induced emphysema and PH could be prevented by inhibition of the phosphodiesterases 4 and 5 in mice.

  6. Sildenafil, a selective phosphodiesterase type 5 inhibitor, enhances memory reconsolidation of an inhibitory avoidance task in mice. (United States)

    Boccia, M M; Blake, M G; Krawczyk, M C; Baratti, C M


    Intracellular levels of the second messengers cAMP and cGMP are maintained through a balance between production, carried out by adenyl cyclase (AC) and guanylyl cyclase (GC), and degradation, carried out by phosphodiesterases (PDEs). Recently, PDEs have gained increased attention as potential new targets for cognition enhancement, with particular reference to phosphodiesterase type 5 (PDE5A). It is accepted that once consolidation is completed memory becomes permanent, but it has also been suggested that reactivation (memory retrieval) of the original memory makes it sensitive to the same treatments that affect memory consolidation when given after training. This new period of sensitivity coined the term reconsolidation. Sildenafil (1, 3, and 10mg/kg, ip), a cGMP-PDE5 inhibitor, facilitated retention performance of a one-trial step-through inhibitory avoidance task, when administered to CF-1 male mice immediately after retrieval. The effects of sildenafil (1mg/kg, ip) were time-dependent, long-lasting and inversely correlated with memory age. The administration of sildenafil (1mg/kg, ip) 30 min prior to the 2nd retention test did not affect retention of mice given post-retrieval injections of either vehicle or sildenafil (1mg/kg, ip). Finally, an enhancement of retention was also observed in CF-1 female mice receiving sildenafil (1mg/kg, ip) immediately, but not 180 min after retrieval. In the present paper we reported for the first time that systemic administration of sildenafil after memory reactivation enhances retention performance of the original learning. Our results indirectly point out cGMP, a component of the NO/cGMP/PKG pathway, as a necessary factor for memory reconsolidation. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Cigarette Smoke-Induced Emphysema and Pulmonary Hypertension Can Be Prevented by Phosphodiesterase 4 and 5 Inhibition in Mice (United States)

    Pichl, Alexandra; Bednorz, Mariola; Ghofrani, Hossein Ardeschir; Schermuly, Ralph Theo; Seeger, Werner; Grimminger, Friedrich; Weissmann, Norbert


    Rationale Chronic obstructive pulmonary disease (COPD) is a widespread disease, with no curative therapies available. Recent findings suggest a key role of NO and sGC-cGMP signaling for the pathogenesis of the disease. Previous data suggest a downregulation/inactivation of the cGMP producing soluble guanylate cyclase, and sGC stimulation prevented cigarette smoke-induced emphysema and pulmonary hypertension (PH) in mice. We thus aimed to investigate if the inhibition of the cGMP degrading phosphodiesterase (PDE)5 has similar effects. Results were compared to the effects of a PDE 4 inhibitor (cAMP elevating) and a combination of both. Methods C57BL6/J mice were chronically exposed to cigarette smoke and in parallel either treated with Tadalafil (PDE5 inhibitor), Piclamilast (PDE4 inhibitor) or both. Functional measurements (lung compliance, hemodynamics) and structural investigations (alveolar and vascular morphometry) as well as the heart ratio were determined after 6 months of tobacco smoke exposure. In addition, the number of alveolar macrophages in the respective lungs was counted. Results Preventive treatment with Tadalafil, Piclamilast or a combination of both almost completely prevented the development of emphysema, the increase in lung compliance, tidal volume, structural remodeling of the lung vasculature, right ventricular systolic pressure, and right ventricular hypertrophy induced by cigarette smoke exposure. Single, but not combination treatment prevented or reduced smoke-induced increase in alveolar macrophages. Conclusion Cigarette smoke-induced emphysema and PH could be prevented by inhibition of the phosphodiesterases 4 and 5 in mice. PMID:26058042

  8. Purification and Characterization of RhoPDE, a Retinylidene/Phosphodiesterase Fusion Protein and Potential Optogenetic Tool from the Choanoflagellate Salpingoeca rosetta. (United States)

    Lamarche, Lindsey B; Kumar, Ramasamy P; Trieu, Melissa M; Devine, Erin L; Cohen-Abeles, Luke E; Theobald, Douglas L; Oprian, Daniel D


    RhoPDE is a type I rhodopsin/phosphodiesterase gene fusion product from the choanoflagellate Salpingoeca rosetta. The gene was discovered around the time that a similar type I rhodopsin/guanylyl cyclase fusion protein, RhoGC, was shown to control phototaxis of an aquatic fungus through a cGMP signaling pathway. RhoPDE has potential as an optogenetic tool catalyzing the hydrolysis of cyclic nucleotides. Here we provide an expression and purification system for RhoPDE, as well as a crystal structure of the C-terminal phosphodiesterase catalytic domain. We show that RhoPDE contains an even number of transmembrane segments, with N- and C-termini both located on the cytoplasmic surface of the cell membrane. The purified protein exhibits an absorption maximum at 490 nm in the dark state, which shifts to 380 nm upon exposure to light. The protein acts as a cGMP-selective phosphodiesterase. However, the activity does not appear to be modulated by light. The protein is also active with cAMP as a substrate, but with a roughly 5-7-fold lower k cat . A truncation consisting solely of the phosphodiesterase domain is also active with a k cat for cGMP roughly 6-9-fold lower than that of the full-length protein. The isolated PDE domain was crystallized, and the X-ray structure showed the protein to be a dimer similar to human PDE9. We anticipate that the purification system introduced here will enable further structural and biochemical experiments to improve our understanding of the function and mechanism of this unique fusion protein.

  9. Use of phosphodiesterase type 5 inhibitors and risk of melanoma: a meta-analysis of observational studies

    Directory of Open Access Journals (Sweden)

    Han X


    Full Text Available Xinming Han,1 Yan Han,2 Yongsheng Zheng,1 Qiang Sun,1 Tao Ma,1 Li Dai,1 Junyi Zhang,1 Lianji Xu1 1Plastic Surgery Department, Beijing Tongren Hospital, Capital Medical University, Beijing, 2Plastic and Reconstructive Surgery Department, Chinese PLA General Hospital, Beijing, China Background: Phosphodiesterase type 5 inhibitor (PE5i administration may stimulate the proliferation and survival of melanocytes. However, discrepancies remain regarding the association between PDE5i use and melanoma risk in observational studies in humans.Aim: To evaluate the association between PDE5i use and melanoma in a meta-analysis.Materials and methods: Studies were identified by searching the PubMed and Embase databases. A random-effects model was applied to synthesize the data. A stratified study was performed to evaluate the influence of study characteristics on outcomes.Results: Four prospective cohort studies and three case–control studies with 1,534,615 male participants and 16,053 melanoma cases were incorporated. Patients who received a PDE5i had a significantly increased risk for melanoma (adjusted risk ratio [RR] =1.12, 95% CI =1.03–1.33, P=0.008 with moderate heterogeneity (I2=54%. Cohort studies (adjusted RR =1.22, 95% CI =1.02–1.46, P=0.03 largely contributed to this result rather than case–control studies. Subsequent stratified analyses revealed that sildenafil was associated with an increased risk of melanoma (adjusted RR =1.26, 95% CI =1.07–1.50, P=0.007, but tadalafil and vardenafil were not. Also, PDE5i use was associated with a significantly increased risk of in situ melanoma (adjusted RR =1.31, 95% CI =1.01–1.69, P=0.04, but not of localized or nonlocalized melanoma.Conclusion: PDE5i use may be associated with a significantly increased risk for melanoma in men. However, further research is needed to determine whether the association is causative. Keywords: phosphodiesterase type 5 inhibitors, melanoma, meta-analysis, sildenafil 

  10. A Role for Phosphodiesterase 11A (PDE11A) in the Formation of Social Memories and the Stabilization of Mood. (United States)

    Kelly, Michy P


    The most recently discovered 3',5'-cyclic nucleotide phosphodiesterase family is the Phosphodiesterase 11 (PDE11) family, which is encoded by a single gene PDE11A. PDE11A is a dual-specific PDE, breaking down both cAMP and cGMP. There are four PDE11A splice variants (PDE11A1-4) with distinct tissue expression profiles and unique N-terminal regulatory regions, suggesting that each isoform could be individually targeted with a small molecule or biologic. PDE11A4 is the PDE11A isoform expressed in brain and is found in the hippocampal formation of humans and rodents. Studies in rodents show that PDE11A4 mRNA expression in brain is, in fact, restricted to the hippocampal formation (CA1, possibly CA2, subiculum, and the adjacently connected amygdalohippocampal area). Within the hippocampal formation of rodents, PDE11A4 protein is expressed in neurons but not astrocytes, with a distribution across nuclear, cytoplasmic, and membrane compartments. This subcellular localization of PDE11A4 is altered in response to social experience in mouse, and in vitro studies show the compartmentalization of PDE11A4 is controlled, at least in part, by homodimerization and N-terminal phosphorylation. PDE11A4 expression dramatically increases in the hippocampus with age in the rodent hippocampus, from early postnatal life to late aging, suggesting PDE11A4 function may evolve across the lifespan. Interestingly, PDE11A4 protein shows a three to tenfold enrichment in the rodent ventral hippocampal formation (VHIPP; a.k.a. anterior in primates) versus dorsal hippocampal formation (DHIPP). Consistent with this enrichment in VHIPP, studies in knockout mice show that PDE11A regulates the formation of social memories and the stabilization of mood and is a critical mechanism by which social experience feeds back to modify the brain and subsequent social behaviors. PDE11A4 likely controls behavior by regulating hippocampal glutamatergic, oxytocin, and cytokine signaling, as well as protein

  11. [Application of precursor ion scanning method in rapid screening of illegally added phosphodiesterase-5 inhibitors and their unknown derivatives in Chinese traditional patent medicines and health foods]. (United States)

    Sun, Jing; Cao, Ling; Feng, Youlong; Tan, Li


    The compounds with similar structure often have similar pharmacological activities. So it is a trend for illegal addition that new derivatives of effective drugs are synthesized to avoid the statutory test. This bring challenges to crack down on illegal addition behavior, however, modified derivatives usually have similar product ions, which allow for precursor ion scanning. In this work, precursor ion scanning mode of a triple quadrupole mass spectrometer was first applied to screen illegally added drugs in complex matrix such as Chinese traditional patent medicines and healthy foods. Phosphodiesterase-5 inhibitors were used as experimental examples. Through the analysis of the structure and mass spectrum characteristics of the compounds, phosphodiesterase-5 inhibitors were classified, and their common product ions were screened by full scan of product ions of typical compounds. Then high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method with precursor ion scanning mode was established based on the optimization of MS parameters. The effect of mass parameters and the choice of fragment ions were also studied. The method was applied to determine actual samples and further refined. The results demonstrated that this method can meet the need of rapid screening of unknown derivatives of phosphodiesterase-5 inhibitors in complex matrix, and prevent unknown derivatives undetected. This method shows advantages in sensitivity, specificity and efficiency, and is worth to be further investigated.

  12. Nebulized solid lipid nanoparticles for the potential treatment of pulmonary hypertension via targeted delivery of phosphodiesterase-5-inhibitor. (United States)

    Makled, Shaimaa; Nafee, Noha; Boraie, Nabila


    Phosphodiesterase type 5 (PDE-5) inhibitors - among which sildenafil citrate (SC) - play a primary role in the treatment of pulmonary hypertension (PH). Yet, SC can be only administered orally or parenterally with lot of risks. Targeted delivery of SC to the lungs via inhalation/nebulization is mandatory. In this study, solid lipid nanoparticles (SLNs) loaded with SC were prepared and characterized in terms of colloidal, morphological and thermal properties. The amount of drug loaded and its release behavior were estimated as a function of formulation variables. The potential of lipid nanocarriers to retain their properties following nebulization and autoclaving was investigated. In addition, toxicity aspects of plain and loaded SLNs on A549 cells were studied with respect to concentration. Spherical SLNs in the size range (100-250nm) were obtained. Particles ensured high encapsulation efficiency (88-100%) and sustained release of the payload over 24h. Cell-based viability experiments revealed a concentration-dependant toxicity for both plain and loaded SLNs recording an IC 50 of 516 and 384μg/mL, respectively. Nebulization with jet nebulizer and sterilization via autoclaving affected neither the colloidal stability of SLNs nor the drug entrapment, proving their potential as pulmonary delivery system. Interaction of SLNs with mucin was a function of the emulsifier coating layer. Results yet seeking clinical evidence - might give promises of new therapy for PH of higher safety, better performance and higher patient compliance. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. East Indian Sandalwood Oil Is a Phosphodiesterase Inhibitor: A New Therapeutic Option in the Treatment of Inflammatory Skin Disease

    Directory of Open Access Journals (Sweden)

    Manju Sharma


    Full Text Available Cyclic adenosine monophosphate phosphodiesterases (PDEs regulate pro-inflammatory cytokine production. One isoform, PDE4, is overactive in chronic relapsing inflammatory skin diseases: psoriasis and eczema/atopic dermatitis, and in several cancers. East Indian sandalwood oil (EISO has significant anti-inflammatory properties. Here, we report that 75% of pediatric eczema/atopic dermatitis patients treated with topical EISO formulations achieved a >50% reduction in their Eczema Area and Severity Index score. EISO treatment of a psoriasis model reduced PDE4 expression and reversed histopathology. EISO directly inhibited PDE enzymatic activity in vitro. In lipopolysaccharide-stimulated human dermal fibroblast, BEAS-2B, A549, and THP-1 cells, EISO suppressed total cellular PDE activity, PDE4, and 7 transcript levels, nuclear factor kappa B (NF-κB activation, and pro-inflammatory cytokines/chemokine production. These results suggest that EISO anti-inflammatory activity is mediated through suppressing PDE activity, thus facilitating cAMP-regulated inhibition of NF-κB and indicate EISO as an attractive natural therapeutic for chronic and acute inflammatory disorders.

  14. Patient preference and satisfaction in erectile dysfunction therapy: a comparison of the three phosphodiesterase-5 inhibitors sildenafil, vardenafil and tadalafil

    Directory of Open Access Journals (Sweden)

    Amr Abdel Raheem


    Full Text Available Amr Abdel Raheem1, Philip Kell21St. Peter’s Andrology Department, The Institute of Urology, London, and Cairo University, Egypt; 2St. Peter’s Andrology Department, The Institute of Urology, London, UKAbstract: Erectile dysfunction (ED is a problem that may affect up to 52% of men between the ages of 40 and 70. It can be distressing because of its negative effect on self-esteem, quality of life, and interpersonal relationships. Oral phosphodiesterase-5 inhibitors (PDE5 inhibitors are now the first choice of treatment in ED. The availability of three (sildenafil citrate, tadalafil, and vardenafil well tolerated and effective oral PDE5 inhibitors gives treatment options for men with ED. Although the mechanism of action is the same for the three drugs, they differ in their pharmacokinetics. Several preference studies were conducted between the three PDE5 inhibitors but they were not free from bias. Because of the lack of overwhelming reliable data showing that one PDE5 inhibitor is superior to another, current opinion is that the individual patient should have the opportunity to test all three drugs and then select the one that best suits him and his partner.Keywords: erectile dysfunction, PDE5 inhibitors, patient preference

  15. Genetic deletion and pharmacological inhibition of phosphodiesterase 10A protects mice from diet-induced obesity and insulin resistance. (United States)

    Nawrocki, Andrea R; Rodriguez, Carlos G; Toolan, Dawn M; Price, Olga; Henry, Melanie; Forrest, Gail; Szeto, Daphne; Keohane, Carol Ann; Pan, Yie; Smith, Karen M; Raheem, Izzat T; Cox, Christopher D; Hwa, Joyce; Renger, John J; Smith, Sean M


    Phosphodiesterase 10A (PDE10A) is a novel therapeutic target for the treatment of schizophrenia. Here we report a novel role of PDE10A in the regulation of caloric intake and energy homeostasis. PDE10A-deficient mice are resistant to diet-induced obesity (DIO) and associated metabolic disturbances. Inhibition of weight gain is due to hypophagia after mice are fed a highly palatable diet rich in fats and sugar but not a standard diet. PDE10A deficiency produces a decrease in caloric intake without affecting meal frequency, daytime versus nighttime feeding behavior, or locomotor activity. We tested THPP-6, a small molecule PDE10A inhibitor, in DIO mice. THPP-6 treatment resulted in decreased food intake, body weight loss, and reduced adiposity at doses that produced antipsychotic efficacy in behavioral models. We show that PDE10A inhibition increased whole-body energy expenditure in DIO mice fed a Western-style diet, achieving weight loss and reducing adiposity beyond the extent seen with food restriction alone. Therefore, chronic THPP-6 treatment conferred improved insulin sensitivity and reversed hyperinsulinemia. These data demonstrate that PDE10A inhibition represents a novel antipsychotic target that may have additional metabolic benefits over current medications for schizophrenia by suppressing food intake, alleviating weight gain, and reducing the risk for the development of diabetes.

  16. Inhibition of human cAMP-phosphodiesterase as a mechanism of the spasmolytic effect of Matricaria recutita L. (United States)

    Maschi, Omar; Cero, Esther Dal; Galli, Germana V; Caruso, Donatella; Bosisio, Enrica; Dell'Agli, Mario


    Mechanisms underlying the spasmolytic activity of chamomile still remain unclear. Inhibition of cAMP- and cGMP-phosphodiesterases (PDE) is one of the mechanisms operated by spasmolytic drugs. In this study, the effect of chamomile on PDE was investigated. Human platelet cAMP-PDE and recombinant PDE5A1 were assayed in the presence of infusions prepared from sifted flowers and capitula. LC-ESI-MS/MS analysis showed different compositions in infusions made with sifted flowers and capitula. Chamomile inhibited cAMP-PDE activity (IC50 = 17.9-40.5 microg/mL), while cGMP-PDE5 was less affected (-15% at 50 microg/mL). Among the individual compounds tested, only flavonoids showed an inhibitory effect (IC50 = 1.3-14.9 microM), contributing to around 39% of the infusion inhibition; other compounds responsible for cAMP-PDE inhibition still remain unknown. Although experimental evidence supporting the use of chamomile for gastrointestinal minor spasms dates back to the fifties, cAMP-PDE inhibition as a likely mechanism underlying the spasmolytic activity is reported for the first time.

  17. Functional exchange of components between light-activated photoreceptor phosphodiesterase and hormone-activated adenylate cyclase systems

    Energy Technology Data Exchange (ETDEWEB)

    Bitensky, M.W.; Wheeler, M.A.; Rasenick, M.M.; Yamazaki, A.; Stein, P.J.; Halliday, K.R.; Wheeler, G.L.


    Previous studies have noted profound similarities between the regulation of light-activated (3',5'-cyclic-nucleotide 5'-nucleotidohydrolase, EC in retinal rods and hormone-activated adenylate cyclase (ATP pyrophosphate-lyase (cyclizing), EC in a variety of tissues. We report ere the functional exchange of components isolated from the photoreceptor system, which displayed predicted functional characteristics when incubated with recipient adenylate cyclase systems from rat cerebral cortical and hypothalamic synaptic membranes and frog erythrocyte ghosts. We demonstrate functional exchange of photoreceptor components at each of three loci: the hormone receptor, the GTP-binding protein (GBP), and the catalytic moiety of adenylate cyclase. Illuminated (but not unilluminated) rhodopsin was found to mimic the hormone-receptor complex, causing GTP-dependent activation of adenylate cyclase. The photoreceptor GBP complexed with guanosine 5'-(..beta..,..gamma..)imidotriphosphate (p(NH)ppG) produced a marked activation of recipient adenylate cyclase systems. Much smaller activation was observed when GBP was not complexed with p(NH)ppG. A heat-stable photoreceptor phosphodiesterase inhibitor reduced both basal and Mn/sup 2 +/-activated adenylate cyclase activites and this inhibition was reversed by photoreceptor GBPp(NH)ppG. These data demonstrate a remarkable functional compatibility between subunits of both systems and furthermore imply that specialized peptide domains responsible for protein-protein interactions are highly conserved.

  18. Genetic variants of phosphodiesterase 4D gene are associated with an enhanced risk for ischemic stroke in young Chinese population. (United States)

    He, Ying; Yang, Dong Zhi; Yu, Hui; Li, Man Yu; Feng, Qing Chuan; Zheng, Hong


    Previous studies have shown that the phosphodiesterase 4D (PDE4D) gene is a susceptibility gene for ischemic stroke (IS) primarily in elder populations. However, few studies have reported the role of the PDE4D gene polymorphisms in a young cohort. To investigate the association between the PDE4D gene polymorphisms and young-onset IS in Chinese population. A total of 186 young patients (18-45 years) with IS and 232 matched control subjects were recruited. Two SNPs (rs918592 and rs2910829) in PDE4D gene were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Odds ratio and 95% confidence intervals (95% CI) were calculated to test the association between the genetic factors and IS. The rs918592A/A genotype frequency and A allele frequency, rs2910829 CT/TT genotype frequency and T allele frequency of young IS group were significantly higher than those of the control group ( P young patients than that in the controls (OR =4.047, 95% CI: 3.521-4.652). Hap (A-C) and Hap (G-C) were associated with decreased risk of IS (OR =0.640, 95% CI: 0.452-0.906; OR =0.675, 95% CI: 0.466-0.978, respectively). Our findings suggest that the rs918592 and rs2910829 polymorphisms and haplotypes of PDE4D gene are significantly associated with IS in Chinese young population.

  19. Human biodistribution and dosimetry of {sup 18}F-JNJ42259152, a radioligand for phosphodiesterase 10A imaging

    Energy Technology Data Exchange (ETDEWEB)

    Laere, Koen van [University Hospital Leuven and KU Leuven, Division of Nuclear Medicine, Leuven (Belgium); University Hospital Leuven - Gasthuisberg, Division of Nuclear Medicine, Leuven (Belgium); Ahmad, Rawaha U.; Hudyana, Hendra; Koole, Michel [University Hospital Leuven and KU Leuven, Division of Nuclear Medicine, Leuven (Belgium); Celen, Sofie; Bormans, Guy [KU Leuven, Laboratory for Radiopharmacy, Leuven (Belgium); Dubois, Kristof; Schmidt, Mark E. [Division of Janssen Pharmaceuticals NV, Janssen Research and Development, Beerse (Belgium)


    Phosphodiesterase 10A (PDE10A) is a cAMP/cGMP-hydrolysing enzyme with a central role in striatal signalling and implicated in neuropsychiatric disorders such as Huntington's disease, Parkinson's disease, schizophrenia and addiction. We have developed a novel PDE10A PET ligand, {sup 18}F-JNJ42259152, and describe here its human dynamic biodistribution, safety and dosimetry. Six male subjects (age range 23-67 years) underwent ten dynamic whole-body PET/CT scans over 6 h after bolus injection of 175.5 {+-} 9.4 MBq {sup 18}F-JNJ42259152. Source organs were delineated on PET/CT and individual organ doses and effective dose were determined using the OLINDA software. F-JNJ42259152 was readily taken up by the brain and showed exclusive retention in the brain, especially in the striatum with good washout starting after 20 min. The tracer was cleared through both the hepatobiliary and the urinary routes. No defluorination was observed. Organ absorbed doses were largest for the gallbladder (239 {mu}Sv/MBq) and upper large intestine (138 {mu}Sv/MBq). The mean effective dose was 24.9 {+-} 4.1 {mu}Sv/MBq. No adverse events were encountered. In humans, {sup 18}F-JNJ42259152 has an appropriate distribution, brain kinetics and safety. The estimated effective dose was within WHO class IIb with low interindividual variability. Therefore, the tracer is suitable for further kinetic evaluation in humans. (orig.)

  20. Prenylated flavonoids as potent phosphodiesterase-4 inhibitors from Morus alba: Isolation, modification, and structure-activity relationship study. (United States)

    Guo, Yan-Qiong; Tang, Gui-Hua; Lou, Lan-Lan; Li, Wei; Zhang, Bei; Liu, Bo; Yin, Sheng


    The bioassay-guided phytochemical study of a traditional Chinese medicine Morus alba led to the isolation of 18 prenylated flavonoids (1-18), of which (±)-cyclomorusin (1/2), a pair of enantiomers, and 14-methoxy-dihydromorusin (3) are the new ones. Subsequent structural modification of the selected components by methylation, esterification, hydrogenation, and oxidative cyclization led to 14 more derivatives (19-32). The small library was screened for its inhibition against phosphodiesterase-4 (PDE4), which is a drug target for the treatment of asthma and chronic obstructive pulmonary disease (COPD). Among them, nine compounds (1-5, 8, 10, 16, and 17) exhibited remarkable activities with IC 50 values ranging from 0.0054 to 0.40 μM, being more active than the positive control rolipram (IC 50  = 0.62 μM). (+)-Cyclomorusin (1), the most active natural PDE4 inhibitor reported so far, also showed a high selectivity across other PDE members with the selective fold greater than 55. The SAR study revealed that the presence of prenyls at C-3 and/or C-8, 2H-pyran ring D, and the phenolic hydroxyl groups were important to the activity, which was further supported by the recognition mechanism study of the inhibitors with PDE4 by using molecular modeling. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  1. The Phosphodiesterase 4 Inhibitor Roflumilast Protects against Cigarette Smoke Extract-Induced Mitophagy-Dependent Cell Death in Epithelial Cells. (United States)

    Kyung, Sun Young; Kim, Yu Jin; Son, Eun Suk; Jeong, Sung Hwan; Park, Jeong Woong


    Recent studies show that mitophagy, the autophagy-dependent turnover of mitochondria, mediates pulmonary epithelial cell death in response to cigarette smoke extract (CSE) exposure and contributes to the development of emphysema in vivo during chronic cigarette smoke (CS) exposure, although the underlying mechanisms remain unclear. In this study, we investigated the role of mitophagy in the regulation of CSE-exposed lung bronchial epithelial cell (Beas-2B) death. We also investigated the role of a phosphodiesterase 4 inhibitor, roflumilast, in CSE-induced mitophagy-dependent cell death. Our results demonstrated that CSE induces mitophagy in Beas-2B cells through mitochondrial dysfunction and increased the expression levels of the mitophagy regulator protein, PTEN-induced putative kinase-1 (PINK1), and the mitochondrial fission protein, dynamin-1-like protein (DRP1). CSE-induced epithelial cell death was significantly increased in Beas-2B cells exposed to CSE but was decreased by small interfering RNA-dependent knockdown of DRP1. Treatment with roflumilast in Beas-2B cells inhibited CSE-induced mitochondrial dysfunction and mitophagy by inhibiting the expression of phospho-DRP1 and -PINK1. Roflumilast protected against cell death and increased cell viability, as determined by the lactate dehydrogenase release test and the MTT assay, respectively, in Beas-2B cells exposed to CSE. These findings suggest that roflumilast plays a protective role in CS-induced mitophagy-dependent cell death. Copyright©2018. The Korean Academy of Tuberculosis and Respiratory Diseases.

  2. Phosphodiesterase 2 negatively regulates adenosine-induced transcription of the tyrosine hydroxylase gene in PC12 rat pheochromocytoma cells. (United States)

    Makuch, Edyta; Kuropatwa, Marianna; Kurowska, Ewa; Ciekot, Jaroslaw; Klopotowska, Dagmara; Matuszyk, Janusz


    Adenosine induces expression of the tyrosine hydroxylase (TH) gene in PC12 cells. However, it is suggested that atrial natriuretic peptide (ANP) inhibits expression of this gene. Using real-time PCR and luciferase reporter assays we found that ANP significantly decreases the adenosine-induced transcription of the TH gene. Results of measurements of cyclic nucleotide concentrations indicated that ANP-induced accumulation of cGMP inhibits the adenosine-induced increase in cAMP level. Using selective phosphodiesterase 2 (PDE2) inhibitors and a synthetic cGMP analog activating PDE2, we found that PDE2 is involved in coupling the ANP-triggered signal to the cAMP metabolism. We have established that ANP-induced elevated levels of cGMP as well as cGMP analog stimulate hydrolytic activity of PDE2, leading to inhibition of adenosine-induced transcription of the TH gene. We conclude that ANP mediates negative regulation of TH gene expression via stimulation of PDE2-dependent cAMP breakdown in PC12 cells. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  3. Phosphodiesterase 5 inhibition improves synaptic function, memory, and amyloid-beta load in an Alzheimer's disease mouse model. (United States)

    Puzzo, Daniela; Staniszewski, Agnieszka; Deng, Shi Xian; Privitera, Lucia; Leznik, Elena; Liu, Shumin; Zhang, Hong; Feng, Yan; Palmeri, Agostino; Landry, Donald W; Arancio, Ottavio


    Memory loss, synaptic dysfunction, and accumulation of amyloid beta-peptides (A beta) are major hallmarks of Alzheimer's disease (AD). Downregulation of the nitric oxide/cGMP/cGMP-dependent protein kinase/c-AMP responsive element-binding protein (CREB) cascade has been linked to the synaptic deficits after A beta elevation. Here, we report that the phosphodiesterase 5 inhibitor (PDE5) sildenafil (Viagra), a molecule that enhances phosphorylation of CREB, a molecule involved in memory, through elevation of cGMP levels, is beneficial against the AD phenotype in a mouse model of amyloid deposition. We demonstrate that the inhibitor produces an immediate and long-lasting amelioration of synaptic function, CREB phosphorylation, and memory. This effect is also associated with a long-lasting reduction of A beta levels. Given that side effects of PDE5 inhibitors are widely known and do not preclude their administration to a senile population, these drugs have potential for the treatment of AD and other diseases associated with elevated A beta levels.

  4. Photodynamics of blue-light-regulated phosphodiesterase BlrP1 protein from Klebsiella pneumoniae and its photoreceptor BLUF domain (United States)

    Tyagi, A.; Penzkofer, A.; Griese, J.; Schlichting, I.; Kirienko, Natalia V.; Gomelsky, Mark


    The BlrP1 protein from the enteric bacterium Klebsiella pneumoniae consists of a BLUF and an EAL domain and may activate c-di-GMP phosphodiesterase by blue-light. The full-length protein, BlrP1, and its BLUF domain, BlrP1_BLUF, are characterized by optical absorption and emission spectroscopy. The cofactor FAD in its oxidized redox state (FAD ox) is brought from the dark-adapted receptor state to the 10-nm red-shifted putative signalling state by violet light exposure. The recovery to the receptor state occurs with a time constant of about 1 min. The quantum yield of signalling state formation is about 0.17 for BlrP1_BLUF and about 0.08 for BlrP1. The fluorescence efficiency of the FAD ox cofactor is small due to photo-induced reductive electron transfer. Prolonged light exposure converts FAD ox in the signalling state to the fully reduced hydroquinone form FAD redH - and causes low-efficient chromophore release with subsequent photo-degradation. The photo-cycle and photo-reduction dynamics in the receptor state and in the signalling state are discussed.

  5. Synthesis, radiolabeling and in vivo evaluation of [{sup 11}C]RAL-01, a potential phosphodiesterase 5 radioligand

    Energy Technology Data Exchange (ETDEWEB)

    Jakobsen, Steen [PET Centre, Aarhus University Hospitals, 8000 Aarhus (Denmark)]. E-mail:; Kodahl, Gitte Munkebo [PET Centre, Aarhus University Hospitals, 8000 Aarhus (Denmark); Olsen, Aage Kristian [PET Centre, Aarhus University Hospitals, 8000 Aarhus (Denmark); Cumming, Paul [PET Centre, Aarhus University Hospitals, 8000 Aarhus (Denmark); Centre for Functionally Integrative Neuroscience, Aarhus University, Aarhus (Denmark)


    Very few tracers are available for imaging studies of second messenger systems. We developed a radiosynthesis for the phosphodiesterase (PDE) 5 inhibitor [{sup 11}C]RAL-01. Whole body distribution studies using positron emission tomography (PET) revealed a time-dependant passage through the liver and accumulation of radioactivity in the bile of the Landrace pig. Displaceable binding was readily discerned in the myocardium, and traces of binding were seen in pulmonary tissue, consistent with the use of this class of drug in the treatment of pulmonary hypertension and heart failure. [{sup 11}C]RAL-01 readily entered the brain and obtained an equilibrium distribution volume of 4-5 ml g{sup -1}. Mean parametric images suggested the presence of a small displaceable binding component, but this binding was not significant in the present group of three pigs. Thus, [{sup 11}C]RAL-01 shows considerable promise for PET studies of biliary elimination and of PDE5 binding in the cardiovascular system. However, analogues of higher affinity may be required for investigations of central nervous system binding sites.

  6. Imaging cAMP-specific phosphodiesterase-4 in human brain with R-[11C]rolipram and positron emission tomography

    International Nuclear Information System (INIS)

    DaSilva, Jean N.; Lourenco, Celia M.; Meyer, Jeffrey H.; Houle, Sylvain; Hussey, Douglas; Potter, William Z.


    Evidence of disruptions in cAMP-mediated signaling in several neuropsychiatric disorders has led to the development of R-[ 11 C]rolipram for imaging phosphodiesterase-4 (PDE4) enzymes with positron emission tomography (PET). The high-affinity PDE4 inhibitor rolipram was previously reported to have an antidepressant effect in humans. PDE4 is abundant in the brain, and it hydrolyzes cAMP produced following stimulation of various neurotransmitter systems. PDE4 is regulated by intracellular cAMP levels. This paper presents the first PET study of R-[ 11 C]rolipram in living human brain. Consistent with the wide distribution of PDE4, high radioactivity retention was observed in all regions representing the gray matter. Rapid metabolism was observed, and kinetic analysis demonstrated that the data fit in a two-tissue compartment model. R-[ 11 C]Rolipram is thus suitable for imaging PDE4 and possibly cAMP signal transduction in the living human brain with PET. (orig.)

  7. Viral phosphodiesterases that antagonize double-stranded RNA signaling to RNase L by degrading 2-5A. (United States)

    Silverman, Robert H; Weiss, Susan R


    The host interferon (IFN) antiviral response involves a myriad of diverse biochemical pathways that disrupt virus replication cycles at many different levels. As a result, viruses have acquired and evolved genes that antagonize the host antiviral proteins. IFNs inhibit viral infections in part through the 2',5'-oligoadenylate (2-5A) synthetase (OAS)/RNase L pathway. OAS proteins are pathogen recognition receptors that exist at different basal levels in different cell types and that are IFN inducible. Upon activation by the pathogen-associated molecular pattern viral double-stranded RNA, certain OAS proteins synthesize 2-5A from ATP. 2-5A binds to the antiviral enzyme RNase L causing its dimerization and activation. Recently, disparate RNA viruses, group 2a betacoronaviruses, and group A rotaviruses, have been shown to produce proteins with 2',5'-phosphodiesterase (PDE) activities that eliminate 2-5A thereby evading the antiviral activity of the OAS/RNase L pathway. These viral proteins are members of the eukaryotic-viral LigT-like group of 2H phosphoesterases, so named for the presence of 2 conserved catalytic histidine residues. Here, we will review the biochemistry, biology, and implications of viral and cellular 2',5'-PDEs that degrade 2-5A. In addition, we discuss alternative viral and cellular strategies for limiting the activity of OAS/RNase L.

  8. Hesperetin, a Selective Phosphodiesterase 4 Inhibitor, Effectively Suppresses Ovalbumin-Induced Airway Hyperresponsiveness without Influencing Xylazine/Ketamine-Induced Anesthesia

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    Chung-Hung Shih


    Full Text Available Hesperetin, a selective phosphodiesterase (PDE4 inhibitor, is present in the traditional Chinese medicine, “Chen Pi.” Therefore, we were interested in investigating its effects on ovalbumin- (OVA- induced airway hyperresponsiveness, and clarifying its rationale for ameliorating asthma and chronic obstructive pulmonary disease (COPD. Hesperetin was revealed to have a therapeutic (PDE4H/PDE4L ratio of >11. Hesperetin (10 ~ 30 μmol/kg, intraperitoneally (i.p. dose-dependently and significantly attenuated the airway hyperresponsiveness induced by methacholine. It also significantly suppressed the increases in total inflammatory cells, macrophages, lymphocytes, neutrophils, and eosinophils, and levels of cytokines, including interleukin (IL-2, IL-4, IL-5, interferon-γ, and tumor necrosis factor-α in bronchoalveolar lavage fluid (BALF. It dose-dependently and significantly suppressed total and OVA-specific immunoglobulin E levels in the BALF and serum. However, hesperetin did not influence xylazine/ketamine-induced anesthesia, suggesting that hesperetin has few or no emetic effects. In conclusion, the rationales for ameliorating allergic asthma and COPD by hesperetin are anti-inflammation, immunoregulation, and bronchodilation.

  9. Expression and Characterization of a Novel Glycerophosphodiester Phosphodiesterase from Pyrococcus furiosus DSM 3638 That Possesses Lysophospholipase D Activity

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    Fanghua Wang


    Full Text Available Glycerophosphodiester phosphodiesterases (GDPD are enzymes which degrade various glycerophosphodiesters to produce glycerol-3-phosphate and the corresponding alcohol moiety. Apart from this, a very interesting finding is that this enzyme could be used in the degradation of toxic organophosphorus esters, which has resulted in much attention on the biochemical and application research of GDPDs. In the present study, a novel GDPD from Pyrococcus furiosus DSM 3638 (pfGDPD was successfully expressed in Escherichia coli and biochemically characterized. This enzyme hydrolyzed bis(p-nitrophenyl phosphate, one substrate analogue of organophosphorus diester, with an optimal reaction temperature 55 °C and pH 8.5. The activity of pfGDPD was strongly dependent on existing of bivalent cations. It was strongly stimulated by Mn2+ ions, next was Co2+ and Ni2+ ions. Further investigations were conducted on its substrate selectivity towards different phospholipids. The results indicated that except of glycerophosphorylcholine (GPC, this enzyme also possessed lysophospholipase D activity toward both sn1-lysophosphatidylcholine (1-LPC and sn2-lysophosphatidylcholine (2-LPC. Higher activity was found for 1-LPC than 2-LPC; however, no hydrolytic activity was found for phosphatidylcholine (PC. Molecular docking based on the 3D-modeled structure of pfGDPD was conducted in order to provide a structural foundation for the substrate selectivity.

  10. Risk of sudden sensorineural hearing loss in adults using phosphodiesterase type 5 inhibitors: Population-based cohort study. (United States)

    Liu, Wei; Antonelli, Patrick J; Dahm, Philipp; Gerhard, Tobias; Delaney, Joseph A C; Segal, Richard; Crystal, Stephen; Winterstein, Almut G


    The objective of the study was to determine the risk of sudden sensorineural hearing loss (SNHL) associated with use of phosphodiesterase type 5 (PDE5) inhibitors. We conducted a retrospective cohort study in the MarketScan Commercial Claims and Encounters Database including adult men who initiated a PDE5 inhibitor (n = 377,722) and 1,957,233 nonusers between 1998 and 2007. Periods of drug exposure were assessed on a weekly basis based on pharmacy billing records, assuming use of 1 dose per week (current use). Incident sudden SNHL was defined based on inpatient or outpatient visits with International Classification of Diseases, Ninth Revision, Clinical Modification codes 389.1x, 389.2x, or 388.2 plus ≥2 procedure codes for audiometric hearing testing within ±30 days of sudden SNHL diagnosis. We used age- and propensity score-adjusted Cox proportional hazards model to evaluate the risk of sudden SNHL during periods of current or recent use compared with that of nonuse. We conducted sensitivity analyses by varying the assumed drug utilization frequency and sudden SNHL case definition. We evaluated 1233 sudden SNHL cases, resulting in an incidence of 4.35, 5.58, and 2.38 per 10,000 person-years for current, recent, and nonuse of PDE5 inhibitors, respectively. Compared with nonuse, the adjusted hazard ratio was 1.25 (1.01-1.55) for current use with a risk difference of 1.97 (1.12-2.82) per 10,000 person-years. For recent use, the adjusted hazard ratio was 1.60 (1.33-1.94) and risk difference was 3.19 (2.24-4.14). Estimates were consistent across the sensitivity analyses. Use of PDE5 inhibitors is associated with a small but significantly increased risk of sudden SNHL. Copyright © 2018 John Wiley & Sons, Ltd.

  11. cGMP-phosphodiesterase inhibition enhances photic responses and synchronization of the biological circadian clock in rodents.

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    Santiago A Plano

    Full Text Available The master circadian clock in mammals is located in the hypothalamic suprachiasmatic nuclei (SCN and is synchronized by several environmental stimuli, mainly the light-dark (LD cycle. Light pulses in the late subjective night induce phase advances in locomotor circadian rhythms and the expression of clock genes (such as Per1-2. The mechanism responsible for light-induced phase advances involves the activation of guanylyl cyclase (GC, cGMP and its related protein kinase (PKG. Pharmacological manipulation of cGMP by phosphodiesterase (PDE inhibition (e.g., sildenafil increases low-intensity light-induced circadian responses, which could reflect the ability of the cGMP-dependent pathway to directly affect the photic sensitivity of the master circadian clock within the SCN. Indeed, sildenafil is also able to increase the phase-shifting effect of saturating (1200 lux light pulses leading to phase advances of about 9 hours, as well as in C57 a mouse strain that shows reduced phase advances. In addition, sildenafil was effective in both male and female hamsters, as well as after oral administration. Other PDE inhibitors (such as vardenafil and tadalafil also increased light-induced phase advances of locomotor activity rhythms and accelerated reentrainment after a phase advance in the LD cycle. Pharmacological inhibition of the main downstream target of cGMP, PKG, blocked light-induced expression of Per1. Our results indicate that the cGMP-dependent pathway can directly modulate the light-induced expression of clock-genes within the SCN and the magnitude of light-induced phase advances of overt rhythms, and provide promising tools to design treatments for human circadian disruptions.

  12. Role of phosphodiesterase 4 expression in the Epac1 signaling-dependent skeletal muscle hypertrophic action of clenbuterol. (United States)

    Ohnuki, Yoshiki; Umeki, Daisuke; Mototani, Yasumasa; Shiozawa, Kouichi; Nariyama, Megumi; Ito, Aiko; Kawamura, Naoya; Yagisawa, Yuka; Jin, Huiling; Cai, Wenqian; Suita, Kenji; Saeki, Yasutake; Fujita, Takayuki; Ishikawa, Yoshihiro; Okumura, Satoshi


    Clenbuterol (CB), a selective β2-adrenergic receptor (AR) agonist, induces muscle hypertrophy and counteracts muscle atrophy. However, it is paradoxically less effective in slow-twitch muscle than in fast-twitch muscle, though slow-twitch muscle has a greater density of β-AR We recently demonstrated that Epac1 (exchange protein activated by cyclic AMP [cAMP]1) plays a pivotal role in β2-AR-mediated masseter muscle hypertrophy through activation of the Akt and calmodulin kinase II (CaMKII)/histone deacetylase 4 (HDAC4) signaling pathways. Here, we investigated the role of Epac1 in the differential hypertrophic effect of CB using tibialis anterior muscle (TA; typical fast-twitch muscle) and soleus muscle (SOL; typical slow-twitch muscle) of wild-type (WT) and Epac1-null mice (Epac1KO). The TA mass to tibial length (TL) ratio was similar in WT and Epac1KO at baseline and was significantly increased after CB infusion in WT, but not in Epac1KO The SOL mass to TL ratio was also similar in WT and Epac1KO at baseline, but CB-induced hypertrophy was suppressed in both mice. In order to understand the mechanism involved, we measured the protein expression levels of β-AR signaling-related molecules, and found that phosphodiesterase 4 (PDE4) expression was 12-fold greater in SOL than in TA These results are consistent with the idea that increased PDE4-mediated cAMP hydrolysis occurs in SOL compared to TA, resulting in a reduced cAMP concentration that is insufficient to activate Epac1 and its downstream Akt and CaMKII/HDAC4 hypertrophic signaling pathways in SOL of WT This scenario can account for the differential effects of CB on fast- and slow-twitch muscles. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  13. Cyclic nucleotide phosphodiesterases in human spermatozoa and seminal fluid: Presence of an active PDE10A in human spermatozoa. (United States)

    Maréchal, Loïze; Guillemette, Christine; Goupil, Serge; Blondin, Patrick; Leclerc, Pierre; Richard, François J


    Cyclic adenosine monophosphate (cAMP) plays a crucial role as a signaling molecule for sperm functions such as capacitation, motility and acrosome reaction. It is well known that cAMP degradation by phosphodiesterase (PDE) enzyme has a major impact on sperm functions. The present study was undertaken to characterize cAMP-PDE activity in human semen. cAMP-PDE activity was measured in human sperm and seminal plasma using family specific PDE inhibitors. Three sperm fractionation methods were applied to assess cAMP-PDE activity in spermatozoa. Western blots were used to validate the presence of specific family in sperm and seminal plasma. Using three sperm fractionation methods, we demonstrated that in human sperm, the major cAMP-PDE activity is papaverine-sensitive and thus ascribed to PDE10. In seminal plasma, total cAMP-PDE activity was 1.14±0.39fmol of cAMP hydrolyzed per minute per μg of protein. Using specific inhibitors, we showed that the major cAMP-PDE activity found in human seminal plasma is ascribed to PDE4 and PDE11. Western blot analysis, immunoprecipitation with a specific monoclonal antibody, and mass spectrometry confirmed the presence of PDE10 in human spermatozoa. This study provides the first demonstration of the presence of functional PDE10 in human spermatozoa and functional PDE4 and PDE11 in human seminal plasma. Since the contribution of cyclic nucleotides in several sperm functions is well known, the finding that PDE10 is an active enzyme in human spermatozoa is novel and may lead to new insight into fertility. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Mechanisms of cyclic nucleotide phosphodiesterases in modulating T cell responses in murine graft-versus-host disease.

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    Michael Weber

    Full Text Available Graft-versus-host disease (GvHD is a key contributor to the morbidity and mortality after allogeneic hematopoetic stem cell transplantation (HSCT. Regulatory Foxp3(+ CD4(+ T cells (Treg suppress conventional T cell activation and can control GvHD. In our previous work, we demonstrate that a basic mechanism of Treg mediated suppression occurs by the transfer of cyclic adenosine monophosphate (cAMP to responder cells. Whether this mechanism is relevant for Treg mediated suppression of GvHD is currently unknown. To address this question, bone marrow and T cells from C57BL/6 mice were transferred into lethally irradiated BALB/c recipients, and the course of GvHD and survival were monitored. Transplanted recipients developed severe GvHD that was strongly ameliorated by the transfer of donor Treg cells. Towards the underlying mechanisms, in vitro studies revealed that Treg communicated with DCs via gap junctions, resulting in functional inactivation of DC by a metabolic pathway involving cAMP that is modulated by the phosphodiesterase (PDE 4 inhibitor rolipram. PDE2 or PDE3 inhibitors as well as rolipram suppressed allogeneic T cell activation, indirectly by enhancing Treg mediated suppression of DC activation and directly by inhibiting responder T cell proliferation. In line with this, we observed a cooperative suppression of GvHD upon Treg transfer and additional rolipram treatment. In conclusion, we propose that an important pathway of Treg mediated control of GvHD is based on a cAMP dependent mechanism. These data provide the basis for future concepts to manipulate allogeneic T cell responses to prevent GvHD.

  15. Phosphodiesterase-4 inhibitors ameliorates cognitive deficits in deoxycorticosterone acetate induced hypertensive rats via cAMP/CREB signaling system. (United States)

    Jabaris, S Sugin Lal; Sumathy, Haridass; Girish, Ramesh; Narayanan, Shridhar; Sugumar, Mani; Saravana Babu, Chidambaram; Thanikachalam, Sadagopan; Thanikachalam, Mohan


    Phosphodiesterase-4 (PDE-4) inhibitors promote memory by blocking the degradation of cAMP. Existing evidence also shows that neuronal survival and plasticity are dependent on the phosphorylation of cAMP-response element-binding protein. In this regard, PDE-4 inhibitors have also been shown to reverse pharmacologically and genetically induced memory impairment in animal models. In the present study, the authors examined the effect of both rolipram and roflumilast (PDE-4 inhibitors) on the impairment of learning and memory observed in hypertensive rats. Deoxycorticosterone acetate (DOCA) salt hypertensive model was used to induce learning and memory deficits. The mRNA expression of different PDE-4 subtypes along with the protein levels of pCREB and BDNF in the hippocampus was quantified. Systolic blood pressure was significantly increased in DOCA salt hypertensive rats when compared to sham operated rats. This effect was reversed by clonidine, an α2 receptor agonist, while PDE-4 inhibitors did not. PDE-4 inhibitors significantly improved the time-induced memory deficits in object recognition task (ORT). In DOCA salt hypertensive rats, the gene expression of PDE-4B and PDE-4D was significantly increased. Furthermore, both pCREB and BDNF showed decreased levels of expression in hypertensive rats in comparison to sham operated rats. Repeated administration of PDE-4 inhibitors significantly decreased both PDE-4B and PDE-4D with an increase in the expression of pCREB and BDNF in hypersensitive rats. Also, rolipram, roflumilast and roflumilast N-oxide showed a linear increase in the plasma and brain concentrations after ORT. Our present findings suggested that PDE-4 inhibitors ameliorate hypertension-induced learning impairment via cAMP/CREB signaling that regulates BDNF expression downstream in the rat hippocampus. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Phosphodiesterase-4 inhibition alters gene expression and improves isoniazid-mediated clearance of Mycobacterium tuberculosis in rabbit lungs.

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    Selvakumar Subbian


    Full Text Available Tuberculosis (TB treatment is hampered by the long duration of antibiotic therapy required to achieve cure. This indolent response has been partly attributed to the ability of subpopulations of less metabolically active Mycobacterium tuberculosis (Mtb to withstand killing by current anti-TB drugs. We have used immune modulation with a phosphodiesterase-4 (PDE4 inhibitor, CC-3052, that reduces tumor necrosis factor alpha (TNF-α production by increasing intracellular cAMP in macrophages, to examine the crosstalk between host and pathogen in rabbits with pulmonary TB during treatment with isoniazid (INH. Based on DNA microarray, changes in host gene expression during CC-3052 treatment of Mtb infected rabbits support a link between PDE4 inhibition and specific down-regulation of the innate immune response. The overall pattern of host gene expression in the lungs of infected rabbits treated with CC-3052, compared to untreated rabbits, was similar to that described in vitro in resting Mtb infected macrophages, suggesting suboptimal macrophage activation. These alterations in host immunity were associated with corresponding down-regulation of a number of Mtb genes that have been associated with a metabolic shift towards dormancy. Moreover, treatment with CC-3052 and INH resulted in reduced expression of those genes associated with the bacterial response to INH. Importantly, CC-3052 treatment of infected rabbits was associated with reduced ability of Mtb to withstand INH killing, shown by improved bacillary clearance, from the lungs of co-treated animals compared to rabbits treated with INH alone. The results of our study suggest that changes in Mtb gene expression, in response to changes in the host immune response, can alter the responsiveness of the bacteria to antimicrobial agents. These findings provide a basis for exploring the potential use of adjunctive immune modulation with PDE4 inhibitors to enhance the efficacy of existing anti-TB treatment.

  17. Protective effects of phosphodiesterase-4-specific inhibitor rolipram on acute ischemia-reperfusion injury in rat kidney. (United States)

    Mammadov, Emin; Aridogan, Ibrahim Atilla; Izol, Volkan; Acikalin, Arbil; Abat, Deniz; Tuli, Abdullah; Bayazit, Yildirim


    To investigate the effect of Rolipram, a phosphodiesterase-4-inhibitor, on renal ischemia-reperfusion injury (IRI) in rats. Thirty rats were divided into 5 different groups of 6 rats. Nothing was done to the control group. In the second group, the renal pedicle was clamped for 30 minutes. In the third group, 1 mg/kg of Rolipram was given by intraperitoneal injection 30 minutes before clamping. The fourth group received the same injection when the clamp was placed, as did the fifth group 30 minutes after the clamp was opened. Clamping time was set at 30 minutes. Twenty-four hours later, nephrectomy was performed in all the groups. Half of each kidney was examined histopathologically. Levels of biochemical agents, such as malondialdehyde, superoxide dismutase, and catalase, were measured in the other half. The malondialdehyde (MDA) levels significantly decreased and reached control levels in the group in which Rolipram was administered 30 minutes after reperfusion (P = .07). The catalase and superoxide dismutase activities obtained from renal homogentisates of the ischemia groups were evaluated; there were striking increases in tissue levels of these 2 enzymes in the groups in which Rolipram was administered during ischemia and 30 minutes after ischemia (P < .001). Histopathologically, there was no significant difference in inflammation between the Rolipram-administrated groups compared with group 1 (control) and group 2 (IRI). Tubular necrosis and apoptosis was significantly lower in group 5 than the other groups, except group 1 (P < .001). We suggest that in surgical procedures that can lead to renal IRI, the administration of Rolipram can decrease oxidative renal tissue damage and the severe deterioration of renal function. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Phosphodiesterase 4 inhibition reduces innate immunity and improves isoniazid clearance of Mycobacterium tuberculosis in the lungs of infected mice.

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    Mi-Sun Koo


    Full Text Available Tuberculosis (TB caused by Mycobacterium tuberculosis (Mtb is one of the leading infectious disease causes of morbidity and mortality worldwide. Though current antibiotic regimens can cure the disease, treatment requires at least six months of drug therapy. One reason for the long duration of therapy is that the currently available TB drugs were selected for their ability to kill replicating organisms and are less effective against subpopulations of non-replicating persistent bacilli. Evidence from in vitro models of Mtb growth and mouse infection studies suggests that host immunity may provide some of the environmental cues that drive Mtb towards non-replicating persistence. We hypothesized that selective modulation of the host immune response to modify the environmental pressure on the bacilli may result in better bacterial clearance during TB treatment. For this proof of principal study, we compared bacillary clearance from the lungs of Mtb-infected mice treated with the anti-TB drug isoniazid (INH in the presence and absence of an immunomodulatory phosphodiesterase 4 inhibitor (PDE4i, CC-3052. The effects of CC-3052 on host global gene expression, induction of cytokines, and T cell activation in the lungs of infected mice were evaluated. We show that CC-3052 modulates the innate immune response without causing generalized immune suppression. Immune modulation combined with INH treatment improved bacillary clearance and resulted in smaller granulomas and less lung pathology, compared to treatment with INH alone. This novel strategy of combining anti-TB drugs with an immune modulating molecule, if applied appropriately to patients, may shorten the duration of TB treatment and improve clinical outcome.

  19. Efficacy of phosphodiesterase type 5 inhibitors for the treatment of distal ureteral calculi: A systematic review and meta-analysis

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    Carlos Eduardo Montes Cardona


    Full Text Available Purpose: To determine the efficacy of phosphodiesterase type 5 inhibitors (PDE5i as medical expulsive therapy (MET for the treatment of distal ureteral calculi. Materials and Methods: A search strategy was conducted in the MEDLINE, CENTRAL, and Embase databases. Searches were also conducted in other databases and unpublished literature. Clinical trials were included without language restrictions. The risk of bias was evaluated with the Cochrane Collaboration’s tool. An analysis of random effects due to statistical heterogeneity was conducted. The primary outcome was the expulsion rate of the distal ureteral calculus in 28 days. The secondary outcomes were the time to expulsion, side effects of treatment, and amount (mg of nonopioid analgesia. The measure of the effect was the risk difference (RD with a 95% confidence interval (CI. The planned interventions were PDE5i vs. placebo, tadalafil vs. placebo, and tadalafil vs. tamsulosin. Results: Four articles were included in the qualitative and quantitative analysis. Records of 580 patients were found among the four studies. A low risk of bias was shown for the majority of the study items. The calculi expulsion rate had an RD of 0.26 (95% CI, 0.15–0.37 and a less prolonged expulsion as a secondary outcome with a mean difference of -4.39 days (95% CI, -6.69 to -2.09 in favor of PDE5i compared with the placebo. No significant difference was found for these outcomes when comparing tadalafil with tamsulosin. Conclusions: Compared with a placebo, PDE5i could be effective as MET for the treatment of distal ureter calculi.

  20. Vasodilatory activity and antihypertensive profile mediated by inhibition of phosphodiesterase type 1 induced by a novel sulfonamide compound. (United States)

    Pontes, Luana Braga; Antunes, Fernanda; Sudo, Roberto Takashi; Raimundo, Juliana Montani; Lima, Lidia Moreira; Barreiro, Eliezer Jesus; Zapata-Sudo, Gisele


    LASSBio-985 is a sulfonamide compound designed as a simplified structure of a nonselective phosphodiesterase type 4 (PDE-4) inhibitor that promotes vasodilatory activity in vitro. PDE are enzymes responsible for the hydrolysis of cyclic adenosine 3',5'- monophosphate and cyclic guanosine 3',5'-monophosphate. Five different isozymes of PDE are found in vascular smooth muscle (PDE1-PDE5). Aortic rings, with or without endothelium, from male normotensive and spontaneously hypertensive rats (SHR) were prepared for isometric tension recording. Blood pressure was measured in Wistar Kyoto (WKY) rats and SHR during intravenous infusion of LASSBio-985 (10 mg/kg/min) during 15 min. LASSBio-985 induced a concentration-dependent vasodilation in aortic rings from normotensive and SHR, which was almost completely inhibited in endothelium-denuded vessels. Vasodilatory activity was also reduced in endothelium-intact aortic rings that had been pretreated with N(ω)-nitro-L-arginine methyl ester hydrochloride (L-NAME), a nitric oxide synthase inhibitor and 1H-[1,2,4]oxadiazolod[4,3-a]quinoxalin-1-one (ODQ), a guanylate cyclase inhibitor. LASSBio-985-induced vasodilation was also inhibited by sildenafil (100 μm) and SQ 22536, a PDE5 inhibitor and adenylate cyclase inhibitor, respectively. To evaluate the involvement of some endothelial receptors, atropine, diphenhydramine, HOE 140, naloxone, propranolol, indomethacin, and wortmannin were tested, but none inhibited the effects of LASSBio-985. The residual effect observed on endothelium-denuded aortic rings was abolished by nicardipine, a voltage-sensitive-Ca(2+)-channel blocker. Intravenous infusion of LASSBio-985 (10 mg/kg/min) significantly reduced systolic and diastolic pressures in both WKY and SHR. LASSBio-985 is a compound with vasodilatory activity, which could be consequent to PDE1 inhibition and voltage-sensitive-Ca(2+)-channel blockade. © 2011 The Authors Fundamental and Clinical Pharmacology © 2011 Société Fran

  1. A Nutrient-Regulated Cyclic Diguanylate Phosphodiesterase Controls Clostridium difficile Biofilm and Toxin Production during Stationary Phase. (United States)

    Purcell, Erin B; McKee, Robert W; Courson, David S; Garrett, Elizabeth M; McBride, Shonna M; Cheney, Richard E; Tamayo, Rita


    The signaling molecule cyclic diguanylate (c-di-GMP) mediates physiological adaptation to extracellular stimuli in a wide range of bacteria. The complex metabolic pathways governing c-di-GMP synthesis and degradation are highly regulated, but the specific cues that impact c-di-GMP signaling are largely unknown. In the intestinal pathogen Clostridium difficile , c-di-GMP inhibits flagellar motility and toxin production and promotes pilus-dependent biofilm formation, but no specific biological functions have been ascribed to any of the individual c-di-GMP synthases or phosphodiesterases (PDEs). Here, we report the functional and biochemical characterization of a c-di-GMP PDE, PdcA, 1 of 37 confirmed or putative c-di-GMP metabolism proteins in C. difficile 630. Our studies reveal that pdcA transcription is controlled by the nutrient-regulated transcriptional regulator CodY and accordingly increases during stationary phase. In addition, PdcA PDE activity is allosterically regulated by GTP, further linking c-di-GMP levels to nutrient availability. Mutation of pdcA increased biofilm formation and reduced toxin biosynthesis without affecting swimming motility or global intracellular c-di-GMP. Analysis of the transcriptional response to pdcA mutation indicates that PdcA-dependent phenotypes manifest during stationary phase, consistent with regulation by CodY. These results demonstrate that inactivation of this single PDE gene is sufficient to impact multiple c-di-GMP-dependent phenotypes, including the production of major virulence factors, and suggest a link between c-di-GMP signaling and nutrient availability. Copyright © 2017 American Society for Microbiology.

  2. The effect of resveratrol on beta amyloid-induced memory impairment involves inhibition of phosphodiesterase-4 related signaling. (United States)

    Wang, Gang; Chen, Ling; Pan, Xiaoyu; Chen, Jiechun; Wang, Liqun; Wang, Weijie; Cheng, Ruochuan; Wu, Fan; Feng, Xiaoqing; Yu, Yingcong; Zhang, Han-Ting; O'Donnell, James M; Xu, Ying


    Resveratrol, a natural polyphenol found in red wine, has wide spectrum of pharmacological properties including antioxidative and antiaging activities. Beta amyloid peptides (Aβ) are known to involve cognitive impairment, neuroinflammatory and apoptotic processes in Alzheimer's disease (AD). Activation of cAMP and/or cGMP activities can improve memory performance and decrease the neuroinflammation and apoptosis. However, it remains unknown whether the memory enhancing effect of resveratrol on AD associated cognitive disorders is related to the inhibition of phosphodiesterase 4 (PDE4) subtypes and subsequent increases in intracellular cAMP and/or cGMP activities. This study investigated the effect of resveratrol on Aβ1-42-induced cognitive impairment and the participation of PDE4 subtypes related cAMP or cGMP signaling. Mice microinfused with Aβ1-42 into bilateral CA1 subregions displayed learning and memory impairment, as evidenced by reduced memory acquisition and retrieval in the water maze and retention in the passive avoidance tasks; it was also significant that neuroinflammatory and pro-apoptotic factors were increased in Aβ1-42-treated mice. Aβ1-42-treated mice also increased in PDE4A, 4B and 4D expression, and decreased in PKA level. However, PKA inhibitor H89, but not PKG inhibitor KT5823, prevented resveratrol's effects on these parameters. Resveratrol also reversed Aβ1-42-induced decreases in phosphorylated cAMP response-element binding protein (pCREB), brain derived neurotrophic factor (BDNF) and anti-apoptotic factor BCl-2 expression, which were reversed by H89. These findings suggest that resveratrol reversing Aβ-induced learning and memory disorder may involve the regulation of neuronal inflammation and apoptosis via PDE4 subtypes related cAMP-CREB-BDNF signaling.

  3. [3H]sildenafil binding to phosphodiesterase-5 is specific, kinetically heterogeneous, and stimulated by cGMP. (United States)

    Corbin, Jackie D; Blount, Mitsi A; Weeks, James L; Beasley, Alfreda; Kuhn, Karl P; Ho, Yew S J; Saidi, Layla F; Hurley, James H; Kotera, Jun; Francis, Sharron H


    Sildenafil (Viagra) potentiates penile erection by acting as a nonhydrolyzable analog of cGMP and competing with this nucleotide for catalysis by phosphodiesterase-5 (PDE5), but the characteristics of direct binding of radiolabeled sildenafil to PDE5 have not been determined. [3H]Sildenafil binding to PDE5 was retained when filtered through nitrocellulose or glass-fiber membranes. Binding was inhibited by excess sildenafil, 2-(2-methylpyridin-4-yl)methyl-4-(3,4,5-trimethoxyphenyl)-8-(pyrimidin-2-yl)methoxy-1,2-dihydro-1-oxo-2,7-naphthyridine-3-carboxylic acid methyl ester hydrochloride (T-0156), 3-isobutyl-1-methylxanthine, EDTA, or cGMP, but not by cAMP or 5'-GMP. PDE5 was the only [3H]sildenafil binding protein detected in human lung extract. Using purified recombinant PDE5, [3H]sildenafil exchange dissociation yielded two components with t1/2 values of 1 and 14 min and corresponding calculated KD values of 12 and 0.83 nM, respectively. This implied the existence of two conformers of the PDE5 catalytic site. [3H]Sildenafil binding isotherm of PDE5 indicated KD was 8.3 to 13.3 nM, and low cGMP decreased the KD to 4.8 nM but only slightly increased Bmax to a maximum of 0.61 mol/mol-subunit. Results suggest that these effects occur via cGMP binding to the allosteric cGMP binding sites of PDE5. Results imply that by inhibiting PDE5 and thereby increasing cGMP, sildenafil accentuates its own binding affinity for PDE5, which further elevates cGMP. The data also indicate that after physiological elevation, cGMP may directly stimulate the catalytic site by binding to the allosteric cGMP-binding sites of PDE5, thus causing negative feedback on this pathway.

  4. The single cyclic nucleotide-specific phosphodiesterase of the intestinal parasite Giardia lamblia represents a potential drug target. (United States)

    Kunz, Stefan; Balmer, Vreni; Sterk, Geert Jan; Pollastri, Michael P; Leurs, Rob; Müller, Norbert; Hemphill, Andrew; Spycher, Cornelia


    Giardiasis is an intestinal infection correlated with poverty and poor drinking water quality, and treatment options are limited. According to the Center for Disease Control and Prevention, Giardia infections afflict nearly 33% of people in developing countries, and 2% of the adult population in the developed world. This study describes the single cyclic nucleotide-specific phosphodiesterase (PDE) of G. lamblia and assesses PDE inhibitors as a new generation of anti-giardial drugs. An extensive search of the Giardia genome database identified a single gene coding for a class I PDE, GlPDE. The predicted protein sequence was analyzed in-silico to characterize its domain structure and catalytic domain. Enzymatic activity of GlPDE was established by complementation of a PDE-deficient Saccharomyces cerevisiae strain, and enzyme kinetics were characterized in soluble yeast lysates. The potency of known PDE inhibitors was tested against the activity of recombinant GlPDE expressed in yeast and against proliferating Giardia trophozoites. Finally, the localization of epitope-tagged and ectopically expressed GlPDE in Giardia cells was investigated. Giardia encodes a class I PDE. Catalytically important residues are fully conserved between GlPDE and human PDEs, but sequence differences between their catalytic domains suggest that designing Giardia-specific inhibitors is feasible. Recombinant GlPDE hydrolyzes cAMP with a Km of 408 μM, and cGMP is not accepted as a substrate. A number of drugs exhibit a high degree of correlation between their potency against the recombinant enzyme and their inhibition of trophozoite proliferation in culture. Epitope-tagged GlPDE localizes as dots in a pattern reminiscent of mitosomes and to the perinuclear region in Giardia. Our data strongly suggest that inhibition of G. lamblia PDE activity leads to a profound inhibition of parasite proliferation and that GlPDE is a promising target for developing novel anti-giardial drugs.

  5. Acidosis is a key regulator of osteoblast ecto-nucleotidase pyrophosphatase/phosphodiesterase 1 (NPP1) expression and activity. (United States)

    Orriss, Isabel R; Key, Michelle L; Hajjawi, Mark O R; Millán, José L; Arnett, Timothy R


    Previous work has shown that acidosis prevents bone nodule formation by osteoblasts in vitro by inhibiting mineralisation of the collagenous matrix. The ratio of phosphate (Pi ) to pyrophosphate (PPi ) in the bone microenvironment is a fundamental regulator of bone mineralisation. Both Pi and PPi , a potent inhibitor of mineralisation, are generated from extracellular nucleotides by the actions of ecto-nucleotidases. This study investigated the expression and activity of ecto-nucleotidases by osteoblasts under normal and acid conditions. We found that osteoblasts express mRNA for a number of ecto-nucleotidases including NTPdase 1-6 (ecto-nucleoside triphosphate diphosphohydrolase) and NPP1-3 (ecto-nucleotide pyrophosphatase/phosphodiesterase). The rank order of mRNA expression in differentiating rat osteoblasts (day 7) was Enpp1 > NTPdase 4 > NTPdase 6 > NTPdase 5 >  alkaline phosphatase > ecto-5-nucleotidase > Enpp3 > NTPdase 1 > NTPdase 3 > Enpp2 > NTPdase 2. Acidosis (pH 6.9) upregulated NPP1 mRNA (2.8-fold) and protein expression at all stages of osteoblast differentiation compared to physiological pH (pH 7.4); expression of other ecto-nucleotidases was unaffected. Furthermore, total NPP activity was increased up to 53% in osteoblasts cultured in acid conditions (P key substrates for NPP1, from osteoblasts, was unaffected by acidosis. Further studies showed that mineralised bone formation by osteoblasts cultured from NPP1 knockout mice was increased compared with wildtypes (2.5-fold, P < 0.001) and was partially resistant to the inhibitory effect of acidosis. These results indicate that increased NPP1 expression and activity might contribute to the decreased mineralisation observed when osteoblasts are exposed to acid conditions. © 2015 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc.

  6. Liposomal-delivery of phosphodiesterase 5 inhibitors augments UT-15C-stimulated ATP release from human erythrocytes. (United States)

    Bowles, Elizabeth A; Feys, Dimitri; Ercal, Nuran; Sprague, Randy S


    The use of liposomes to affect targeted delivery of pharmaceutical agents to specific sites may result in the reduction of side effects and an increase in drug efficacy. Since liposomes are delivered intravascularly, erythrocytes, which constitute almost half of the volume of blood, are ideal targets for liposomal drug delivery. In vivo, erythrocytes serve not only in the role of oxygen transport but also as participants in the regulation of vascular diameter through the regulated release of the potent vasodilator, adenosine triphosphate (ATP). Unfortunately, erythrocytes of humans with pulmonary arterial hypertension (PAH) do not release ATP in response to the physiological stimulus of exposure to increases in mechanical deformation as would occur when these cells traverse the pulmonary circulation. This defect in erythrocyte physiology has been suggested to contribute to pulmonary hypertension in these individuals. In contrast to deformation, both healthy human and PAH erythrocytes do release ATP in response to incubation with prostacyclin analogs via a well-characterized signaling pathway. Importantly, inhibitors of phosphodiesterase 5 (PDE5) have been shown to significantly increase prostacyclin analog-induced ATP release from human erythrocytes. Here we investigate the hypothesis that targeted delivery of PDE5 inhibitors to human erythrocytes, using a liposomal delivery system, potentiates prostacyclin analog- induced ATP release. The findings are consistent with the hypothesis that directed delivery of this class of drugs to erythrocytes could be a new and important method to augment prostacyclin analog-induced ATP release from these cells. Such an approach could significantly limit side effects of both classes of drugs without compromising their therapeutic effectiveness in diseases such as PAH.

  7. Host cell contact induces expression of virulence factors and VieA, a cyclic di-GMP phosphodiesterase, in Vibrio cholerae. (United States)

    Dey, Amit K; Bhagat, Abha; Chowdhury, Rukhsana


    Vibrio cholerae, a noninvasive bacterium, colonizes the intestinal epithelium and secretes cholera toxin (CT), a potent enterotoxin that causes the severe fluid loss characteristic of the disease cholera. In this study, we demonstrate that adherence of V. cholerae to the intestinal epithelial cell line INT 407 strongly induces the expression of the major virulence genes ctxAB and tcpA and the virulence regulatory gene toxT. No induction of toxR and tcpP, which encode transcriptional activators of toxT, was observed in adhered bacteria, and the adherence-dependent upregulation of toxT expression was independent of ToxR and TcpP. A sharp increase in the expression of the vieA gene, which encodes a cyclic di-GMP (c-di-GMP) phosphodiesterase, was observed in INT 407-adhered V. cholerae immediately after infection. Induction of toxT, ctxAB, and tcpA in INT 407-adhered vieA mutant strain O395 ΔvieA was consistently lower than in the parent strain, although no effect was observed in unadhered bacteria, suggesting that VieA has a role in the upregulation of toxT expression specifically in host cell-adhered V. cholerae. Furthermore, though VieA has both a DNA binding helix-turn-helix domain and an EAL domain conferring c-di-GMP phosphodiesterase activity, the c-di-GMP phosphodiesterase activity of VieA is necessary and sufficient for the upregulation of toxT expression.

  8. Effect of cilostazol, a phosphodiesterase type III inhibitor, on histamine-induced increase in [Ca2+]i and force in middle cerebral artery of the rabbit


    Shiraishi, Yoshihisa; Kanmura, Yuichi; Itoh, Takeo


    The effect of cilostazol, an inhibitor of phosphodiesterase type III (PDE III), on the contraction induced by histamine was studied by making simultaneous measurements of isometric force and the intracellular concentration of Ca2+ ([Ca2+]i) in endothelium-denuded muscle strips from the peripheral part of the middle cerebral artery of the rabbit.High K+ (80 mM) produced a phasic, followed by a tonic increase in both [Ca2+]i and force. Cilostazol (10 μM) did not modify the resting [Ca2+]i, but ...

  9. Adherence to Phosphodiesterase Type 5 Inhibitors in the Treatment of Erectile Dysfunction in Long-Term Users: How Do Men Use the Inhibitors?

    Directory of Open Access Journals (Sweden)

    Ana Carvalheira, PhD


    Conclusion: The analysis of men's narratives revealed a combination of factors that influence the adherence to PDE5-i. The psychological and medication-related factors were the most prevalent. This study highlighted the importance of taking these factors into account, both at the time of prescription and during the follow-up in order to improve adherence. Carvalheira A, Forjaz V, and Pereira NM. Adherence to phosphodiesterase type 5 inhibitors in the treatment of erectile dysfunction in long-term users: How do men use the inhibitors? Sex Med 2014;2:96–102.

  10. Pulmonary hemodynamics and effects of phosphodiesterase type 5 inhibition in heart failure: a meta-analysis of randomized trials. (United States)

    Hwang, In-Chang; Kim, Yong-Jin; Park, Jun-Bean; Yoon, Yeonyee E; Lee, Seung-Pyo; Kim, Hyung-Kwan; Cho, Goo-Yeong; Sohn, Dae-Won


    Previous studies suggested that phosphodiesterase 5 inhibitors (PDE5i) have a beneficial effect in patients with heart failure (HF), although the results were inconsistent. We performed a meta-analysis to evaluate the effect of PDE5i in HF patients, and investigated the relationship between PDE5i effects and pulmonary hemodynamics. We searched PubMed, EMBASE and the Cochrane Library for randomized controlled trials (RCTs) that compared PDE5i with placebo in HF with reduced ejection fraction (HFrEF) or HF with preserved EF (HFpEF). PDE5i effects were interpolated according to baseline pulmonary arterial pressure (PAP) or according to changes in PAP after PDE5i treatment. Thirteen RCTs enrolling 898 HF patients, and two sub-analysis studies with different study outcomes, were included in the meta-analysis. Among patients with HFrEF, PDE5i improved peak VO 2 (mean difference [MD], 3.76 mL/min/kg; 95% confidence interval [CI], 3.27 to 4.25; P < 0.00001), VE/VCO 2 slope (MD, -6.04; 95% CI, -7.45 to -4.64; P < 0.00001), LVEF (MD, 4.30%; 95% CI, 2.18 to 6.42; P < 0.0001), and pulmonary vascular resistance (MD, -80.74 dyn·sec/cm 5 ; 95% CI, -110.69 to -50.79; P < 0.00001). The effects of PDE5i in patients with HFpEF were heterogeneous. Meta-regression analyses indicated that the beneficial effect of PDE5i was related to the baseline PAP as well as the extent of PDE5i-mediated PAP decrease. PDE5i improved pulmonary hemodynamics and exercise capacity in patients with HFrEF, but not in HFpEF. The relationship between the benefits by PDE5i with the baseline PAP and the changes in PAP indicates the therapeutic potential of PDE5i in HF according to pulmonary hemodynamics.

  11. Cyclic GMP-mediated memory enhancement in the object recognition test by inhibitors of phosphodiesterase-2 in mice. (United States)

    Lueptow, Lindsay M; Zhan, Chang-Guo; O'Donnell, James M


    Cyclic nucleotide phosphodiesterase-2 (PDE2) is a potential therapeutic target for the treatment of cognitive dysfunction. Using the object recognition test (ORT), this study assessed the effects of two PDE2 inhibitors, Bay 60-7550 and ND7001, on learning and memory, and examined underlying mechanisms. To assess the role of PDE2 inhibition on phases of memory, Bay 60-7550 (3 mg/kg) was administered: 30 min prior to training; 0, 1, or 3 h after training; or 30 min prior to recall testing. To assess cyclic nucleotide involvement in PDE2 inhibitor-enhanced memory consolidation, either the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME; 20 mg/kg; intraperitoneal (IP)), soluble guanylyl cyclase inhibitor 1H-[-1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ; 20 mg/kg; IP), protein kinase G inhibitor KT5823 (2.5 μg; intracerebroventricular (ICV)), or protein kinase A inhibitor H89 (1 μg; ICV) was administered 30 min prior to the PDE2 inhibitor Bay 60-7550 (3 mg/kg) or ND7001 (3 mg/kg). Changes in the phosphorylation of 3'5'-cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) at Ser-133 and vasodilator-stimulated phosphoprotein (VASP) at Ser-239 were determined to confirm activation of cAMP and 3'5'-cyclic guanosine monophosphate (cGMP) signaling. Bay 60-7550 (3 mg/kg) enhanced memory of mice in the ORT when given 30 min prior to training, immediately after training, or 30 min prior to recall. Inhibitors of the cGMP pathway blocked the memory-enhancing effects of both Bay 60-7550 (3 mg/kg) and ND7001 (3 mg/kg) on early consolidation processes. Bay 60-7550 (3 mg/kg) enhanced phosphorylation of CREB and VASP, both targets of cGMP-dependent protein kinase (PKG). These results confirm a potential of PDE2, or components of its signaling pathway, as a therapeutic target for drug discovery focused on restoring memory function.

  12. The Phosphodiesterase 10A Selective Inhibitor TAK-063 Improves Cognitive Functions Associated with Schizophrenia in Rodent Models. (United States)

    Shiraishi, Eri; Suzuki, Kazunori; Harada, Akina; Suzuki, Noriko; Kimura, Haruhide


    Cognitive deficits in various domains, including recognition memory, attention, impulsivity, working memory, and executive function, substantially affect functional outcomes in patients with schizophrenia. TAK-063 [1-[2-fluoro-4-(1H-pyrazol-1-yl)phenyl]-5-methoxy-3-(1-phenyl-1H-pyrazol-5-yl)pyridazin-4(1H)-one] is a potent and selective phosphodiesterase 10A inhibitor that produces antipsychotic-like effects in rodent models of schizophrenia. We evaluated the effects of TAK-063 on multiple cognitive functions associated with schizophrenia using naïve and drug-perturbed rodents. TAK-063 at 0.1 and 0.3 mg/kg p.o. improved time-dependent memory decay in object recognition in naïve rats. TAK-063 at 0.1 and 0.3 mg/kg p.o. increased accuracy rate, and TAK-063 at 0.3 mg/kg p.o. reduced impulsivity in a five-choice serial reaction time task in naïve rats. N-methyl-d-aspartate receptor antagonists, such as phencyclidine and MK-801 [(5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine], were used to induce working memory deficits relevant to schizophrenia in animals. TAK-063 at 0.3 mg/kg p.o. attenuated both phencyclidine-induced working memory deficits in a Y-maze test in mice and MK-801-induced working memory deficits in an eight-arm radial maze task in rats. An attentional set-shifting task using subchronic phencyclidine-treated rats was used to assess the executive function. TAK-063 at 0.3 mg/kg p.o. reversed cognitive deficits in extradimensional shifts. These findings suggest that TAK-063 has a potential to ameliorate deficits in multiple cognitive domains impaired in schizophrenia. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  13. Phosphodiesterase activity is regulated by CC2D1A that is implicated in non-syndromic intellectual disability

    KAUST Repository

    Altawashi, Azza


    Background: Cyclic adenosine 3?5?-monophosphate (cAMP) is a key regulator of many cellular processes, including in the neuronal system, and its activity is tuned by Phosphodiesterase (PDE) activation. Further, the CC2D1A protein, consisting of N-Terminal containing four DM14 domains and C-terminal containing C2 domain, was shown to regulate the cAMP-PKA pathway. A human deletion mutation lacking the fourth DM14 and the adjacent C2 domain results in Non Syndromic Intellectual Disability (NSID) also referred to as Non Syndromic Mental Retardation (NSMR). Findings. Here we demonstrate that in Mouse Embryonic Fibroblasts (MEF) CC2D1A co-localizes with PDE4D in the cytosol before cAMP stimulation and on the periphery after stimulation, and that the movement to the periphery requires the full-length CC2D1A. In CC2D1A mouse mutant cells, the absence of three of the four DM14 domains abolishes migration of the complex to the periphery and causes constitutive phosphorylation of PDE4D Serine 126 (Sssup126esup) via the cAMP-dependent protein kinase A (PKA) resulting in PDE4D hyperactivity. Suppressing PDE4D activity with Rolipram in turn restores the down-stream phosphorylation of the "cAMP response element-binding protein" (CREB) that is defective in mouse mutant cells. Conclusion: Our findings suggest that CC2D1A is a novel regulator of PDE4D. CC2D1A interacts directly with PDE4D regulating its activity and thereby fine-tuning cAMP-dependent downstream signaling. Based on our in vitro evidence we propose a model which links CC2D1A structure and function to cAMP homeostasis thereby affecting CREB phosphorylation. We speculate that CC2D1A and/or PDE4D may be promising targets for therapeutic interventions in many disorders with impaired PDE4D function such as NSID. 2013 Al-Tawashi and Gehring; licensee BioMed Central Ltd.

  14. The pde2 gene of Saccharomyces cerevisiae is allelic to rca1 and encodes a phosphodiesterase which protects the cell from extracellular cAMP. (United States)

    Wilson, R B; Renault, G; Jacquet, M; Tatchell, K


    The high affinity cAMP phosphodiesterase, encoded by PDE2, is an important component of the cAMP-dependent protein kinase signaling system in Saccharomyces cerevisiae. An unexpected phenotype of pde2 mutants is sensitivity to external cAMP. This trait has been found independently for rca1 mutants and has been used to monitor the effects of cAMP on several biological processes. We demonstrate here that RCA1 is identical to PDE2. Further analysis of the phenotype of pde2 deletions reveal that exogenously added cAMP results in an increase in the internal level of cAMP. This increase slows down the rate of cell division by increasing the length of the G1 phase of the cell cycle and leads to increased cell volume. Also, cells with a disrupted PDE2 gene previously arrested by nutrient starvation rapidly lose thermotolerance when incubated with exogenous cAMP. From these observations we propose that a role of the PDE2-encoded phosphodiesterase may be to help insulate the internal cAMP pools from the external environment. This protective role might also be important in other eukaryotic organisms where cAMP is a key second messenger.

  15. Association of the polymorphism of codon 121 in the ecto-nucleotide pyrophosphatase/phosphodiesterase 1 gene with polycystic ovary syndrome in Chinese woman

    International Nuclear Information System (INIS)

    Shi, Y.; Chen, Z.; Zhang, P.; Zhao, Y.; You, L.; Sun, X.


    Objective was to determine the association of polymorphism of codon 121 in the ecto-nucleotide pyrophosphastase/phosphodiesterase 1 (E-NPP1/PC-1) gene in Chinese women with polycystic ovary syndrome (PCOS). A total of 51 PCOS patients and 61 healthy women from Chinese Han population from the Center Reproductive Medicine of Provincial Hospital affiliated to Shandong University from June 2005 to July 2006 were recruited for the determination of the polymorphism of the E-NPP/PC-1 gene. Genomic DNA was extracted from peripheral blood monocytes of patients and controls and genotyping of the gene was performed by using polymerase chain reaction, which was followed by sequencing. The frequency of the 121Q allele was 13 and 18%, respectively, in PCOS patients and healthy women, while the frequency of the 121K allele was 87 and 82% in the 2 groups. There is no significant difference in the E-NPP1/PC-1 polymorphism between PCOS patients and healthy controls among Chinese Han women. ecto-nucleotide pyrophosphatase/phosphodiesterase 1 polymorphism has no association with PCOS. Further studies are still needed to elucidate whether or not the E-NPP1/PC-1 gene has a functional role in PCOS. (author)

  16. cGMP-phosphodiesterase 6, transducin and Wnt5a/Frizzled-2-signaling control cGMP and Ca(2+) homeostasis in melanoma cells. (United States)

    Bazhin, Alexandr V; Tambor, Vojtech; Dikov, Boyan; Philippov, Pavel P; Schadendorf, Dirk; Eichmüller, Stefan B


    Malignant melanoma is one of the most aggressive human neoplasms which develop from the malignant transformation of normal epithelial melanocytes and share the lineage with retinal cells. cGMP-phosphodiesterase 6 (PDE6) is one of the cancer-retina antigens newly identified in melanoma cells. Normally, PDE6 hydrolyzes the photoreceptor second messenger cGMP allowing the visual signal transduction in photoreceptor cells. cGMP also play an important signaling role in stimulating melanogenesis in human melanocytes. Here, we present evidence that PDE6 is a key enzyme regulating the cGMP metabolism in melanoma cells. Decrease in intracellular cGMP leads to calcium accumulation in melanoma cells. In these cells, cGMP-phosphodiesterase 6 can be activated by another cancer-retina antigen, transducin, through Wnt5a-Frizzled-2 cascade, which leads to a lowering of cGMP and an increase in intracellular calcium mobilization. Thus, the aberrant expression of PDE6 may control cGMP metabolism and calcium homeostasis in melanoma cells.

  17. Discovery and Early Clinical Development of 2-{6-[2-(3,5-Dichloro-4-pyridyl)acetyl]-2,3-dimethoxyphenoxy}-N-propylacetamide (LEO 29102), a Soft-Drug Inhibitor of Phosphodiesterase 4 for Topical Treatment of Atopic Dermatitis

    DEFF Research Database (Denmark)

    Felding, Jakob; D. Sørensen, Morten; Poulsen, Tina D.


    Development of orally available phosphodiesterase 4 (PDE4) inhibitors as anti-inflammatory drugs has been going on for decades. However, only roflumilast has received FDA approval. One key challenge has been the low therapeutic window observed in the dinic for PDE4 inhibitors, primarily due to PDE4...

  18. The cAMP phosphodiesterase-4D7 (PDE4D7) is downregulated in androgen-independent prostate cancer cells and mediates proliferation by compartmentalising cAMP at the plasma membrane of VCaP prostate cancer cells

    NARCIS (Netherlands)

    D.J.P. Henderson (D. J P); A. Byrne (A.); K. Dulla (K.); G.W. Jenster (Guido); R. Hoffmann (R.); G.S. Baillie (G.); M.D. Houslay (M.)


    textabstractBackground: Isoforms of the PDE4 family of cAMP-specific phosphodiesterases (PDEs) are expressed in a cell type-dependent manner and contribute to underpinning the paradigm of intracellular cAMP signal compartmentalisation. Here we identify the differential regulation of the PDE4D7

  19. Inhibition of cGMP-specific phosphodiesterase type 5 reduces sodium excretion and arterial blood pressure in patients with NaCl retention and ascites

    DEFF Research Database (Denmark)

    Thiesson, Helle C; Jensen, Boye L; Jespersen, Bente


    In the present study, we tested the hypothesis that inhibition of renal phosphodiesterase type 5 (PDE5) in patients with liver cirrhosis and ascites increases sodium excretion. The effect of sildenafil citrate was studied in a randomized double-blind. placebo-controlled crossover study. Diuretics...... were withdrawn, and a fixed sodium diet (100 mmol/day) was given to the patients for 5 days before both study days. After a 60-min basal period, eight patients received either oral sildenafil (50 mg) or placebo. Glomerular filtration rate (GFR) and renal blood flow (RBF) were determined by 99m...... ANG II, and aldosterone concentrations significantly after 60 min. Plasma cGMP concentration was increased after 120 and 180 min, and urinary sodium excretion and mean arterial blood pressure were decreased significantly at 120 and 180 min. Plasma ANP concentration, GFR, and RBF did not change after...

  20. Application of Structure-Based Design and Parallel Chemistry to Identify a Potent, Selective, and Brain Penetrant Phosphodiesterase 2A Inhibitor. (United States)

    Helal, Christopher J; Arnold, Eric P; Boyden, Tracey L; Chang, Cheng; Chappie, Thomas A; Fennell, Kimberly F; Forman, Michael D; Hajos, Mihaly; Harms, John F; Hoffman, William E; Humphrey, John M; Kang, Zhijun; Kleiman, Robin J; Kormos, Bethany L; Lee, Che-Wah; Lu, Jiemin; Maklad, Noha; McDowell, Laura; Mente, Scot; O'Connor, Rebecca E; Pandit, Jayvardhan; Piotrowski, Mary; Schmidt, Anne W; Schmidt, Christopher J; Ueno, Hirokazu; Verhoest, Patrick R; Yang, Edward X


    Phosphodiesterase 2A (PDE2A) inhibitors have been reported to demonstrate in vivo activity in preclinical models of cognition. To more fully explore the biology of PDE2A inhibition, we sought to identify potent PDE2A inhibitors with improved brain penetration as compared to current literature compounds. Applying estimated human dose calculations while simultaneously leveraging synthetically enabled chemistry and structure-based drug design has resulted in a highly potent, selective, brain penetrant compound 71 (PF-05085727) that effects in vivo biochemical changes commensurate with PDE2A inhibition along with behavioral and electrophysiological reversal of the effects of NMDA antagonists in rodents. This data supports the ability of PDE2A inhibitors to potentiate NMDA signaling and their further development for clinical cognition indications.

  1. Inhibition of phosphodiesterase 3, 4, and 5 induces endolymphatic hydrops in mouse inner ear, as evaluated with repeated 9.4T MRI

    DEFF Research Database (Denmark)

    Degerman, Eva; In 't Zandt, Rene; Pålbrink, Annki


    GMP signaling. METHOD: To evaluate the role of PDE3, 4, and 5 and associated cAMP and cGMP pools in inner ear function, the effect of cilostamide (PDE3 inhibitor), rolipram (PDE4 inhibitor), and sildenafil (PDE5 inhibitor), administrated via mini-osmotic pumps, on mouse inner ear fluid homeostasis was evaluated......CONCLUSION: The data indicate important roles for phosphodiesterase (PDE) 3, 4, 5, and related cAMP and cGMP pools in the regulation of inner ear fluid homeostasis. Thus, dysfunction of these enzymes might contribute to pathologies of the inner ear. OBJECTIVE: The mechanisms underlying...... endolymphatic hydrops, a hallmark of inner ear dysfunction, are not known in detail; however, altered balance in cAMP and cGMP signaling systems appears to be involved. Key components of these systems are PDEs, enzymes that modulate the amplitude, duration, termination, and specificity of cAMP and c...

  2. Late airway obstruction and neutrophil infiltration in sensitized mice after antigen provocation were suppressed by selective and non-selective phosphodiesterase inhibitors

    Directory of Open Access Journals (Sweden)

    Osamu Kaminuma


    Full Text Available Suppression of antigen-induced late airway obstruction associated with neutrophilic inflammation by selective and non-selective phosphodiesterase (PDE inhibitors was investigated in mice. Respiratory resistance (Rrs increased in sensitized BDF1 mice 4-6 h after antigen provocation, whereas no obvious immediate reaction was observed. This reaction was associated with marked airway neutrophilia without significant infiltration of eosinophils. A selective PDE IV inhibitor, T-440 (10-30 mg/kg, and a non-selective PDE inhibitor, theophylline (10 mg/kg, significantly inhibited airway obstruction and neutrophilia when administered orally. An anti-allergic drug, ketotifen (1 mg/kg, caused slight inhibition of airway obstruction, whereas it did not affect airway neutrophilia. These results suggest that neutrophilic inflammation plays a role in the airway obstructive reaction and that PDE has a regulatory role in obstructive airway disease associated with airway inflammation.

  3. Early and rapid development of insulin resistance, islet dysfunction and glucose intolerance after high-fat feeding in mice overexpressing phosphodiesterase 3B

    DEFF Research Database (Denmark)

    Walz, Helena A; Härndahl, Linda; Wierup, Nils


    Inadequate islet adaptation to insulin resistance leads to glucose intolerance and type 2 diabetes. Here we investigate whether beta-cell cAMP is crucial for islet adaptation and prevention of glucose intolerance in mice. Mice with a beta-cell-specific, 2-fold overexpression of the c......AMP-degrading enzyme phosphodiesterase 3B (RIP-PDE3B/2 mice) were metabolically challenged with a high-fat diet. We found that RIP-PDE3B/2 mice early and rapidly develop glucose intolerance and insulin resistance, as compared with wild-type littermates, after 2 months of high-fat feeding. This was evident from....../2 mice. We conclude that accurate regulation of beta-cell cAMP is necessary for adequate islet adaptation to a perturbed metabolic environment and protective for the development of glucose intolerance and insulin resistance....

  4. Tryptophan and aspartic acid residues present in the glycerophosphoryl diester phosphodiesterase (GDPD) domain of the Loxosceles laeta phospholipase D are essential for substrate recognition. (United States)

    Catalán, Alejandro; Cortés, William; Muñoz, Christian; Araya, Jorge E


    It is known that the family of phospholipases D (PLD) from spiders of the genus Loxosceles, hydrolyze the substrates sphingomyelin and lisophosphatidylcholine, by their catalytic acid-base action which involves two histidines. However, little is known about the amino acids that participate on substrate recognition. In this study we identified highly conserved amino acids of the glycerophosphoryl diester phosphodiesterase (GDPD) domain of recombinant LlPLD1, which interact with the substrate sphingomyelin. The mutation of W256 to serine and D259 to glycine decreased significantly the sphingomyelinase and hemolytic activity when compared to wild type LlPLD1. The interaction of LlPLD1 with sphingomyelin was also strongly reduced in both mutants LlPLD1-W256S and LlPLD1-D259G. The results show the importance of these residues in the interaction of the protein with its substrate sphingomyelin in cell membranes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Identification of PDE5A:E90K: a polymorphism in the canine phosphodiesterase 5A gene affecting basal cGMP concentrations of healthy dogs. (United States)

    Stern, J A; Reina-Doreste, Y; Chdid, L; Meurs, K M


    Cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase (PDE5A) is the target of phosphodiesterase inhibitors such as sildenafil. Polymorphisms in the PDE5A gene that may predict response to therapy with sildenafil and nitric oxide, be linked to disease progression, and aid in risk assessment have been identified in human beings. Identification of polymorphisms in PDE5A could affect the physiologic actions of PDE5A and the effects of phosphodiestrase type 5 inhibitor drugs. Functional polymorphisms exist in the canine PDE5A gene. Specific objectives were to identify PDE5A polymorphisms and evaluate their functional relevance. Seventy healthy dogs. The exonic, splice-site, 3' and 5' untranslated regions of the canine PDE5A gene were sequenced in 15 dogs and aligned with the canine reference sequence. Identified polymorphisms were evaluated in 55 additional, healthy, unrelated dogs of 20 breeds. Plasma was collected from 51 of these dogs and cGMP was measured. An unpaired t-test and one-way ANOVA with Dunnett's test of multiple comparisons were used to evaluate the effect of genotype on cGMP. A common exonic polymorphism was identified that changed glutamic acid to lysine and resulted in significantly lower cGMP concentrations in the group with polymorphism versus the wild type group (P = .014). Additionally, 6 linked single nucleotide polymorphisms in the 3' untranslated region were identified that did not alter cGMP concentrations. A polymorphism exists in the canine PDE5A gene that is associated with variable circulating cGMP concentrations in healthy dogs and warrants investigation in diseases such as pulmonary hypertension. Copyright © 2013 by the American College of Veterinary Internal Medicine.

  6. Ligand-dependent and -independent regulation of human hepatic sphingomyelin phosphodiesterase acid-like 3A expression by pregnane X receptor and crosstalk with liver X receptor. (United States)

    Jeske, Judith; Bitter, Andreas; Thasler, Wolfgang E; Weiss, Thomas S; Schwab, Matthias; Burk, Oliver


    Pregnane X receptor (PXR) mainly regulates xenobiotic metabolism and detoxification. Additionally, it exerts pleiotropic effects on liver physiology, which in large parts depend on transrepression of other liver-enriched transcription factors. Based on the hypothesis that lower expression levels of PXR may reduce the extent of this inhibition, an exploratory genome-wide transcriptomic profiling was performed using HepG2 cell clones with different expression levels of PXR. This screen and confirmatory real-time RT-PCR identified sphingomyelin phosphodiesterase acid-like (SMPDL) 3A, a novel nucleotide phosphodiesterase and phosphoramidase, as being up-regulated by PXR-deficiency. Transient siRNA-mediated knock-down of PXR in HepG2 cells and primary human hepatocytes similarly induced mRNA up-regulation, which translated into increased intracellular and secreted extracellular protein levels. Interestingly, ligand-dependent PXR activation also induced SMPDL3A in HepG2 cells and primary human hepatocytes. Electrophoretic mobility shift assays and chromatin immunoprecipitation demonstrated binding of PXR to the previously identified liver X receptor (LXR)-binding DR4 motif as well as to an adjacent ER8 motif in intron 1 of SMPDL3A. Constitutive binding of the unliganded receptor to the intron 1 chromatin indicated ligand-independent repression of SMPDL3A by PXR. Transient transfection and reporter gene analysis confirmed the specific role of these motifs in PXR- and LXR-dependent activation of the SMPDL3A intronic enhancer. PXR inhibited LXR mainly by competition for binding sites. In conclusion, this study describes that a decrease in PXR expression levels and ligand-dependent activation of PXR and LXR increase hepatic SMPDL3A levels, which possibly connects these receptors to hepatic purinergic signaling and phospholipid metabolism and may result in drug-drug interactions with phosphoramidate pro-drugs. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Regulation of the pro-inflammatory cytokine osteopontin by GIP in adipocytes - A role for the transcription factor NFAT and phosphodiesterase 3B

    Energy Technology Data Exchange (ETDEWEB)

    Omar, Bilal [Department of Experimental Medical Sciences, Diabetes, Metabolism and Endocrinology, Biomedical Center, Lund University, Lund (Sweden); Banke, Elin, E-mail: [Department of Experimental Medical Sciences, Diabetes, Metabolism and Endocrinology, Biomedical Center, Lund University, Lund (Sweden); Guirguis, Emilia [Cardiovascular Pulmonary Branch, NHLBI, NIH, Bethesda, MD (United States); Aakesson, Lina [Department of Clinical Sciences, Diabetes and Celiac Disease Unit, Clinical Research Centre, Lund University, Malmoe (Sweden); Manganiello, Vincent [Cardiovascular Pulmonary Branch, NHLBI, NIH, Bethesda, MD (United States); Lyssenko, Valeriya; Groop, Leif [Department of Clinical Sciences, Diabetes and Endocrinology, Clinical Research Centre, Lund University, Malmoe (Sweden); Gomez, Maria F. [Department of Clinical Sciences, Vascular ET Coupling, Clinical Research Centre, Lund University, Malmoe (Sweden); Degerman, Eva [Department of Experimental Medical Sciences, Diabetes, Metabolism and Endocrinology, Biomedical Center, Lund University, Lund (Sweden)


    Highlights: Black-Right-Pointing-Pointer GIP stimulates lipogenesis and osteopontin expression in primary adipocytes. Black-Right-Pointing-Pointer GIP-induced osteopontin expression is NFAT-dependent. Black-Right-Pointing-Pointer Osteopontin expression is PDE3-dependent. Black-Right-Pointing-Pointer Osteopontin expression is increased in PDE3B KO mice. -- Abstract: The incretin - glucose-dependent insulinotropic polypeptide (GIP) - and the pro-inflammatory cytokine osteopontin are known to have important roles in the regulation of adipose tissue functions. In this work we show that GIP stimulates lipogenesis and osteopontin expression in primary adipocytes. The GIP-induced increase in osteopontin expression was inhibited by the NFAT (the transcription factor nuclear factor of activated T-cells) inhibitor A-285222. Also, the NFAT kinase glycogen synthase kinase (GSK) 3 was upregulated by GIP. To test whether cAMP might be involved in GIP-mediated effects on osteopontin a number of strategies were used. Thus, the {beta}3-adrenergic receptor agonist CL316,243 stimulated osteopontin expression, an effects which was mimicked by OPC3911, a specific inhibitor of phosphodiesterase 3. Furthermore, treatment of phosphodiesterase 3B knock-out mice with CL316,243 resulted in a dramatic upregulation of osteopontin in adipose tissue which was not the case in wild-type mice. In summary, we delineate mechanisms by which GIP stimulates osteopontin in adipocytes. Given the established link between osteopontin and insulin resistance, our data suggest that GIP by stimulating osteopontin expression, also could promote insulin resistance in adipocytes.

  8. Eurycomanone, the major quassinoid in Eurycoma longifolia root extract increases spermatogenesis by inhibiting the activity of phosphodiesterase and aromatase in steroidogenesis. (United States)

    Low, Bin-Seng; Choi, Sy-Bing; Abdul Wahab, Habibah; Das, Prashanta Kumar; Chan, Kit-Lam


    Eurycoma longifolia Jack (Simaroubaceae family), known locally as 'Tongkat Ali' by the ethnic population, is popularly taken as a traditional remedy to improve the male libido, sexual prowess and fertility. Presently, many tea, coffee and carbonated beverages, pre-mixed with the root extract are available commercially for the improvement of general health and labido. Eurycomanone, the highest concentrated quassinoid in the root extract of E. longifolia improved fertility by increasing testosterone and spermatogenesis of rats through the hypothalamus-pituitary-gonadal axis, but the mechanisms underlying the effects are not totally clear. To provide evidences on the plant ethnopharmacological use and the involvement of eurycomanone, the major indigenous plant quassinoid in testosterone steroidogenesis and spermatogenesis increase. The rat testicular Leydig cell-rich interstitial cells were isolated and incubated in the culture medium M199. The viability of the cells was determined with trypan blue staining and the concentration of the viable cells was counted with a haemocytometer. The 3β-hydroxysteroid dehydrogenase (HSD) staining method was used to measure the abundance of Leydig cells in the preparation. Eurycomanone and the standard steroidogenesis inhibitors were incubated with 1.0 × 10(5) cells, and after 2h, the testosterone and the oestrogen concentrations were determined by the ELISA method. Computational molecular docking was performed to determine the binding affinity of the compound at the respective steroidogenesis enzymes. Eurycomanone (EN) significantly increased testosterone production dose-dependently at 0.1, 1.0 and 10.0 μM (P<0.05), but the two lower doses when combined with 3-isobutyl-1-methylxanthine (IBMX), the phosphodiesterase inhibitor were not significantly higher than EN or IBMX alone, except at a higher concentration. The molecular docking studies indicated EN and IBMX were binding at different sites of the enzyme. EN has no reversal of

  9. Postulated vasoactive neuropeptide immunopathology affecting the blood–brain/blood–spinal barrier in certain neuropsychiatric fatigue-related conditions: A role for phosphodiesterase inhibitors in treatment?

    Directory of Open Access Journals (Sweden)

    Sonya Marshall-Gradisnik


    contribute to the BBB and BSB integrity and contain PACAP and VIP receptors. Autoimmunity of these receptors would likely affect BBB and VRS function and therefore may contribute to the etiology of these conditions by affecting CNS and immunological homeostasis, including promoting neuropsychological symptomatology. PACAP and VIP, as potent activators of adenylate cyclase (AC, have a key role in cyclic adenosine monophosphate (cAMP production affecting regulatory T cell (Treg and other immune functions. Phosphodiesterase enzymes (PDEs catalyze cAMP and PDE inhibitors (PDEIs maintain cAMP levels and have proven and well known therapeutic benefit in animal models such as experimental allergic encephalomyelitis (EAE. Therefore PDEIs may have a role in therapy for certain neuropsychiatric fatigue-related conditions.Keywords: vasoactive neuropeptides, multiple sclerosis, Parkinson’s disease, chronic fatigue syndrome, phosphodiesterase inhibitors, cyclic AMP, adenylate cyclase, Virchow–Robin spaces

  10. PdeH, a high-affinity cAMP phosphodiesterase, is a key regulator of asexual and pathogenic differentiation in Magnaporthe oryzae.

    Directory of Open Access Journals (Sweden)

    Ravikrishna Ramanujam


    Full Text Available Cyclic AMP-dependent pathways mediate the communication between external stimuli and the intracellular signaling machinery, thereby influencing important aspects of cellular growth, morphogenesis and differentiation. Crucial to proper function and robustness of these signaling cascades is the strict regulation and maintenance of intracellular levels of cAMP through a fine balance between biosynthesis (by adenylate cyclases and hydrolysis (by cAMP phosphodiesterases. We functionally characterized gene-deletion mutants of a high-affinity (PdeH and a low-affinity (PdeL cAMP phosphodiesterase in order to gain insights into the spatial and temporal regulation of cAMP signaling in the rice-blast fungus Magnaporthe oryzae. In contrast to the expendable PdeL function, the PdeH activity was found to be a key regulator of asexual and pathogenic development in M. oryzae. Loss of PdeH led to increased accumulation of intracellular cAMP during vegetative and infectious growth. Furthermore, the pdeHDelta showed enhanced conidiation (2-3 fold, precocious appressorial development, loss of surface dependency during pathogenesis, and highly reduced in planta growth and host colonization. A pdeHDelta pdeLDelta mutant showed reduced conidiation, exhibited dramatically increased (approximately 10 fold cAMP levels relative to the wild type, and was completely defective in virulence. Exogenous addition of 8-Br-cAMP to the wild type simulated the pdeHDelta defects in conidiation as well as in planta growth and development. While a fully functional GFP-PdeH was cytosolic but associated dynamically with the plasma membrane and vesicular compartments, the GFP-PdeL localized predominantly to the nucleus. Based on data from cAMP measurements and Real-Time RTPCR, we uncover a PdeH-dependent biphasic regulation of cAMP levels during early and late stages of appressorial development in M. oryzae. We propose that PdeH-mediated sustenance and dynamic regulation of cAMP signaling

  11. Diminished responsiveness to dobutamine as an inotrope in mice with cecal ligation and puncture-induced sepsis: attribution to phosphodiesterase 4 upregulation. (United States)

    Sakai, Mari; Suzuki, Tokiko; Tomita, Kengo; Yamashita, Shigeyuki; Palikhe, Sailesh; Hattori, Kohshi; Yoshimura, Naoki; Matsuda, Naoyuki; Hattori, Yuichi


    Dobutamine has been used in septic shock for many years as an only inotrope, but its benefit has been questioned. We weighed the effects of dobutamine and milrinone as inotropes in mice with cecal ligation and puncture (CLP)-induced polymicrobial sepsis. CLP-induced septic mice exhibited significant cardiac inflammation, as indicated by greatly increased mRNAs of proinflammatory cytokines and robust infiltration of inflammatory cells in the ventricular myocardium. Elevations of plasma cardiac troponin-I showed cardiac injury in CLP mice. Noninvasive echocardiographic assessment of cardiac function revealed that despite preserved left ventricular function in the presence of fluid replacement, the dobutamine inotropic response was significantly impaired in CLP mice compared with sham-operated controls. By contrast, milrinone exerted inotropic effects in sham-operated and CLP mice in an equally effective manner. Surface expression levels of β 1 -adrenoceptors and α-subunits of three main G protein families in the myocardium were unaffected by CLP-induced sepsis. Plasma cAMP levels were significantly elevated in both sham-operated and CLP mice in response to milrinone but only in sham-operated controls in response to dobutamine. Of phosphodiesterase (PDE) isoforms, PDE4D, but not PDE3A, both of which are responsible for cardiac cAMP hydrolysis, was significantly upregulated in CLP mouse myocardium. We define a novel mechanism for the impaired responsiveness to dobutamine as an inotrope in sepsis, and understanding the role of PDE4D in modulating cardiac functional responsiveness in sepsis may open the potential of a PDE4D-targeted therapeutic option in septic patients with low cardiac output who have a need for inotropic support. NEW & NOTEWORTHY Advisability of the usefulness of dobutamine in septic shock management is limited. Here, we reveal that the effect of dobutamine as a positive inotrope is impaired in mice with cecal ligation and puncture-induced sepsis

  12. Benefits and risks of testosterone treatment for hypoactive sexual desire disorder in women: a critical review of studies published in the decades preceding and succeeding the advent of phosphodiesterase type 5 inhibitors

    Directory of Open Access Journals (Sweden)

    Sandra Léa Bonfim Reis


    Full Text Available With advancing age, there is an increase in the complaints of a lack of a libido in women and erectile dysfunction in men. The efficacy of phosphodiesterase type 5 inhibitors, together with their minimal side effects and ease of administration, revolutionized the treatment of erectile dysfunction. For women, testosterone administration is the principal treatment for hypoactive sexual desire disorder. We sought to evaluate the use of androgens in the treatment of a lack of libido in women, comparing two periods, i.e., before and after the advent of the phosphodiesterase type 5 inhibitors. We also analyzed the risks and benefits of androgen administration. We searched the Latin-American and Caribbean Health Sciences Literature, Cochrane Library, Excerpta Medica, Scientific Electronic Library Online, and Medline (PubMed databases using the search terms disfunção sexual feminina/female sexual dysfunction, desejo sexual hipoativo/female hypoactive sexual desire disorder, testosterona/testosterone, terapia androgênica em mulheres/androgen therapy in women, and sexualidade/sexuality as well as combinations thereof. We selected articles written in English, Portuguese, or Spanish. After the advent of phosphodiesterase type 5 inhibitors, there was a significant increase in the number of studies aimed at evaluating the use of testosterone in women with hypoactive sexual desire disorder. However, the risks and benefits of testosterone administration have yet to be clarified.

  13. Phosphodiesterase-5 inhibitors and their analogues as adulterants of herbal and food products: analysis of the Malaysian market, 2014-16. (United States)

    Bujang, Nur Baizura; Chee, Chin Fei; Heh, Choon Han; Rahman, Noorsaadah Abd; Buckle, Michael J C


    Adulteration of herbal health supplements with phosphodiesterase-5 (PDE-5) inhibitors and their analogues is becoming a worldwide problem. The aim of this study was to investigate herbal and food products sold in the Malaysian market for the presence of these adulterants. Sixty-two products that claim to enhance men's sexual health were sampled between April 2014 and April 2016. These products included unregistered products seized by the Pharmacy Enforcement Division of the Ministry of Health (n = 39), products sent to the National Pharmaceutical Regulatory Agency for pre-registration testing (n = 9) and products investigated under the post-registration market surveillance programme (n = 14). The products were tested against an in-house spectral library consisting of 61 PDE-5 inhibitors and analogues using a validated liquid chromatography-mass spectrometry ion-trap-time-of-flight (LC-MS IT-TOF) method. Thirty-two (82%) of the unregistered products and two (14%) of the registered products were found to be adulterated with at least one PDE-5 inhibitor or analogue, while none of the pre-registration products contained adulterants. A total of 16 different adulterants were detected and 36% of the adulterated products contained a mixture of two or more adulterants. This study has demonstrated that the adulteration of unregistered herbal products in the Malaysian market is an alarming issue that needs to be urgently addressed by the relevant authorities.

  14. Synthesis, SAR study, and biological evaluation of novel quinoline derivatives as phosphodiesterase 10A inhibitors with reduced CYP3A4 inhibition. (United States)

    Hamaguchi, Wataru; Masuda, Naoyuki; Miyamoto, Satoshi; Shiina, Yasuhiro; Kikuchi, Shigetoshi; Mihara, Takuma; Moriguchi, Hiroyuki; Fushiki, Hiroshi; Murakami, Yoshihiro; Amano, Yasushi; Honbou, Kazuya; Hattori, Kouji


    A novel class of phosphodiesterase 10A inhibitors with potent PDE10A inhibitory activity and reduced CYP3A4 inhibition was designed and synthesized starting from 2-[4-({[1-methyl-4-(pyridin-4-yl)-1H-pyrazol-3-yl]oxy}methyl)phenyl]quinoline (1). Replacement of pyridine ring of 1 with N-methyl pyridone ring drastically improved CYP3A4 inhibition, and further optimization of these quinoline analogues identified 1-methyl-5-(1-methyl-3-{[4-(quinolin-2-yl)phenoxy]methyl}-1H-pyrazol-4-yl)pyridin-2(1H)-one (42b), which showed potent PDE10A inhibitory activity and a good CYP3A4 inhibition profile. A PET study with (11)C-labeled 42b indicated that 42b exhibited good brain penetration and specifically accumulated in the rodent striatum. Further, oral administration of 42b dose-dependently attenuated phencyclidine-induced hyperlocomotion in mice with an ED50 value of 2.0mg/kg and improved visual-recognition memory impairment at 0.1 and 0.3mg/kg in mice novel object recognition test. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Synthesis and characterization of mononuclear oxovanadium(IV) complexes and their enzyme inhibition studies with a carbohydrate metabolic enzyme phosphodiesterase I. (United States)

    Mahroof-Tahir, Mohammad; Brezina, Dan; Fatima, Naheed; Choudhary, Muhammad Iqbal; Atta-ur-Tahman


    The increasing interest in vanadium coordination chemistry is based on its well-established chemical and biological functions. A beta-diketonato complex of oxovanadium(IV) is known to be having numerous catalytic applications and also exhibits promising insulin mimetic properties. In continuation of our structure activity relationship studies of metal complexes, we report herein the synthesis and characterization of the vanadium complexes of beta-diketonato ligand system with systematic variations of electronic and steric factors. Two complexes, VO(tmh)(2) (tmh = 2,2,6,6,-tetramethyl-3,5-heptanedione), and VO(hd)(2) (hd = 3,5-heptanedione) were synthesized and characterized by using different spectroscopic techniques. Elemental and mass spectral analysis supports the presence of two beta-diketonato ligands per VO(2+) unit. UV-Vis spectra in different solvents indicate coordination of coordinating solvent molecules at sixth position resulting in red shift of the band I transition. NMR and IR spectra reveal binding of coordinating solvent molecule at vacant sixth position trans to oxo group without releasing beta-diketonato ligands. Enzyme inhibition studies of these and other related oxovanadium(IV) complexes with beta-diketonato ligand system are conducted with snake venom phosphodiesterase I (SPVDE). All of these complexes showed significant inhibitory potential and were found to be non-competitive inhibitors against this enzyme.

  16. Phosphodiesterase type 5 inhibitor administered immediately after radical prostatectomy temporarily increases the need for incontinence pads, but improves final continence status

    Directory of Open Access Journals (Sweden)

    Yasuhiro Kaiho


    Full Text Available Purpose: To evaluate the effects of phosphodiesterase type 5 inhibitor (PDE5i on urinary continence recovery after bilateral nerve-sparing radical prostatectomy (BNSRP. Materials and Methods: Between 2002 and 2012, 137 of 154 consecutive patients who underwent BNSRP in our institution retrospectively divided into 3 groups that included patients taking PDE5i immediately after surgery (immediate PDE5i group, n=41, patients starting PDE5i at an outpatient clinic after discharge (PDE5i group, n=56, and patients taking no medication (non-PDE5i group, n=40. Using self-administered questionnaires, the proportion of patients who did not require incontinence pads (pad-free patients was calculated preoperatively and at 1, 3, 6, 12, 18, and 24 months after BNSRP. Severity of incontinence was determined based on the pad numbers and then compared among the 3 groups. Results: Proportions of pad-free patients and severity of incontinence initially deteriorated in all of the groups to the lowest values soon after undergoing BNSRP, with gradual improvement noted thereafter. The deterioration was most prominent in the immediate PDE5i group. As compared to the non-PDE5i group, both the PDE5i and immediate PDE5i groups exhibited a better final continence status. Conclusions: PDE5i improves final continence status. However, administration of PDE5i immediately after surgery causes a distinct temporary deterioration in urinary incontinence.

  17. Discovery of novel purine nucleoside derivatives as phosphodiesterase 2 (PDE2) inhibitors: Structure-based virtual screening, optimization and biological evaluation. (United States)

    Qiu, Xiaoxia; Huang, Yiyou; Wu, Deyan; Mao, Fei; Zhu, Jin; Yan, Wenzhong; Luo, Hai-Bin; Li, Jian


    Phosphodiesterase 2 (PDE2) has received much attention for the potential treatment of the central nervous system (CNS) disorders and pulmonary hypertension. Herein, we identified that clofarabine (4), an FDA-approved drug, displayed potential PDE2 inhibitory activity (IC 50  = 3.12 ± 0.67 μM) by structure-based virtual screening and bioassay. Considering the potential therapeutic benefit of PDE2, a series of purine nucleoside derivatives based on the structure and binding mode of 4 were designed, synthesized and evaluated, which led to the discovery of the best compound 14e with a significant improvement of inhibitory potency (IC 50  = 0.32 ± 0.04 μM). Further molecular docking and molecular dynamic (MD) simulations studies revealed that 5'-benzyl group of 14e could interact with the unique hydrophobic pocket of PDE2 by forming extra van der Waals interactions with hydrophobic residues such as Leu770, Thr768, Thr805 and Leu809, which might contribute to its enhancement of PDE2 inhibition. These potential compounds reported in this article and the valuable structure-activity relationships (SARs) might bring significant instruction for further development of potent PDE2 inhibitors. Copyright © 2017. Published by Elsevier Ltd.

  18. A structural basis for the regulation of an H-NOX-associated cyclic-di-GMP synthase/phosphodiesterase enzyme by nitric oxide-bound H-NOX. (United States)

    Lahiri, Tanaya; Luan, Bowu; Raleigh, Daniel P; Boon, Elizabeth M


    Biofilms are surface-attached communities of bacteria enclosed in a polysaccharide matrix. Bacteria in a biofilm are extremely resistant to antibiotics. Several recent reports have linked the signaling molecule nitric oxide (NO) with biofilm dispersal. We have previously reported that an H-NOX (heme-nitric oxide/oxygen binding) protein in the biofilm-dwelling bacterium Shewanella woodyi mediates NO-induced biofilm dispersal. In S. woodyi, H-NOX (SwH-NOX) is cocistronic with a gene encoding a dual-functioning diguanylate cyclase/phosphodiesterase enzyme, designated here as HaCE (H-NOX-associated cyclic-di-GMP processing enzyme). Enzymes such as these are responsible for regulating the intracellular concentrations of cyclic-di-GMP, a secondary signaling molecule essential to biofilm formation in bacteria. We have demonstrated that NO-bound SwH-NOX regulates both enzymatic activities of SwHaCE, resulting in decreased cellular cyclic-di-GMP levels and disruption of biofilm formation. Thus, H-NOX/HaCE represents a potential drug target for regulating biofilm formation. In this work, the SwH-NOX surface residues critical for the formation of a protein complex with SwHaCE are identified using nuclear magnetic resonance, fluorescence quenching, and cosedimentation. Enzyme assays confirm this protein-protein interface and its importance for H-NOX/HaCE function.

  19. Early and rapid development of insulin resistance, islet dysfunction and glucose intolerance after high-fat feeding in mice overexpressing phosphodiesterase 3B

    DEFF Research Database (Denmark)

    Walz, Helena A; Härndahl, Linda; Wierup, Nils


    advanced fasting hyperinsulinemia and early development of hyper-glycemia, in spite of hyperinsulinemia, as well as impaired capacity of insulin to suppress plasma glucose in an insulin tolerance test. In vitro analyses of insulin-stimulated lipogenesis in adipocytes and glucose uptake in skeletal muscle......AMP-degrading enzyme phosphodiesterase 3B (RIP-PDE3B/2 mice) were metabolically challenged with a high-fat diet. We found that RIP-PDE3B/2 mice early and rapidly develop glucose intolerance and insulin resistance, as compared with wild-type littermates, after 2 months of high-fat feeding. This was evident from...... perturbations, such as centrally located alpha-cells and reduced immunostaining for insulin and GLUT2 in islets from RIP-PDE3B/2 mice. Additionally, in vitro experiments revealed that the insulin secretory response to glucagon-like peptide-1 stimulation was markedly reduced in islets from high-fat-fed RIP-PDE3B...

  20. Resonant-Mie-scattering of aggregates of phosphomolybdate and papaverine for measuring activities and screening inhibitors of cyclic nucleotide phosphodiesterase isozymes. (United States)

    Zhang, Yi; Yang, Xiaolan; Hu, Xiaolei; Liu, Miaomiao; Chen, Chunyan; Xie, Yanling; Pu, Jun; Wu, Jing; Long, Gaobo; Liao, Fei


    A resonant-light-scattering (RLS) method was proposed to quantify phosphate for screening inhibitors of isozymes of cyclic nucleotide phosphodiesterase (PDE). In acidified mixtures of phosphate, papaverine and molybdate, there were aggregates exhibiting micrometre sizes, no absorbance peaks over 360 nm but strong RLS peaks at 392 nm; Mie scattering thus accounted for the RLS signals. When papaverine was added before molybdate to acidified samples of phosphate, RLS signals at 392 nm were stable from 5 to 25 min since the addition of molybdate; after optimization, phosphate from 0.40 to 3.60 μM was quantifiable. This RLS method tolerated 60 mg L(-1) proteins besides common PDE inhibitors and dimethyl sulfoxide in acidified samples of phosphate; the integration of this RLS method with the coupled action of a phosphomonoesterase on PDE product was thus rational to measure PDE activities without the removal of proteins in samples. By quantifying activities of a truncated mutant of human PDE4B2 via this RLS method, Michaelis-Menten constant, inhibition constants of rolipram, papaverine and theophylline varied over three magnitudes and were consistent with those estimated by an improved malachite green assay of phosphate, respectively. Hence, this novel RLS method was promising for screening inhibitors of PDE isozymes. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Regulation of cyclic AMP phosphodiesterase from Mucor rouxii by phosphorylation and proteolysis. Interrelationship of the activatable and insensitive forms of the enzyme. (United States)

    Kerner, N; Moreno, S; Passeron, S


    DEAE-cellulose chromatography of mycelial extracts of Mucor rouxii grown to mid-exponential phase resolves two types of low-Km cyclic AMP phosphodiesterase (EC; PDE): PDE I, highly activatable (4-6-fold) by phosphorylation or proteolysis, and PDE II, unresponsive to activation. The enzymic profile of PDE activity obtained from germlings shows only PDE I activity, whereas PDE activity from mycelia grown to stationary phase is eluted from the DEAE-cellulose column at the position of PDE II, and like PDE II is unresponsive to activation. Endogenous proteolysis or controlled trypsin treatment transforms PDE I into PDE II. The insensitive forms of PDE exhibit a slightly smaller sedimentation coefficient than the activatable forms, as judged by sucrose-gradient centrifugation. The basal activity of the highly activatable form of PDE is elevated almost to the value in the presence of trypsin on storage at 4 degrees C in the absence of proteinase inhibitors. Benzamidine, leupeptin, antipain or EGTA prevents the activation produced by storage. PDE I remains strongly activatable by phosphorylation and proteolysis after resolution by polyacrylamide-gel electrophoresis. PMID:6326757

  2. Combination of preparative HPLC and HSCCC methods to separate phosphodiesterase inhibitors from Eucommia ulmoides bark guided by ultrafiltration-based ligand screening. (United States)

    Shi, Shu-Yun; Peng, Mi-Jun; Zhang, Yu-Ping; Peng, Sheng


    Phosphodiesterase (PDE) inhibitors are widely used because of their various pharmacological properties, and natural products are considered the most productive source of PDE inhibitors. In this work, a new ultrafiltration-high-performance liquid chromatography (HPLC)-diode-array detection-mass spectrometry based ligand screening was developed for the first screening of PDE inhibitors from Eucommia ulmoides bark, and then the target bioactive compounds were prepared by combination of stepwise preparative HPLC and high-speed countercurrent chromatography (HSCCC) methods. Experiments were conducted to optimize the parameters in ultrafiltration, stepwise preparative HPLC, and HSCCC to allow rapid and effective screening and isolation of active compounds from complex mixtures. Seven lignans with purity over 97 % were isolated and identified by their UV, electrospray ionization mass spectrometry, and NMR data as (+)-pinoresinol-4,4'-di-O-β-D-glucopyranoside (1), (+)-pinoresinol-4-O-β-D-glucopyranosyl(1 → 6)-β-D-glucopyranoside (2), (+)-medioresinol-4,4'-di-O-β-D-glucopyranoside (3), (+)-syringaresinol-4,4'-di-O- β-D-glucopyranoside (4), (-)-olivil-4'-O-β-D-glucopyranoside (5), (-)-olivil-4-O-β-D- glucopyranoside (6), and (+)-pinoresinol-4-O-β-D-glucopyranoside (7). Compound 2 was first isolated from the genus Eucommia. Lignan diglucopyranosides (compounds 1-4) shower a greater inhibitory effect than lignan monoglucopyranosides (compounds 5-7). The method developed could be widely applied for high-throughput screening and preparative isolation of PDE inhibitors from natural products.

  3. Long-acting phosphodiesterase 5 inhibitor, tadalafil, and superoxide dismutase mimetic, tempol, protect against acute hypoxia-induced pulmonary hypertension in rats. (United States)

    Rashid, M; Kotwani, A; Fahim, M


    Long-acting phosphodiesterase 5 (PDE5) inhibitor, tadalafil, was recently approved for the treatment of pulmonary hypertension. Apart from being a PDE5 inhibitor, tadalafil also possesses antioxidant activity. The aim of this study was to probe whether tadalafil has any beneficial effect over tempol owing to its antioxidant action in addition to PDE5 inhibitory activity. Albino Wistar rats were pretreated with tadalafil (10 mg/kg) or vehicle 2 h before hypoxic exposure, whereas tempol (20 mg/kg) was given 5 min before induction of hypoxia. Right ventricular systolic pressure (RVSP), mean arterial pressure (MAP), heart rate (HR), right ventricular contractility (RVdP/dtmax) and cardiac output (CO) were recorded while subjecting rats to acute hypoxia for 30 min. Lipid peroxidation and reduced glutathione were estimated in serum before and after hypoxia exposure. Tadalafil as well as tempol significantly prevented hypoxia-induced rise in RVSP (p tempol pretreatment partially prevented (p tempol led to a significant fall (p tempol pretreatment completely prevented hypoxia-induced oxidative stress. Results suggest that tadalafil because of its antioxidant action in addition to PDE5 inhibitory activity is more appropriate for the prevention of hypoxic pulmonary hypertension than tempol. Tempol also produced undesirable systemic hypotension as side effect, which was not seen with tadalafil because of its pulmonary selective action.

  4. Crystal Structure of the Leishmania Major Phosphodiesterase LmjPDEB1 and Insight into the Design of hte Parasite-Selective Inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Wang,H.; Yan, Z.; Geng, J.; Kunz, S.; Seebeck, T.; Ke, H.


    Human leishmaniasis is a major public health problem in many countries, but chemotherapy is in an unsatisfactory state. Leishmania major phosphodiesterases (LmjPDEs) have been shown to play important roles in cell proliferation and apoptosis of the parasite. Thus LmjPDE inhibitors may potentially represent a novel class of drugs for the treatment of leishmaniasis. Reported here are the kinetic characterization of the LmjPDEB1 catalytic domain and its crystal structure as a complex with 3-isobutyl-1-methylxanthine (IBMX) at 1.55 Angstroms resolution. The structure of LmjPDEB1 is similar to that of human PDEs. IBMX stacks against the conserved phenylalanine and forms a hydrogen bond with the invariant glutamine, in a pattern common to most inhibitors bound to human PDEs. However, an extensive structural comparison reveals subtle, but significant differences between the active sites of LmjPDEB1 and human PDEs. In addition, a pocket next to the inhibitor binding site is found to be unique to LmjPDEB1. This pocket is isolated by two gating residues in human PDE families, but constitutes a natural expansion of the inhibitor binding pocket in LmjPDEB1. The structure particularity might be useful for the development of parasite-selective inhibitors for the treatment of leishmaniasis.

  5. Sexual Rehabilitation After Nerve-Sparing Radical Prostatectomy: Free-of-Charge Phosphodiesterase Type 5 Inhibitor Administration Improves Compliance to Treatment. (United States)

    Siena, Giampaolo; Mari, Andrea; Canale, Aude; Mondaini, Nicola; Chindemi, Andrea; Greco, Isabella; Saleh, Omar; Serni, Sergio; Nicita, Giulio; Minervini, Andrea; Carini, Marco


    In December 2006, the region of Tuscany (Italy) authorized the free-of-charge provision of phosphodiesterase type 5 inhibitors (PDE5I) for all patients with Tuscan citizenship who undergo nerve-sparing radical prostatectomy (NSRP). To compare sexual rehabilitation outcomes in patients with low risk of erectile dysfunction and minimal comorbidities who received PDE5Is free of charge (PDE5I-F) with those who paid for PDE5Is (PDE5I-P) after bilateral NSRP. We reviewed prospectively recorded clinical data of 2,368 patients with Tuscan (PDE5I-F) and non-Tuscan (PDE5I-P) citizenship treated with NSRP at 3 different institutions in Tuscany from 2008 to 2013. Inclusion criteria for the final analysis were open or robot-assisted bilateral NSRP; low risk of postoperative erectile dysfunction according to the Briganti risk stratification tool; no smoking and no drug and alcohol abuse; no cardiovascular risk factors; no major surgery before and after NSRP; no neoadjuvant or adjuvant treatment; and no biochemical relapse. Dropout was defined as an interruption longer than 40 days of the treatment protocol indicated in the inclusion criteria. Treatment compliance was defined as more than 90% consumption of the prescribed PDE5I. The Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) and the Italian version of the University of California-Los Angeles Prostate Cancer Index sexual function (UCLA-PCI-s) questionnaires were administered to assess patients' satisfaction with PDE5I treatment and sexual function. Overall, 648 patients in the PDE5I-F group and 182 in the PDE5I-P group met the inclusion criteria and were eligible for the study. Patients had comparable preoperative and surgical characteristics. The PDE5I-F group had a significantly higher early rehabilitation onset (P < .001), lower treatment dropout at 12, 24, and 36 months (P < .001 for all comparisons), and higher compliance to the treatment protocol at 6 and 12 months (P = .01 and P < .001, respectively

  6. Leptin receptor expressing neurons express phosphodiesterase-3B (PDE3B) and leptin induces STAT3 activation in PDE3B neurons in the mouse hypothalamus. (United States)

    Sahu, Maitrayee; Sahu, Abhiram


    Leptin signaling in the hypothalamus is critical for normal food intake and body weight regulation. Cumulative evidence suggests that besides the signal transducer and activator of transcription-3 (STAT3) pathway, several non-STAT3 pathways including the phosphodiesterase-3B (PDE3B) pathway mediate leptin signaling in the hypothalamus. We have shown that PDE3B is localized in various hypothalamic sites implicated in the regulation of energy homeostasis and that the anorectic and body weight reducing effects of leptin are mediated by the activation of PDE3B. It is still unknown if PDE3B is expressed in the long form of the leptin-receptor (ObRb)-expressing neurons in the hypothalamus and whether leptin induces STAT3 activation in PDE3B-expressing neurons. In this study, we examined co-localization of PDE3B with ObRb neurons in various hypothalamic nuclei in ObRb-GFP mice that were treated with leptin (5mg/kg, ip) for 2h. Results showed that most of the ObRb neurons in the arcuate nucleus (ARC, 93%), ventromedial nucleus (VMN, 94%), dorsomedial nucleus (DMN, 95%), ventral premammillary nucleus (PMv, 97%) and lateral hypothalamus (LH, 97%) co-expressed PDE3B. We next examined co-localization of p-STAT3 and PDE3B in the hypothalamus in C57BL6 mice that were treated with leptin (5mg/kg, ip) for 1h. The results showed that almost all p-STAT3 positive neurons in different hypothalamic nuclei including ARC, VMN, DMN, LH and PMv areas expressed PDE3B. These results suggest the possibility for a direct role for the PDE3B pathway in mediating leptin action in the hypothalamus. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Synthesis, 18F-Radiolabelling and Biological Characterization of Novel Fluoroalkylated Triazine Derivatives for in Vivo Imaging of Phosphodiesterase 2A in Brain via Positron Emission Tomography

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    Susann Schröder


    Full Text Available Phosphodiesterase 2A (PDE2A is highly and specifically expressed in particular brain regions that are affected by neurological disorders and in certain tumors. Development of a specific PDE2A radioligand would enable molecular imaging of the PDE2A protein via positron emission tomography (PET. Herein we report on the syntheses of three novel fluoroalkylated triazine derivatives (TA2–4 and on the evaluation of their effect on the enzymatic activity of human PDE2A. The most potent PDE2A inhibitors were 18F-radiolabelled ([18F]TA3 and [18F]TA4 and investigated regarding their potential as PET radioligands for imaging of PDE2A in mouse brain. In vitro autoradiography on rat brain displayed region-specific distribution of [18F]TA3 and [18F]TA4, which is consistent with the expression pattern of PDE2A protein. Metabolism studies of both [18F]TA3 and [18F]TA4 in mice showed a significant accumulation of two major radiometabolites of each radioligand in brain as investigated by micellar radio-chromatography. Small-animal PET/MR studies in mice using [18F]TA3 revealed a constantly increasing uptake of activity in the non-target region cerebellum, which may be caused by the accumulation of brain penetrating radiometabolites. Hence, [18F]TA3 and [18F]TA4 are exclusively suitable for in vitro investigation of PDE2A. Nevertheless, further structural modification of these promising radioligands might result in metabolically stable derivatives.

  8. Phosphodiesterase 4D (PDE4D) regulates baseline sarcoplasmic reticulum Ca2+ release and cardiac contractility, independently of L-type Ca2+current (United States)

    Simpson, Jeremy A.; Zhao, Dongling; Farman, Gerrie P.; Jones, Peter; Tian, Xixi; Wilson, Lindsay S.; Ahmad, Faiyaz; Chen, S.R. Wayne; Movsesian, Matthew A.; Manganiello, Vincent; Maurice, Donald H.; Conti, Marco; Backx, Peter H.


    Rationale Baseline contractility of mouse hearts is modulated in a PI3Kγ-dependent manner by type 4 phosphodiesterases (PDE4), which regulate cAMP levels within microdomains containing the sarcoplasmic reticular (SR) calcium-ATPase (SERCA2a). Objective To determine whether PDE4D regulates basal cAMP levels, phospholamban (PLN) phosphorylation and SERCA2a activity in SR microdomains. Methods & Results We assessed myocardial function in PDE4D-deficient (PDE4D−/−) and littermate wild-type (WT) mice at 10-12 weeks of age. Baseline cardiac contractility in PDE4D−/− mice was elevated in vivo and in Langendorff perfused hearts, while isolated PDE4D−/− cardiomyocytes showed increased Ca2+ transient amplitudes and SR Ca2+content, but unchanged ICa(L), compared to WT. The PKA inhibitor, Rp-cAMPS, lowered Ca2+ transient amplitudes and SR Ca2+ content in PDE4D−/− cardiomyocytes to WT levels. The PDE4 inhibitor rolipram (ROL) had no effect on cardiac contractility, Ca2+ transients or SR Ca2+ content in PDE4D−/− preparations but increased these parameters in WT hearts to levels indistinguishable from those in PDE4D−/−. The functional changes in PDE4D−/− myocardium were associated with increased PLN phosphorylation (pPLN) but not RyR2 receptor phosphorylation. ROL increased pPLN in WT cardiomyocytes to levels indistinguishable from those in PDE4D−/− cardiomyocytes. In murine and failing human hearts, PDE4D co-immunoprecipitated with SERCA2a but not with RyR2. Conclusions PDE4D regulates basal cAMP levels in SR microdomains through its interactions with SERCA2a-PLN. Since Ca2+ transient amplitudes are reduced in failing human myocardium, these observations may have therapeutic implications for patients with heart failure. PMID:21903937

  9. Cows are not mice: the role of cyclic AMP, phosphodiesterases, and adenosine monophosphate-activated protein kinase in the maintenance of meiotic arrest in bovine oocytes. (United States)

    Bilodeau-Goeseels, Sylvie


    Meiotic maturation in mammalian oocytes is initiated during fetal development, and is then arrested at the dictyate stage - possibly for several years. Oocyte meiosis resumes in preovulatory follicles in response to the lutenizing hormone (LH) surge or spontaneously when competent oocytes are removed from follicles and cultured. The mechanisms involved in meiotic arrest and resumption in bovine oocytes are not fully understood, and several studies point to important differences between oocytes from rodent and livestock species. This paper reviews earlier and contemporary studies on the effects of cAMP-elevating agents and phosphodiesterase (PDE) enzyme inhibitors on the maintenance of meiotic arrest in bovine oocytes in vitro. Contrary to results obtained with mouse oocytes, bovine oocyte meiosis is inhibited by activators of the energy sensor adenosine monophosphate-activated protein kinase (AMPK, mammalian gene PRKA), which is activated by AMP, the degradation product of cAMP. It is not clear whether or not the effects were due to AMPK activation, and they may depend on culture conditions. Evidence suggests that other signaling pathways (for example, the cGMP/nitric oxide pathway) are involved in bovine oocyte meiotic arrest, but further studies are needed to understand the interactions between the signaling pathways that lead to maturation promoting factor (MPF) being inactive or active. An improved understanding of the mechanisms involved in the control of bovine oocyte meiosis will facilitate better control of the process in vitro, resulting in increased developmental competence and increased efficiency of in vitro embryo production procedures. Copyright © 2011 Wiley Periodicals, Inc.

  10. The Global Online Sexuality Survey (GOSS): the United States of America in 2011 chapter II: phosphodiesterase inhibitors utilization among English speakers. (United States)

    Shaeer, Osama


    Utility of phosphodiesterase inhibitors (PDEi's) for the treatment of erectile dysfunction (ED) has been the focus of experimental and clinical studies. However, public preferences, attitudes, and experiences with PDEi's are rarely addressed from a population/epidemiology viewpoint. The Global Online Sexuality Survey (GOSS) is a worldwide epidemiologic study of sexuality and sexual disorders, first launched in the Middle East in 2010, followed by the United States in 2011. To describe the utilization rates, trends, and attitudes toward PDEi's in the United States in the year 2011. GOSS was randomly deployed to English-speaking male Web surfers in the United States via paid advertising on Facebook®, comprising 146 questions. Utilization rates and preferences for PDEi's by brand. Six hundred three subjects participated; mean age 53.43 years ± 13.9. Twenty-three point seven percent used PDEi's on more consistent basis, 37.5% of those with ED vs. 15.6% of those without ED (recreational users). Unrealistic safety concerns including habituation were pronounced. Seventy-nine point six percent of utilization was on prescription basis. PDEi's were purchased through pharmacies (5.3% without prescription) and in 16.5% over the Internet (68% without prescription). Nine point six percent nonprescription users suffered coronary heart disease. Prescription use was inclined toward sildenafil, generally, and particularly in severe cases, and shifted toward tadalafil in moderate ED and for recreational use, followed by vardenafil. Nonprescription utilization trends were similar, except in recreational use where sildenafil came first. In the United States unrealistic safety concerns over PDEi's utility exist and should be addressed. Preference for particular PDEi's over the others is primarily dictated by health-care providers, despite lack of guidelines that govern physician choice. Online and over-the-counter sales of PDEi's are common, and can expose a subset of users to health

  11. Primary role of functional ischemia, quantitative evidence for the two-hit mechanism, and phosphodiesterase-5 inhibitor therapy in mouse muscular dystrophy.

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    Akihiro Asai


    Full Text Available Duchenne Muscular Dystrophy (DMD is characterized by increased muscle damage and an abnormal blood flow after muscle contraction: the state of functional ischemia. Until now, however, the cause-effect relationship between the pathogenesis of DMD and functional ischemia was unclear. We examined (i whether functional ischemia is necessary to cause contraction-induced myofiber damage and (ii whether functional ischemia alone is sufficient to induce the damage.In vivo microscopy was used to document assays developed to measure intramuscular red blood cell flux, to quantify the amount of vasodilatory molecules produced from myofibers, and to determine the extent of myofiber damage. Reversal of functional ischemia via pharmacological manipulation prevented contraction-induced myofiber damage in mdx mice, the murine equivalent of DMD. This result indicates that functional ischemia is required for, and thus an essential cause of, muscle damage in mdx mice. Next, to determine whether functional ischemia alone is enough to explain the disease, the extent of ischemia and the amount of myofiber damage were compared both in control and mdx mice. In control mice, functional ischemia alone was found insufficient to cause a similar degree of myofiber damage observed in mdx mice. Additional mechanisms are likely contributing to cause more severe myofiber damage in mdx mice, suggestive of the existence of a "two-hit" mechanism in the pathogenesis of this disease.Evidence was provided supporting the essential role of functional ischemia in contraction-induced myofiber damage in mdx mice. Furthermore, the first quantitative evidence for the "two-hit" mechanism in this disease was documented. Significantly, the vasoactive drug tadalafil, a phosphodiesterase 5 inhibitor, administered to mdx mice ameliorated muscle damage.

  12. Phosphodiesterase-5 inhibitors for erectile dysfunction in patients with diabetes mellitus: A systematic review and meta-analysis of randomized controlled trials

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    Yatan Pal Singh Balhara


    Full Text Available Background and Aims: Patients with diabetes mellitus frequently experience erectile dysfunction. This systematic review and meta-analysis were conducted to find efficacy and tolerability of phosphodiesterase 5 (PDE5 inhibitors in patients with diabetes mellitus experiencing erectile dysfunction. Methodology: Electronic searches were carried out to identify English language peer-reviewed randomized controlled trials (RCTs, which reported clinical efficacy of any PDE5 inhibitor in patients with diabetes mellitus having erectile dysfunction. Effect sizes were computed using Cohen′s d, and I 2-test was used to assess heterogeneity. Pooled mean effect sizes were computed using random-effects model. Number needed to treat (NNT, and the adverse event rates were computed. Results: The systematic review included a total of 17 studies yielding 25 comparisons. Three studies were open RCTs while others were double-blind RCTs. The pooled mean effect size of any PDE5 inhibitor over placebo was 0.926 (95% confidence intervals [CI]: 0.864-0.987; I 2 =26.3. The pooled mean effect size for sildenafil was 1.198 (CI: 1.039-1.357; I 2 =, for tadalafil was 0.910 (CI: 0.838-0.981; I 2 =33.6, and for vardenafil was 0.678 (CI: 0.627-0.729; I 2 =. In pooled analysis, the NNT for sildenafil, tadalafil, vardenafil and any PDE5 inhibitor was 2.4, 2.6, 4.1 and 3.0 respectively. The most common side effects were headache, flushing, and nasal congestion. Conclusions: PDE5 inhibitors are effective and safe medications for the treatment of sexual dysfunction in patients with diabetes mellitus experiencing erectile dysfunction.

  13. Recreational Use of Phosphodiesterase 5 Inhibitors and Its Associated Factors among Undergraduate Male Students in an Ethiopian University: A Cross-Sectional Study

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    Eyob Alemayehu Gebreyohannes


    Full Text Available Purpose: To assess the prevalence of phosphodiesterase 5 (PDE5 inhibitor use and associated factors among University of Gondar undergraduate students. Materials and Methods: An institution-based, cross-sectional study, using a survey questionnaire, was conducted from October to December 2015 to assess PDE5 inhibitor use and associated factors among male students at the University of Gondar. A Self-Esteem and Relationship questionnaire (14 items, an International Index of Erectile Function questionnaire (15 items and a questionnaire on PDE5 inhibitor use (14 items were included in the survey. Results: Across all respondents (age, 21.9±1.88 years, more than half (55.7%, n=233 had heard about PDE5 inhibitors, but only 23 men (5.5% reported trying a PDE5 inhibitor drug at least once. Older students were more likely to use PDE5 inhibitors compared to younger students (adjusted odds ratio [AOR], 1.40; 95% confidence interval [CI], 1.109∼1.768. Those students who were smokers were 5.15 times more likely to use PDE5 inhibitors as compared to their non-smoking counterparts (AOR, 5.15; 95% CI, 2.096∼12.687. In addition, multivariate logistic regression showed that being in a relationship, alcohol use, greater number of cigarettes smoked per day, and more sexual partners were significantly associated with PDE5 inhibitor use. Conclusions: The prevalence of PDE5 inhibitor use among undergraduate students was 5.5%. Cigarette smoking and other substance use, older age, and greater number of sexual partners were significantly associated factors for PDE5 inhibitor use. These findings suggest that restricting access to PDE5 inhibitor drugs is essential to curtailing misuse among university students.

  14. Constitutively active signaling by the G protein βγ-subunit mediates intrinsically increased phosphodiesterase-4 activity in human asthmatic airway smooth muscle cells.

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    Aihua Hu

    Full Text Available Signaling by the Gβγ subunit of Gi protein, leading to downstream c-Src-induced activation of the Ras/c-Raf1/MEK-ERK1/2 signaling pathway and its upregulation of phosphodiesterase-4 (PDE4 activity, was recently shown to mediate the heightened contractility in proasthmatic sensitized isolated airway smooth muscle (ASM, as well as allergen-induced airway hyperresponsiveness and inflammation in an in vivo animal model of allergic asthma. This study investigated whether cultured human ASM (HASM cells derived from asthmatic donor lungs exhibit constitutively increased PDE activity that is attributed to intrinsically upregulated Gβγ signaling coupled to c-Src activation of the Ras/MEK/ERK1/2 cascade. We show that, relative to normal cells, asthmatic HASM cells constitutively exhibit markedly increased intrinsic PDE4 activity coupled to heightened Gβγ-regulated phosphorylation of c-Src and ERK1/2, and direct co-localization of the latter with the PDE4D isoform. These signaling events and their induction of heightened PDE activity are acutely suppressed by treating asthmatic HASM cells with a Gβγ inhibitor. Importantly, along with increased Gβγ activation, asthmatic HASM cells also exhibit constitutively increased direct binding of the small Rap1 GTPase-activating protein, Rap1GAP, to the α-subunit of Gi protein, which serves to cooperatively facilitate Ras activation and, thereby, enable enhanced Gβγ-regulated ERK1/2-stimulated PDE activity. Collectively, these data are the first to identify that intrinsically increased signaling via the Gβγ subunit, facilitated by Rap1GAP recruitment to the α-subunit, mediates the constitutively increased PDE4 activity detected in asthmatic HASM cells. These new findings support the notion that interventions targeted at suppressing Gβγ signaling may lead to novel approaches to treat asthma.

  15. Perioperative management with phosphodiesterase type 5 inhibitor and prostaglandin E1 for moderate portopulmonary hypertension following adult-to-adult living-donor liver transplantation: a case report. (United States)

    Onoe, Takashi; Tanaka, Asuka; Ishiyama, Kohei; Ide, Kentaro; Tashiro, Hirotaka; Ohdan, Hideki


    Portopulmonary hypertension (PPH) is a relatively rare but well-recognized complication of end-stage liver disease. Moderate or severe PPH (mean pulmonary artery pressure [mPAP] ≥ 35 mmHg) is usually a contraindication for liver transplantation due to high operation-related mortality. Here, we report on a patient with moderate PPH whose condition was successfully managed with a phosphodiesterase type 5 (PDE5) inhibitor (tadalafil) and prostaglandin E1, who experienced rapid improvement of PPH after living-donor liver transplantation (LDLT). A 63-year-old woman with alcoholic decompensated cirrhosis was referred to our hospital for LDLT. She had mild dyspnea on exertion as well as fatigue. Echocardiography and subsequent cardiac catheterization revealed a high mPAP (35 mmHg), and she was diagnosed with moderate PPH. We commenced treatment with oral tadalafil for the PPH. A second preoperative echocardiography demonstrated improved PPH, and she underwent LDLT. An intravenous infusion of prostaglandin E1 was introduced instead of tadalafil during and after the operation. The mPAP value showed a rapid decrease in mPAP value to 22 mmHg in 2 days. After discontinuation of the prostaglandin E1, the mPAP value remained 23 mmHg. Postoperative catheterization 2 months after LDLT showed no exacerbation of PPH. She was discharged on foot 70 days after LDLT in good condition and has shown a good clinical condition more than 2 years after LDLT. LDLT could be a radical treatment for PPH with careful management and adequate patient selection. PDE5 inhibitor and PGE1 is effective and feasible for perioperative management of the patient with moderate portopulmonary hypertension in LDLT.

  16. Reduction of alcohol drinking of alcohol-preferring (P) and high-alcohol drinking (HAD1) rats by targeting phosphodiesterase-4 (PDE4). (United States)

    Franklin, Kelle M; Hauser, Sheketha R; Lasek, Amy W; McClintick, Jeanette; Ding, Zheng-Ming; McBride, William J; Bell, Richard L


    Phosphodiesterase-4 (PDE4) and neuroimmune signaling have been posited to regulate alcohol drinking. This study evaluated the involvement of PDE4 and Il22ra2 on ethanol (EtOH) intake by alcohol-preferring (P) and high-alcohol-drinking (HAD1) rats. Exp 1 determined the dose-response effects of PDE4 inhibitors, rolipram, and Ro 20-1724, on 2 h/day free-choice EtOH intake by adult P and HAD1 rats. Exps 2-3 examined the effects of repeated administration with the PDE4 inhibitors on EtOH or sucrose intake and locomotor behavior. Exp 4 determined Pde4-associated gene expression differences in subregions of the extended amygdala, between high- and low-alcohol-consuming rat lines. Exp 5 evaluated the effects of infusing short hairpin RNA to knock down Il22ra2 in the nucleus accumbens (NAc) shell on a 24-h free-choice EtOH drinking by P rats. Administration of rolipram or Ro 20-1724 reduced EtOH intake by P rats; Ro 20-1724 reduced EtOH intake by HAD1 rats. Repeated rolipram or Ro 20-1724 exposure reduced EtOH intake by P and HAD1 rats. PDE4 inhibition induced motor impairment during the first hour of EtOH intake by P rats. Higher gene expression levels for PDE4A were found in the NAc shell of P vs NP rats. ShRNAs targeting Il22ra2 in the NAc shell significantly reduced chronic EtOH intake. PDE4 and neuroinflammatory/immune signaling pathways could represent molecular targets for the treatment of alcohol use disorders in genetically predisposed subjects. This study underscores the importance of testing compounds over multiple days and rat lines when determining efficacy to disrupt excessive alcohol intake.

  17. Phosphodiesterase inhibition mediates matrix metalloproteinase activity and the level of collagen degradation fragments in a liver fibrosis ex vivo rat model

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    Veidal Sanne Skovgård


    Full Text Available Abstract Background Accumulation of extracellular matrix (ECM and increased matrix metalloproteinase (MMP activity are hallmarks of liver fibrosis. The aim of the present study was to develop a model of liver fibrosis combining ex vivo tissue culture of livers from CCl4 treated animals with an ELISA detecting a fragment of type III collagen generated in vitro by MMP-9 (C3M, known to be associated with liver fibrosis and to investigate cAMP modulation of MMP activity and liver tissue turnover in this model. Findings In vivo: Rats were treated for 8 weeks with CCl4/Intralipid. Liver slices were cultured for 48 hours. Levels of C3M were determined in the supernatants of slices cultured without treatment, treated with GM6001 (positive control or treated with IBMX (phosphodiesterase inhibitor. Enzymatic activity of MMP-2 and MMP-9 were studied by gelatin zymography. Ex vivo: The levels of serum C3M increased 77% in the CCl4-treated rats at week 8 (p 4-treated animals had highly increased MMP-9, but not MMP-2 activity, compared to slices derived from control animals. Conclusions We have combined an ex vivo model of liver fibrosis with measurement of a biochemical marker of collagen degradation in the condition medium. This technology may be used to evaluate the molecular process leading to structural fibrotic changes, as collagen species are the predominant structural part of fibrosis. These data suggest that modulation of cAMP may play a role in regulation of collagen degradation associated with liver fibrosis.

  18. Analysis of Pseudomonas aeruginosa diguanylate cyclases and phosphodiesterases reveals a role for bis-(3′-5′)-cyclic-GMP in virulence (United States)

    Kulesekara, Hemantha; Lee, Vincent; Brencic, Anja; Liberati, Nicole; Urbach, Jonathan; Miyata, Sachiko; Lee, Daniel G.; Neely, Alice N.; Hyodo, Mamoru; Hayakawa, Yoshihiro; Ausubel, Frederick M.; Lory, Stephen


    The opportunistic pathogen Pseudomonas aeruginosa is responsible for systemic infections in immunocompromised individuals and chronic respiratory disease in patients with cystic fibrosis. Cyclic nucleotides are known to play a variety of roles in the regulation of virulence-related factors in pathogenic bacteria. A set of P. aeruginosa genes, encoding proteins that contain putative domains characteristic of diguanylate cyclases (DGCs) and phosphodiesterases (PDEs) that are responsible for the maintenance of cellular levels of the second messenger bis-(3′-5′)-cyclic dimeric GMP (c-di-GMP) was identified in the annotated genomes of P. aeruginosa strains PAO1 and PA14. Although the majority of these genes are components of the P. aeruginosa core genome, several are located on presumptive horizontally acquired genomic islands. A comprehensive analysis of P. aeruginosa genes encoding the enzymes of c-di-GMP metabolism (DGC- and PDE-encoding genes) was carried out to analyze the function of c-di-GMP in two disease-related phenomena, cytotoxicity and biofilm formation. Analysis of the phenotypes of DGC and PDE mutants and overexpressing clones revealed that certain virulence-associated traits are controlled by multiple DGCs and PDEs through alterations in c-di-GMP levels. A set of mutants in selected DGC- and PDE-encoding genes exhibited attenuated virulence in a mouse infection model. Given that insertions in different DGC and PDE genes result in distinct phenotypes, it seems likely that the formation or degradation of c-di-GMP by these enzymes is in highly localized and intimately linked to particular targets of c-di-GMP action. PMID:16477007

  19. Antenatal Maternally-Administered Phosphodiesterase Type 5 Inhibitors Normalize eNOS Expression in the Fetal Lamb Model of Congenital Diaphragmatic Hernia (United States)

    Shue, Eveline H; Schecter, Samuel C.; Gong, Wenhui; Etemadi, Mozziyar; Johengen, Michael; Iqbal, Corey; Derderian, S. Christopher; Oishi, Peter; Fineman, Jeffrey R.; Miniati, Doug


    Purpose Pulmonary hypertension (pHTN), a main determinant of survival in congenital diaphragmatic hernia (CDH), results from in utero vascular remodeling. Phosphodiesterase type 5 (PDE5) inhibitors have never been used antenatally to treat pHTN. The purpose of this study is to determine if antenatal PDE5 inhibitors can prevent pHTN in the fetal lamb model of CDH. Methods CDH were created in pregnant ewes. Postoperatively, pregnant ewes received oral placebo or tadalafil, a PDE5 inhibitor, until delivery. Near term gestation, lambs underwent resuscitations, and lung tissue was snap frozen for protein analysis. Results Mean cGMP levels were 0.53±0.11 in placebo-treated fetal lambs and 1.73±0.21 in tadalafil-treated fetal lambs (p=0.002). Normalized expression of eNOS was 82±12% in Normal-Placebo, 61±5% in CDH-Placebo, 116±6% in Normal-Tadalafil, and 86±8% in CDH-Tadalafil lambs. Normalized expression of β-sGC was 105±15% in Normal-Placebo, 82±3% in CDH-Placebo, 158±16% in Normal-Tadalafil, and 86±8% in CDH-Tadalafil lambs. Endothelial NOS and β-sGC were significantly decreased in CDH (p = 0.0007 and 0.01 for eNOS and β-sGC, respectively), and tadalafil significantly increased eNOS expression (p = 0.0002). Conclusions PDE5 inhibitors can cross the placental barrier. β-sGC and eNOS are downregulated in fetal lambs with CDH. Antenatal PDE5 inhibitors normalize eNOS and may prevent in utero vascular remodeling in CDH. PMID:24439578

  20. Expression, immunolocalization, and serological reactivity of a novel sphingomyelin phosphodiesterase-like protein, an excretory/secretory antigen from Clonorchis sinensis. (United States)

    Huang, Yanwei; Zheng, Youwei; Li, Yuzhe; Yang, Mei; Li, Ting; Zeng, Suxiang; Yu, Xinbing; Huang, Huaiqiu; Hu, Xuchu


    Clonorchiasis, caused by Clonorchis sinensis infection, is a zoonotic parasitic disease of hepatobiliary system in which the proteins released by adult are major pathogenetic factors. In this study, we first characterized a putative sphingomyelin phosphodiesterase (CsSMPase) A-like secretory protein, which was highly expressed in the adult worm. The full-length gene was cloned. The putative protein is of relatively low homology comparing with SMPase from other species, and of rich T cell and B cell epitopes, suggesting that it is an antigen of strong antigenicity. The complete coding sequence of the gene was expressed in the Escherichia coli. The recombinant CsSMPase (rCsSMPase) can be recognized by C. sinensis-infected serum, and the protein immunoserum can recognize a specific band in excretory/secretory products (ESPs) of C. sinensis adult by western blotting. Immunolocalization revealed that CsSMPase was not only localized on tegument, ventral sucker of metacercaria, and the intestine of adult but also on the nearby epithelium of bile duct of the infected Sprague-Dawley rats, implying that CsSMPase was mainly secreted and excreted through adult intestine and directly interacted with bile duct epithelium. Although immunized rats evoked high level antibody response, the antigen level was low in clonorchiasis patients. And the sensitivity and specificity of rCsSMPase were 50.0 % (12/24) and 88.4 % (61/69), in sera IgG-ELISA, respectively. It is likely due to the fact that CsSMPase binding to the plasma membrane of biliary epithelium decreases the antigen immune stimulation.

  1. OPA-15406, a novel, topical, nonsteroidal, selective phosphodiesterase-4 (PDE4) inhibitor, in the treatment of adult and adolescent patients with mild to moderate atopic dermatitis (AD): A phase-II randomized, double-blind, placebo-controlled study. (United States)

    Hanifin, Jon M; Ellis, Charles N; Frieden, Ilona J; Fölster-Holst, Regina; Stein Gold, Linda F; Secci, Angelo; Smith, Angela J; Zhao, Cathy; Kornyeyeva, Elena; Eichenfield, Lawrence F


    Peripheral leukocytes in patients with atopic dermatitis (AD) have elevated phosphodiesterase-4 activity, which is associated with production of proinflammatory mediators. OPA-15406 is a phosphodiesterase-4 inhibitor with high selectivity for phosphodiesterase-4-B. We sought to assess effectiveness and tolerability of topical OPA-15406 in patients with AD. This was a randomized, double-blind, vehicle-controlled, phase-II study. Patients 10 to 70 years of age with mild or moderate AD received topical OPA-15406 0.3% (n = 41), OPA-15406 1% (n = 43), or vehicle (n = 37) twice daily for 8 weeks. The primary end point, Investigator Global Assessment of Disease Severity score of 0 or 1 with greater than or equal to 2-grade reduction, was met at week 4 in the OPA-15406 1% group (P = .0165 vs vehicle). Mean percentage improvement from baseline Eczema Area and Severity Index score for OPA-15406 1% was notable in week 1 (31.4% vs 6.0% for vehicle; P = .0005), even larger in week 2 (39.0% vs 3.0%; P = .0001), and persisted for 8 weeks. Visual analog scale pruritus scores improved from moderate to mild within the first week in the OPA-15406 1% group (36.4% mean change; P = .0011). OPA-15406 levels in blood were negligible. Incidence of adverse events was low, with most events mild in intensity. Further confirmatory phase-III studies are required. OPA-15406 ointment may provide an effective therapeutic modality for patients with mild to moderate AD. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  2. Phosphodiesterase-3B-cAMP pathway of leptin signalling in the hypothalamus is impaired during the development of diet-induced obesity in FVB/N mice. (United States)

    Sahu, M; Anamthathmakula, P; Sahu, A


    The phosphodiesterase-3B (PDE3B)-cAMP pathway plays an important role in transducing the action of leptin in the hypothalamus. Obesity is usually associated with hyperleptinaemia and resistance to anorectic and body weight-reducing effects of leptin. To determine whether the hypothalamic PDE3B-cAMP pathway of leptin signalling is impaired during the development of diet-induced obesity (DIO), we fed male FVB/N mice a high-fat diet (HFD: 58% kcal as fat) or low-fat diet (LFD: 6% kcal as fat) for 4 weeks. HFD fed mice developed DIO in association with hyperphagia, hyperleptinaemia and hyperinsulinaemia. Leptin (i.p.) significantly increased hypothalamic PDE3B activity and phosphorylated (p)-Akt levels in LFD-fed but not in HFD-fed mice. However, basal p-Akt levels in hypothalamus were increased in DIO mice. Additionally, amongst six-microdissected brain nuclei examined, leptin selectively decreased cAMP levels in the arcuate nucleus (ARC) of LFD-fed mice but failed to do so in HFD-fed mice. We next tested whether both the PBE3B and Akt pathways of leptin signalling remained impaired in DIO mice on the HFD for 12 weeks (long-term). DIO mice were hyperinsulinaemic and hyperleptinaemic in association with impaired glucose and insulin tolerance. Although, in LFD-fed mice, leptin significantly increased PDE3B activity and p-Akt levels in the hypothalamus, it failed to do so in HFD-fed mice. Also, basal p-Akt levels in the hypothalamus were increased in DIO mice and leptin had no further effect. Similarly, immunocytochemistry showed that leptin increased the number of p-Akt-positive cells in the ARC of LFD-fed but not in HFD-fed mice, and there was an increased basal number of p-Akt positive cells in the ARC of DIO mice. These results suggest that the PDE3B-cAMP- and Akt-pathways of leptin signalling in the hypothalamus are impaired during the development of DIO. Thus, a defect in the regulation by leptin of the hypothalamic PDE3B-cAMP pathway and Akt signalling may be one

  3. Unfractionated and Low-Molecular-Weight Heparin and the Phosphodiesterase Inhibitors, IBMX and Cilostazol, BlockEx VivoEquid Herpesvirus Type-1-Induced Platelet Activation. (United States)

    Stokol, Tracy; Serpa, Priscila Beatriz da Silva; Zahid, Muhammad N; Brooks, Marjory B


    Equid herpes virus type-1 (EHV-1) is a major pathogen of horses, causing abortion storms and outbreaks of herpes virus myeloencephalopathy. These clinical syndromes are partly attributed to ischemic injury from thrombosis in placental and spinal vessels. The mechanism of thrombosis in affected horses is unknown. We have previously shown that EHV-1 activates platelets through virus-associated tissue factor-initiated thrombin generation. Activated platelets participate in thrombus formation by providing a surface to localize coagulation factor complexes that amplify and propagate thrombin generation. We hypothesized that coagulation inhibitors that suppress thrombin generation (heparins) or platelet inhibitors that impede post-receptor thrombin signaling [phosphodiesterase (PDE) antagonists] would inhibit EHV-1-induced platelet activation ex vivo . We exposed platelet-rich plasma (PRP) collected from healthy horses to the RacL11 abortigenic and Ab4 neuropathogenic strains of EHV-1 at 1 plaque-forming unit/cell in the presence or absence of unfractionated heparin (UFH), low-molecular-weight heparin (LMWH) or the PDE inhibitors, 3-isobutyl-1methylxanthine (IBMX), and cilostazol. We assessed platelet activation status in flow cytometric assays by measuring P-selectin expression. We found that all of the inhibitors blocked EHV-1- and thrombin-induced platelet activation in a dose-dependent manner. Platelet activation in PRP was maximally inhibited at concentrations of 0.05 U/mL UFH and 2.5 μg/mL LMWH. These concentrations represented 0.1-0.2 U/mL anti-factor Xa activity measured in chromogenic assays. Both IBMX and cilostazol showed maximal inhibition of platelet activation at the highest tested concentration of 50 μM, but inhibition was lower than that seen with UFH and LMWH. Our results indicate that heparin anticoagulants and strong non-selective (IBMX) or isoenzyme-3 selective (cilostazol) PDE antagonists inhibit ex vivo EHV-1-induced platelet activation

  4. Unfractionated and low-molecular-weight heparin and the phosphodiesterase inhibitors, IBMX and cilostazol, block ex vivo Equid Herpesvirus type-1-induced platelet activation

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    Tracy Stokol


    Full Text Available Equid herpes virus type-1 (EHV-1 is a major pathogen of horses, causing abortion storms and outbreaks of herpes virus myeloencephalopathy. These clinical syndromes are partly attributed to ischemic injury from thrombosis in placental and spinal vessels. The mechanism of thrombosis in affected horses is unknown. We have previously shown that EHV-1 activates platelets through virus-associated tissue factor-initiated thrombin generation. Activated platelets participate in thrombus formation by providing a surface to localize coagulation factor complexes that amplify and propagate thrombin generation. We hypothesized that coagulation inhibitors that suppress thrombin generation (heparins or platelet inhibitors that impede post-receptor thrombin signaling (phosphodiesterase [PDE] antagonists would inhibit EHV-1-induced platelet activation ex vivo. We exposed platelet-rich plasma collected from healthy horses to the RacL11 abortigenic and Ab4 neuropathogenic strains of EHV-1 at 1 plaque forming unit/cell in the presence or absence of unfractionated heparin (UFH, low-molecular-weight (LMWH heparin or the PDE inhibitors, 3-isobutyl-1methylxanthine (IBMX and cilostazol. We assessed platelet activation status in flow cytometric assays by measuring P-selectin expression. We found that all of the inhibitors blocked EHV-1- and thrombin-induced platelet activation in a dose-dependent manner. Platelet activation in PRP was maximally inhibited at concentrations of 0.05 U/mL UFH and 2.5 μg/mL LMWH. These concentrations represented 0.1 to 0.2 U/mL anti-Factor Xa activity measured in chromogenic assays. Both IBMX and cilostazol showed maximal inhibition of platelet activation at the highest tested concentration of 50 μM but inhibition was lower than that seen with UFH and LMWH. Our results indicate that heparin anticoagulants and strong non-selective (IBMX or isoenzyme-3 selective (cilostazol PDE antagonists inhibit ex vivo EHV-1-induced platelet activation

  5. Characterization of [{sup 11}C]Lu AE92686 as a PET radioligand for phosphodiesterase 10A in the nonhuman primate brain

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Kai-Chun; Stepanov, Vladimir; Amini, Nahid; Martinsson, Stefan; Takano, Akihiro; Halldin, Christer [Karolinska Institutet, Karolinska University Hospital, Department of Clinical Neuroscience, Center for Psychiatric Research, Stockholm (Sweden); Nielsen, Jacob [H. Lundbeck A/S, Synaptic Transmission, Valby (Denmark); Bundgaard, Christoffer; Bang-Andersen, Benny [H. Lundbeck A/S, Discovery Chemistry and DMPK, Valby (Denmark); Grimwood, Sarah [Pfizer Inc., Neuroscience and Pain Research Unit, Cambridge, MA (United States); Farde, Lars [Karolinska Institutet, Karolinska University Hospital, Department of Clinical Neuroscience, Center for Psychiatric Research, Stockholm (Sweden); AstraZeneca PET Science Center at Karolinska Institutet, Personalized Health Care and Biomarkers, Stockholm (Sweden); Finnema, Sjoerd J. [Karolinska Institutet, Karolinska University Hospital, Department of Clinical Neuroscience, Center for Psychiatric Research, Stockholm (Sweden); Yale University, Department of Radiology and Biomedical Imaging, New Haven, CT (United States)


    [{sup 11}C]Lu AE92686 is a positron emission tomography (PET) radioligand that has recently been validated for examining phosphodiesterase 10A (PDE10A) in the human striatum. [{sup 11}C]Lu AE92686 has high affinity for PDE10A (IC{sub 50} = 0.39 nM) and may also be suitable for examination of the substantia nigra, a region with low density of PDE10A. Here, we report characterization of regional [{sup 11}C]Lu AE92686 binding to PDE10A in the nonhuman primate (NHP) brain. A total of 11 PET measurements, seven baseline and four following pretreatment with unlabeled Lu AE92686 or the structurally unrelated PDE10A inhibitor MP-10, were performed in five NHPs using a high resolution research tomograph (HRRT). [{sup 11}C]Lu AE92686 binding was quantified using a radiometabolite-corrected arterial input function and compartmental and graphical modeling approaches. Regional time-activity curves were best described with the two-tissue compartment model (2TCM). However, the distribution volume (V{sub T}) values for all regions were obtained by the Logan plot analysis, as reliable cerebellar V{sub T} values could not be derived by the 2TCM. For cerebellum, a proposed reference region, V{sub T} values increased by ∝30 % with increasing PET measurement duration from 63 to 123 min, while V{sub T} values in target regions remained stable. Both pretreatment drugs significantly decreased [{sup 11}C]Lu AE92686 binding in target regions, while no significant effect on cerebellum was observed. Binding potential (BP{sub ND}) values, derived with the simplified reference tissue model (SRTM), were 13-17 in putamen and 3-5 in substantia nigra and correlated well to values from the Logan plot analysis. The method proposed for quantification of [{sup 11}C]Lu AE92686 binding in applied studies in NHP is based on 63 min PET data and SRTM with cerebellum as a reference region. The study supports that [{sup 11}C]Lu AE92686 can be used for PET examinations of PDE10A binding also in substantia

  6. Treatment satisfaction among men with concurrent benign prostatic hyperplasia and erectile dysfunction treated with tadalafil or other phosphodiesterase type-5 inhibitor combinations

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    Lee LK


    Full Text Available Lulu K Lee,1 Amir Goren,1 Natalie N Boytsov,2 Craig F Donatucci,2 Kevin T McVary3 1Health Outcomes Practice, Kantar Health, New York, NY, 2US Real World Outcomes Research, Eli Lily & Company, Indianapolis, IN, 3Division of Urology, Southern Illinois University School of Medicine, Springfield, IL, USA Objective: Erectile dysfunction (ED and benign prostatic hyperplasia (BPH frequently co-occur in men aged ≥40, along with lower urinary tract symptoms (LUTS secondary to BPH. Given little real-world evidence on treatment use or satisfaction with treatment for concurrent BPH/LUTS and/or ED, this study examined medication regimens and differences in satisfaction and health-related quality of life (HRQoL across regimens among men with concurrent BPH and ED. Methods: A cross-sectional study was conducted using an Internet survey of participants recruited through an online panel. Respondents (N=736 included men (aged ≥40 who self-reported a diagnosis of both ED and BPH with prescription treatment in the past 3 months for both conditions. Treatment satisfaction (eg, convenience and ease of planning and HRQoL (eg, International Prostate Symptom Score, sleep quality were self-reported. Generalized linear models examined the association of regimen with treatment satisfaction and HRQoL, adjusting for covariates (eg, age and comorbidities. Results: Final analyses included participants (N=507 using: tadalafil once-daily monotherapy (22%, tadalafil for ED with an alternate BPH therapy (36%, or another phosphodiesterase type-5 inhibitor (PDE5-I combination (41%. These groups represented the major categories of treatment regimens found in the sample, excluded participants with ambiguous regimens, and were aligned with current standard of care for BPH and ED. Overall, patients reported moderate levels of BPH and a moderate-to-severe degree of ED. Tadalafil monotherapy patients had higher treatment satisfaction scores and greater reported ease of treatment

  7. Inhibition of Phosphodiesterase 4 by FCPR03 Alleviates Lipopolysaccharide-Induced Depressive-Like Behaviors in Mice: Involvement of p38 and JNK Signaling Pathways

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    Hui Yu


    Full Text Available Inflammatory responses induced by peripheral administration of lipopolysaccharide (LPS triggers depressive-like behavioral syndrome in rodents. Inhibition of phosphodiesterase 4 (PDE4 produces a robust anti-inflammatory effect in inflammatory cells. Unfortunately, archetypal PDE4 inhibitors cause intolerable gastrointestinal side-effects, such as vomiting and nausea. N-isopropyl-3-(cyclopropylmethoxy-4-difluoromethoxy benzamide (FCPR03 is a novel, selective PDE4 inhibitor with little, or no, emetic potency. Our previous studies show that FCPR03 is effective in attenuating neuroinflammation in mice treated with LPS. However, whether FCPR03 could exert antidepressant-like effect induced by LPS is largely unknown. In the present study, mice injected intraperitoneally (i.p. with LPS was established as an in vivo animal model of depression. The antidepressant-like activities of FCPR03 were evaluated using a tail suspension test, forced swimming test, and sucrose preference test. We demonstrated that administration of FCPR03 (1 mg/kg produced antidepressant-like effects in mice challenged by LPS, as evidenced by decreases in the duration of immobility in the forced swim and tail suspension tests, while no significant changes in locomotor activity were observed. FCPR03 also increased sucrose preference in mice treated with LPS. In addition, treatment with FCPR03 abolished the downregulation of brain-derived neurotrophic factor induced by LPS and decreased the level of corticosterone in plasma. Meanwhile, periphery immune challenge by LPS induced enhanced phosphorylation of p38-mitogen activated protein kinase (p38 and c-Jun N-terminal kinase (JNK in both the cerebral cortex and hippocampus in mice. Interestingly, treatment with FCPR03 significantly blocked the role of LPS and reduced the levels of phosphorylated p38 and JNK. Collectively, these results indicate that FCPR03 shows antidepressant-like effects in mice challenged by LPS, and the p38/JNK

  8. Inhibition of the striatal specific phosphodiesterase PDE10A ameliorates striatal and cortical pathology in R6/2 mouse model of Huntington's disease.

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    Carmela Giampà


    Full Text Available Huntington's disease is a devastating neurodegenerative condition for which there is no therapy to slow disease progression. The particular vulnerability of striatal medium spiny neurons to Huntington's pathology is hypothesized to result from transcriptional dysregulation within the cAMP and CREB signaling cascades in these neurons. To test this hypothesis, and a potential therapeutic approach, we investigated whether inhibition of the striatal-specific cyclic nucleotide phosphodiesterase PDE10A would alleviate neurological deficits and brain pathology in a highly utilized model system, the R6/2 mouse.R6/2 mice were treated with the highly selective PDE10A inhibitor TP-10 from 4 weeks of age until euthanasia. TP-10 treatment significantly reduced and delayed the development of the hind paw clasping response during tail suspension, deficits in rotarod performance, and decrease in locomotor activity in an open field. Treatment prolonged time to loss of righting reflex. These effects of PDE10A inhibition on neurological function were reflected in a significant amelioration in brain pathology, including reduction in striatal and cortical cell loss, the formation of striatal neuronal intranuclear inclusions, and the degree of microglial activation that occurs in response to the mutant huntingtin-induced brain damage. Striatal and cortical levels of phosphorylated CREB and BDNF were significantly elevated.Our findings provide experimental support for targeting the cAMP and CREB signaling pathways and more broadly transcriptional dysregulation as a therapeutic approach to Huntington's disease. It is noteworthy that PDE10A inhibition in the R6/2 mice reduces striatal pathology, consistent with the localization of the enzyme in medium spiny neurons, and also cortical pathology and the formation of neuronal nuclear inclusions. These latter findings suggest that striatal pathology may be a primary driver of these secondary pathological events. More

  9. A review of analytical methods for the determination of four new phosphodiesterase type 5 inhibitors in biological samples and pharmaceutical preparations

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    Cristiane Franco Codevilla


    Full Text Available The introduction of oral phosphodiesterase type 5 inhibitor therapy in 1998 revolutionized the treatment of erectile dysfunction. Erectile dysfunction is the most common sexual problem in men. It often has a profound effect on intimate relationships and quality of life. The analysis of pharmaceuticals is an important part of the drug development process as well as for routine analysis and quality control of commercial formulations. Whereas the determination of sildenafil citrate, vardenafil and tadalafil are well documented by a variety of methods, there are few publications about the determination of udenafil, lodenafil carbonate, mirodenafil and avanafil. The paper presents a brief review of the action mechanism, adverse effects, pharmacokinetics and the most recent analytical methods that can determine drug concentration in biological matrices and pharmaceutical formulations of these four drugs.A introdução da terapia oral com inibidores da fosfodiesterase tipo 5, em 1998, revolucionou o tratamento da disfunção erétil. A disfunção erétil é o problema sexual mais comum em homens. Muitas vezes tem um efeito profundo nas relações íntimas e na qualidade de vida. A análise de produtos farmacêuticos é uma parte importante do processo de desenvolvimento de fármacos, bem como para a análise de rotina e controle de qualidade das formulações comerciais. Enquanto a determinação do citrato de sildenafila, vardenafila e tadalafila está bem documentada por uma variedade de métodos, existem poucas publicações sobre a determinação de udenafila, carbonato de lodenafila, mirodenafila e avanafila. O artigo apresenta uma breve revisão do mecanismo de ação, efeitos adversos, farmacocinética e os mais recentes métodos analíticos, que podem determinar a concentração do fármaco em matrizes biológicas e formulações farmacêuticas destes quatro fármacos.

  10. Phosphodiesterase profile of human B lymphocytes from normal and atopic donors and the effects of PDE inhibition on B cell proliferation (United States)

    Gantner, Florian; Götz, Christine; Gekeler, Volker; Schudt, Christian; Wendel, Albrecht; Hatzelmann, Armin


    CD19+ B lymphocytes were purified from the peripheral blood of normal and atopic subjects to analyse and compare the phosphodiesterase (PDE) activity profile, PDE mRNA expression and the importance of PDE activity for the regulation of B cell function.The majority of cyclic AMP hydrolyzing activity of human B cells was cytosolic PDE4, followed by cytosolic PDE7-like activity; marginal PDE3 activity was found only in the particulate B cell fraction. PDE1, PDE2 and PDE5 activities were not detected.By cDNA-PCR analysis mRNA of the PDE4 subtypes A, B (splice variant PDE4B2) and D were detected. In addition, a weak signal for PDE3A was found.No differences in PDE activities or mRNA expression of PDE subtypes were found in B cells from either normal or atopic subjects.Stimulation of B lymphocytes with the polyclonal stimulus lipopolysaccharide (LPS) induced a proliferative response in a time- and concentration-dependent manner, which was increased in the presence of interleukin-4 (IL-4). PDE4 inhibitors (rolipram, piclamilast) led to an increase in the cellular cyclic AMP concentration and to an augmentation of proliferation, whereas a PDE3 inhibitor (motapizone) was ineffective, which is in accordance with the PDE profile found. The proliferation enhancing effect of the PDE4 inhibitors was partly mimicked by the cyclic AMP analogues dibutyryl (db) cyclic AMP and 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole-3′,5′-cyclic monophosphorothioate, Sp-isomer (dcl-cBIMPS), respectively. However, at concentrations exceeding 100 μM db-cyclic AMP suppressed B lymphocyte proliferation, probably as a result of cytotoxicity. Prostaglandin E2 (PGE2, 1 μM) and forskolin (10 μM) did not affect B cell proliferation, even when given in combination with rolipram.Inhibition of protein kinase A (PKA) by differentially acting selective inhibitors (KT 5720, Rp-8-Br-cyclic AMPS) decreased the proliferative response of control cells and reversed the proliferation enhancing effects

  11. Phosphodiesterases in the rat ovary

    DEFF Research Database (Denmark)

    Petersen, Tonny Studsgaard; Stahlhut, Martin; Andersen, Claus Yding


    that augmented cAMP levels stimulate primordial follicle growth. The present study examined the gene expression, enzyme activity and immunolocalization of the different cAMP hydrolysing PDEs families in the rat ovary. Further, the effect of PDE4 inhibition on primordial follicle activation in cultured neonatal...... rat ovaries was also evaluated. We found varied expression of all eight families in the ovary with Pde7b and Pde8a having the highest expression each accounting for more than 20% of the total PDE mRNA. PDE4 accounted for 15-26% of the total PDE activity. Immunoreactive PDE11A was found in the oocytes...... and PDE2A in the corpora lutea. Incubating neonatal rat ovaries with PDE4 inhibitors did not increase primordial follicle activation or change the expression of the developing follicle markers Gdf9, Amh, Inha, the proliferation marker Mki67 or the primordial follicle marker Tmeff2. In addition, the c...

  12. Peripheral phosphodiesterase 4 inhibition produced by 4-[2-(3,4-Bis-difluoromethoxyphenyl)-2-[4-(1,1,1,3,3,3-hexafluoro-2-hydroxypropan-2-yl)-phenyl]-ethyl]-3-methylpyridine-1-oxide (L-826,141) prevents experimental autoimmune encephalomyelitis

    DEFF Research Database (Denmark)

    Moore, Craig S.; Earl, Nathalie; Frenette, Richard


    Administration of phosphodiesterase 4 (PDE4) inhibitors suppresses the pathogenesis associated with experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). In the present study, we compared the effects of rolipram and 4-[2-(3,4-bis-difluoromethoxyphenyl)-2...

  13. A Pterin-Dependent Signaling Pathway Regulates a Dual-Function Diguanylate Cyclase-Phosphodiesterase Controlling Surface Attachment in Agrobacterium tumefaciens. (United States)

    Feirer, Nathan; Xu, Jing; Allen, Kylie D; Koestler, Benjamin J; Bruger, Eric L; Waters, Christopher M; White, Robert H; Fuqua, Clay


    The motile-to-sessile transition is an important lifestyle switch in diverse bacteria and is often regulated by the intracellular second messenger cyclic diguanylate monophosphate (c-di-GMP). In general, high c-di-GMP concentrations promote attachment to surfaces, whereas cells with low levels of signal remain motile. In the plant pathogen Agrobacterium tumefaciens, c-di-GMP controls attachment and biofilm formation via regulation of a unipolar polysaccharide (UPP) adhesin. The levels of c-di-GMP in A. tumefaciens are controlled in part by the dual-function diguanylate cyclase-phosphodiesterase (DGC-PDE) protein DcpA. In this study, we report that DcpA possesses both c-di-GMP synthesizing and degrading activities in heterologous and native genetic backgrounds, a binary capability that is unusual among GGDEF-EAL domain-containing proteins. DcpA activity is modulated by a pteridine reductase called PruA, with DcpA acting as a PDE in the presence of PruA and a DGC in its absence. PruA enzymatic activity is required for the control of DcpA and through this control, attachment and biofilm formation. Intracellular pterin analysis demonstrates that PruA is responsible for the production of a novel pterin species. In addition, the control of DcpA activity also requires PruR, a protein encoded directly upstream of DcpA with a predicted molybdopterin-binding domain. PruR is hypothesized to be a potential signaling intermediate between PruA and DcpA through an as-yet-unidentified mechanism. This study provides the first prokaryotic example of a pterin-mediated signaling pathway and a new model for the regulation of dual-function DGC-PDE proteins. Pathogenic bacteria often attach to surfaces and form multicellular communities called biofilms. Biofilms are inherently resilient and can be difficult to treat, resisting common antimicrobials. Understanding how bacterial cells transition to the biofilm lifestyle is essential in developing new therapeutic strategies. We have

  14. Early decrease of type 1 cannabinoid receptor binding and phosphodiesterase 10A activity in vivo in R6/2 Huntington mice. (United States)

    Ooms, Maarten; Rietjens, Roma; Rangarajan, Janaki Raman; Vunckx, Kathleen; Valdeolivas, Sara; Maes, Frederik; Himmelreich, Uwe; Fernandez-Ruiz, Javier; Bormans, Guy; Van Laere, Koen; Casteels, Cindy


    Several lines of evidence imply early alterations in endocannabinoid and phosphodiesterase 10A (PDE10A) signaling in Huntington disease (HD). Using [(18)F]MK-9470 and [(18)F]JNJ42259152 small-animal positron emission tomography (PET), we investigated for the first time cerebral changes in type 1 cannabinoid (CB1) receptor binding and PDE10A levels in vivo in presymptomatic, early symptomatic, and late symptomatic HD (R6/2) mice, in relation to glucose metabolism ([(18)F]FDG PET), brain morphology (magnetic resonance imaging) and motor function. Ten R6/2 and 16 wild-type (WT) mice were investigated at 3 different time points between the age of 4 and 13 weeks. Parametric CB1 receptor and PDE10A images were anatomically standardized to Paxinos space and analyzed voxelwise. Volumetric microMRI imaging was performed to assess HD pathology. In R6/2 mice, CB1 receptor binding was decreased in comparison with WT in a cluster comprising the bilateral caudate-putamen, globus pallidus, and thalamic nucleus at week 5 (-8.1% ± 2.6%, p = 1.7 × 10(-5)). Longitudinal follow-up showed further progressive decline compared with controls in a cluster comprising the bilateral hippocampus, caudate-putamen, globus pallidus, superior colliculus, thalamic nucleus, and cerebellum (late vs. presymptomatic age: -13.7% ± 3.1% for R6/2 and +1.5% ± 4.0% for WT, p = 1.9 × 10(-5)). In R6/2 mice, PDE10A binding potential also decreased over time to reach significance at early and late symptomatic HD (late vs. presymptomatic age: -79.1% ± 1.9% for R6/2 and +2.1% ± 2.7% for WT, p = 1.5 × 10(-4)). The observed changes in CB1 receptor and PDE10A binding were correlated to anomalies exhibited by R6/2 animals in motor function, whereas no correlation was found with magnetic resonance imaging-based striatal volume. Our findings point to early regional dysfunctions in endocannabinoid and PDE10A signaling, involving the caudate-putamen and lateral globus pallidus, which may play a role

  15. Off-Label Use of Phosphodiesterase Type 5 Inhibitor Erectile Dysfunction Medication to Enhance Sex Among Gay and Bisexual Men in Australia: Results From the FLUX Study. (United States)

    Hammoud, Mohamed A; Jin, Fengyi; Lea, Toby; Maher, Lisa; Grierson, Jeffrey; Prestage, Garrett


    be representative of all GBMs in Australia. GBMs who used an oral EDM in the previous 6 months often used it for recreational purposes, but many of those who used it on a weekly basis also might have used it for therapeutic reasons. GBMs often use EDMs to enhance their sexual experiences often in the context of intensive sex partying (which can include risky sexual behavior). Hammoud MA, Jin F, Lea T, et al. Off-Label Use of Phosphodiesterase Type 5 Inhibitor Erectile Dysfunction Medication to Enhance Sex Among Gay and Bisexual Men in Australia: Results From the FLUX Study. J Sex Med 2017;14:774-784. Copyright © 2017 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

  16. Inibidores de fosfodiesterases: novas perspectivas de uma antiga terapia na asma? Phosphodiesterase inhibitors: new perspectives on an old therapy for asthma?

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    Hisbello Campos


    shifted the treatment toward either prevention or the inhibition of inflammatory markers. In light of this, new drug formulations have been considered. In addition to the beta2 agonists, theophylline, and corticosteroids currently being used, the second generation of selective phosphodiesterase inhibitors has shown promising results. Recent studies suggest that these drugs may soon offer a novel alternative in the treatment of asthma.

  17. Stimulation of the hypothalamo-pituitary-adrenal axis in the rat by three selective type-4 phosphodiesterase inhibitors: in vitro and in vivo studies (United States)

    Kumari, Meena; Cover, Patricia O; Poyser, Robert H; Buckingham, Julia C


    Previous studies in our laboratory have shown that the synthetic xanthine analogue denbufylline, a selective type 4 phosphodiesterase (PDE-4) inhibitor, is a potent activator of the hypothalamo-pituitary-adrenal (HPA) axis when given orally or intraperitoneally (i.p.) to adult male rats. This paper describes the results of experiments in which well established in vivo and in vitro methods were used to compare the effects of denbufylline on HPA function with those of two other selective PDE-4 inhibitors, rolipram and BRL 61063 (1,3-dicyclopropylmethyl-8-amino-xanthine). For comparison, parallel measurements of the immunoreactive- (ir-) luteinising hormone (LH) were made where appropriate. When injected intraperitoneally, rolipram (40 and 200 μg kg−1, P0.05). By contrast, intracerebroventricular (i.c.v.) injection of rolipram (8 ng–1 μg kg−1) or denbufylline (50 ng–1 μg kg−1) failed to influence the serum ir-corticosterone concentration. BRL 61063 (8–120 ng kg−1, i.c.v.) was also ineffective in this regard although at a higher dose (1 μg kg−1, i.c.v.) it produced a small but significant (P0.05). In vitro rolipram (10 μM, P0.05); the rank order of potency was thus BRL 61063>rolipram>denbufylline. The adenylyl cyclase activator forskolin (100 μM, PN6-cyclo-hexyladenosine (CHA, 100 nM, P<0.05) which alone had no significant effect on ir-CRH-41 release. ADA (0.1–10 u ml−1) and DPCPX (1 nM) had weak stimulant and inhibitory effects, respectively, on the release of ir-ACTH from the pituitary gland while CHA (0.1–10 nM) was without effect. Ligand binding studies with [3H]-DPCPX as a probe demonstrated the presence of specific high affinity A1 binding sites in the hypothalamus (Kd=0.7 nM; Bmax=367±32 fmol mg−1 protein) and in the hippocampus (Kd=1 nM; Bmax=1165±145 fmol mg−1 protein). In both tissues binding of the ligand was displaced by CHA (IC50=1 nM (hypothalamus) and 2

  18. Necrose digital em paciente com lúpus eritematoso sistêmico e esclerose sistêmica tratada com inibidores da fosfodiesterase Digital necrosis treated with phosphodiesterase inhibitors in a patient with connective tissue disease

    Directory of Open Access Journals (Sweden)

    Lílian Scussel Lonzetti


    Full Text Available Os inibidores da fosfodiesterase têm sido introduzidos, nos últimos anos, como novos agentes farmacológicos no tratamento dos pacientes com fenômeno de Raynaud e isquemia digital. Será descrito o caso de uma paciente com lúpus eritematoso sistêmico e esclerose sistêmica limitada apresentando fenômeno de Raynaud grave e necrose digital refratária à terapia. A paciente obteve excelente resposta à associação de imunossupressão e sildenafil.The phosphodiesterase inhibitors have been used recently for the treatment of Raynaud's phenomenon and digital ischaemia. We report the case of a patient affected by systemic lupus erythematosus and limited systemic sclerosis who presented severe Raynaud's phenomenon with digital necrosis despite treatment. The patient presented an excellent response to the association of immunosuppressant therapy and sildenafil.

  19. Theobromine, the primary methylxanthine found in Theobroma cacao, prevents malignant glioblastoma proliferation by negatively regulating phosphodiesterase-4, extracellular signal-regulated kinase, Akt/mammalian target of rapamycin kinase, and nuclear factor-kappa B. (United States)

    Sugimoto, Naotoshi; Miwa, Shinji; Hitomi, Yoshiaki; Nakamura, Hiroyuki; Tsuchiya, Hiroyuki; Yachie, Akihiro


    Theobromine, a caffeine derivative, is the primary methylxanthine produced by Theobroma cacao. We previously showed that methylxanthines, including caffeine and theophylline, have antitumor and antiinflammatory effects, which are in part mediated by their inhibition of phosphodiesterase (PDE). A member of the PDE family, PDE4, is widely expressed in and promotes the growth of glioblastoma, the most common type of brain tumor. The purpose of this study was to determine whether theobromine could exert growth inhibitory effects on U87-MG, a cell line derived from human malignant glioma. We show that theobromine treatment elevates intracellular cAMP levels and increases the activity of p38 mitogen-activated protein kinase and c-Jun N-terminal kinase, whereas it attenuates p44/42 extracellular signal-regulated kinase activity and the Akt/mammalian target of rapamycin kinase and nuclear factor-kappa B signal pathways. It also inhibits cell proliferation. These results suggest that foods and beverages containing cocoa bean extracts, including theobromine, might be extremely effective in preventing human glioblastoma.

  20. Frequent phosphodiesterase 11A gene (PDE11A) defects in patients with Carney complex (CNC) caused by PRKAR1A mutations: PDE11A may contribute to adrenal and testicular tumors in CNC as a modifier of the phenotype. (United States)

    Libé, Rossella; Horvath, Anelia; Vezzosi, Delphine; Fratticci, Amato; Coste, Joel; Perlemoine, Karine; Ragazzon, Bruno; Guillaud-Bataille, Marine; Groussin, Lionel; Clauser, Eric; Raffin-Sanson, Marie-Laure; Siegel, Jennifer; Moran, Jason; Drori-Herishanu, Limor; Faucz, Fabio Rueda; Lodish, Maya; Nesterova, Maria; Bertagna, Xavier; Bertherat, Jerome; Stratakis, Constantine A


    Carney complex (CNC) is an autosomal dominant multiple neoplasia, caused mostly by inactivating mutations of the regulatory subunit 1A of the protein kinase A (PRKAR1A). Primary pigmented nodular adrenocortical disease (PPNAD) is the most frequent endocrine manifestation of CNC with a great inter-individual variability. Germline, protein-truncating mutations of phosphodiesterase type 11A (PDE11A) have been described to predispose to a variety of endocrine tumors, including adrenal and testicular tumors. Our objective was to investigate the role of PDE11A as a possible gene modifier of the phenotype in a series of 150 patients with CNC. A higher frequency of PDE11A variants in patients with CNC compared with healthy controls was found (25.3 vs. 6.8%, P CNC patients, those with PPNAD were significantly more frequently carriers of PDE11A variants compared with patients without PPNAD (30.8 vs. 13%, P = 0.025). Furthermore, men with PPNAD were significantly more frequently carriers of PDE11A sequence variants (40.7%) than women with PPNAD (27.3%) (P CNC patients, a high frequency of PDE11A variants, suggesting that PDE11A is a genetic modifying factor for the development of testicular and adrenal tumors in patients with germline PRKAR1A mutation.

  1. Skin cancer associated with commonly prescribed drugs: tumor necrosis factor alpha inhibitors (TNF-αIs), angiotensin-receptor blockers (ARBs), phosphodiesterase type 5 inhibitors (PDE5Is) and statins -weighing the evidence. (United States)

    Nardone, Beatrice; Orrell, Kelsey A; Vakharia, Paras P; West, Dennis P


    Skin cancers, including both malignant melanoma (MM) and nonmelanoma skin cancer (NMSC), are the most commonly diagnosed cancers in the US. The incidence of both MM and NMSC continues to rise. Areas covered: Current evidence for an association between four of the most commonly prescribed classes of drugs in the U.S. and risk for MM and NMSC is reported. Medline was searched (January 2000 to May 2017) for each drug in the classes and for 'basal cell carcinoma', 'squamous cell carcinoma', 'non-melanoma skin cancer', 'skin cancer' and 'melanoma'. Skin cancer risk information was reported for: tumor necrosis factor alpha inhibitors (TNF-αIs), angiotensin-receptor blockers (ARBs), phosphodiesterase type 5 inhibitors (PDE5Is) and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA)-reductase inhibitors (statins). Expert opinion: Since skin cancer risk is associated with all four classes of these commonly prescribed drugs that represent nearly 20% of the Top 100 drugs in the U.S., these important findings warrant enhanced education, especially for prescribers and those patients at high risk for skin cancer.

  2. Freqüência de uso de inibidores de fosfodiesterase-5 por estudantes universitários Uso de inhibidores de fosfodiesterasa-5 por estudiantes universitários Use of phosphodiesterase-5 inhibitors by college students

    Directory of Open Access Journals (Sweden)

    Vanessa Mello de Freitas


    Full Text Available O objetivo do estudo foi identificar o uso de inibidores da fosfodiesterase-5 por estudantes universitários da cidade de São Paulo (SP, em 2006. Alunos do sexo masculino (n=360 responderam questionário sobre diagnóstico de disfunção erétil, freqüência e motivo do uso, medicamento utilizado, existência de prescrição médica e relato de efeitos adversos. Os resultados mostraram que 53 (14,7% dos alunos já haviam utilizado esses medicamentos, dos quais 53% relataram uso de sildenafila, 37% tadalafila e 10% vardenafila, adquiridos sem prescrição médica ou diagnóstico de disfunção erétil. Os principais efeitos adversos relatados foram cefaléia (23% e rubor facial (10%, e as principais motivações para uso foram a curiosidade (70% e potencialização da ereção (12%.El objetivo del estudio fue identificar el uso de inhibidores de la fosfodiesterasa-5 por estudiantes universitarios de la ciudad de Sao Paulo (SP, en 2006. Alumnos del sexo masculino (n=360 respondieron un cuestionario sobre el diagnóstico de disfunción eréctil, frecuencia e motivo del uso, medicamento utilizado, existencia de prescripción medica y descripción de efectos adversos. Los resultados mostraron que 53 (14,7% de los alumnos ya habían utilizado esos medicamentos, de los cuales 53% señalaron uso de sildenafila, 37% tadalafila y 10% vardenafila, adquiridos sin prescripción medica o diagnóstico de disfunción eréctil. Los principales efectos adversos mencionados fueron cefalea (23% y enrojecimiento facial (10%, y las principales motivaciones para su uso fueron la curiosidad (70% y potenciación de la erección (12%.The objective of this study was to identify the use of phosphodiesterase type 5 inhibitors among university students from the city of Sao Paulo (SP in Brazil. Male students (n=350 replied to a questionnaire about diagnosis of erectile dysfunction, the frequency and reason for the use of phosphodiesterase type 5 inhibitors, the specific

  3. Open radical retropubic prostatectomy using high anterior release of the levator fascia and constant haptic feedback in bilateral neurovascular bundle preservation plus early postoperative phosphodiesterase type 5 inhibition: a contemporary series. (United States)

    Hubanks, J Mikel; Umbreit, Eric C; Karnes, R Jeffrey; Myers, Robert P


    Patients with newly diagnosed localized prostate cancer who choose surgery want cure and decent quality of life, namely, pad-free urinary control and, often, erectile function satisfactory for sexual intercourse. Determine in a prospective study the positive surgical margin rate and functional outcomes for a consecutive series of patients undergoing open radical retropubic prostatectomy (ORRP) with bilateral neurovascular bundle preservation (BNVBP) performed by one experienced surgeon. Of 197 consecutive patients undergoing BNVBP during 2008, 123 were evaluable, allowing both immediate postoperative phosphodiesterase type 5 inhibition (PDE5i) and a third-party questionnaire with validated urinary and erectile function domains provided preoperatively and at 3, 6, and 12 mo postoperatively. Two interventions were used: (1) ORRP with ×4.3 optical loupes and constant digital tactile monitoring during BNVBP preceded by high anterior release (HAR) of levator fascia and neurovascular bundles and (2) early postoperative PDE5i. Age; biopsy Gleason score; clinical stage; preoperative prostate-specific antigen level; pathologic grade; stage; margin status; University of California, Los Angeles Prostate Cancer Index domain for urinary pad use and bother; and International Index of Erectile Function-5 (IIEF-5) were used. Surgical margins were positive in 1 of the 123 evaluable patients (1%). At 1 yr, 95% of patients were pad-free. Satisfactory erectile function was achieved by 109 patients (89%): 82 (67%) scored an IIEF-5 of 22-25, and 27 (22%) scored erection within the first year. Mean hospital stay was 1.3 d. Limitations were (1) observational, noncomparative, single-surgeon series and (2) in third-party methodology, failure to capture patient answers for all questionnaire intervals with resultant inability to address durability of functional results for all patients. ORRP using ×4.3 optical loupe magnification, constant haptic feedback in BNVBP with HAR, and immediate

  4. Heat shock proteins and experimental autoimmune encephalomyelitis (EAE): I. Immunization with a peptide of the myelin protein 2',3' cyclic nucleotide 3' phosphodiesterase that is cross-reactive with a heat shock protein alters the course of EAE. (United States)

    Birnbaum, G; Kotilinek, L; Schlievert, P; Clark, H B; Trotter, J; Horvath, E; Gao, E; Cox, M; Braun, P E


    We describe sequence similarity and immunologic cross-reactivity between a peptide of the mycobacterial hsp, HSP65, and the myelin protein 2',3' cyclic nucleotide 3' phosphodiesterase (CNP). We demonstrate that immunization with the homologous cross-reactive CNP peptide (hsp-CNP peptide) has significant biological consequences. Rats immunized with hsp-CNP peptide in either complete Freund's adjuvant (CFA) or incomplete Freund's adjuvant (IFA) produce large amounts of peptide-specific antibody. Isotypes of antibodies in animals immunized with peptide in CFA are IgG1 and IgG2a. Isotypes of antibodies in rats immunized with peptide in IFA are predominantly IgG1, with low titers of IgG2a. T cell proliferative responses to HSP65 are present in rats immunized with peptide in CFA. T cell responses to HSP65 initially are absent in rats immunized with peptide in IFA but develop over time. T cell proliferative responses to hsp-CNP peptide were not detected. None of the groups of rats developed clinical or histologic evidence of experimental autoimmune encephalomyelitis (EAE). To induce EAE, rats preimmunized with hsp-CNP peptide were challenged with guinea pig spinal cord (GPSC) emulsified in CFA. Rats preimmunized with peptide in CFA developed severe EAE. Rats preimmunized with hsp-CNP peptide in IFA were protected from EAE, with both a lower incidence and severity of disease. Injecting the murine monoclonal antibody recognizing the shared HSP65 and CNP epitope did not protect against EAE. Our data suggest that a Th2 pattern of immune response to a CNP peptide that itself is non-encephalitogenic protects against EAE. Immune responses to either hsp or myelin proteins cross-reactive with hsp may play an important role in the development of EAE.

  5. Proof-of-Concept Randomized Controlled Study of Cognition Effects of the Proprietary Extract Sceletium tortuosum (Zembrin Targeting Phosphodiesterase-4 in Cognitively Healthy Subjects: Implications for Alzheimer’s Dementia

    Directory of Open Access Journals (Sweden)

    Simon Chiu


    Full Text Available Introduction. Converging evidence suggests that PDE-4 (phosphodiesterase subtype 4 plays a crucial role in regulating cognition via the PDE-4-cAMP cascade signaling involving phosphorylated cAMP response element binding protein (CREB. Objective. The primary endpoint was to examine the neurocognitive effects of extract Sceletium tortuosum (Zembrin and to assess the safety and tolerability of Zembrin in cognitively healthy control subjects. Method. We chose the randomized double-blind placebo-controlled cross-over design in our study. We randomized normal healthy subjects (total n=21 to receive either 25 mg capsule Zembrin or placebo capsule once daily for 3 weeks, in a randomized placebo-controlled 3-week cross-over design. We administered battery of neuropsychological tests: CNS Vital Signs and Hamilton depression rating scale (HAM-D at baseline and regular intervals and monitored side effects with treatment emergent adverse events scale. Results. 21 subjects (mean age: 54.6 years ± 6.0 yrs; male/female ratio: 9/12 entered the study. Zembrin at 25 mg daily dosage significantly improved cognitive set flexibility (P<0.032 and executive function (P<0.022, compared with the placebo group. Positive changes in mood and sleep were found. Zembrin was well tolerated. Conclusion. The promising cognitive enhancing effects of Zembrin likely implicate the PDE-4-cAMP-CREB cascade, a novel drug target in the potential treatment of early Alzheimer’s dementia. This trial is registered with NCT01805518.

  6. Alpha-1 adrenergic antagonists, 5-alpha reductase inhibitors, phosphodiesterase type 5 inhibitors, and phytotherapic compounds in men with lower urinary tract symptoms suggestive of benign prostatic obstruction: A systematic review and meta-analysis of urodynamic studies. (United States)

    Fusco, Ferdinando; Creta, Massimiliano; De Nunzio, Cosimo; Gacci, Mauro; Li Marzi, Vincenzo; Finazzi Agrò, Enrico


    To perform a systematic review and meta-analysis of studies evaluating the urodynamic outcomes of alpha-1 adrenergic antagonists (ABs), 5-alpha reductase inhibitors (5-ARIs), phosphodiesterase type 5 inhibitors (PDE5is), and phytotherapic compounds in patients with lower urinary tract symptoms related to benign prostatic obstruction (LUTS/BPO). A systematic review of PubMed/Medline, ISI Web of Knowledge, and Scopus databases was performed in June 2017. We included full papers that met the following criteria: original research; English language; human studies; enrolling LUTS/BPO patients; reporting maximum urinary flow (Qmax), and detrusor pressure at maximum urinary flow (PdetQmax). The primary endpoint was variation in bladder outlet obstruction index (BOOI). Secondary endpoints were variations in Qmax and PdetQmax. Twenty-three studies involving 1044 patients were included in the final analysis. Eighteen, three, two, and one study evaluated the urodynamic outcomes of ABs, 5-ARIs, PDE5is, and phytotherapic compounds, respectively. BOOI, PdetQmax, and Qmax improved in a statistically significant manner in patients receiving ABs and in those receiving 5-ARIs. The overall pooled data showed a mean BOOI change of -15.40 (P < 0.00001) and of -10.55 (P = 0,004) for ABs and 5-ARIs, respectively. Mean PdetQmax and Qmax changes were:12.30 cm H 2 O (P < 0.00001) and +2.27 ml/s (P < 0.00001) for ABs and -9.63 cm H 2 O (P = 0.05), and +1.18 mL/s (P = 0.04) for 5-ARIs. PDE5is and phytotherapic compounds had no significant effects on urodynamic parameters. ABs and 5-ARIs efficiently improve BOOI in men with LUTS/BPO. Both treatments are associated with a clinically significant decrease in PdetQmax but only marginal improvements in Qmax. © 2018 Wiley Periodicals, Inc.

  7. Low doses of cyclic AMP-phosphodiesterase inhibitors rapidly evoke opioid receptor-mediated thermal hyperalgesia in naïve mice which is converted to prominent analgesia by cotreatment with ultra-low-dose naltrexone. (United States)

    Crain, Stanley M; Shen, Ke-Fei


    Systemic (s.c.) injection in naïve mice of cyclic AMP-phosphodiesterase (cAMP-PDE) inhibitors, e.g. 3-isobutyl-1-methylxanthine [(IBMX) or caffeine, 10 mg/kg] or the more specific cAMP-PDE inhibitor, rolipram (1 mug/kg), rapidly evokes thermal hyperalgesia (lasting >5 h). These effects appear to be mediated by enhanced excitatory opioid receptor signaling, as occurs during withdrawal in opioid-dependent mice. Cotreatment of these mice with ultra-low-dose naltrexone (NTX, 0.1 ng/kg-1 pg/kg, s.c.) results in prominent opioid analgesia (lasting >4 h) even when the dose of rolipram is reduced to 1 pg/kg. Cotreatment of these cAMP-PDE inhibitors in naïve mice with an ultra-low-dose (0.1 ng/kg) of the kappa-opioid receptor antagonist, nor-binaltorphimine (nor-BNI) or the mu-opioid receptor antagonist, beta-funaltrexamine (beta-FNA) also results in opioid analgesia. These excitatory effects of cAMP-PDE inhibitors in naïve mice may be mediated by enhanced release of small amounts of endogenous bimodally-acting (excitatory/inhibitory) opioid agonists by neurons in nociceptive networks. Ultra-low-dose NTX, nor-BNI or beta-FNA selectively antagonizes high-efficacy excitatory (hyperalgesic) Gs-coupled opioid receptor-mediated signaling in naïve mice and results in rapid conversion to inhibitory (analgesic) Gi/Go-coupled opioid receptor-mediated signaling which normally requires activation by much higher doses of opioid agonists. Cotreatment with a low subanalgesic dose of kelatorphan, an inhibitor of multiple endogenous opioid peptide-degrading enzymes, stabilizes endogenous opioid agonists released by cAMP-PDE inhibitors, resulting in conversion of the hyperalgesia to analgesia without requiring selective blockade of excitatory opioid receptor signaling. The present study provides a novel pharmacologic paradigm that may facilitate development of valuable non-narcotic clinical analgesics utilizing cotreatment with ultra-low-dose rolipram plus ultra-low-dose NTX or related

  8. ZATT (ZNF451)-mediated resolution of topoisomerase 2 DNA-protein cross-links. (United States)

    Schellenberg, Matthew J; Lieberman, Jenna Ariel; Herrero-Ruiz, Andrés; Butler, Logan R; Williams, Jason G; Muñoz-Cabello, Ana M; Mueller, Geoffrey A; London, Robert E; Cortés-Ledesma, Felipe; Williams, R Scott


    Topoisomerase 2 (TOP2) DNA transactions proceed via formation of the TOP2 cleavage complex (TOP2cc), a covalent enzyme-DNA reaction intermediate that is vulnerable to trapping by potent anticancer TOP2 drugs. How genotoxic TOP2 DNA-protein cross-links are resolved is unclear. We found that the SUMO (small ubiquitin-related modifier) ligase ZATT (ZNF451) is a multifunctional DNA repair factor that controls cellular responses to TOP2 damage. ZATT binding to TOP2cc facilitates a proteasome-independent tyrosyl-DNA phosphodiesterase 2 (TDP2) hydrolase activity on stalled TOP2cc. The ZATT SUMO ligase activity further promotes TDP2 interactions with SUMOylated TOP2, regulating efficient TDP2 recruitment through a "split-SIM" SUMO2 engagement platform. These findings uncover a ZATT-TDP2-catalyzed and SUMO2-modulated pathway for direct resolution of TOP2cc. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  9. Trypanosoma cruzi gene expression in response to gamma radiation.

    Directory of Open Access Journals (Sweden)

    Priscila Grynberg

    Full Text Available Trypanosoma cruzi is an organism highly resistant to ionizing radiation. Following a dose of 500 Gy of gamma radiation, the fragmented genomic DNA is gradually reconstructed and the pattern of chromosomal bands is restored in less than 48 hours. Cell growth arrests after irradiation but, while DNA is completely fragmented, RNA maintains its integrity. In this work we compared the transcriptional profiles of irradiated and non-irradiated epimastigotes at different time points after irradiation using microarray. In total, 273 genes were differentially expressed; from these, 160 were up-regulated and 113 down-regulated. We found that genes with predicted functions are the most prevalent in the down-regulated gene category. Translation and protein metabolic processes, as well as generation of precursor of metabolites and energy pathways were affected. In contrast, the up-regulated category was mainly composed of obsolete sequences (which included some genes of the kinetoplast DNA, genes coding for hypothetical proteins, and Retrotransposon Hot Spot genes. Finally, the tyrosyl-DNA phosphodiesterase 1, a gene involved in double-strand DNA break repair process, was up-regulated. Our study demonstrated the peculiar response to ionizing radiation, raising questions about how this organism changes its gene expression to manage such a harmful stress.

  10. The cutting edges in DNA repair, licensing, and fidelity: DNA and RNA repair nucleases sculpt DNA to measure twice, cut once. (United States)

    Tsutakawa, Susan E; Lafrance-Vanasse, Julien; Tainer, John A


    To avoid genome instability, DNA repair nucleases must precisely target the correct damaged substrate before they are licensed to incise. Damage identification is a challenge for all DNA damage response proteins, but especially for nucleases that cut the DNA and necessarily create a cleaved DNA repair intermediate, likely more toxic than the initial damage. How do these enzymes achieve exquisite specificity without specific sequence recognition or, in some cases, without a non-canonical DNA nucleotide? Combined structural, biochemical, and biological analyses of repair nucleases are revealing their molecular tools for damage verification and safeguarding against inadvertent incision. Surprisingly, these enzymes also often act on RNA, which deserves more attention. Here, we review protein-DNA structures for nucleases involved in replication, base excision repair, mismatch repair, double strand break repair (DSBR), and telomere maintenance: apurinic/apyrimidinic endonuclease 1 (APE1), Endonuclease IV (Nfo), tyrosyl DNA phosphodiesterase (TDP2), UV Damage endonuclease (UVDE), very short patch repair endonuclease (Vsr), Endonuclease V (Nfi), Flap endonuclease 1 (FEN1), exonuclease 1 (Exo1), RNase T and Meiotic recombination 11 (Mre11). DNA and RNA structure-sensing nucleases are essential to life with roles in DNA replication, repair, and transcription. Increasingly these enzymes are employed as advanced tools for synthetic biology and as targets for cancer prognosis and interventions. Currently their structural biology is most fully illuminated for DNA repair, which is also essential to life. How DNA repair enzymes maintain genome fidelity is one of the DNA double helix secrets missed by James Watson and Francis Crick, that is only now being illuminated though structural biology and mutational analyses. Structures reveal motifs for repair nucleases and mechanisms whereby these enzymes follow the old carpenter adage: measure twice, cut once. Furthermore, to measure

  11. Structural and functional characterization of a novel molluskan ortholog of TRAF and TNF receptor-associated protein from disk abalone (Haliotis discus discus). (United States)

    Lee, Youngdeuk; Elvitigala, Don Anushka Sandaruwan; Whang, Ilson; Lee, Sukkyoung; Kim, Hyowon; Zoysa, Mahanama De; Oh, Chulhong; Kang, Do-Hyung; Lee, Jehee


    Immune signaling cascades have an indispensable role in the host defense of almost all the organisms. Tumor necrosis factor (TNF) signaling is considered as a prominent signaling pathway in vertebrate as well as invertebrate species. Within the signaling cascade, TNF receptor-associated factor (TRAF) and TNF receptor-associated protein (TTRAP) has been shown to have a crucial role in the modulation of immune signaling in animals. Here, we attempted to characterize a novel molluskan ortholog of TTRAP (AbTTRAP) from disk abalone (Haliotis discus discus) and analyzed its expression levels under pathogenic stress. The complete coding sequence of AbTTRAP consisted of 1071 nucleotides, coding for a 357 amino acid peptide, with a predicted molecular mass of 40 kDa. According to our in-silico analysis, AbTTRAP resembled the typical TTRAP domain architecture, including a 5'-tyrosyl DNA phosphodiesterase domain. Moreover, phylogenetic analysis revealed its common ancestral invertebrate origin, where AbTTRAP was clustered with molluskan counterparts. Quantitative real time PCR showed universally distributed expression of AbTTRAP in selected tissues of abalone, from which more prominent expression was detected in hemocytes. Upon stimulation with two pathogen-derived mitogens, lipopolysaccharide (LPS) and polyinosinic:polycytidylic acid (poly I:C), transcript levels of AbTTRAP in hemocytes and gill tissues were differentially modulated with time. In addition, the recombinant protein of AbTTRAP exhibited prominent endonuclease activity against abalone genomic DNA, which was enhanced by the presence of Mg(2+) in the medium. Collectively, these results reinforce the existence of the TNF signaling cascade in mollusks like disk abalone, further implicating the putative regulatory behavior of TTRAP in invertebrate host pathology. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Four Novel p.N385K, p.V36A, c.1033–1034insT and c.1417–1418delCT Mutations in the Sphingomyelin Phosphodiesterase 1 (SMPD1 Gene in Patients with Types A and B Niemann-Pick Disease (NPD

    Directory of Open Access Journals (Sweden)

    Masoumeh Dehghan Manshadi


    Full Text Available Background: Types A and B Niemann-Pick disease (NPD are autosomal-recessive lysosomal storage disorders caused by the deficient activity of acid sphingomyelinase due to mutations in the sphingomyelin phosphodiesterase 1 (SMPD1 gene. Methods: In order to determine the prevalence and distribution of SMPD1 gene mutations, the genomic DNA of 15 unrelated Iranian patients with types A and B NPD was examined using PCR, DNA sequencing and bioinformatics analysis. Results: Of 8 patients with the p.G508R mutation, 5 patients were homozygous, while the other 3 were heterozygous. One patient was heterozygous for both the p.N385K and p.G508R mutations. Another patient was heterozygous for both the p.A487V and p.G508R mutations. Two patients (one homozygous and one heterozygous showed the p.V36A mutation. One patient was homozygous for the c.1033–1034insT mutation. One patient was homozygous for the c.573delT mutation, and 1 patient was homozygous for the c.1417–1418delCT mutation. Additionally, bioinformatics analysis indicated that two new p.V36A and p.N385K mutations decreased the acid sphingomyelinase (ASM protein stability, which might be evidence to suggest the pathogenicity of these mutations. Conclusion: with detection of these new mutations, the genotypic spectrum of types A and B NPD is extended, facilitating the definition of disease-related mutations. However, more research is essential to confirm the pathogenic effect of these mutations.

  13. Phosphodiesterase type 2 distribution in the guinea pig urinary bladder. (United States)

    Rahnama'i, M S; Hohnen, R; Van Kerrebroeck, Ph E V; van Koeveringe, G A


    Nitric oxide-stimulated cGMP synthesis represents an important signalling pathway in the urinary bladder. Inhibitors of the PDE1 and PDE5 enzyme have been studied to treat storage and voiding disorders in clinical settings. The distribution of PDE2 in the bladder is unknown. This study focuses on the distribution and site of action of PDE2 within the guinea pig urinary bladder wall. Six male guinea pig bladders were dissected and treated in 2 ml Krebs' solution and 10 µM of the specific PDE2 inhibitor, Bay 60-7550 at 36 °C for 30 min. After stimulating tissues with 100 µM of diethylamine-NONOate for 10 min, the tissues were snap frozen and cut in 10 µm sections which were examined for cGMP immune-reactivity, co-stained with either vimentin, synaptic vesicle protein 2, calcitonin gene-related protein and protein gene product 9.5. PDE2 inhibitor Bay 60-7550 inhibits cGMP breakdown the most in the urothelial and suburothelial layers, as well as on the nerve fibres. After inhibition by Bay 60-7550, cGMP was mainly expressed in the intermuscle interstitial cells and the nerve fibres of the outer muscle layers of lateral wall, indicating the presence of PDE2 activity. Our study is the first to show the distribution of PDE2 in the bladder which was shown to be present in the urothelium, mainly umbrella cells, the interstitial cells of the suburothelium and the outer muscle, as well as in nerve fibres.

  14. Phosphodiesterase 1 regulation is a key mechanism in vascular aging

    DEFF Research Database (Denmark)

    Niño, Paula K Bautista; Durik, Matej; Danser, A H Jan


    Reduced nitric oxide (NO)/cGMP signalling is observed in age-related vascular disease. We hypothesize that this disturbed signalling involves effects of genomic instability, a primary causal factor in aging, on vascular smooth muscle cells (VSMCs) and that the underlying mechanism plays a role...... in human age-related vascular disease. To test our hypothesis, we combined experiments in mice with genomic instability resulting from the defective nucleotide excision repair gene ERCC1 (Ercc1(d/-) mice), human VSMC cultures and population genome-wide association studies (GWAS). Aortic rings of Ercc1(d...... in lungs was higher in Ercc1(d/-) mice. No differences in activity or levels of cGMP-dependent protein kinase 1 or sGC were observed in Ercc1(d/-) mice compared with WT. Senescent human VSMC showed elevated PDE1A and PDE1C and PDE5 mRNA levels (11.6-, 9- and 2.3-fold respectively), which associated...

  15. Phosphodiesterase 5 inhibitors (PDE5i) and pulmonary embolism

    NARCIS (Netherlands)

    Gerritsen, R.F.; Bijl, A.; Van Puijenbroek, E.P.

    Introduction: PDE5i-related arterial thromboembolism is described in literature. Published venous thrombotic events are limited to one case of pulmonary embolism (tadalafil) and of recurrent deep venous thrombosis (DVT) related to sildenafil. Aim of the study: Presentation of two cases of vardenafil

  16. Characterization of the "Escherichia Coli" Acyl Carrier Protein Phosphodiesterase (United States)

    Thomas, Jacob


    Acyl carrier protein (ACP) is a small essential protein that functions as a carrier of the acyl intermediates of fatty acid synthesis. ACP requires the posttranslational attachment of a 4'phosphopantetheine functional group, derived from CoA, in order to perform its metabolic function. A Mn[superscript 2+] dependent enzymatic activity that removes…

  17. Dualselektive Phosphodiesterase 3 und 4 Inhibition in experimenteller pulmonaler Hypertonie


    Dony, Eva Maria Marlene


    Verschiedene Phosphodiesterasehemmer sind zur Zeit in der Erprobung zur Behandlung der pulmonalen Hypertonie. Einige PDE 5-Inhibitoren sind bereits zur Therapie der pulmonalarteriellen Hypertonie zugelassen, jedoch ist bisher weniger über den therapeutischen Nutzen von PDE 3-, PDE 4- und insbesondere dualselektiven PDE 3/4-Inhibitoren bekannt. Die vorliegende Studie untersucht die chronisch-therapeutischen Effekte von Pumafentrine, einem oral verfügbaren, gemischtselektiven PDE 3/4-Hemmst...

  18. A review of phosphodiesterase type 5 inhibitors | Schellack | South ...

    African Journals Online (AJOL)

    Newer studies are investigating the use of these drugs for other conditions, including hypertension, ischaemia or reperfusion injury, myocardial infarction, cardiac hypertrophy, heart failure and other peripheral circulatory conditions, e.g. Raynaud's disease. The article provides a broad overview of the mechanism of action, ...

  19. Atividade das fosfodiesterases em tecido de granulação submetido a irradiação de elétrons - estudo experimental em ratos Activity of phosphodiesterases in granulation tissue submitted to electron irradiation - experimental study in rats

    Directory of Open Access Journals (Sweden)

    Frab Norberto BÓSCOLO


    Full Text Available Os autores estudaram o efeito de baixas doses de radiação de elétrons na atividade de fosfodiesterases presentes no tecido de granulação, induzido por esponja de PVC, subcutaneamente, na região dorsal de 84 ratos Wistar, divididos em dois grupos, controle e irradiado. A atividade enzimática foi avaliada segundo a evolução do tecido de granulação aos 5, 7, 10, 14, 17, 20 e 24 dias. Os animais foram irradiados com um feixe de elétrons de 6 MeV, dose de 1 Gy, 3 dias após a implantação da esponja, sendo que no momento da irradiação, foram protegidos por uma lâmina de 4 mm de chumbo, tendo sido irradiada somente a área correspondente ao local onde encontrava-se a esponja. Considerando-se a dose e o tipo de radiação empregada, pode-se concluir que houve influência direta da radiação na atividade da enzima 5’-nucleotidase e da ATPase no início do processo de reparação tecidual, aos 5 e 7 dias. Já a enzima fosfatase alcalina não sofreu a ação direta da radiação. É possível que o principal fator tenha sido danos nos constituintes celulares que são responsáveis pela formação do tecido de granulação, determinando a produção enzimática conforme a necessidade.The present study evaluated the effect of low doses of electron radiation on the activity of phosphodiesterases in granulation tissue. In order to induce growth of granulation tissue, a PVC sponge disk was introduced under the dorsal skin of 84 Wistar rats. The rats were divided in two groups, control and irradiated. The enzymatic activity was evaluated according to the evolution of the granulation tissue after 5, 7, 10, 14, 17, 20 and 24 days. Irradiation was carried out 3 days after the implantation of the sponge, by means of a linear accelerator, with energy of 6 MeV, and dose of 1.0 Gy. The results of this study showed that 5’-nucleotidase and ATPase had their activity directly affected by irradiation only in the beginning of the tissue repairing

  20. Erectile dysfunction in patients taking psychotropic drugs and treated with phosphodiesterase-5 inhibitors

    Directory of Open Access Journals (Sweden)

    Rossella Mazzilli


    Full Text Available Objectives: The aim of this study was to assess the prevalence of patients with Erectile Dysfunction (ED receiving psychotropic drugs, the impact of these drugs on hormonal profile, and the efficacy of PDE5-i in these patients. Materials and methods: We recruited 1872 patients referring for ED to our Andrology Unit. Assessment included serum testosterone, gonadotropins, TSH, prolactin, and PSA, and the IIEF-5 questionnaire for ED diagnosis. Inclusion criteria were age 21-75 years and IIEF-5 total score ≤ 21; exclusion criteria included hypogonadism, diabetes mellitus, previous prostatectomy, other medication intake, and ED diagnosis prior to psychotropic drug treatment. Efficacy was rated with the IIEF-5 (remission: total score ≥ 22. Results: The prevalence of ED patients treated with psychotropic drugs since ≥ 3 months was 9.5% (178/1872, subdivided according to the drugs used into: Group A, 16 patients treated with atypical antipsychotics (9.0%; Group B, 55 patients with benzodiazepines (30.9%; Group C, 33 patients with antidepressant drugs (18.5%; and Group D, 74 patients with multiple psychotropic drugs (41.6%. Patients in Group A were significantly younger than other groups (p < 0.05. The hormonal profile presented only higher prolactin level in patients treated with antipsychotics, alone or in combination (p < 0.05. Overall, 146 patients received PDE5-i. Remission rate, after three months of treatment, was significantly higher in Group B compared to C and D groups (p < 0.05. Conclusions: A substantial portion of patients receiving psychotropic drugs show ED. Sexual performance in these patients benefits from PDE5-i. Age, effects of psychiatric disorders, psychotropic drugs, and PDE5-i treatment modality accounted for variability of response in this sample.

  1. Comparison of phosphodiesterase type V inhibitors use in eight European cities through analysis of urban wastewater

    DEFF Research Database (Denmark)

    Causanilles, Ana; Rojas Cantillano, Daniela; Emke, Erik


    In this work a step forward in investigating the use of prescription drugs, namely erectile dysfunction products, at European level was taken by applying the wastewater-based epidemiology approach. 24-h composite samples of untreated wastewater were collected at the entrance of eight wastewater....... The concentrations were transformed into normalized measured loads and the estimated actual consumption of sildenafil was back-calculated from these loads. In addition, national prescription data from five countries was gathered in the form of the number of prescribed daily doses and transformed into predicted loads...... in wastewater than expected from the prescription data. This study illustrates the potential of wastewater-based epidemiology to investigate the use of counterfeit medication and rogue online pharmacy sales....

  2. Stress history increases alcohol intake in relapse: Relation to phosphodiesterase 10A


    Logrip, Marian L.; Zorrilla, Eric P.


    Stressful experiences in humans can result in elevated alcohol drinking, as exemplified in many individuals with post-traumatic stress disorder. However, how stress history, rather than acute stressors, influences alcohol intake remains uncertain. To model the protracted effects of past stress, male Wistar rats were subjected to light-cued footshock stress (Stress History) or light cues alone (Control) prior to their acquisition of alcohol self-administration (1-h sessions, fixed ratio1–3, 10...

  3. Human 2'-phosphodiesterase localizes to the mitochondrial matrix with a putative function in mitochondrial RNA turnover

    DEFF Research Database (Denmark)

    Poulsen, Jesper Buchhave; Andersen, Kasper Røjkjær; Kjær, Karina Hansen


    . Interestingly, 2′-PDE shares both functionally and structurally characteristics with the CCR4-type exonuclease–endonuclease–phosphatase family of deadenylases. Here we show that 2′-PDE locates to the mitochondrial matrix of human cells, and comprise an active 3′–5′ exoribonuclease exhibiting a preference...... for oligo-adenosine RNA like canonical cytoplasmic deadenylases. Furthermore, we document a marked negative association between 2′-PDE and mitochondrial mRNA levels following siRNA-directed knockdown and plasmid-mediated overexpression, respectively. The results indicate that 2′-PDE, apart from playing...

  4. New insight into the role of phosphodiesterase 3A in porcine oocyte maturation

    Directory of Open Access Journals (Sweden)

    Richard François J


    Full Text Available Abstract Background The ovulatory surge of gonadotropins triggers oocyte maturation and rupture of the ovarian follicle. The resumption of nuclear maturation in the oocyte from the prophase stage is characterized by germinal vesicle breakdown (GVBD. It has previously been shown that specific inhibition of cAMP degradation by PDE3 prevents the resumption of oocyte meiosis. However, no report has characterized the activity of PDE3 in the porcine oocyte, or the implication of the cAMP-PDE3 pathway in the entire nuclear maturation process. In this study, PDE3 activity in the oocyte was assessed during in vitro maturation (IVM and the possible roles of the cAMP-PDE3 pathway in the resumption and progression of meiosis were investigated in terms of different models of oocyte maturation. Results Cyclic AMP-degrading PDE activity was detected in the cumulus-oocyte complex (COC and was partially inhibited by a specific PDE3 inhibitor, cilostamide. When measured only in the denuded oocyte, PDE activity was almost completely inhibited by cilostamide, suggesting that cAMP-PDE3 activity is the major cAMP-PDE in porcine oocytes. PDE3A mRNA was detected by RT-PCR. PDE3 activity did not vary significantly during the early hours of IVM, but a maximum was observed at 13 hours. In cumulus-oocyte complexes, meiosis resumed after 20.81 hours of culture. PDE3 inhibition no longer maintained meiotic arrest if sustained beyond 17.65 hours of IVM, 3 hours prior to resumption of meiosis. Thereafter, PDE3 inhibition progressively lost its efficacy in GVBD. When the protein phosphatase 1 and 2A inhibitor okadaic acid was continuously or transiently (3 hours present during IVM, meiosis resumed prematurely; PDE3 inhibition was unable to prevent GVBD. However, PDE3 inhibition in COC treated with OA for 3 hours significantly delayed meiosis at the intermediate stage. Conclusion The present investigation has demonstrated that PDE3A is the major cAMP-degrading PDE in the oocyte. It regulates the resumption of meiosis until 3 hours prior to GVBD and transiently affects meiotic progression.

  5. Phosphodiesterase 3 inhibitor cilostazol induces migraine-like attacks via cyclic AMP increase

    DEFF Research Database (Denmark)

    Guo, Song; Olesen, Jes; Ashina, Messoud


    The initiating mechanisms of migraine attacks are very complex but may involve the cyclic AMP signalling pathway. It is unknown whether intracellular cyclic AMP accumulation induces migraine attacks. We investigated whether administration of cilostazol, which causes cyclic AMP accumulation, may...... and that cilostazol-induced attacks responded to their usual migraine treatment. Median time of medication intake was 6 h (range 4-11 h). The present study suggests that intracellular cyclic AMP accumulation plays a crucial role in migraine induction. This knowledge is a further step in our understanding...

  6. Nitric oxide-induced changes in endothelial expression of phosphodiesterases 2, 3, and 5

    DEFF Research Database (Denmark)

    Schankin, Christoph J; Kruse, Lars S; Reinisch, Veronika M


    continued DETA NONOate administration. RESULTS: This study shows the expression of PDE2A, PDE3B, and PDE5A mRNA and PDE3B and PDE5A protein in human cerebral endothelial cells. Long-term DETA NONOate administration induced an immediate mRNA up-regulation of PDE5A (1.9-fold, 0.5 hour), an early peak of PDE2A...

  7. Porcine ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1/CD203a)

    DEFF Research Database (Denmark)

    Petersen, Cathrine Bie; Hillig, Ann-Britt Nygaard; Viuff, Birgitte


    Swine workshop cluster 9 (SWC9) antibody identifying a porcien epitope on macrophages and thymocytes was used to precipitate and characterize the molecule from biotinylated macrophages and to obtain peptide sequence by mass spectrometry. The protein was identified as ecto-nucleotide pyrophosphatase...... and verification of the specificity of an SWC9 reacting monoclonal antibody. The antibody was used for immunohistochemical examination of various porcine tissues. Most prominent expression of NPP1/CD203a was found in lung macrophages and liver sinusoids....

  8. Novel selective phosphodiesterase type 1 inhibitors cause vasodilatation and lower blood pressure in rats

    DEFF Research Database (Denmark)

    Laursen, Morten; Thinggaard, Lilliana Beck; Kehler, Jan


    BACKGROUND AND PURPOSE: The PDE enzymes (PDE1-11) hydrolyse and thus inactivate cyclic nucleotides and are important in the regulation of the cardiovascular system. Here,we have investigated the effects on the cardiovascular system, of two novel selective PDE1 inhibitors, Lu AF41228 and Lu AF5802...

  9. Neuronal nitric oxide synthase supports Renin release during sodium restriction through inhibition of phosphodiesterase 3

    DEFF Research Database (Denmark)

    Sällström, Johan; Jensen, Boye L; Skøtt, Ole


    by measurements of inulin- and para-amino hippuric acid (PAH) clearances, respectively. RESULTS: The basal PRC was reduced in nNOS⁻(/)⁻ compared to the wild types. Administration of milrinone caused a more pronounced PRC increase in nNOS⁻(/)⁻, resulting in normalized renin levels, whereas PDE5 inhibition did...

  10. 2'-phosphodiesterase and 2',5'-oligoadenylate synthetase activities in the lowest metazoans, sponge [porifera

    DEFF Research Database (Denmark)

    Saby, Emilie; Poulsen, Jesper Buchhave; Justesen, Just


    not all been identified in sponges. Here, we demonstrate for the first time that in addition to the OAS activity, sponges possess a 2′-PDE activity, which highlights the probable existence of a premature 2–5A system. Indeed, Suberites domuncula and Crella elegans exhibited this 2–5A degrading activity...

  11. The influence of phosphodiesterase inhibitor, rolipram, on hemodynamics in lipopolysaccharide-treated rats. (United States)

    Dutta, P; Ryan, D E; Tabrizchi, R


    Administration of bacterial endotoxin (lipopolysaccharide, LPS) intravenously has been noted to produce a shock state, which is characterized by hypotension and multi-organ system failure. The aim of the present investigation was to (a) examine the influence of rolipram on hemodynamics, plasma levels of tumor necrosis factor-alpha (TNF-alpha) levels, and production of inducible nitric oxide synthase (iNOS) in the lungs, ex vivo, in LPS-treated rats, and (b) determine the cardiovascular effects of a selective alpha1-adrenoceptor agonist, methoxamine, in the absence or presence of rolipram in rats treated with LPS. Blood pressure, cardiac index, heart rate and arterial resistance were assessed in Long-Evans rats anesthetized with thiobutabarbital. Administration of LPS to animals resulted in a significant reduction in cardiac index over time. The administration of LPS to rats resulted in a substantial rise in the plasma levels of TNF-alpha. Furthermore, the injection of LPS resulted in a significant increase in the iNOS activity in the lungs. Pre-treatment with rolipram prevented the decline in cardiac index in animals that received LPS. Infusion of methoxamine into animals injected with rolipram and pre-treated with LPS did not result in significant changes in cardiac index. Pre-treatment with rolipram or dexamethasone in animals injected with LPS significantly prevented the rise in TNF-alpha when compared to the respective values in vehicle-treated animals. Our present observations support the view that the cardiac index can be maintained in animals treated with LPS independent of iNOS inhibition.

  12. Guanidine-based polymer brushes grafted onto silica nanoparticles as efficient artificial phosphodiesterases. (United States)

    Savelli, Claudia; Salvio, Riccardo


    Polymer brushes grafted to the surface of silica nanoparticles were fabricated by atom-transfer radical polymerization (ATRP) and investigated as catalysts in the cleavage of phosphodiesters. The surfaces of silica nanoparticles were functionalized with an ATRP initiator. Surface-initiated ATRP reactions, in varying proportions, of a methacrylate moiety functionalized with a phenylguanidine moiety and an inert hydrophilic methacrylate species afforded hybrid nanoparticles that were characterized with potentiometric titrations, thermogravimetric analysis, and SEM. The activity of the hybrid nanoparticles was tested in the transesterification of the RNA model compound 2-hydroxypropyl para-nitrophenylphosphate (HPNP) and diribonucleoside monophosphates. A high catalytic efficiency and a remarkable effective molarity, thus overcoming the effective molarities previously observed for comparable systems, indicate the existence of an effective cooperation of the guanidine/guanidinium units and a high level of preorganization in the nanostructure. The investigated system also exhibits a marked and unprecedented selectivity for the diribonucleoside sequence CpA. The results presented open up the way for a novel and straightforward strategy for the preparation of supramolecular catalysts. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Structure and Mechanism of PhnP, a Phosphodiesterase of the Carbon-Phosphorus Lyase Pathway

    DEFF Research Database (Denmark)

    He, Shu-Mei; Wathier, Matthew; Podzelinska, Kateryna


    phenylphosphate diesters with leaving group pKa values ranging from 4 to 8.4. With bis(p-nitrophenyl)phosphate as a substrate, there was a 10-fold decrease in kcat/KM, primarily the result of a large increase in KM. Moreover, the nickel ion-activated H200A PhnP displayed a bell-shaped pH dependence for kcat....../KM with pKa values (pKa1 = 6.3; pKa2 = 7.8) that were comparable to those of the wild-type enzyme (pKa1 = 6.5; pKa2 = 7.8). Such modest effects are counter to what is expected for a general acid catalyst and suggest an alternate role for H200 in this enzyme. A Brønsted analysis of the PhnP reaction...

  14. Erectogenic Effects of Clerodendron capitatum: Involvement of Phosphodiesterase Type-5 Inhibition

    Directory of Open Access Journals (Sweden)

    Siddig Ibrahim Abdelwahab


    Full Text Available Clerodendron capitatum (Willd (family: verbenaceae is locally named as Gung and used traditionally to treat erectile dysfunction. Therefore, the current study was designed to investigate the erectogenic properties of C. capitatum. The relaxation effect of this plant was tested on phenylephrine precontracted rabbit corpus cavernosum smooth muscle (CCSM. The effects of C. capitatum were also examined on isolated Guinea pig atria alone, in the presence of calcium chloride (Ca2+ channel blocker, atropine (cholinergic blocker, and glibenclamide (ATP-sensitive K+ channel blocker. These effects were confirmed on isolated rabbit aortic strips. The extract, when tested colorimetrically for its inhibitory activities on phosphordiesterase-5 (PDE-5 in vitro towards p-nitrophenyl phenyl phosphate (PNPPP, was observed to induce significant dose-dependent inhibition of PDE-5, with an ID50 of 0.161 mg/ml (<.05. In conclusion, our results suggest that C. capitatum possesses a relaxant effect on CCSM, which is attributable to the inhibition of PDE-5, but not mediated by the release calcium, activation of adrenergic or cholinergic receptors, or the activation of potassium channels.

  15. Spezifische Spaltung von RNA-Dinucleotiden durch eine synthetische dreikernige Metall(II)-Phosphodiesterase auf Calix[4]aren-Basis

    NARCIS (Netherlands)

    Molenveld, P.; Engbersen, Johannes F.J.; Reinhoudt, David


    Große Geschwindigkeitssteigerung und beachtliche Spezifität für Nucleobasen in der katalytischen Umesterung von RNA-Dinucleotiden werden mit dem Calix[4]aren-Enzymmimetikum 1-Zn3 beobachtet (gezeigt ist das Computermodell des Komplexes mit dem Dinucleotid GpG). Die höhere Aktivität für GpG gegenüber

  16. A controlled trial of 6-weeks' treatment with a novel inhaled phosphodiesterase type-4 inhibitor in COPD

    DEFF Research Database (Denmark)

    Vestbo, J; Tan, L; Atkinson, G


    was observed at any dose of UK-500,001 after 6 weeks of treatment. However, after the first 2 weeks of treatment, an improvement in a number of outcome measures in the 1.0 mg b.i.d. dose group was observed compared with placebo. The drug was well tolerated, although PDE4 inhibitor-related side-effects were...

  17. Structure of PhnP: a phosphodiesterase of the carbon-phosphorous lyase pathway for phosphonate degradation

    DEFF Research Database (Denmark)

    Podzelinska, Kateryna; He, Shu-Mei; Wathier, Matthew


    Carbon-phosphorus lyase is a multienzyme system encoded by the phn operon that enables bacteria to metabolize organophosphonates when the preferred nutrient, inorganic phosphate, is scarce. One of the enzymes encoded by this operon, PhnP, is predicted by sequence homology to be a metal-dependent ...

  18. The single cyclic nucleotide-specific phosphodiesterase of the intestinal parasite Giardia lamblia represents a potential drug target

    NARCIS (Netherlands)

    Kunz, Stefan; Balmer, Vreni; Sterk, Geert Jan; Pollastri, Michael P.; Leurs, Rob; Müller, Norbert; Hemphill, Andrew; Spycher, Cornelia


    Background: Giardiasis is an intestinal infection correlated with poverty and poor drinking water quality, and treatment options are limited. According to the Center for Disease Control and Prevention, Giardia infections afflict nearly 33% of people in developing countries, and 2% of the adult

  19. Effects of the non-selective phosphodiesterase inhibitor pentoxifylline on regional cerebral blood flow and large arteries in healthy subjects

    DEFF Research Database (Denmark)

    Kruuse, Christina; Jacobsen, T B; Thomsen, Lars Lykke


    -inhalation SPECT. High-frequency ultrasound was used for measurements of temporal and radial artery diameter. Cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) concentrations were assessed in plasma. Except for increased heart rate (P

  20. Antidiarrheal and Antispasmodic Activities of Buddleja polystachya are Mediated Through Dual Inhibition of Ca(++) Influx and Phosphodiesterase Enzyme. (United States)

    Rehman, Najeeb-ur; Gilani, Anwarul-Hassan; Khan, Aslam; Nazneen, Maryam; El Gamal, Ali A; Fawzy, Ghada A; Al-Ati, Hanan Y; Abdel-kader, Maged S


    This study describes the antidiarrheal and antispasmodic activities of the hydro-alcoholic extract of Buddleja polystachya (Bp.Cr) with possible mode of action explored along with activity-directed fractionation. Bp.Cr and its aqueous (Bp.Aq) and organic fractions, petroleum ether (Bp.Pet), dichloromethane (Bp.DCM), ethylacetate (Bp.EtAc) and butanol (Bp.But), were tested using the in-vivo and in-vitro assays. The crude extract (100-300 mg/kg) showed 20 and 60% protection of castor oil-induced diarrhea in mice. In isolated rabbit jejunum, Bp.Cr like papaverine inhibited spontaneous and high K(+) (80 mM)-induced contractions equi-potently. In guinea-pig ileum, Bp.Cr showed a moderate spasmogenic effect. The activity-directed fractionation revealed that the spasmolytic activity was concentrated in the organic fractions and spasmogenic component in the aqueous fraction. Amongst the organic fractions, BP.DCM and Bp.Pet inhibited spontaneous and high K(+) -induced contractions equi-potently, while Bp.But, like verapamil was more potent against high K(+) . The crude extract and its organic fractions caused rightward shift in the Ca(++) -concentration response curves (CRCs), similar to verapamil, and all except Bp.But potentiated the isoprenaline-inhibitory CRCs to the left, similar to papaverine. The results of this study indicate that the crude extract of B. polystachya possesses antidiarrheal and antispasmodic activities, mediated possibly through dual inhibition of Ca(++) influx and phospodiesterase enzyme. Copyright © 2015 John Wiley & Sons, Ltd.

  1. Liposomal-delivery of phosphodiesterase 5 inhibitors augments UT-15C-stimulated ATP release from human erythrocytes

    Directory of Open Access Journals (Sweden)

    Elizabeth A. Bowles


    Here we investigate the hypothesis that targeted delivery of PDE5 inhibitors to human erythrocytes, using a liposomal delivery system, potentiates prostacyclin analog- induced ATP release. The findings are consistent with the hypothesis that directed delivery of this class of drugs to erythrocytes could be a new and important method to augment prostacyclin analog-induced ATP release from these cells. Such an approach could significantly limit side effects of both classes of drugs without compromising their therapeutic effectiveness in diseases such as PAH.

  2. Sildenafil and Phosphodiesterase-5 Inhibitors to Reduce Cardiotoxicity and Enhance the Response of Breast Tumor Cells to Doxorubicin (United States)


    24. Bivalacqua TJ et al (2009) Sildenafil inhibits superoxide forma- tion and prevents endothelial dysfunction in a mouse model of secondhand smoke ...lines and one murine breast tumor line. Sildenafil did not interfere with the effectiveness of Adriamycin in any of the cell lines tested. Sildenafil...sildenafil did not attenuate the antitumor effects of Adriamycin; furthermore, the combination of sildenafil with Adriamycin was no more toxic to the animals

  3. Sildenafil and analogous phosphodiesterase type 5 (PDE-5) inhibitors in herbal food supplements sampled on the Dutch market

    NARCIS (Netherlands)

    Reeuwijk, N.M.; Venhuis, B.J.; Kaste, de D.; Hoogenboom, L.A.P.; Rietjens, I.; Martena, M.J.


    Herbal food supplements, claiming to enhance sexual potency, may contain deliberately added active pharmacological ingredients (APIs) that can be used for the treatment of erectile dysfunction (ED). The aim of this study was to determine whether herbal food supplements on the Dutch market indeed

  4. The phosphodiesterase 5 inhibitor sildenafil has no effect on cerebral blood flow or blood velocity, but nevertheless induces headache in healthy subjects

    DEFF Research Database (Denmark)

    Kruuse, Christina; Thomsen, Lars Lykke; Jacobsen, Torsten Bjørn


    and headache induction. Ten healthy subjects were included in a double-blind, placebo-controlled crossover study where placebo or sildenafil 100 mg (highest therapeutic dose) were administered on two separate days. Blood velocity in the middle cerebral artery (Vmca) was recorded by transcranial Doppler......, and regional cerebral blood flow in the perfusion area of the middle cerebral artery (rCBFmca) was measured using single photon emission computed tomography and xenon inhalation. Radial and temporal artery diameters were studied using high-frequency ultrasound. Blood pressure and heart rate were recorded...

  5. Investigation of a Putative Estrogen-Imprinting Gene, Phosphodiesterase Type IV Variant (PDE4D4), in Determining Prostate Cancer Risk (United States)


    treatment for prostate disease/ cancer . - Specific antibody against PDE4D4 was custom-made and it will be used for IHC studies for rat normal and...Currently, prostate can- er is the most common non- skin cancer in males and is the econd leading cause of cancer deaths in American men [1]. ccording...bone morphogenic protein 4 Bmp4), sonic hedgehog (Shh) and fibroblast growth factor- 0 (Fgf10) in the normal developing rat prostate lobes and hose

  6. A cAMP Biosensor-Based High-Throughput Screening Assay for Identification of Gs-Coupled GPCR Ligands and Phosphodiesterase Inhibitors

    DEFF Research Database (Denmark)

    Vedel, Line; Bräuner-Osborne, Hans; Mathiesen, Jesper Mosolff


    in living cells. We used the β2-adrenergic receptor (β2AR) as a representative Gs-coupled receptor and characterized two cell lines with different expression levels. Low receptor expression allowed detection of desensitization kinetics and delineation of partial agonism, whereas high receptor expression...

  7. Hexachlorophene and cuprizone induce the spongy change of the developing rat brain by different mechanisms: the role of 2', 3'-cyclic nucleotide 3'-phosphodiesterase (CNPase). (United States)

    Kanno, Takeshi; Sasaki, Satoshi; Yamada, Naoaki; Kawasako, Kazufumi; Tsuchitani, Minoru


    The goal of this research was to identify mechanisms responsible for the spongy change induced in rats after repeated hexachlorophene (HCP) or cuprizone (CPZ) dosing. Rats were dosed with 35 mg/kg HCP for 5 days followed by drug withdrawal for 7 days suffered spongy changes to the white matter of the cerebrum, cerebellum, medulla oblongata, and spinal cord that were accompanied by degeneration of oligodendroglia. The severity of both lesions increased prominently on day 5; however, the spongy change decreased and degeneration of oligodendroglia reversed on day 12 (7 days after dosing ceased). On day 12, cerebral cortex oligodendroglia were stained strongly by anti-CNPase. Other rats were fed for 8 days with powdered chow containing 1% (w/w) CPZ, which was then withdrawn for 16 days. The rats exhibited the spongy change in the white matter of the cerebrum and cerebellum as well as oligodendroglial cell death from day 3. The severity of both lesions increased prominently on day 8. Cerebral cortex oligodendroglia were stained strongly by anti-CNPase on days 3 to 8 and decreased to the control levels by day 24 (16 days after dosing ceased). Electron microscopy revealed that oligodendroglia frequently displayed apoptotic morphology. These findings suggest that CNPase expression was induced in the course of restoration following HCP-induced insults to oligodendroglia and the myelin sheath, and in the course of demyelination by CPZ-induced damage to oligodendroglia. However, the role of CNPase on both courses is unclear.

  8. Drug Repositioning for Preeclampsia Therapeutics by In Vitro Screening: Phosphodiesterase-5 Inhibitor Vardenafil Restores Endothelial Dysfunction via Induction of Placental Growth Factor. (United States)

    Kakigano, Aiko; Tomimatsu, Takuji; Mimura, Kazuya; Kanayama, Tomoko; Fujita, Satoko; Minato, Kenji; Kumasawa, Keiichi; Taniguchi, Yukiko; Kanagawa, Takeshi; Endo, Masayuki; Ishihara, Tomoaki; Namba, Takushi; Mizushima, Tohru; Kimura, Tadashi


    We screened a library of 528 approved drugs to identify candidate compounds with therapeutic potential as preeclampsia treatments via their proangiogenic properties. Using human umbilical vein endothelial cells (HUVECs), we assessed whether the screened drugs induced placental growth factor (PIGF) and restored damaged endothelial cell function. Enzyme-linked immunosorbent assays (ELISAs) were carried out to measure levels of PlGF in conditioned media treated with each drug (100 µmol/L) in the drug library. Tube formation assays were performed using HUVECs to evaluate the angiogenic effects of drugs that induced PlGF. We also performed ELISA, quantitative reverse transcription polymerase chain reaction, and tube formation assays after treatment with a range of concentrations of the candidate drug. Of the drugs that induced PlGF, vardenafil was the only compound that significantly facilitated tube formation in comparison with the control cells (P Treatment with vardenafil at concentrations of 50, 100, and 250 µmol/L increased expression of PlGF in a dose-dependent manner. Vardenafil (250 µmol/L) significantly improved tube formation which was inhibited in the presence of soluble fms-like tyrosine kinase 1 (100 ng/mL) and/or soluble endoglin (100 ng/mL). Production of PlGF from HUVECs in the presence of sera derived from patients with preeclampsia was significantly elevated by administration of vardenafil (250 µmol/L). By assessing drug repositioning through screening a library of approved drugs, we identified vardenafil as a potential protective agent against preeclampsia. The therapeutic mechanism of vardenafil may involve inhibition of the systemic maternal antiangiogenic state that leads to preeclampsia, in addition to its vasodilating effect. As concentrations used are high and unlikely to be useful clinically, further work is needed before testing it in humans. © The Author(s) 2015.

  9. Cyclic adenosine monophosphate metabolism in synaptic growth, strength, and precision: neural and behavioral phenotype-specific counterbalancing effects between dnc phosphodiesterase and rut adenylyl cyclase mutations. (United States)

    Ueda, Atsushi; Wu, Chun-Fang


    Two classic learning mutants in Drosophila, rutabaga (rut) and dunce (dnc), are defective in cyclic adenosine monophosphate (cAMP) synthesis and degradation, respectively, exhibiting a variety of neuronal and behavioral defects. We ask how the opposing effects of these mutations on cAMP levels modify subsets of phenotypes, and whether any specific phenotypes could be ameliorated by biochemical counter balancing effects in dnc rut double mutants. Our study at larval neuromuscular junctions (NMJs) demonstrates that dnc mutations caused severe defects in nerve terminal morphology, characterized by unusually large synaptic boutons and aberrant innervation patterns. Interestingly, a counterbalancing effect led to rescue of the aberrant innervation patterns but the enlarged boutons in dnc rut double mutant remained as extreme as those in dnc. In contrast to dnc, rut mutations strongly affect synaptic transmission. Focal loose-patch recording data accumulated over 4 years suggest that synaptic currents in rut boutons were characterized by unusually large temporal dispersion and a seasonal variation in the amount of transmitter release, with diminished synaptic currents in summer months. Experiments with different rearing temperatures revealed that high temperature (29-30°C) decreased synaptic transmission in rut, but did not alter dnc and wild-type (WT). Importantly, the large temporal dispersion and abnormal temperature dependence of synaptic transmission, characteristic of rut, still persisted in dnc rut double mutants. To interpret these results in a proper perspective, we reviewed previously documented differential effects of dnc and rut mutations and their genetic interactions in double mutants on a variety of physiological and behavioral phenotypes. The cases of rescue in double mutants are associated with gradual developmental and maintenance processes whereas many behavioral and physiological manifestations on faster time scales could not be rescued. We discuss factors that could contribute to the effectiveness of counterbalancing interactions between dnc and rut mutations for phenotypic rescue.

  10. Phosphodiesterase inhibitor KMUP-3 displays cardioprotection via protein kinase G and increases cardiac output via G-protein-coupled receptor agonist activity and Ca2+ sensitization

    Directory of Open Access Journals (Sweden)

    Chung-Pin Liu


    Full Text Available KMUP-3 (7-{2-[4-(4-nitrobenzene piperazinyl]ethyl}-1, 3-dimethylxanthine displays cardioprotection and increases cardiac output, and is suggested to increase cardiac performance and improve myocardial infarction. To determine whether KMUP-3 improves outcomes in hypoperfused myocardium by inducing Ca2+ sensitization to oppose protein kinase (PKG-mediated Ca2+ blockade, we measured left ventricular systolic blood pressure, maximal rates of pressure development, mean arterial pressure and heart rate in rats, and measured contractility and expression of PKs/RhoA/Rho kinase (ROCKII in beating guinea pig left atria. Hemodynamic changes induced by KMUP-3 (0.5–3.0 mg/kg, intravenously were inhibited by Y27632 [(R-(+-trans-4-1-aminoethyl-N-(4-Pyridyl cyclohexane carboxamide] and ketanserin (1 mg/kg, intravenously. In electrically stimulated left guinea pig atria, positive inotropy induced by KMUP-3 (0.1–100μM was inhibited by the endothelial NO synthase (eNOS inhibitors N-nitro-l-arginine methyl ester (L-NAME and 7-nitroindazole, cyclic AMP antagonist SQ22536 [9-(terahydro-2-furanyl-9H-purin-6-amine], soluble guanylyl cyclase (sGC antagonist ODQ (1H-[1,2,4] oxadiazolo[4,3-a] quinoxalin-1-one, RhoA inhibitor C3 exoenzyme, β-blocker propranolol, 5-hydroxytryptamine 2A antagonist ketanserin, ROCK inhibitor Y27632 and KMUP-1 (7-{2-[4-(2-chlorobenzene piperazinyl]ethyl}-1, 3-dimethylxanthine at 10μM. Western blotting assays indicated that KMUP-3 (0.1–10μM increased PKA, RhoA/ROCKII, and PKC translocation and CIP-17 (an endogenous 17-kDa inhibitory protein activation. In spontaneous right atria, KMUP-3 induced negative chronotropy that was blunted by 7-nitroindazole and atropine. In neonatal myocytes, L-NAME inhibited KMUP-3-induced eNOS phosphorylation and RhoA/ROCK activation. In H9c2 cells, Y-27632 (50μM and PKG antagonist KT5823 [2,3,9,10,11,12-hexahydro-10R- methoxy-2,9-dimethyl-1-oxo-9S,12R-epoxy-1H-diindolo(1,2,3-fg:3′,2′,1′-kl pyrrolo(3,4-i(1,6benzodiazocine-10-carboxylic acid, methyl ester] (3μM reversed KMUP-3 (1–100μM-induced Ca2+-entry blockade. GPCR agonist activity of KMUP-3 appeared opposed to KMUP-1, and increased cardiac output via Ca2+ sensitization, and displayed cardioprotection via cyclic GMP/PKG-mediated myocardial preconditioning in animal studies.

  11. Synthesis and phosphodiesterase 5 inhibitory activity of novel pyrido[1,2-e]purin-4(3H)-one derivatives. (United States)

    Xia, Guangxin; Li, Jianfeng; Peng, Aiming; Lai, Shunan; Zhang, Shujun; Shen, Jingshan; Liu, Zhonghua; Chen, Xinjian; Ji, Ruyun


    Synthesis and primary SAR of a novel series of 2-phenylpyrido[1,2-e]purin-4(3H)-one derivatives with piperazinyl sulfonamide substituents were described herein. As potential PDE5 inhibitors for erectile dysfunction (ED) treatment, representative compounds exhibit improved selectivity versus PDE1 and PDE6. Meanwhile, compound 3e demonstrated functional efficacy on rabbit corpus cavernosum strip in vitro.

  12. Different effects of adenylyl cyclase activators and phosphodiesterases inhibitors on cervical cancer (HeLa) and breast cancer (MCF-7) cells proliferation. (United States)

    Mahdian, Davood; Shafiee-Nick, Reza; Mousavi, Seyed Hadi


    Breast and cervical cancers are the most common cancers in Iran and worldwide. Hormonal stimulation of cyclic adenosine mono phosphate (cAMP) and the cAMP-dependent protein kinase PKA regulates cell growth by different mechanism. cAMP can stimulate cell growth in many cell types while inhibiting cell growth in others. In some cell lines have been shown that the proliferation of tumor cells is reduced by increasing cAMP in cells. In this study, we evaluate growth arrest of selective PDE3 and non-selective PDE inhibitors, which lead to increase level of cAMP in cervical (HeLa) and breast cancer (MCF7) cell lines have been studied. Cells were incubated with different concentrations of selective, non-selective PDE inhibitors, beta adrenergic receptor agonist and direct stimulator of adenylyl cyclase. Cell viability was quantitated by MTT assay. Apoptotic cells were determined using PI staining of DNA fragmentation by flow cytometry (sub-G1 peak). Result showed that selective PDE inhibitors decreased cell viability in HeLa and MCF-7 cells as a time-dependent manner. Non-selective inhibitor and beta-adrenergic receptor agonist also decrease cell viability but they are less powerful than selective PDE3 inhibitors. Forskolin had no effect in viability of cells. Analysis of DNA fragmentation by flow cytometry showed apoptosis involved in selective PDE3 inhibitors induced toxicity in HeLa cell. Thus, the growth inhibitory effects of selective PDE3 inhibitors are more effective than non-selective inhibitor. Further studies are needed to investigate the mechanism of action is on the field.

  13. Investigation of a Putative Estrogen-Imprinting Gene, Phosphodiesterase Type IV Variant (Pde4d4), in Determining Prostate Cancer Risk (United States)


    Wan-Yee Tang,b Jessica Belmonte,a and Shuk-Mei Hob a Department of Urology, University of Illinois at Chicago, Chicago, Illinois; and b Department of...therapeutic implications. Endocr Rev 2005; 26 :833–76. 35 Bosland MC, Ford H, Horton L. Induction at high incidence of ductal prostate...Disruption of the epigenome or induction of “epimutations” [21] certainly underlies disease development [8–10]. Therefore, disease suscepti- bility is

  14. ORF Alignment: NC_003280 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available in T23G7.1 [Caenorhabditis elegans] ... gb|AAK19021.1| DPL-1 [Caenorhabditis elegans] ... ref|...h ... LIN-35 Rb to antagonize Ras signaling (67.9 kD) (dpl-1) ... [...Caenorhabditis elegans] sp|Q22703|TDP1_CAEEL ... Transcription factor dpl-1 pir||T25207 hypothetical

  15. Efficacy and gastrointestinal tolerability of ML3403, a selective inhibitor of p38 MAP kinase and CBS-3595, a dual inhibitor of p38 MAP kinase and phosphodiesterase 4 in CFA-induced arthritis in rats. (United States)

    Koch, Diana A; Silva, Rodrigo B M; de Souza, Alessandra H; Leite, Carlos E; Nicoletti, Natália F; Campos, Maria M; Laufer, Stefan; Morrone, Fernanda B


    Mitogen-activated protein kinase (MAPK) p38 inhibitors have entered the clinical phase, although many of them have failed due to high toxicity and lack of efficacy. In the present study we compared the effects of the selective p38 inhibitor ML3403 and the dual p38-PDE4 inhibitor CBS-3595, on inflammatory and nociceptive parameters in a model of polyarthritis in rats. Male Wistar rats (180-200 g) were used for the complete Freund's adjuvant (CFA)-induced arthritis model and they were evaluated at 14-21 days. We also analysed the effects of these pharmacological tools on liver and gastrointestinal toxicity and on cytokine levels. Repeated CBS-3595 (3 mg/kg) or ML3403 (10 mg/kg) administration produced significant anti-inflammatory actions in the chronic arthritis model induced by CFA. CBS-3595 and ML3403 treatment also markedly reduced the production of the proinflammatory cytokine IL-6 in the paw tissue, whereas it widely increased the levels of the anti-inflammatory cytokine IL-10. Moreover, CBS-3595 produced partial anti-allodynic effects in the CFA model at 4 and 8 days after treatment. Notably, ML3403 and CBS-3595 did not show marked signs of hepatoxicity, as supported by unaltered histological observations in the liver sections. Finally, both compounds were safe in the gastrointestinal tract, according to evaluation of intestinal biopsies. CBS-3595 displayed a superior profile regarding its anti-inflammatory effects. Thus p38 MAPK/PDE4 blocking might well constitute a relevant strategy for the treatment of RA.

  16. Conversion of a heme-based oxygen sensor to a heme oxygenase by hydrogen sulfide: effects of mutations in the heme distal side of a heme-based oxygen sensor phosphodiesterase (Ec DOS)

    Czech Academy of Sciences Publication Activity Database

    Du, Y.; Liu, G.; Yan, Y.; Huang, D.; Luo, W.; Martínková, M.; Man, Petr; Shimizu, T.


    Roč. 26, č. 5 (2013), s. 839-852 ISSN 0966-0844 Institutional support: RVO:61388971 Keywords : Heme oxygenase * Heme protein * Hydrogen sulfide Subject RIV: CE - Biochemistry Impact factor: 2.689, year: 2013

  17. Phenotype overlap in Xylella fastidiosa is controlled by the cyclic di-GMP phosphodiesterase Eal in response to antibiotic exposure and diffusible signal factor-mediated cell-cell signaling. (United States)

    de Souza, Alessandra A; Ionescu, Michael; Baccari, Clelia; da Silva, Aline M; Lindow, Steven E


    Eal is an EAL domain protein in Xylella fastidiosa homologous to one involved in resistance to tobramycin in Pseudomonas aeruginosa. EAL and HD-GYP domain proteins are implicated in the hydrolysis of the secondary messenger bis-(3'-5')-cyclic dimeric GMP (cyclic di-GMP). Cell density-dependent communication mediated by a Diffusible Signal Factor (DSF) also modulates cyclic di-GMP levels in X. fastidiosa, thereby controlling the expression of virulence genes and genes involved in insect transmission. The possible linkage of Eal to both extrinsic factors such as antibiotics and intrinsic factors such as quorum sensing, and whether both affect virulence, was thus addressed. Expression of eal was induced by subinhibitory concentrations of tobramycin, and an eal deletion mutant was more susceptible to this antibiotic than the wild-type strain and exhibited phenotypes similar to those of an rpfF deletion mutant blocked in DSF production, such as hypermotility, reduced biofilm formation, and hypervirulence to grape. Consistent with that, the rpfF mutant was more susceptible than the wild-type strain to tobramycin. Therefore, we propose that cell-cell communication and antibiotic stress can apparently lead to similar modulations of cyclic di-GMP in X. fastidiosa, resulting in similar phenotypes. However, the effect of cell density is dominant compared to that of antibiotic stress, since eal is suppressed by RpfF, which may prevent inappropriate behavioral changes in response to antibiotic stress when DSF accumulates.

  18. Main: 1JH6 [RPSD[Archive

    Lifescience Database Archive (English)

    Full Text Available ineered: Yes Hydrolase 3.1.4.- (Cyclic Phosphodiesterase) A.Hofmann, M.Grella, I.Bo...Orderedlocusnames=At4g18930; Orfnames=F13c5.100, F13c5_100; Arabidopsis Thaliana Molecule: Cyclic Phosphodiesterase; Chain: A, B; Eng

  19. The pharmacological management of erectile dysfunction – Update ...

    African Journals Online (AJOL)

    Erectile dysfunction (ED) is a trivial condition with a prevailing incidence worldwide. Phosphodiesterase-5 inhibitors ... Keywords: cardiovascular disease, erectile dysfunction, phosphodiesterase-5 inhibitors, prostaglandin, testosterone. South African Family ..... among older adults in the United States. N Engl J Med. 2007 ...

  20. NCBI nr-aa BLAST: CBRC-OANA-01-2190 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OANA-01-2190 ref|YP_484804.1| diguanylate phosphodiesterase [Rhodopseudomonas ...palustris HaA2] gb|ABD05893.1| diguanylate phosphodiesterase [Rhodopseudomonas palustris HaA2] YP_484804.1 3.2 32% ...

  1. Treatment of infertility in men with spinal cord injury

    DEFF Research Database (Denmark)

    Brackett, N.L.; Lynne, C.M.; El Dib, Hussein Ibrahim El Desouki Hussein


    Most men with spinal cord injury (SCI) are infertile. Erectile dysfunction, ejaculatory dysfunction and semen abnormalities contribute to the problem. Treatments for erectile dysfunction include phosphodiesterase type 5 inhibitors, intracavernous injections of alprostadil, penile prostheses...

  2. Pulmonary Hypertension Overview (United States)

    ... a tank can help relieve shortness of breath. Medicines that can be used to treat pulmonary hypertension include the following: Endothelin receptor antagonists Phosphodiesterase-5 inhibitors Prostacyclins Anticoagulants (blood-thinning medicine) ...

  3. Tetomilast.

    LENUS (Irish Health Repository)

    O'Mahony, Seamus


    Otsuka is developing a once-daily oral formulation of the phosphodiesterase-4 inhibitor tetomilast for the potential treatment of ulcerative colitis (phase III) and chronic obstructive pulmonary disease (phase II).

  4. Saquinavir (United States)

    ... Pentam); pimozide (Orap); rifampin (Rifadin, Rimactane, in Rifamate); sildenafil (only Revatio brand used for lung disease); simvastatin ( ... in Zegerid); certain phosphodiesterase (PDE5) inhibitors such as sildenafil (Viagra), quetiapine (Seroquel); tadalafil (Adcirca, Cialis), and vardenafil ( ...

  5. Cobicistat (United States)

    ... Ranexa); rifampin (Rimactane, Rifadin, in Rifamate, in Rifater); sildenafil (only Revatio brand used for lung disease); simvastatin ( ... certain phosphodiesterase (PDE5) inhibitors such as avanafil (Stendra), sildenafil (Viagra), tadalafil (Adcirca, Cialis), and vardenafil (Levitra); quetiapine ( ...

  6. Cyclic nucleotides differentially regulate the synthesis of tumour necrosis factor-alpha and interleukin-1 beta by human mononuclear cells

    NARCIS (Netherlands)

    Endres, S; Fülle, H J; Sinha, B; Stoll, D; Dinarello, C A; Gerzer, R; Weber, P.C.

    Recent reports have shown that phosphodiesterase (PDE) inhibitors suppress production of tumour necrosis factor-alpha (TNF-alpha) in mouse macrophages. In the present study we show that theophylline, pentoxifylline and 3-isobutyl-1-methylxanthine markedly suppress the lipopolysaccharide

  7. Identification of several high-risk HPV inhibitors and drug targets with a novel high-throughput screening assay.

    Directory of Open Access Journals (Sweden)

    Mart Toots


    Full Text Available Human papillomaviruses (HPVs are oncogenic viruses that cause numerous different cancers as well as benign lesions in the epithelia. To date, there is no effective cure for an ongoing HPV infection. Here, we describe the generation process of a platform for the development of anti-HPV drugs. This system consists of engineered full-length HPV genomes that express reporter genes for evaluation of the viral copy number in all three HPV replication stages. We demonstrate the usefulness of this system by conducting high-throughput screens to identify novel high-risk HPV-specific inhibitors. At least five of the inhibitors block the function of Tdp1 and PARP1, which have been identified as essential cellular proteins for HPV replication and promising candidates for the development of antivirals against HPV and possibly against HPV-related cancers.

  8. Women taking the “blue pill” (sildenafil citrate: such a big deal?

    Directory of Open Access Journals (Sweden)

    Lo Monte G


    Full Text Available Giuseppe Lo Monte, Angela Graziano, Isabella Piva, Roberto Marci Department of Morphology, Surgery, and Experimental Medicine, University of Ferrara, Ferrara, Italy Abstract: For years, phosphodiesterase type 5 inhibitors have been used for the treatment of erectile dysfunctions. Due to the similarities between male and female sexual response, several studies have assessed the effects of sildenafil citrate (Viagra® in women affected by female sexual arousal disorder. The results are still conflicting and the drug is not devoid of adverse effects. Furthermore, female sexual arousal disorder is a heterogeneous condition whose underlying causes are difficult to diagnose and appropriate treatment requires a thorough sexual, psychological, and medical history along with specialist consultations. The clinician should pursue a global approach to the patient with sexual difficulties, while non-hormonal treatment such as phosphodiesterase type 5 inhibitors (ie, sildenafil citrate should be kept as the last option. Keywords: phosphodiesterase type 5 inhibitors, female sexual arousal disorder (FSAD, sildenafil citrate

  9. Effects and mechanisms of action of sildenafil citrate in human chorionic arteries

    Directory of Open Access Journals (Sweden)

    Lynch Tadhg


    Full Text Available Abstract Objectives Sildenafil citrate, a specific phosphodiesterase-5 inhibitor, is increasingly used for pulmonary hypertension in pregnancy. Sildenafil is also emerging as a potential candidate for the treatment of intra-uterine growth retardation and for premature labor. Its effects in the feto-placental circulation are not known. Our objectives were to determine whether phosphodiesterase-5 is present in the human feto-placental circulation, and to characterize the effects and mechanisms of action of sildenafil citrate in this circulation. Study Design Ex vivo human chorionic plate arterial rings were used in all experiments. The presence of phosphodiesterase-5 in the feto-placental circulation was determined by western blotting and immunohistochemical staining. In a subsequent series of pharmacologic studies, the effects of sildenafil citrate in pre-constricted chorionic plate arterial rings were determined. Additional studies examined the role of cGMP and nitric oxide in mediating the effects of sildenafil. Results Phosphodiesterase-5 mRNA and protein was demonstrated in human chorionic plate arteries. Immunohistochemistry demonstrated phosphodiesterase-5 within the arterial muscle layer. Sildenafil citrate produced dose dependent vasodilatation at concentrations at and greater than 10 nM. Both the direct cGMP inhibitor methylene blue and the cGMP-dependent protein kinase inhibitor Rp-8-Br-PET-cGMPS significantly attenuated the vasodilation produced by sildenafil citrate. Inhibition of NO production with L-NAME did not attenuate the vasodilator effects of sildenafil. In contrast, sildenafil citrate significantly enhanced the vasodilation produced by the NO donor sodium nitroprusside. Conclusion Phosphodiesterase-5 is present in the feto-placental circulation. Sildenafil citrate vasodilates the feto-placental circulation via a cGMP dependent mechanism involving increased responsiveness to NO.

  10. Effects and mechanisms of action of sildenafil citrate in human chorionic arteries.

    LENUS (Irish Health Repository)

    Maharaj, Chrisen H


    OBJECTIVES: Sildenafil citrate, a specific phosphodiesterase-5 inhibitor, is increasingly used for pulmonary hypertension in pregnancy. Sildenafil is also emerging as a potential candidate for the treatment of intra-uterine growth retardation and for premature labor. Its effects in the feto-placental circulation are not known. Our objectives were to determine whether phosphodiesterase-5 is present in the human feto-placental circulation, and to characterize the effects and mechanisms of action of sildenafil citrate in this circulation. STUDY DESIGN: Ex vivo human chorionic plate arterial rings were used in all experiments. The presence of phosphodiesterase-5 in the feto-placental circulation was determined by western blotting and immunohistochemical staining. In a subsequent series of pharmacologic studies, the effects of sildenafil citrate in pre-constricted chorionic plate arterial rings were determined. Additional studies examined the role of cGMP and nitric oxide in mediating the effects of sildenafil. RESULTS: Phosphodiesterase-5 mRNA and protein was demonstrated in human chorionic plate arteries. Immunohistochemistry demonstrated phosphodiesterase-5 within the arterial muscle layer. Sildenafil citrate produced dose dependent vasodilatation at concentrations at and greater than 10 nM. Both the direct cGMP inhibitor methylene blue and the cGMP-dependent protein kinase inhibitor Rp-8-Br-PET-cGMPS significantly attenuated the vasodilation produced by sildenafil citrate. Inhibition of NO production with L-NAME did not attenuate the vasodilator effects of sildenafil. In contrast, sildenafil citrate significantly enhanced the vasodilation produced by the NO donor sodium nitroprusside. CONCLUSION: Phosphodiesterase-5 is present in the feto-placental circulation. Sildenafil citrate vasodilates the feto-placental circulation via a cGMP dependent mechanism involving increased responsiveness to NO.

  11. Management options for the treatment of benign prostatic hyperplasia with or without erectile dysfunction: a focus on tadalafil and patient considerations

    Directory of Open Access Journals (Sweden)

    Alsaikhan B


    Full Text Available Bader Alsaikhan, Khalid Alrabeeah, Serge CarrierMcGill University Health Centre, Montreal, Quebec, QC, CanadaAbstract: Lower urinary tract symptoms (LUTS and erectile dysfunction increase with age. Several studies have identified a true association between these two disorders. Basic research studies have shown a significant decrease in the nitric oxide/cyclic guanosine monophosphate pathway with age that leads to decreased relaxation of the bladder wall and prostate and worsening LUTS. In this review article, we will focus on the potential use and clinical significance of phosphodiesterase-5 inhibitors in the treatment of LUTS secondary to benign prostate hyperplasia.Keywords: lower urinary tract symptoms, phosphodiesterase-5 inhibitors

  12. Biofilm formation and antibiotic production in Ruegeria mobilis are influenced by intracellular concentrations of cyclic dimeric guanosinmonophosphate

    DEFF Research Database (Denmark)

    D'Alvise, Paul; Magdenoska, Olivera; Melchiorsen, Jette


    species Ruegeria mobilis are associated with intracellular concentrations of the signal compound cyclic dimeric guanosinmonophosphate (c-di-GMP), which in bacteria regulates transitions between motile and sessile life stages. Genes for diguanylate cyclases and phosphodiesterases, which are involved in c...... formation and production of the potent antibiotic tropodithietic acid (TDA). An introduced phosphodiesterase gene decreased c-di-GMP and reduced biofilm formation and TDA production. tdaC, a key gene for TDA biosynthesis, was expressed only in attached or biofilm-forming cells, and expression was induced...

  13. Hemorrhagic Cholecystitis in an Elderly Patient Taking Aspirin and Cilostazol

    Directory of Open Access Journals (Sweden)

    David S. Morris


    Full Text Available Hemorrhage is a rare complication of acute cholecystitis. Patients who develop this complication often are receiving anticoagulation therapy or have a pathologic coagulopathy. We present a case of an elderly patient who developed hemorrhagic cholecystitis while taking aspirin and cilostazol, a phosphodiesterase inhibitor. The patient underwent an emergent abdominal exploration. A large, blood-filled gallbladder was found along with a large hematoma between the liver and gallbladder. We also briefly review the literature regarding hemorrhagic cholecystitis, hemorrhage into the biliary tree, and hemorrhage as a complication of aspirin and phosphodiesterase inhibitor therapy.

  14. Cerebral haemodynamic response or excitability is not affected by sildenafil

    DEFF Research Database (Denmark)

    Kruuse, Christina; Hansen, Adam E; Larsson, Henrik B W


    Sildenafil (Viagra), a cyclic guanosine monophosphate-degrading phosphodiesterase 5 inhibitor, induces headache and migraine. Such headache induction may be caused by an increased neuronal excitability, as no concurrent effect on cerebral arteries is found. In 13 healthy females (23+/-3 years, 70...

  15. Migraine can be induced by sildenafil without changes in middle cerebral artery diameter

    DEFF Research Database (Denmark)

    Kruuse, Christina Rostrup; Thomsen, Lars Lykke; Birk, Steffen


    GMP)-mediated vasodilatation. We examined whether sildenafil (Viagra), a selective inhibitor of cGMP-hydrolysing phosphodiesterase 5 (PDE5), which acts exclusively by increasing cGMP, can induce migraine and dilatation of cerebral arteries. We included 12 patients with migraine without aura in this double-blind, placebo...

  16. Development of ATX and DUSP inhibitors : inhibiting phosphate ester hydrolysis in biology

    NARCIS (Netherlands)

    Albers, Harald Matheas Henricus Gerardus


    The first part of this thesis describes the development of inhibitors of autotaxin (ATX or ENPP2), a phosphodiesterase that is responsible for the production of the lipid lysophosphatidic acid (LPA) in the circulation. ATX is implicated in several diseases including inflammation, fibrotic disease

  17. Outcome of Pediatric Patients With Pulmonary Arterial Hypertension in the Era of New Medical Therapies

    NARCIS (Netherlands)

    van Loon, Rosa Laura E.; Roofthooft, Marcus T. R.; Delhaas, Tammo; van Osch-Gevers, Magdalena; ten Harkel, Arend D. J.; Strengers, Jan L. M.; Backx, Ad; Hillege, Hans L.; Berger, Rolf M. F.


    Little is known about the effects of "second-generation drugs" (prostanoids, endothelin receptor antagonists, 5-phosphodiesterase inhibitors) in children with pulmonary arterial hypertension (PAH). This study describes the outcome of a national cohort of children with PAH in an era when these drugs

  18. Genomewide Association Study of African Children Identifies Association of SCHIP1 and PDE8A with Facial Size and Shape

    Czech Academy of Sciences Publication Activity Database

    Cole, J.B.; Manyama, M.; Kimwaga, E.; Mathayo, J.; Larson, J.R.; Liberton, D.K.; Lukowiak, K.; Ferrara, T.M.; Riccardi, S.L.; Li, M.; Mio, W.; Procházková, Michaela; Williams, T.; Li, H.; Jones, K. L.; Klein, O. D.; Santorico, S.A.; Hallgrimsson, B.; Spritz, R.A.


    Roč. 12, č. 8 (2016), č. článku e1006174. ISSN 1553-7404 Institutional support: RVO:68378050 Keywords : cause char-syndrome * wide association * phosphodiesterase 8a * heritability * recognition * mutations * allometry * variants * parents Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.100, year: 2016

  19. Mænd med rejsningsbesvær efter radikal prostatektomi bør behandles efter sædvanlige retningslinjer

    DEFF Research Database (Denmark)

    Fode, Mikkel; Hansen, Rikke Bølling; Maigaard, Thomas


    Penile rehabilitation programmes aim to improve long-term sexual function after nerve-sparing radical prostatectomy. Programmes aim to improve cavernous oxygenation to avoid structural damage in penile tissue. Especially, daily use of phosphodiesterase type 5 (PDE5) inhibitors has been studied. T......, urethral suppositories and penile implants....

  20. Mænd med rejsningsbesvær efter radikal prostatektomi bør behandles efter sædvanlige retningslinjer

    DEFF Research Database (Denmark)

    Fode, Mikkel; Hansen, Rikke Bølling; Maigaard, Thomas


    Penile rehabilitation programmes aim to improve long-term sexual function after nerve-sparing radical prostatectomy. Programmes aim to improve cavernous oxygenation to avoid structural damage in penile tissue. Especially, daily use of phosphodiesterase type 5 (PDE5) inhibitors has been studied. T......, urethral suppositories and penile implants....

  1. Erectile Dysfunction Among Men Attending Surgical Outpatients ...

    African Journals Online (AJOL)

    LTFUP: Lost to follow-up, PDE5-I: Phosphodiesterase Type 5 inhibitor, ORX: Other therapy such as modification of antihypertensives, anxiolytics, physiotherapy, intramuscular testosterone, varicocelctomy rehydration, and analgesics of study, there were 16 patients, and this dropped to seven at the last year of study with an ...

  2. Darunavir (United States)

    ... to treat human immunodeficiency virus (HIV) infection in adults and children 3 years of age and older. Darunavir is in a class of medications called ... certain phosphodiesterase inhibitors (PDE-5 inhibitors) used for erectile dysfunction such as avanafil (Stendra), sildenafil (Viagra), tadalafil (Cialis), ...

  3. Avanafil for treatment of erectile dysfunction: review of its potential

    Directory of Open Access Journals (Sweden)

    Burke RM


    Full Text Available Ryan M Burke,1 Jeffery D Evans21The University of Louisiana at Monroe College of Pharmacy, Monroe, LA, 2The University of Louisiana at Monroe College of Pharmacy, Shreveport, LA, USAAbstract: Avanafil is a medication that was recently approved by the US Food and Drug Administration for the management of erectile dysfunction. Avanafil is a new phosphodiesterase type 5 inhibitor similar to sildenafil and tadalafil. Avanafil was studied in over 1300 patients during clinical trials, including patients with diabetes mellitus and those who had undergone radical prostatectomy, and was found to be more effective than placebo in all men who were randomized to the drug. The medication was studied with on-demand dosing that may occur after food and/or alcohol. Avanafil is dosed as 50 mg, 100 mg, or 200 mg tablets. Avanafil may differentiate itself from the other phosphodiesterase type 5 inhibitors with its quicker onset and higher specificity for phosphodiesterase type 5 versus other phosphodiesterase subtypes, but may lead to complications of therapy.Keywords: avanafil, safety, efficacy, erectile dysfunction

  4. Does tadalafil prevent erectile dysfunction in patients undergoing radiation therapy for prostate cancer?

    NARCIS (Netherlands)

    L. Incrocci (Luca)


    textabstractA recently published paper addressed the interesting topic of prevention of erectile dysfunction (ED) with tadalafil, a phosphodiesterase-type 5 inhibitor (PDE5i) in patients undergoing radiation therapy for localized prostate cancer. [1]Tadalafil 5 mg or placebo was

  5. Type B Aortic Dissection After the Use of Tadalafil

    NARCIS (Netherlands)

    Lameijer, Charlotte M.; Tielliu, Ignace F. J.; van Driel, Mels F.; Zeebregts, Clark J.

    A 63-year-old male patient with a type B aortic dissection after the use of tadalafil, a phosphodiesterase type 5 inhibitor, is presented. The possible role of a novel predisposing factor-sexual activity combined with tadalafil-is reviewed. This report and three other cases add a new dimension to

  6. Effect of tadalafil on blood flow, pain, and function in chronic cold Complex Regional Pain Syndrome: A randomized controlled trial

    NARCIS (Netherlands)

    J.G. Groeneweg (George); F.J.P.M. Huygen (Frank); S.P. Niehof (Sjoerd); F. Wesseldijk (Feikje); J.B.J. Bussmann (Hans); F.C. Schasfoort (Fabiënne); D.L. Stronks (Dirk); F.J. Zijlstra (Freek)


    textabstractBackground. This double-blind, randomized, controlled trial investigated the effect of the phosphodiesterase-5 inhibitor tadalafil on the microcirculation in patients with cold Complex Regional Pain Syndrome (CRPS) in one lower extremity. Methods. Twenty-four patients received 20 mg

  7. The pharmacological management of erectile dysfunction – Update ...

    African Journals Online (AJOL)

    Erectile dysfunction (ED) is a trivial condition with a prevailing incidence worldwide. Phosphodiesterase-5 inhibitors (PDE-5) have revolutionised the treatment of ED and are regarded as one of the most successful drug groups in modern medicine. Generally PDE-5 inhibitors are well tolerated and the incidence of ...

  8. Pharmacotherapy of erectile dysfunction: Current standards

    Directory of Open Access Journals (Sweden)

    Kew-Kim Chew


    Full Text Available Pharmacotherapy is currently the therapeutic option of choice for erectile dysfunction. Comprising mainly intracavernosal injection therapy using alprostadil or alprostadil combined with phentolamine and/or papaverine and oral phosphodiesterase-5 inhibitors, it is safe and effective if appropriately prescribed and administered. The medications in current use produce satisfactory erectile responses by enhancing cavernosal vasodilatation mainly through their ability to promote relaxation of the smooth muscle cells in the corpora cavernosa involving the synthesis and activity of nitric oxide via the cyclic guanosine monophosphate and cyclic adenosine monophosphate biochemical pathways. The main side-effects and complications of intracavernosal injections are postinjection pain, prolonged erections, priapism and penile fibrosis. There may be a variety of side-effects with phosphodiesterase-5 inhibition but these are usually inconsequential. Recent serious ill health and the need for ongoing long-acting nitrate therapy or frequent use of short-acting nitrates for angina are absolute contraindications to the use of phosphodiesterase-5 inhibitors. Caution has to be exercised in prescribing phosphodiesterase-5 inhibitors for patients with impaired renal or hepatic functions or receiving multi-drug therapy for any systemic disease. All patients presenting with erectile dysfunction should be investigated and treated for cardiovascular risk factors. They should also be counseled regarding lifestyle factors particularly healthy balanced diet, regular physical exercise and inappropriate social habits.

  9. The Wonders of Phosphodiesterase‑5 Inhibitors: A Majestic History ...

    African Journals Online (AJOL)

    The main enzyme involved in the termination of cGMP effects is phosphodiesterase enzyme 5 (PDE‑5), which is overexpressed in ventricular hypertrophy and heart failure. A milestone in drug discovery was the selective inhibitors of PDE‑5 that developed to be a multibillion dollar blockbuster in drug market. PDE‑5 ...

  10. Effect of gamma irradiation on the production and degradation system of the second hormonal messenger

    International Nuclear Information System (INIS)

    Tine, J.; Kergonou, J.F.; Rocquet, G.


    Gamma irradiation of rat liver plasma membranes leads to a decrease of the adenylcyclase activities stimulated by glucagon and fluoride. The observed inhibition is more important for the activity stimulated with glucagon. The 5'-nucleotisade activity is not changed by irradiation. When the phosphodiesterase system is submitted to gamma irradiation, the radiosensibility of enzymatic complex is more important [fr

  11. N Termini of apPDE4 Isoforms Are Responsible for Targeting the Isoforms to Different Cellular Membranes (United States)

    Jang, Deok-Jin; Park, Soo-Won; Lee, Jin-A; Lee, Changhoon; Chae, Yeon-Su; Park, Hyungju; Kim, Min-Jeong; Choi, Sun-Lim; Lee, Nuribalhae; Kim, Hyoung; Kaang, Bong-Kiun


    Phosphodiesterases (PDEs) are known to play a key role in the compartmentalization of cAMP signaling; however, the molecular mechanisms underlying intracellular localization of different PDE isoforms are not understood. In this study, we have found that each of the supershort, short, and long forms of apPDE4 showed distinct localization in the…

  12. Critical finger ischemia and myocardial fibrosis development after sudden interruption of sildenafil treatment in a systemic sclerosis patient. (United States)

    Bruni, C; Bellando-Randone, S; Gargani, L; Picano, E; Pingitore, A; Matucci-Cerinic, M; Guiducci, S


    Systemic sclerosis (SSc) is a connective tissue disease frequently associated with Raynaud's Phenomenon (RP). Among possible pharmacological treatments, phosphodiesterase 5 inhibitors are considered in cases of severe non -responsive RP. We present the case of a male SSc patient wh presented with critical finger ischemia and concomitant appearance of myocardial fibrosis after sudden interruption of sildenafil treatment.

  13. The cardiovascular effects of methylxanthines

    NARCIS (Netherlands)

    Riksen, N.P.; Smits, P.; Rongen, G.A.P.J.M.


    In the concentration range that is normally achieved in humans, e.g., after the drinking of coffee or in patients treated with theophylline, the cardiovascular effects of methylxanthines are primarily due to antagonism of adenosine A(1) and A(2) receptors. Inhibition of phosphodiesterases or

  14. Sildenafil does not influence hepatic venous pressure gradient in patients with cirrhosis

    DEFF Research Database (Denmark)

    Clemmesen, Jens-Otto; Giraldi, Annamaria; Ott, Peter


    AIM: To investigate if sildenafil increases splanchnic blood flow and changes the hepatic venous pressure gradient (HVPG) in patients with cirrhosis. Phosphodiesterase type-5 inhibitors are valuable in the treatment of erectile dysfunction and pulmonary hypertension in patients with end-stage liver...

  15. A reversed phase HPLC method for the analysis of nucleotides to ...

    African Journals Online (AJOL)

    5'-Phosphodiesterase (5'-PDE) can be extracted from barley roots and used as a catalyst in the hydrolysis of RNA to produce 5'-nucleotides. The assay of enzyme activity is essential for the production of 5'-PDE. To improve the conventional assays, we developed and validated a new method for the analysis of 5'-PDE ...

  16. Sildenafil does not influence hepatic venous pressure gradient in patients with cirrhosis

    DEFF Research Database (Denmark)

    Clemmesen, Jens-Otto; Giraldi, Annamaria; Ott, Peter


    disease. However, the effect of phosphodiesterase type-5 inhibitors on splanchnic blood flow and portal hypertension remains essentially unknown. METHODS: Ten patients with biopsy proven cirrhosis (five females/five males, mean age 54 +/- 8 years) and an HVPG above 12 mmHg were studied after informed...

  17. Pharmacotherapy of pulmonary hypertension (according to the 2015 ESC/EAS Guidelines for the diagnosis and treatment of pulmonary hypertension

    Directory of Open Access Journals (Sweden)

    E. L. Trisvetova


    Full Text Available Indications and efficacy of drugs used for the treatment of pulmonary hypertension are considered. Stages of the treatment of pulmonary arterial hypertension are discussed, including maintenance therapy, specific therapy with calcium channel blockers, prostacyclin analogues, endothelin receptor antagonists, phosphodiesterase-5 inhibitors, prostacyclin agonists, guanylate cyclase stimulators, combination treatment.

  18. Pharmacotherapy of pulmonary hypertension (according to the 2015 ESC/EAS Guidelines for the diagnosis and treatment of pulmonary hypertension)


    E. L. Trisvetova; S. V. Gubkin


    Indications and efficacy of drugs used for the treatment of pulmonary hypertension are considered. Stages of the treatment of pulmonary arterial hypertension are discussed, including maintenance therapy, specific therapy with calcium channel blockers, prostacyclin analogues, endothelin receptor antagonists, phosphodiesterase-5 inhibitors, prostacyclin agonists, guanylate cyclase stimulators, combination treatment.

  19. Agro 02

    African Journals Online (AJOL)

    5'monophosphate (cAMP). The cAMP triggers the production of sensitive lipase and hydrolysis of fat. The function of phosphodiesterase is to reduce the hydrolysis of fat and causes the animal to loss weight (Guyton, 1969) and possibly abdominal fat. Theobromine through the action of cAMP brings about lipolysis (Joseph, ...

  20. Lithocholic acid disrupts phospholipid and sphingolipid homeostasis leading to cholestasis


    Matsubara, Tsutomu; Tanaka, Naoki; Patterson, Andrew D.; Cho, Joo-Youn; Krausz, Kristopher W.; Gonzalez, Frank J.


    Lithocholic acid (LCA) is an endogenous compound associated with hepatic toxicity during cholestasis. LCA exposure in mice resulted in decreased serum lysophosphatidylcholine (LPC) and sphingomyelin levels due to elevated lysophosphatidylcholine acyltransferase (LPCAT) and sphingomyelin phosphodiesterase (SMPD) expression. Global metabolome analysis indicated significant decreases in serum palmitoyl-, stearoyl-, oleoyl- and linoleoyl-LPC levels after LCA exposure. LCA treatment also resulted ...

  1. Possible Overlapping Time Frames of Acquisition and Consolidation Phases in Object Memory Processes: A Pharmacological Approach (United States)

    Akkerman, Sven; Blokland, Arjan; Prickaerts, Jos


    In previous studies, we have shown that acetylcholinesterase inhibitors and phosphodiesterase inhibitors (PDE-Is) are able to improve object memory by enhancing acquisition processes. On the other hand, only PDE-Is improve consolidation processes. Here we show that the cholinesterase inhibitor donepezil also improves memory performance when…

  2. 75 FR 12764 - Government-Owned Inventions; Availability for Licensing (United States)


    ... mammary glands. These cells lines were obtained from spontaneously transformed primary cell cultures...), NIH, have made available samples of patient-derived adrenal and heart tumors that harbor genetic.... Commercially, phosphodiesterase inhibitors are widely used in the treatment of various disorders, including...

  3. Decreased catalytic activity and altered activation properties of PDE6C mutants associated with autosomal recessive achromatopsia

    DEFF Research Database (Denmark)

    Grau, Tanja; Artemyev, Nikolai O; Rosenberg, Thomas


    Mutations in the gene encoding the catalytic subunit of the cone photoreceptor phosphodiesterase (PDE6C) have been recently reported in patients with autosomal recessive inherited achromatopsia (ACHM) and early-onset cone photoreceptor dysfunction. Here we present the results of a comprehensive...

  4. Lipopolysaccharide induces expression of tumour necrosis factor alpha in rat brain : inhibition by methylprednisolone and by rolipram

    NARCIS (Netherlands)

    Buttini, M; Mir, A; Appel, K; Wiederhold, KH; Limonta, S; GebickeHaerter, PJ; Boddeke, HWGM


    1 We have investigated the effects of the phosphodiesterase (PDE) type TV inhibitor rolipram and of the glucocorticoid methylprednisolone on the induction of tumour necrosis factor alpha (TNF-alpha) mRNA and protein in brains of rats after peripheral administration of lipopolysaccharide (LPS). 2

  5. substituted pyrazoles

    Indian Academy of Sciences (India)

    the development of Alzheimer's disease.3 Other exam- ples are Sildenafil,4 an inhibitor of 5-phosphodiesterase, used for the treatment of erectile dysfunction, Cele- brex, an inhibitor of cyclooxygenase-2 (COX-2), used as potent antiinflammatory,5 and Acomplia, antagonist of the CB-1 cannabinoid receptor, used for the ...

  6. Syntetické modely metaloenzymů katalyzující štěpení fosfodiesterové vazby

    Czech Academy of Sciences Publication Activity Database

    Bím, Daniel; Rulíšek, Lubomír; Hodačová, J.


    Roč. 109, č. 9 (2015), s. 658-665 ISSN 0009-2770 Institutional support: RVO:61388963 Keywords : synthetic models of phosphodiesterases * metalloenzymes * phosphate ester bond cleavage Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.279, year: 2015

  7. Women taking the "blue pill" (sildenafil citrate): such a big deal? (United States)

    Lo Monte, Giuseppe; Graziano, Angela; Piva, Isabella; Marci, Roberto


    For years, phosphodiesterase type 5 inhibitors have been used for the treatment of erectile dysfunctions. Due to the similarities between male and female sexual response, several studies have assessed the effects of sildenafil citrate (Viagra(®)) in women affected by female sexual arousal disorder. The results are still conflicting and the drug is not devoid of adverse effects. Furthermore, female sexual arousal disorder is a heterogeneous condition whose underlying causes are difficult to diagnose and appropriate treatment requires a thorough sexual, psychological, and medical history along with specialist consultations. The clinician should pursue a global approach to the patient with sexual difficulties, while non-hormonal treatment such as phosphodiesterase type 5 inhibitors (ie, sildenafil citrate) should be kept as the last option.

  8. Women taking the “blue pill” (sildenafil citrate): such a big deal? (United States)

    Lo Monte, Giuseppe; Graziano, Angela; Piva, Isabella; Marci, Roberto


    For years, phosphodiesterase type 5 inhibitors have been used for the treatment of erectile dysfunctions. Due to the similarities between male and female sexual response, several studies have assessed the effects of sildenafil citrate (Viagra®) in women affected by female sexual arousal disorder. The results are still conflicting and the drug is not devoid of adverse effects. Furthermore, female sexual arousal disorder is a heterogeneous condition whose underlying causes are difficult to diagnose and appropriate treatment requires a thorough sexual, psychological, and medical history along with specialist consultations. The clinician should pursue a global approach to the patient with sexual difficulties, while non-hormonal treatment such as phosphodiesterase type 5 inhibitors (ie, sildenafil citrate) should be kept as the last option. PMID:25422584

  9. Cardiovascular drugs and erectile dysfunction - a symmetry analysis

    DEFF Research Database (Denmark)

    Rasmussen, Lotte; Hallas, Jesper; Madsen, Kenneth Grønkjaer


    for erectile dysfunction (NNTH). RESULTS: We identified 20 072 males with a median age of 64 years (IQR 60-70) who initiated a cardiovascular drug and a 5-phosphodiesterase inhibitor within a 6 month interval. Sequence ratios showed minor asymmetry in prescription orders after adjustment for trends......AIM: Erectile dysfunction is a common problem among patients with cardiovascular diseases and the influence of cardiovascular drugs is much debated. The aim of this study was to evaluate the short term potential for different cardiovascular drugs to affect the risk of being prescribed a drug...... against erectile dysfunction. METHODS: We employed a symmetry analysis design and included all Danish male individuals born before 1950 who filled their first ever prescription for a cardiovascular drug and a 5-phosphodiesterase inhibitor within a 6 month interval during 2002-2012. If the cardiovascular...

  10. Cyclic AMP system in muscle tissue during prolonged hypokinesia (United States)

    Antipenko, Y. A.; Bubeyev, Y. A.; Korovkin, B. F.; Mikhaleva, N. P.


    Components of the cyclic Adenosine-cyclic-35-monophosphate (AMP) system in the muscle tissue of white rats were studied during 70-75 days of hypokinesia, created by placing the animals in small booths which restricted their movements, and during the readaptation period. In the initial period, cyclic AMP levels and the activities of phosphodiesterase and adenylate cyclase in muscle tissue were increased. The values for these indices were roughly equal for controls and experimental animals during the adaptation period, but on the 70th day of the experiment cAMP levels dropped, phosphodiesterase activity increased, and the stimulative effect of epinephrine on the activity of adenylate cyclase decreased. The indices under study normalized during the readaptation period.

  11. Depressing effect of caffeine at crayfish neuromuscular synapses II. Initial search for possible sites of action. (United States)

    Celenza, Kathryn M; Shugert, Elizabeth; Vélez, Samuel J


    Caffeine's unexpected depression of synaptic transmission in the superficial flexor muscle system (SFM) of Procambarus clarkii was studied by looking at three known sites of action of this drug: via adenosine and ryanodine receptors and inhibition of phosphodiesterase.1. JPs did not change in size when exposed to physiological concentrations of adenosine, suggesting that the SFM system lacks presynaptic adenosine receptors.2. JPs slightly increased in size in the presence of a phosphodiesterase inhibitor, the opposite response to that obtained with caffeine, suggesting that caffeine is not acting via this pathway.3. A calcium ionophore immediately enhanced synaptic transmission in the SFM system but when given in combination with caffeine the enhancement is reduced and declines over time.4. Serotonin enhanced synaptic transmission in the SFM system, but when given in combination with caffeine this enhancement was not observed.5. These caffeine effects are interpreted in terms of alterations to the calcium homeostatic mechanisms of the terminals.

  12. Tadalafil para o tratamento da hipertensão arterial pulmonar idiopática Tadalafil as treatment for idiopathic pulmonary arterial hypertension

    Directory of Open Access Journals (Sweden)

    Adriana Castro de Carvalho


    Full Text Available O uso de inibidores de fosfodiesterase, mais especificamente o sildenafil, no tratamento da hipertensão arterial pulmonar mostrou bons resultados, indicados por melhora dos parâmetros hemodinâmicos e da capacidade funcional. Poucos estudos existem a respeito dos efeitos de seus análogos como o tadalafil. O presente caso refere-se a uma paciente com hipertensão arterial pulmonar idiopática em classe funcional IV (NYHA com resposta significativa ao uso de tadalafil.Phosphodiesterase inhibitors like sildenafil have already been shown to improve functional capacity and hemodynamics in the treatment of pulmonary arterial hypertension. Few studies address the effects of new phosphodiesterase inhibitors as tadalafil. We report a case of a patient with idiopathic pulmonary arterial hypertension in functional class IV (New York Heart Association with significant response to treatment with tadalafil.

  13. Effects of cholera toxin and isobutylmethylxanthine on growth of human fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza, B.; Wharton, W.


    Cholera toxin produced a dose-dependent decrease in the restimulation of G0/G1 traverse in density-arrested human fibroblasts but did not inhibit the stimulation of cells arrested in G0 after serum starvation at low density. In addition, cholera toxin did not inhibit the proliferation of sparse logarithmically growing human fibroblasts, even when low concentrations of the phosphodiesterase inhibitor isobutylmethylxanthine (IBMX) were also present. However, the final density to which sparse cells grew was limited by cholera toxin, when added either alone or together with low concentrations of IBMX. In contrast, high concentrations of the phosphodiesterase inhibitor alone produced a profound inhibition in the growth of sparse human fibrobasts. IBMX produced an inhibition both in the G1 and in the G2 phases of the cell cycle by a mechanism(s) that was not related to the magnitude of the increases in adenosine 3,5-cyclic monophosphate concentrations.

  14. Sildenafil citrate for female sexual arousal disorder: a future possibility? (United States)

    Schoen, Corina; Bachmann, Gloria


    Female sexual arousal disorder (FSAD) is a common disorder encountered in clinical practice, with self-reported arousal difficulties reported in up to 26% of American women. Various oral therapies for FSAD have been studied, including sildenafil citrate, a phosphodiesterase inhibitor that is currently used to treat male erectile dysfunction. In vitro studies of sildenafil citrate have demonstrated smooth-muscle relaxation in clitoral tissue, and phosphodiesterase type-5 has been shown to be present in vaginal, clitoral and labial smooth muscle; these findings have led to theories that sildenafil citrate might be successful for treating FSAD. This Review discusses the data from clinical trials that have assessed sildenafil citrate for the treatment of FSAD; the trials show that sildenafil citrate is moderately effective. Sildenafil citrate may also be effective in women with FSAD secondary to multiple sclerosis, diabetes or antidepressant use; however, more trials in these patient populations are required to confirm these findings.

  15. Pharmacological analysis of feeding in a caterpillar: different transduction pathways for umami and saccharin? (United States)

    Pszczolkowski, Maciej A.; Durden, Kevin; Marquis, Juleah; Ramaswamy, Sonny B.; Brown, John J.


    Neonate larvae of codling moth, Cydia pomonella (L.), modify their behavior in the presence of saccharin, monosodium glutamate (MSG), or L(+)-2-amino-4-phosphonobutyric acid (L-AP4) by commencing their feeding earlier. Previously published pharmacological analysis demonstrated that phagostimulatory effects of MSG and L-AP4 (which elicit umami taste sensation in humans) are reversed by adenylate cyclase activator and phosphodiesterase inhibitor. In this study, by measuring the time needed to start ingestion of foliage treated with mixtures of phagostimulants and signal transduction modulators, we show that phagostimulatory effects of l-aspartate (the third hallmark umami substance) are also abolished by both adenylate cyclase activator and phosphodiesterase inhibitor, but not by phospholipase C inhibitor. However, stimulatory effects of hemicalcium saccharin were affected only by phospholipase C inhibitor. The results suggest that codling moth neonates use different transduction pathways for perception of hemicalcium saccharin and umami.

  16. Testosterone therapy improves erectile function and libido in hypogonadal men. (United States)

    Rizk, Paul J; Kohn, Taylor P; Pastuszak, Alexander W; Khera, Mohit


    Erectile dysfunction and decreased libido are common complaints in the older male population. Recent studies have elucidated the role testosterone therapy (TTh) can play in men with low testosterone levels. The aim of this review is to provide an overview of these findings and the utility of TTh. We specifically examine the role of TTh on erectile function, coadministration with phosphodiesterase type 5 inhibitors, and libido. Recent publications suggest that TTh improves mild erectile dysfunction, though may be less useful in men with more severe erectile dysfunction. In men unresponsive to phosphodiesterase type 5 inhibitors and with mild erectile dysfunction, TTh can further improve erectile function. TTh has also shown consistent benefit in improving libido in men with low testosterone levels at baseline, with no additional improvements once testosterone levels are normalized. The available literature supports a role for TTh in men with low testosterone levels, erectile dysfunction, and low libido, with symptomatic improvement in these men.

  17. Effects of cholera toxin and isobutylmethylxanthine on growth of human fibroblasts

    International Nuclear Information System (INIS)

    Espinoza, B.; Wharton, W.


    Cholera toxin produced a dose-dependent decrease in the restimulation of G 0 /G 1 traverse in density-arrested human fibroblasts but did not inhibit the stimulation of cells arrested in G 0 after serum starvation at low density. In addition, cholera toxin did not inhibit the proliferation of sparse logarithmically growing human fibroblasts, even when low concentrations of the phosphodiesterase inhibitor isobutylmethylxanthine (IBMX) were also present. However, the final density to which sparse cells grew was limited by cholera toxin, when added either alone or together with low concentrations of IBMX. In contrast, high concentrations of the phosphodiesterase inhibitor alone produced a profound inhibition in the growth of sparse human fibrobasts. IBMX produced an inhibition both in the G 1 and in the G 2 phases of the cell cycle by a mechanism(s) that was not related to the magnitude of the increases in adenosine 3,5-cyclic monophosphate concentrations

  18. Apremilast for the management of moderate to severe plaque psoriasis. (United States)

    Vangipuram, Ramya; Alikhan, Ali


    Psoriasis is a chronic inflammatory skin disease characterized by erythematous plaques on extensor surfaces, scalp, and back. Current therapies for psoriasis are limited by route of administration, side effects, and cost. Apremilast is the first oral phosphodiesterase inhibitor approved for moderate-to-severe plaque psoriasis. It is a small molecule inhibitor of phosphodiesterase-4, and decreases the inflammatory activity associated with psoriasis. Areas covered: This review will discuss the pharmacology of apremilast, mechanism of action, results from key clinical trials, and its use in managing psoriasis. Currently approved treatments are also discussed. Expert commentary: The advantages of apremilast include convenient oral administration and dosing, a favorable safety and tolerability profile, and significant efficacy in moderate-to-severe plaque psoriasis.

  19. Repair of DNA treated with γ-irradiation and chemical carcinogens. Comprehensive report of entire period of ERDA support from June 1, 1975--January 15, 1978

    International Nuclear Information System (INIS)

    Goldthwait, D.A.


    A partially purified enzyme fraction isolated from E. coli showed an N-glycosidase activity as well as a phosphodiesterase activity on DNA treated with methylnitrosourea, and with 7-bromomethylbenz(a)anthracene and a phosphodiesterase activity against γ-irradiated DNA. Both 0-6 methyl guanine and 3-methyladenine were released from DNA treated with MNU; the adenine and guanine derivatives from the DNA treated with 7-bromomethyl-12-methylbenz(a)anthracene were also liberated. Progress is also reported on studies on Endonucleases II and VI and Exonuclease III of E. coli; methods for assay and for synthesis of substrates; attempts at purification of repair enzymes from mammalian tissues; and β-propiolactone reactions with deoxynucleosides and with DNA

  20. Distribution in rat tissues of modulator-binding protein of particulate nature

    International Nuclear Information System (INIS)

    Sobue, K.; Muramoto, Y.; Kakiuchi, S.; Yamazaki, R.


    Studies on Ca 2+ -activatable cyclic nucleotide phosphodiesterase led to the discovery of a protein modulator that is required for the activation of this enzyme by Ca 2+ . Later, this protein has been shown to cause the Ca 2+ -dependent activation of several enzymes that include phosphodiesterase, adenylate cyclase, a protein kinase from muscles, phosphorylase b kinase, actomyosin ATPase, membranous ATPase from erythrocytes and nerve synapses. Thus, modulator protein appears to be an intracellular mediator of actions of Ca 2+ . The present work shows the distribution of this particulate modulator-binding component in rat tissues. This paper also describes the labeling of modulator protein with tritium without deteriorating its biological activities and application of this 3 H-modulator protein to the determination of the Ca ++ dependent binding of modulator protein with membranous protein. This technique proves to be useful in studying enzymes or proteins whose functions are regulated by Ca ++ /modulator protein system. (Auth.)

  1. New Drugs and Treatment Targets in Psoriasis

    DEFF Research Database (Denmark)

    Kofoed, Kristian; Skov, Lone; Zachariae, Claus


    , and phosphodiesterase inhibitors. We review published clinical trials, and conference abstracts presented during the last years, concerned with new drugs under development for the treatment of psoriasis. In conclusion, our psoriasis armamentarium will be filled with several new effective therapeutic options the coming...... years. We need to be aware of the limitations of drug safety data when selecting new novel treatments. Monitoring and clinical registries are still important tools....

  2. Microgravity changes in heart structure and cyclic-AMP metabolism (United States)

    Philpott, D. E.; Fine, A.; Kato, K.; Egnor, R.; Cheng, L.


    The effects of microgravity on cardiac ultrastructure and cyclic AMP metabolism in tissues of rats flown on Spacelab 3 are reported. Light and electron microscope studies of cell structure, measurements of low and high Km phosphodiesterase activity, cyclic AMP-dependent protein kinase activity, and regulatory subunit compartmentation show significant deviations in flight animals when compared to ground controls. The results indicate that some changes have occurred in cellular responses associated with catecholamine receptor interactions and intracellular signal processing.

  3. Theobromine up-regulates cerebral brain-derived neurotrophic factor and facilitates motor learning in mice


    Yoneda, Mitsugu; Sugimoto, Naotoshi; Katakura, Masanori; Matsuzaki, Kentaro; Tanigami, Hayate; Yachie, Akihiro; Ohno-Shosaku, Takako; Shido, Osamu


    Theobromine, which is a caffeine derivative, is the primary methylxanthine produced by Theobroma cacao. Theobromine works as a phosphodiesterase (PDE) inhibitor to increase intracellular cyclic adenosine monophosphate (cAMP). cAMP activates the cAMP-response element-binding protein (CREB), which is involved in a large variety of brain processes, including the induction of the brain-derived neurotrophic factor (BDNF). BDNF supports cell survival and neuronal functions, including learning and m...

  4. USSR Report, Life Sciences, Biomedical and Behavioral Sciences (United States)


    Introduction of Nitrogen-Fixing Cyanobacterium t° Tobacco Plants (L. V. Pivovarova, T. G. Korzhenevskaya, et al.; IZVESTIYA AKADEMU NAUK SSSR: SERIYA...K+-ATPase (Yu. A. Ovchinnikov, N. Ye. Broude, et al.; DOKLADY AKADEMII NAUK SSSR, No 6, Apr 86) 8 Cyclic GMP -Phosphodiesterase of Bovine...INTRODUCTION OF NITROGEN-FIXING CYANOBACTERIUM TO TOBACCO PLANTS Moscow IZVESTIYA AKADEMII NAUK SSSR: SERIYA BIOLOGICHESKAYA in Russian No 5, Sep-Oct

  5. Tadalafil in the treatment of erectile dysfunction; an overview of the clinical evidence


    Frajese, Giovanni Vanni; Pozzi, Flavio; Frajese, Gaetano


    Prevalence and severity of erectile dysfunction (ED) increase with aging and are often associated with illnesses, like diabetes mellitus, heart disease, and hypertension, pathologically characterized by endothelial dysfunction and whose prevalence increases with age. The assumption that ED is mainly a neurovascular disease is supported by the evidence that specific phosphodiesterase type 5 (PDE5) inhibition produces an efficient erection in a wide range of ages and conditions. The availabilit...

  6. Efecto neuroprotector del sildenafilo frente a la isquemia química inducida por la toxina mitocondrial malonato


    Barros-Miñones, L. (Lucía); Aguirre, N. (Norberto)


    Phosphodiesterase 5 inhibitors (PDE5i) have recently been reported to exert beneficial effects against ischemia-reperfusion injury in several organs but their neuroprotective effects in brain stroke models are scarce. The present study was undertaken to assess the effects of sildenafil against cell death caused by intrastriatal injection of malonate, an inhibitor of succinate dehydrogenase; which produces both energy depletion and lesions similar to those seen in cerebral ischemia. Our data d...

  7. Evaluation of the Adult Goldfish Brain as a Model for the Study of Progenitor Cells (United States)


    degeneración y regeneración del sistema nervioso , Madrid: Moya. English translation: Degeneration and Regeneration of the Nervous System (trans. and...Stratum Moleculare) c-FLIP Cellular FLICE-Inhibitory Protein cm Centimeter CNP 2’, 3’-Cyclic Nucleotide 3’-Phosphodiesterase CNS Central Nervous...System CP Central Posterior Thalamic Nucleus (Nucleus Centralis Posterior Thalami) xviii CY3 Cyanine 3 d Day DAB 3,3’ Diaminobenzidine

  8. Non pigmenting mucosal fixed drug eruption due to tadalafil: A report of two cases

    Directory of Open Access Journals (Sweden)

    Sudip Das


    Full Text Available Various ′sex-stimulant′ medicines with fancy names and attractive packaging are available over the counter. Most contain phosphodiesterase 5 inhibitors in various strengths, often with herbal additions. These drugs are used erratically by the lay public, driven by folklore that such usage leads to increase in the length, girth or firmness of the penis. Such indiscriminate use by an otherwise healthy population leads to undue side effects.

  9. The Siblings With Ischemic Stroke Study (SWISS): A Progress Report


    Meschia, James F.; Kissela, Brett M.; Brott, Thomas G.; Brown, Robert D.; Worrall, Bradford B.; Beck, Jeanne; Skarp, Alexa N.


    There is increasing evidence that genetic factors are associated with ischemic stroke, including multiple recent reports of association with the gene PDE4D, encoding phosphodiesterase 4D, on chromosome 5q12. Genetic studies of stroke are important but can be logistically difficult to perform. This article reviews the design of the Siblings With Ischemic Stroke Study (SWISS) and discusses problems in performing a sibling-based pedigree study where proband-initiated consent is used to enroll pe...

  10. Effect of roflumilast on inflammatory cells in the lungs of cigarette smoke-exposed mice


    Martorana, Piero A; Lunghi, Benedetta; Lucattelli, Monica; De Cunto, Giovanna; Beume, Rolf; Lungarella, Giuseppe


    Abstract Background We reported that roflumilast, a phosphodiesterase 4 inhibitor, given orally at 5 mg/kg to mice prevented the development of emphysema in a chronic model of cigarette smoke exposure, while at 1 mg/kg was ineffective. Here we investigated the effects of roflumilast on the volume density (VV) of the inflammatory cells present in the lungs after chronic cigarette smoke exposure. Methods Slides were obtained from blocks of the previous study and VV was assessed immunohistochemi...

  11. Effect of PDE5 inhibition on the modulation of sympathetic α-adrenergic vasoconstriction in contracting skeletal muscle of young and older recreationally active humans

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin; Piil, Peter Bergmann; Egelund, Jon


    Aging is associated with an altered regulation of blood flow to contracting skeletal muscle; however, the precise mechanisms remain unclear. We recently demonstrated that inhibition of cGMP-binding phosphodiesterase 5 (PDE5) increased blood flow to contracting skeletal muscle of older but not young......- and α2-adrenergic receptors. The level of the sympatholytic compound ATP was measured in venous plasma by use of the microdialysis technique. Sildenafil increased (P

  12. Therapeutische Effekte von Iloprost und dem PDE 3/4-Inhibitor Tolafentrin im Modell der Monocrotalin-induzierten chronischen pulmonalen Hypertonie der Ratte


    Kreißelmeier, Klaus-Peter


    Die schwere pulmonale Hypertonie ist eine erheblich die Lebensqualität einschränkende Erkrankung mit einer hohen Mortalität. Wir untersuchten die therapeutischen Effekte von Iloprost, einem langwirksamen Prostazyklinanalogon, und dem dual-selektiven Phosphodiesterase 3/4-Inhibitor Tolafentrin während akuter Gabe sowie bei Dauertherapie in einem Tiermodell der Monocrotalin-induzierten pulmonalen Hypertonie der Ratte. Achtundzwanzig Tage nach Gabe des Alkaloids war der rechtsventrikuläre syste...

  13. Cell cycle arrest induced by theophylline in root meristem of Haplopappus gracilis. (United States)

    Levi, M; Chiatante, D; Sparvoli, E


    Theophylline, an inhibitor of cyclic nucleotide phosphodiesterase, induced a block of the cell cycle in G1, a temporary arrest in G2 and 70% decrease in the uptake of labelled thymidine in roots of Haplopappus. These effects are compared to those previously found with aminophylline and discussed in view of the possible involvement of cAMP in the regulation of the cell cycle in plants.

  14. Autotaxin (ATX): a multi-functional and multi-modular protein possessing enzymatic lysoPLD activity and matricellular properties. (United States)

    Yuelling, Larra M; Fuss, Babette


    Recent studies have established that autotaxin (ATX), also known as phosphodiesterase Ialpha/autotaxin (PD-Ialpha/ATX) or (ecto)nucleotide pyrophosphatase/phosphodiesterase 2 [(E)NPP2], represents a multi-functional and multi-modular protein. ATX was initially thought to function exclusively as a phosphodiesterase/pyrophosphatase. However, it has become apparent that this enzymatically active site, which is ultimately responsible for ATX's originally discovered property of tumor cell motility stimulation, mediates the conversion of lysophosphatidylcholine (LPC) to lysophosphatidic acid (LPA). In addition, a separate functionally active domain, here referred to as the Modulator of Oligodendrocyte Remodeling and Focal adhesion Organization (MORFO) domain, was discovered in studies analyzing the role of ATX during the differentiation of myelinating cells of the central nervous system (CNS), namely oligodendrocytes. This novel domain was found to mediate anti-adhesive, i.e. matricellular, properties and to promote morphological maturation of oligodendrocytes. In this review, we summarize our current understanding of ATX's structure-function domains and discuss their contribution to the presently known main functional roles of ATX.

  15. Analysis of pyrimidine dimer content of isolated DNA by nuclease digestion

    International Nuclear Information System (INIS)

    Farland, W.H.; Sutherland, B.M.


    Isolated DNA is highly susceptible to degradation by exogenous nucleases. Complete digestion is possible with a number of well-characterized enzymes from a variety of sources. Treatment of DNA with a battery of enzymes including both phosphodiesterase and phosphatase activities yields a mixture of nucleosides and inorganic phosphate (P/sub i/) as a final product. Unlike native DNA, ultraviolet-irradiated DNA is resistant to complete digestion. Setlow et al. demonstrated that the structural changes in the DNA responsible for the nuclease resistance were the formation of cyclobutyl pyrimidine dimers, the major photoproduct in UV-irradiated DNA. Using venom phosphodiesterase, they demonstrated that UV irradiation of DNA affected both the rate and extent of enzymatic hydrolysis. In addition, it was demonstrated that the major nuclease-resistant product of this hydrolysis was an oligonucleotide containing dimerized pyrimidines. Treatment of the DNA to split the dimers, either photochemically or photoenzymatically, rendered the polymer more susceptible to hydrolysis by the phosphodiesterase. The specificity of photoreactivating enzyme for pyrimidine dimers lends support to the role of these structures in conferring nuclease resistance to UV-irradiated DNA. The nuclease resistance of DNA containing dimers has been the basis of several assays for the measurement of these photoproducts. Sutherland and Chamberlin reported the development of a rapid and sensitive assay for dimers in 32 P-labeled DNA

  16. [Treatment of erectile dysfunction in patients with plastic induration of the penis]. (United States)

    Sokol'shchik, M M; Gagarina, S V; Petrovich, R Iu; Sadakova, I V


    In selection of patients with erectile dysfunction perspective for conservative treatment we conducted a sialis-test (oral test with tadalafil which is a vasoactive drug, inhibitor of phosphodiesterase of type 5). In sialis negative test we studied a hormonal status of the patient (testosteron level in the blood serum) and performed dopplerography of penile vessels in the course of intracavernous injection of a vasoactive drug. In 2002-2005 we treated 115 patients with erectile dysfunction suffering from plastic induration of the penis. We gave conservative treatment to 66 patients and surgical treatment - to 50 (43%) patients. All surgical patients had evident alterations of penile vessels of cavernous tissue and were not perspective for conservative treatment. Treatment policy in erectile dysfunction in Peyronie's disease is the following: in positive sialis test the patients receive conservative treatment - inhibitors of phosphodiesterase of type 5; in negative sialis test blood hormones (testosteron) should be measured and penile vessels should be studied (dopplerography). In detection of low level of testosteron and normal penile vessels the patients receive combined treatment - replacement hormonal therapy plus inhibitors of phosphodiesterase type 5. In vascular pathology verified at dopplerography and negative tadalafil test the patients receive surgical treatment.

  17. Structural similarities and functional differences clarify evolutionary relationships between tRNA healing enzymes and the myelin enzyme CNPase. (United States)

    Muruganandam, Gopinath; Raasakka, Arne; Myllykoski, Matti; Kursula, Inari; Kursula, Petri


    Eukaryotic tRNA splicing is an essential process in the transformation of a primary tRNA transcript into a mature functional tRNA molecule. 5'-phosphate ligation involves two steps: a healing reaction catalyzed by polynucleotide kinase (PNK) in association with cyclic phosphodiesterase (CPDase), and a sealing reaction catalyzed by an RNA ligase. The enzymes that catalyze tRNA healing in yeast and higher eukaryotes are homologous to the members of the 2H phosphoesterase superfamily, in particular to the vertebrate myelin enzyme 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase). We employed different biophysical and biochemical methods to elucidate the overall structural and functional features of the tRNA healing enzymes yeast Trl1 PNK/CPDase and lancelet PNK/CPDase and compared them with vertebrate CNPase. The yeast and the lancelet enzymes have cyclic phosphodiesterase and polynucleotide kinase activity, while vertebrate CNPase lacks PNK activity. In addition, we also show that the healing enzymes are structurally similar to the vertebrate CNPase by applying synchrotron radiation circular dichroism spectroscopy and small-angle X-ray scattering. We provide a structural analysis of the tRNA healing enzyme PNK and CPDase domains together. Our results support evolution of vertebrate CNPase from tRNA healing enzymes with a loss of function at its N-terminal PNK-like domain.

  18. Influence of metabolism modifiers of cyclic nucleotides on contractility of right ventricle of rat heart with intact and removed endocardial endothelium

    Directory of Open Access Journals (Sweden)

    Savić Slađana


    Full Text Available Introduction. Endocardial endothelium, a natural biological barrier between circulating blood in heart ventricle and cells, creates a complex yet finely tuned balance of interactions with the immediate environment. Objective. We investigated the roles of theophylline, nonspecific phosphodiesterase inhibitor, and imidazole, an activator of phosphodiesterase on contractility of the right ventricle of rat heart, with intact and removed endocardial endothelium. Methods. Adult rats, of both sexes, type Wistar albino, were used in this experiment. All experiments were conducted on the preparations of the right ventricle using two experimental models. In the first experimental model, an endocardial endothelium (EE was preserved, and in the second model, an endocardial endothelium (-EE was removed using 1% solution Triton X-100. Results. Theophylline (1x10-2 mol/l expressed the positive inotropic effect on the heart, regardless of the presence of the endocardial endothelium. Inotropic response as multiple process can be induced by inhibition of phosphodiesterase, accumulation of cyclic nucleotides and activation of Ca2+ channels. Imidazole (2x10-3 mol/l increased the contractility of the right ventricle of the heart with EE. The modulator effect of endocardial endothelium on contractility of imidazole proved to be significant. As imidazole influenced the contractility of the right ventricle only in the presence of the endocardial endothelium, it is assumed that its effect is mediated via deliverance of endothelial mediators with positive inotropic effect. Conclusion. An intact endocardial endothelium is necessary for completion of contractile performance of the heart.

  19. Sildenafil citrate-restored eNOS and PDE5 regulation in sickle cell mouse penis prevents priapism via control of oxidative/nitrosative stress. (United States)

    Bivalacqua, Trinity J; Musicki, Biljana; Hsu, Lewis L; Berkowitz, Dan E; Champion, Hunter C; Burnett, Arthur L


    Sildenafil citrate revolutionized the practice of sexual medicine upon its federal regulatory agency approval approximately 15 years ago as the prototypical phosphodiesterase type 5 inhibitor indicated for the treatment of male erectile dysfunction. We now provide scientific support for its alternative use in the management of priapism, a clinical disorder of prolonged and uncontrolled penile erection. Sildenafil administered continuously to sickle cell mice, which show a priapism phenotype, reverses oxidative/nitrosative stress effects in the penis, mainly via reversion of uncoupled endothelial nitric oxide synthase to the functional coupled state of the enzyme, which in turn corrects aberrant signaling and function of the nitric oxide/cyclic GMP/protein kinase G/phosphodiesterase type 5 cascade. Priapism tendencies in these mice are reverted partially toward normal neurostimulated erection frequencies and durations after sildenafil treatment in association with normalized cyclic GMP concentration, protein kinase G activity and phosphodiesterase type 5 activity in the penis. Thus, sildenafil exerts pleiotropic effects in the penis that extend to diverse erection disorders.

  20. Sexual function in hypertensive patients receiving treatment

    Directory of Open Access Journals (Sweden)

    Thorsten Reffelmann


    Full Text Available Thorsten Reffelmann, Robert A KlonerUniversity of Southern California, The Heart Institute, Good Samaritan Hospital, Division of Cardiovascular Medicine, Keck School of Medicine, Los Angeles, CA, USAAbstract: In many forms of erectile dysfunction (ED, cardiovascular risk factors, in particular arterial hypertension, seem to be extremely common. While causes for ED are related to a broad spectrum of diseases, a generalized vascular process seems to be the underlying mechanism in many patients, which in a large portion of clinical cases involves endothelial dysfunction, ie, inadequate vasodilation in response to endothelium-dependent stimuli, both in the systemic vasculature and the penile arteries. Due to this close association of cardiovascular disease and ED, patients with ED should be evaluated as to whether they may suffer from cardiovascular risk factors including hypertension, cardiovascular disease or silent myocardial ischemia. On the other hand, cardiovascular patients, seeking treatment of ED, must be evaluated in order to decide whether treatment of ED or sexual activity can be recommended without significantly increased cardiac risk. The guideline from the first and second Princeton Consensus Conference may be applied in this context. While consequent treatment of cardiovascular risk factors should be accomplished in these patients, many antihypertensive drugs may worsen sexual function as a drug specific side-effect. Importantly, effective treatment for arterial hypertension should not be discontinued as hypertension itself may contribute to altered sexual functioning; to the contrary, alternative antihypertensive regimes should be administered with individually tailored drug regimes with minimal side-effects on sexual function. When phosphodiesterase-5 inhibitors, such as sildenafil, tadalafil and vardenafil, are prescribed to hypertensive patients on antihypertensive drugs, these combinations of antihypertensive drugs and

  1. Macro- and microrheological parameters of blood in patients with cerebral and peripheral atherosclerosis: the molecular change mechanisms after pentoxifylline treatment. (United States)

    Muravyov, Alexei V; Bulaeva, Svetlana V; Tikhomirova, Irina A; Zamishlayev, Andrey V; Uzikova, Ekaterina V; Miloradov, Mikhail Ju


    This study was designed to evaluate hemorheological changes in patients with cerebrovascular disease (CVD) and peripheral arterial disease (PAD) after 4 weeks of pentoxifylline therapy as well as to study red blood cell microrheological variables after the cell incubation with pentoxifylline and some phosphodiesterase (PDE) activity inhibitors. The patients with CVD (n = 50) and PAD (n = 33) were treated with pentoxifylline (400 mg, thrice a day) for 4 weeks. Before and after drug therapy the hemorheological measurements including plasma and whole blood viscosity, red blood cell aggregation (RBCA) and deformability (RBCD) were completed. In vitro study RBCs were incubated with: 1) Vinpocetine--inhibitor PDE-1, 10 μM; 2) Rolipram--PDE-4, 10 μM; 3) Isobutyl-methylxanthine (IBMX)--nonselective PDE inhibitor, 100 μM and with pentoxifylline, 10 μM The cell incubation was performed at 37 °C for 15 min. There were the positive changes of hemorheological profile after 4 weeks of the pentoxifylline therapy both in CVD and PAD patients. The marked RBCD changes were observed after the in vitro cell pentoxifylline treatment as well. Perhaps it is connected with the inhibition of the phosphodiesterase activity in RBCs. An application of drugs and chemicals that can inhibit the PDE activity resulted in RBCD rise and RBCA decrease. The experiments with the use of selective PDE inhibitors have revealed the similar red cell deformability changes. Vinpocetine increased RBCD significantly (p RBCA, but the most pronounced effect had Vinpocetine (50%; p < 0.05). Thus, administered pentoxifylline, daily (1200 mg), during four weeks improves hemorheological profile and especially its microrheological part as well as the blood transport capacity in subjects with cerebral and peripheral vascular disorders. It is most probably red cell microrheological control mechanisms may be associated with the phosphodiesterase activity alterations.

  2. The use of a single daily dose of tadalafil to treat signs and symptoms of benign prostatic hyperplasia and erectile dysfunction

    Directory of Open Access Journals (Sweden)

    Gacci M


    Full Text Available Mauro Gacci,1 Matteo Salvi,1 Arcangelo Sebastianelli,1 Linda Vignozzi,2 Giovanni Corona,3 Kevin T McVary,4 Steven A Kaplan,5 Mario Maggi,2 Marco Carini,1 Matthias Oelke6 1Department of Urology, University of Florence, Florence, 2Sexual Medicine and Andrology Unit, Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, 3Endocrinology Unit, Maggiore-Bellaria Hospital, Bologna, Italy; 4Division of Urology, Department of Surgery, Southern Illinois University School of Medicine, Springfield, IL, 5Department of Urology, Weill Cornell Medical College, Cornell University, New York, NY, USA; 6Department of Urology, Hannover Medical School, Hannover, Germany Abstract: A strong and independent association between lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH and erectile dysfunction (ED has been widely evidenced in several clinical epidemiologic studies. Preclinical animal models have provided a great deal of information on potential common pathogenic mechanisms underlying these two clinical identities. Although the efficacy of the most commonly used treatments for LUTS/BPH is well defined, the negative impact of these treatments on sexual function – in particular, on ED – has triggered the search for new treatment options. In this regard, a new role for phosphodiesterase type 5 inhibitors in the treatment of LUTS/BPH and ED has been claimed. Tadalafil is one of the most extensively investigated phosphodiesterase type 5 inhibitors for this new indication. All evidence reported to date suggests that tadalafil 5 mg once daily is a safe and effective treatment option for both LUTS/BPH and ED. Keywords: phosphodiesterase type 5 inhibitor, LUTS/BPH, ED, sexual function, Cialis

  3. Effect of sildenafil on gastric emptying and postprandial frequency of antral contractions in healthy humans

    DEFF Research Database (Denmark)

    Madsen, J L; Søndergaard, S B; Fuglsang, S


    BACKGROUND: Sildenafil is known to block phosphodiesterase type 5, which degrades nitric oxide-stimulated cyclic guanosine monophosphate, thereby relaxing smooth muscle cells in various organs. The effect of sildenafil on gastric motor function after a meal was investigated in healthy humans...... gastric emptying and postprandial frequency of antral contractions. RESULTS: The area under the curve of gastric retention versus time of liquid or solid radiolabelled marker was not changed by sildenafil intake, nor was the postprandial frequency of antral contractions affected by sildenafil. CONCLUSION......: A single dose of 50 mg sildenafil does not change gastric emptying or postprandial frequency of antral contractions in healthy volunteers....

  4. Synthesis and biological evaluation of phosphonate derivatives as autotaxin (ATX) inhibitors. (United States)

    Cui, Peng; Tomsig, Jose L; McCalmont, William F; Lee, Sangderk; Becker, Christopher J; Lynch, Kevin R; Macdonald, Timothy L


    Autotaxin (ATX) is an autocrine motility factor that promotes cancer cell invasion, cell migration, and angiogenesis. ATX, originally discovered as a nucleotide phosphodiesterase, is known now to be responsible for the lysophospholipid-preferring phospholipase D activity in plasma. As such, it catalyzes the production of lysophosphatidic acid (LPA) from lysophophatidylcholine (LPC). ATX is thus an attractive drug target; small molecular inhibitors might be efficacious in slowing the spread of cancers. With this study we have generated a series of beta-keto and beta-hydroxy phosphonate derivatives of LPA, some of which are potent ATX inhibitors.

  5. Advances in the treatment of Raynaud’s phenomenon (United States)

    Levien, Terri L


    Raynaud’s phenomenon is a common condition characterized by vasospasm of the digital arteries and resulting cyanosis and redness. It often does not require pharmacologic management, but in some cases symptoms are severe and pharmacologic management is necessary. Calcium channel blockers are often used first-line, but in some patients are ineffective. Patients with severe symptoms or intolerance to available therapies have prompted exploration of alternative therapies, including endothelin antagonists, phosphodiesterase-5 inhibitors, antioxidants, newer vasodilators, statins, and botulinum toxin. These newer therapies provide the focus for this review. PMID:20448801

  6. Evidence-based management of Raynaud's phenomenon. (United States)

    Herrick, Ariane L


    Raynaud's phenomenon (RP) is relevant to the rheumatologist because it may signify an underlying connective tissue disease and also because it can be very challenging to treat, especially when it has progressed to digital ulceration or critical ischaemia. This review article discusses diagnosis (does this patient have an underlying connective tissue disease?), including the role for nailfold capillaroscopy, and treatment. Management of 'uncomplicated' RP is first described and then treatment of RP complicated by progression to digital ulceration or critical ischaemia, highlighting recent advances (including phosphodiesterase type 5 inhibition, and endothelin 1 receptor antagonism) and the evidence base underpinning these. Possible future therapies are briefly discussed.

  7. Low-intensity shockwave therapy for erectile dysfunction

    DEFF Research Database (Denmark)

    Fode, Mikkel; Hatzichristodoulou, Georgios; Serefoglu, Ege Can


    Erectile dysfunction (ED) affects ∼30% of all men above the age of 40 years and its prevalence steadily increases with age. Current nonsurgical treatment options, including phosphodiesterase type 5 inhibitors (PDE5I), provide temporary relief but have failed to provide a permanent improvement...... of the condition. Low-intensity extracorporeal shockwave therapy (Li-ESWT) is noninvasive and uses acoustic waves, which can pass through tissue and be focussed to target specific areas or organs to induce the desired effects. The use of Li-ESWT has previously been described in other disease contexts...

  8. A multi-targeted liquid chromatography-mass spectrometry screening procedure for the detection in human urine of drugs non-prohibited in sport commonly used by the athletes. (United States)

    Mazzarino, Monica; Cesarei, Lorenzo; de la Torre, Xavier; Fiacco, Ilaria; Robach, Paul; Botrè, Francesco


    This work presents an analytical method for the simultaneous analysis in human urine of 38 pharmacologically active compounds (19 benzodiazepine-like substances, 7 selective serotonin reuptake inhibitors, 4 azole antifungal drugs, 5 inhibitors of the phosphodiesterases type 4 and 3 inhibitors of the phosphodiesterase type 5) by liquid-chromatography coupled with tandem mass spectrometry. The above substances classes include both the most common "non banned" drugs used by the athletes (based on the information reported on the "doping control form") and those drugs who are suspected to be performance enhancing and/or act as masking agents in particular conditions. The chromatographic separation was performed by a reverse-phase octadecyl column using as mobile phases acetonitrile and ultra-purified water, both with 0.1% formic acid. The detection was carried out using a triple quadrupole mass spectrometric analyser, positive electro-spray as ionization source and selected reaction monitoring as acquisition mode. Sample pre-treatment consisted in an enzymatic hydrolysis followed by a liquid-liquid extraction in neutral field using tert-butyl methyl-ether. The analytical procedure, once developed, was validated in terms of sensitivity (lower limits of detection in the range of 1-50 ng mL(-1)), specificity (no interferences were detected at the retention time of all the analytes under investigation), recovery (≥60% with a satisfactory repeatability, CV % lower than 10), matrix effect (lower than 30%) and reproducibility of retention times (CV% lower than 0.1) and of relative abundances (CV% lower than 15). The performance and the applicability of the method was evaluated by analyzing real samples containing benzodiazepines (alprazolam, diazepam, zolpidem or zoplicone) or inhibitors of the phosphodiesterases type 5 (sildenafil or vardenafil) and samples obtained incubating two of the phosphodiesterases type 4 studied (cilomilast or roflumilast) with pooled human liver

  9. Endovascular treatment of vasculogenic erectile dysfunction


    O. B. Zhukov; S. N. Shcherbinin; V. A. Ukolov


    Method of choice for surgical treatment of vasculogenic erectile dysfunction (ED) is the genesis of arteriovenous falloprosthetics. In the initial stages of the disease, young men, dissatisfied inhibitor therapy 5-phosphodiesterase and/or intracavernous injections do not agree to such a view of his proposed lecheniya. Authors give the results we operated 26 patients 25–48 year old (mean age 34.3± 7.4) with vasculogenic ED. Of these, 23 patients with venoocclusive ED, 3 patients had arterial i...

  10. Six New Tetraprenylated Alkaloids from the South China Sea Gorgonian Echinogorgia pseudossapo

    Directory of Open Access Journals (Sweden)

    Zhang-Hua Sun


    Full Text Available Six new tetraprenylated alkaloids, designated as malonganenones L–Q (1–6, were isolated from the gorgonian Echinogorgia pseudossapo, collected in Daya Bay of Guangdong Province, China. The structures of 1–6 featuring a methyl group at N-3 and a tetraprenyl chain at N-7 in the hypoxanthine core were established by extensive spectroscopic analyses. Compounds 1–6 were tested for their inhibitory activity against the phosphodiesterases (PDEs-4D, 5A, and 9A, and compounds 1 and 6 exhibited moderate inhibitory activity against PDE4D with IC50 values of 8.5 and 20.3 µM, respectively.

  11. Does tadalafil prevent erectile dysfunction in patients undergoing radiation therapy for prostate cancer?

    Directory of Open Access Journals (Sweden)

    Luca Incrocci


    Full Text Available A recently published paper addressed the interesting topic of prevention of erectile dysfunction (ED with tadalafil, a phosphodiesterase-type 5 inhibitor (PDE5i in patients undergoing radiation therapy for localized prostate cancer. [1] Tadalafil 5 mg or placebo was administered once-daily for 24 weeks in patients undergoing external-beam radiotherapy (EBRT or brachytherapy (BT for prostate cancer. This randomized trial did not show superior efficacy of the active drug compared with placebo 4-6 weeks after stopping the study drug. Furthermore, patients younger than 65 years did not respond significantly better than older patients.

  12. Synthesis and characterization of related substances and metabolite of tadalafil, a PDE-5 inhibitor

    Directory of Open Access Journals (Sweden)

    Goverdhan Gilla


    Full Text Available Tadalafil (Cialis is a potent and selective inhibitor of cyclic guanosine monophosphate (cGMP-specific phosphodiesterase type-5 (PDE-5 and it is administered orally for the treatment of erectile dysfunction (ED. Two synthetic schemes were evaluated to study the impurity profile of tadalafil. Six impurities were detected in the bulk substance (prepared by two methods at a level of 0.1-0.15%. Identification, synthesis, characterization of impurities (related substances and metabolite and origin of their formation is described .

  13. TSH-induced cyclic AMP production in an ovine thyroid cell line: OVNIS 5H. (United States)

    Fayet, G; Aouani, A; Hovsépian, S


    The TSH-induced cyclic AMP response was studied using a 3-year-old ovine thyroid cell line TSH-independent for growth: OVNIS 5H. The kinetics of cyclic AMP production was followed both in cell layers and in cell culture media, with or without phosphodiesterase inhibitor. It is noteworthy that following the first wave in cyclic AMP obtained within minutes, we observed later a sustained exponential increase in cyclic AMP during the 5 days following TSH stimulation. A bioassay of TSH was derived allowing measurement of 1 microU/ml TSH from a crude bTSH preparation.

  14. [Juvenile hormone in diapausing Pieris brassicae and mutations. Tetrahydrofolic acid and pterins incubated in chrysalids, provoking ontogenic and mutagenic genetic information alterations in Drosophila melanogaster]. (United States)

    L'Helias, C


    Study of AMPc phosphodiesterase shows presence of JH in diapausing chrysalids and antogonistic action of FH and pterines. Study of farnesoldeshydrogenase and farnesal deshydrogenase in Dm shows that FH4 and pterines inhibite FDH, active ADH. Conclusion is JH in diapause chrysalides is active factor with FH4 provoking genesis of pigmentary mutation, cellular proliferation or growth deficiencies. Comparison with JH+FH4+ teromes incubated in Bar (Muller 5) mutants of Dm in place of diapausing chrysalids reproduce larval deficiences, mosaics and mutations observed in precedent experiments.

  15. Intracellular mechanism of the action of inhibin on the secretion of follicular stimulating hormone and of luteinizing hormone induced by LH-RH in vitro (United States)

    Lecomte-Yerna, M. J.; Hazee-Hagelstein, M. T.; Charlet-Renard, C.; Franchimont, P.


    The FSH secretion-inhibiting action of inhibin in vitro under basal conditions and also in the presence of LH-RH is suppressed by the addition of MIX, a phosphodiesterase inhibitor. In the presence of LH-RH, inhibin reduces significantly the intracellular level of cAMP in isolated pituitary cells. In contrast, the simultaneous addition of MIX and inhibin raises the cAMP level, and this stimulation is comparable to the increase observed when MIX is added alone. These observations suggest that one mode of action of inhibin could be mediated by a reduction in cAMP within the pituitary gonadotropic cell.

  16. Stimulation of prostaglandin synthesis in rat cerebral cortex via a beta-adrenoceptor. (United States)

    Hillier, K; Templeton, W W


    1. Synthesis of prostaglandin E2 (PGE2) and prostaglandin F2 alpha (PGF2 alpha) in rat cerebral cortex slices is increased by beta-adrenoceptor agonists. 2. Phenylephrine, an alpha-adrenoceptor agonist, has no effect while oxymetazoline increased PGF2 alpha only. 3. PG synthesis stimulation by noradrenaline (NA) was prevented by beta- but not by alpha-adrenoceptor antagonists. 4. Dibutyryl cyclic AMP and inhibitors of cyclic nucleotide phosphodiesterase augment PG synthesis. 5. Stimulation of PG synthesis in rat cerebral cortex by NA is mediated by a beta-adrenoceptor.

  17. Genetic Analysis of Chromomere 3d4 in DROSOPHILA MELANOGASTER . II. Regulatory Sites for the Dunce Gene


    Salz, Helen K.; Kiger, John A.


    Chromomere 3D4 of the X chromosome of D. melanogaster contains two genes, dunce (dnc) and sperm amotile (sam ). Mutations in dnc cause defects in memory formation and female fertility and reduce or eliminate the activity of a cAMP-specific phosphodiesterase designated form II. A fine structure map of this region has been constructed showing the locations of two sam mutations, five dnc mutations and a newly identified locus designated control of fertility (cf) that acts in cis to regulate the...

  18. Antidepressant-like properties of sildenafil in a genetic rat model of depression: Role of cholinergic cGMP-interactions

    DEFF Research Database (Denmark)

    Liebenberg, Nico; Brink, Christiaan; Brand, Linda


    of the phosphodiesterase type 5 (PDE5) inhibitor, sildenafil. Specifically, we demonstrated that chronic (11 days) treatment with a combination of sildenafil (10 mg/kg/day) + atropine (1 mg/kg/day) produces antidepressant-like effects in the forced swim test (FST) in Sprague Dawley rats. Neither of these drugs produced...... was scored during five minutes swim in the FST. In addition, locomotor activity was evaluated in the Open Field Test 2 hours prior to the FST. Results: Fluoxetine and imipramine separately decreased immobility in FSL rats, comparable to that of FRL control rats, after 14 but not after 7 days. Likewise, when...

  19. Targeting PDE10A GAF Domain with Small Molecules: A Way for Allosteric Modulation with Anti-Inflammatory Effects. (United States)

    García, Ana M; Brea, José; González-García, Alejandro; Pérez, Concepción; Cadavid, María Isabel; Loza, María Isabel; Martinez, Ana; Gil, Carmen


    Phosphodiesterase (PDE) enzymes regulate the levels of cyclic nucleotides, cAMP, and/or cGMP, being attractive therapeutic targets. In order to modulate PDE activity in a selective way, we focused our efforts on the search of allosteric modulators. Based on the crystal structure of the PDE10A GAF-B domain, a virtual screening study allowed the discovery of new hits that were also tested experimentally, showing inhibitory activities in the micromolar range. Moreover, these new PDE10A inhibitors were able to decrease the nitrite production in LPS-stimulated cells, thus demonstrating their potential as anti-inflammatory agents.

  20. Organizing signal transduction through A-kinase anchoring proteins (AKAPs). (United States)

    Logue, Jeremy S; Scott, John D


    A fundamental role for protein-protein interactions in the organization of signal transduction pathways is evident. Anchoring, scaffolding and adapter proteins function to enhance the precision and directionality of these signaling events by bringing enzymes together. The cAMP signaling pathway is organized by A-kinase anchoring proteins. This family of proteins assembles enzyme complexes containing the cAMP-dependent protein kinase, phosphoprotein phosphatases, phosphodiesterases and other signaling effectors to optimize cellular responses to cAMP and other second messengers. Selected A-kinase anchoring protein signaling complexes are highlighted in this minireview. © 2010 The Authors Journal compilation © 2010 FEBS.

  1. Novel anti-inflammatory agents in COPD

    DEFF Research Database (Denmark)

    Loukides, Stelios; Bartziokas, Konstantinos; Vestbo, Jørgen


    Inflammation plays a central role in chronic obstructive pulmonary disease (COPD). COPD related inflammation is less responsive to inhaled steroids compared to asthma. There are three major novel anti-inflammatory approaches to the management of COPD. The first approach is phosphodiesterase...... on these strategies exist at the moment. A third potential approach involves novel agents whose mechanism of action is closely related to COPD mechanisms and pathophysiology. Such novel treatments are of great interest since they may treat both COPD and co-morbidities. Several novel agents are currently under...

  2. Pharmacologic treatment options for hypoactive sexual desire disorder. (United States)

    Bolour, Sheila Y; Braunstein, Glenn D


    Hypoactive sexual desire disorder is the most common cause of sexual dysfunction in women. According to a national survey, approximately a third of all women experience low sexual desire. The etiology of the disorder is often multifactorial. Research in treatment options for hypoactive sexual desire disorder is limited. In this article, treatment options including sex therapy, hormone therapy (estrogen, testosterone, dehydroepiandrosterone, tibolone), non-hormonal medical therapies (buproprion, buspirone, phosphodiesterase-5 inhibitors, amantadine and apomorphine) and herbal therapies (Avlimil(R), Arginmax(R), Zestra(R), yohimbine and Ginkgo biloba) are reviewed.

  3. AcEST: DK957622 [AcEST

    Lifescience Database Archive (English)

    Full Text Available 34 0.54 sp|P22355|PSPB_RAT Pulmonary surfactant-associated protein B OS=... 33 0.92 sp|P50405|PSPB_MOUSE Pulmonary surfactant...myelin phosphodiesterase A OS=Dictyo... 33 1.6 sp|P15781|PSPB_BOVIN Pulmonary surfactant-associated protein ...+ + T Q Y PN Sbjct: 114 VVSYVNVNMGLKIRQLLWFHISCLTFGRETVLEYLVSVGVWIRTPQAYRPPN 165 >sp|P22355|PSPB_RAT Pulmonary surfactant... MQIYAAPNKLCGETKLCP 503 Q P +C LCP Sbjct: 125 FQGQIKPKAICSHVGLCP 142 >sp|P50405|PSPB_MOUSE Pulmonary surfa...ctant-associated protein B OS=Mus musculus GN=Sftpb PE=2 SV=1 Length = 377 Score =

  4. Modulation of cGMP in Heart Failure (United States)

    Boerrigter, Guido; Lapp, Harald; Burnett, John C.


    Heart failure (HF) is a common disease that continues to be associated with high morbidity and mortality warranting novel therapeutic strategies. Cyclic guanosine monophosphate (cGMP) is the second messenger of several important signaling pathways based on distinct guanylate cyclases (GCs) in the cardiovascular system. Both the nitric oxide/soluble GC (NO/sGC) as well as the natriuretic peptide/GC-A (NP/GC-A) systems are disordered in HF, providing a rationale for their therapeutic augmentation. Soluble GC activation with conventional nitrovasodilators has been used for more than a century but is associated with cGMP-independent actions and the development of tolerance, actions which novel NO-independent sGC activators now in clinical development lack. Activation of GC-A by administration of naturally occurring or designer natriuretic peptides is an emerging field, as is the inhibition of enzymes that degrade endogenous NPs. Finally, inhibition of cGMP-degrading phosphodiesterases, particularly phosphodiesterase 5 provides an additional strategy to augment cGMP-signaling. PMID:19089342

  5. PDE5 Inhibitors-Loaded Nanovesicles: Physico-Chemical Properties and In Vitro Antiproliferative Activity

    Directory of Open Access Journals (Sweden)

    Roberta F. De Rose


    Full Text Available Novel therapeutic approaches are required for the less differentiated thyroid cancers which are non-responsive to the current treatment. In this study we tested an innovative formulation of nanoliposomes containing sildenafil citrate or tadalafil, phosphodiesterase-5 inhibitors, on two human thyroid cancer cell lines (TPC-1 and BCPAP. Nanoliposomes were prepared by the thin layer evaporation and extrusion methods, solubilizing the hydrophilic compound sildenafil citrate in the aqueous phase during the hydration step and dissolving the lipophilic tadalafil in the organic phase. Nanoliposomes, made up of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine monohydrate (DPPC, cholesterol, and N-(carbonyl-methoxypolyethylene glycol-2000-1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE-mPEG2000 (6:3:1 molar ratio, were characterized by a mean diameter of ~100 nm, a very low polydispersity index (~0.1 and a negative surface charge. The drugs did not influence the physico-chemical properties of the systems and were efficiently retained in the colloidal structure. By using cell count and MTT assay, we found a significant reduction of the viability in both cell lines following 24 h treatment with both nanoliposomal-encapsulated drugs, notably greater than the effect of the free drugs. Our findings demonstrate that nanoliposomes increase the antiproliferative activity of phosphodiesterase-5 inhibitors, providing a useful novel formulation for the treatment of thyroid carcinoma.

  6. Electroretinography and immunohistochemistry of retina in rabbits treated with sildenafil citrate

    Directory of Open Access Journals (Sweden)

    A.V.C. Amaral


    Full Text Available Sildenafil citrate is a type-5 phosphodiesterase inhibitor (PDE-5, able to inhibit type-6 phosphodiesterase (PDE-6 as well, providing clinical benefits and paraeffects, some of them potentially related to the retina. The effects of the sildenafil on the retrobulbar and retinal circulation were studied in 27 adult male rabbits of the White New Zealand breed. The electric activity of the retina was evaluated before and at the end of the treatments, and immunohistochemistry studies were conducted. An amplitude increase of the b wave was found in the mixed response of cones and rods after 7 days of treatment with sildenafil citrate. However, in the other evaluations and periods, the values did not differ from the basal ones. Through immunohistochemistry, no significant decrease of the expression of PDE-5 and PDE-6 proteins was observed. Based on the results obtained, it is possible to admit that the sildenafil citrate did not change the expression of PDE-5 and PDE-6, neither the electroretinographic activity of the retina of male rabbits of the White New Zealand breed.

  7. Is a calmodulin-opiopeptide interaction related to the mechanism of opioid action? (United States)

    Clouet, D H; Williams, N; Yonehara, N


    The effect of several opioids: methadone, etorphine, beta-endorphin and D-ala2met enkephalin on Ca++/calmodulin stimulation of enzyme activities either in pure solution (cyclic nucleotide phosphodiesterase) or in striatal membranes (protein kinases in synaptic membranes) were compared to see if a direct opioid/calmodulin interaction could eliminate the stimulation of enzyme activity as part of the mechanism by which opioids alter ion flow and neurotransmitter release. In other experiments, in which endogenous phosphorylation of proteins in striatal synaptic membranes was altered by opioid treatments, the possibility of restoring protein kinase activity to normal levels in the membrane preparation by supplementation with calmodulin at optimal Ca++ concentration was examined. Some opioids (methadone and D-ala2met enkephalin) did not inhibit calmodulin-stimulated phosphodiesterase, which suggests that they were not able to bind to calmodulin. In addition, it was not possible to restore decreases in protein kinase activity to normal levels by adding calmodulin to the assay in the presence of optimal Ca++. We conclude that a direct binding of opioids to calmodulin is not a general mechanism of opioid action, although the binding may participate in the action of some neuropeptides, including beta-endorphin.

  8. Management of erectile dysfunction post-radical prostatectomy

    Directory of Open Access Journals (Sweden)

    Saleh A


    Full Text Available Alan Saleh, Hamid Abboudi, MB Ghazal-Aswad, Erik K Mayer, Justin A Vale Division of Surgery and Cancer, Imperial College Healthcare NHS Trust, St Mary's Hospital, London, UK Abstract: Radical prostatectomy is a commonly performed procedure for the treatment of localized prostate cancer. One of the long-term complications is erectile dysfunction. There is little consensus on the optimal management; however, it is agreed that treatment must be prompt to prevent fibrosis and increase oxygenation of penile tissue. It is vital that patient expectations are discussed, a realistic time frame of treatment provided, and treatment started as close to the prostatectomy as possible. Current treatment regimens rely on phosphodiesterase 5 inhibitors as a first-line therapy, with vacuum erection devices and intraurethral suppositories of alprostadil as possible treatment combination options. With nonresponders to these therapies, intracavernosal injections are resorted to. As a final measure, patients undergo the highly invasive penile prosthesis implantation. There is no uniform, objective treatment program for erectile dysfunction post-radical prostatectomy. Management plans are based on poorly conducted and often underpowered studies in combination with physician and patient preferences. They involve the aforementioned drugs and treatment methods in different sequences and doses. Prospective treatments include dietary supplements and gene therapy, which have shown promise with there proposed mechanisms of improving erectile function but are yet to be applied successfully in human patients. Keywords: erectile dysfunction, phosphodiesterase 5 inhibitors, vacuum erection devices, intraurethral suppositories, intracavernosal injections

  9. Sildenafil in the treatment of pulmonary hypertension

    Directory of Open Access Journals (Sweden)

    Christopher F Barnett


    Full Text Available Christopher F Barnett1,2, Roberto F Machado1,21Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD, USA; 2Vascular Medicine Branch, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USAAbstract: The therapy of pulmonary hypertension has evolved rapidly in the last 10 years from the use of non-selective vasodilators to drugs that specifically target pulmonary vasodilation, endothelial function, and vascular remodeling. Sildenafil is a phosphodiesterase type 5 inhibitor that has an expanding role in the treatment of pulmonary hypertension. Case series and small studies, as well as the first large randomized controlled trial, have  demonstrated the safety and efficacy of sildenafil in improving mean pulmonary artery pressure, pulmonary vascular resistance, cardiac index, and exercise tolerance in pulmonary arterial hypertension. It may be useful in adults, children, and neonates after cardiac surgery, with left heart failure, in fibrotic pulmonary disease, high altitude exposure, and thromboembolic disease, and in combination with other therapies for pulmonary hypertension, such as inhaled iloprost. The oral formulation and favorable adverse effect profile make sildenafil an attractive alternative in the treatment of selected patients with pulmonary hypertension. Keywords: sildenafil, phosphodiesterase inhibitor, pulmonary hypertension, right heart failure

  10. Translational Perspective on the Role of Testosterone in Sexual Function and Dysfunction. (United States)

    Podlasek, Carol A; Mulhall, John; Davies, Kelvin; Wingard, Christopher J; Hannan, Johanna L; Bivalacqua, Trinity J; Musicki, Biljana; Khera, Mohit; González-Cadavid, Nestor F; Burnett, Arthur L


    The biological importance of testosterone is generally accepted by the medical community; however, controversy focuses on its relevance to sexual function and the sexual response, and our understanding of the extent of its role in this area is evolving. To provide scientific evidence examining the role of testosterone at the cellular and molecular levels as it pertains to normal erectile physiology and the development of erectile dysfunction and to assist in guiding successful therapeutic interventions for androgen-dependent sexual dysfunction. In this White Paper, the Basic Science Committee of the Sexual Medicine Society of North America assessed the current basic science literature examining the role of testosterone in sexual function and dysfunction. Testosterone plays an important role in sexual function through multiple processes: physiologic (stimulates activity of nitric oxide synthase), developmental (establishes and maintains the structural and functional integrity of the penis), neural (development, maintenance, function, and plasticity of the cavernous nerve and pelvic ganglia), therapeutically for dysfunctional regulation (beneficial effect on aging, diabetes, and prostatectomy), and phosphodiesterase type 5 inhibition (testosterone supplement to counteract phosphodiesterase type 5 inhibitor resistance). Despite controversies concerning testosterone with regard to sexual function, basic science studies provide incontrovertible evidence for a significant role of testosterone in sexual function and suggest that properly administered testosterone therapy is potentially advantageous for treating male sexual dysfunction. Published by Elsevier Inc.

  11. Effects of Red Wine Vinegar Beverage on the Colonic Tissue of Rodents: Biochemical, Functional and Pharmacological Analyses. (United States)

    Enkhsaikhan, Azjargal; Takahara, Akira; Nakamura, Yuji; Goto, Ai; Chiba, Koki; Lubna, Nur Jaharat; Hagiwara-Nagasawa, Mihoko; Izumi-Nakaseko, Hiroko; Ando, Kentaro; Naito, Atsuhiko T; Sugiyama, Atsushi


    A beverage made of red wine vinegar and grape juice (Yamanashi-no-megumi™) was developed as a supplemental fluid containing polyphenols, which has been clinically shown to enhance the colonic transit. In this study, we assessed the mechanism of its prokinetic action by analyzing the effects on both the colonic phosphodiesterase activity of rats (n=4) and the isolated colonic strip preparation of guinea pigs (n=4). The 7% (v/v) solution of the beverage significantly decreased the phosphodiesterase activity by 9% (n=4). The beverage in concentrations of 0.7, 2.1 and 7% (v/v) relaxed the colonic strips pre-contracted by 1 µmol/L of carbachol in a concentration-related manner with 50, 58 and 79%, each response of which was diminished to 11, 19 and 46%, respectively in the presence of 100 µmol/L of L-nitro-arginine methyl ester. These results obtained by biochemical, functional and pharmacological analyses suggest that the beverage could relax the colon through both cAMP-associated and nitric oxide-dependent pathways, which may partly explain clinically observed prokinetic effect of the beverage.

  12. Tadalafil in the treatment of erectile dysfunction

    Directory of Open Access Journals (Sweden)

    Robert M Coward


    Full Text Available Robert M Coward, Culley C CarsonDivision of Urologic Surgery, University of North Carolina, Chapel Hill, NC, USAAbstract: The treatment for erectile dysfunction (ED was revolutionized with the development of phosphodiesterase type 5 (PDE5 inhibitors. Tadalafil (Cialis®; Eli Lilly and Company, Indianapolis, IN, USA is the newest and most versatile PDE5 inhibitor in the clinical armamentarium for the treatment of ED. Its most unique characteristic is its long half-life of 17.5 hours, which lends itself to a longer therapeutic window with on-demand dosing and effective steady-state plasma concentrations with once-daily dosing. Clinical trials have proven its safety and efficacy with both dosing strategies for all severities and etiologies of ED, including difficult-to-treat ED. This thorough review will discuss ED, the physiology of penile erection and the role of PDE5, and all aspects of tadalafil, from its development, through its pharmacology, to its latest clinical studies and indications.Keywords: tadalafil, Cialis, PDE5 inhibitors, phosphodiesterase type 5, erectile dysfunction, penile erection

  13. Tadalafil once daily in the management of erectile dysfunction: patient and partner perspectives

    Directory of Open Access Journals (Sweden)

    Pierre Costa


    Full Text Available Pierre Costa1, Thierry Grivel2, Naji Gehchan31Service d’Urologie–Andrologie, Hôpital Caremeau, Nîmes, France; 2159, Avenue Sainte-Marguerite, Nice, France; 3Eli Lilly and Company, Lilly France – Medical Division, Suresnes, FranceAbstract: Erectile dysfunction (ED is a prevalent condition that affects men and their partners. Significant improvements in the sexual lives of these couples have been achieved with the introduction of phosphodiesterase 5 (PDE5 inhibitors. A PDE5 inhibitor is now widely recognized as the first-line therapy for the majority of men with ED. Currently, three PDE5 inhibitors – sildenafil, tadalafil and vardenafil – are approved to be taken as needed in anticipation of sexual activity, but only one of these, tadalafil, has been approved to be taken once daily. The primary aims of this review are to summarize the patients’ and partners’ viewpoints of ED management with PDE5 inhibitors, and to determine whether once-daily tadalafil can contribute to improving some psychological aspects of ED (such as sexual self-confidence, spontaneity and time concerns compared with on-demand tadalafil or other PDE5 inhibitors taken by patients with ED.Keywords: erectile dysfunction, once-daily treatment, patient and partner perspectives, phosphodiesterase 5 (PDE5 inhibitor

  14. Cyclic guanosine monophosphate in the regulation of the cell function

    Directory of Open Access Journals (Sweden)

    Małgorzata Zbrojkiewicz


    Full Text Available Intracellular concentration of cGMP depends on the activity of guanylate cyclase, responsible for its synthesis, on the activity of cyclic nucleotide degrading enzymes - phosphodiesterases (PDEs. There are two forms of guanylate cyclase: the membrane-bound cyclase and the soluble form. The physiological activators of the membrane guanylate cyclase are natriuretic peptides (NPs, and of the cytosolic guanylate cyclase - nitric oxide (NO and carbon monoxide (CO. Intracellular cGMP signaling pathways arise from its direct effect on the activity of G protein kinases, phosphodiesterases and cyclic nucleotide dependent cation channels. It has been shown in recent years that cGMP can also affect other signal pathways in cell signaling activity involving Wnt proteins and sex hormones. The increased interest in the research on the role of cGMP, resulted also in the discovery of its role in the regulation of phototransduction in the eye, neurotransmission, calcium homeostasis, platelet aggregation, heartbeat, bone remodeling, lipid metabolism and the activity of the cation channels. Better understanding of the mechanisms of action of cGMP in the regulation of cell function can create new opportunities for the cGMP affecting drugs use in the pharmacotherapy.

  15. MicroRNA-378 controls classical brown fat expansion to counteract obesity. (United States)

    Pan, Dongning; Mao, Chunxiao; Quattrochi, Brian; Friedline, Randall H; Zhu, Lihua J; Jung, Dae Young; Kim, Jason K; Lewis, Brian; Wang, Yong-Xu


    Both classical brown adipocytes and brown-like beige adipocytes are considered as promising therapeutic targets for obesity; however, their development, relative importance and functional coordination are not well understood. Here we show that a modest expression of miR-378/378* in adipose tissue specifically increases classical brown fat (BAT) mass, but not white fat (WAT) mass. Remarkably, BAT expansion, rather than miR-378 per se, suppresses formation of beige adipocytes in subcutaneous WAT. Despite this negative feedback, the expanded BAT depot is sufficient to prevent both genetic and high-fat diet-induced obesity. At the molecular level, we find that miR-378 targets phosphodiesterase Pde1b in BAT but not in WAT. Indeed, miR-378 and Pde1b inversely regulate brown adipogenesis in vitro in the absence of phosphodiesterase inhibitor isobutylmethylxanthine. Our work identifies miR-378 as a key regulatory component underlying classical BAT-specific expansion and obesity resistance, and adds novel insights into the physiological crosstalk between BAT and WAT.

  16. Enzymatic activity of granulations tissues under low doses of radiation. Biochemical analysis in rats

    International Nuclear Information System (INIS)

    Tosoni, Guilherme Monteiro; Boscolo, Frab Norberto; Cury, Jaime Aparecido; Watanabe, Plauto Christopher Aranha


    This paper was designed to investigate in the rat subcutaneous sponge-induced granulation tissue under low doses of X-ray, the activity of alkaline phosphatase, 5'nucleotide phosphodiesterase and adenosine triphosphatase (ATPase) enzymes. One hundred and fourteen Wistar rats were divided into three groups, as follows: Group I as control, Group II that received single 7,14 R in split-dosis immediately after sponge-implantation at the third and fifth days postoperatively. Biopsies were taken after 7, 11, 14, 21 and 28 days and the activity of the three enzymes was determined. The results have shown that in Group II alkaline phosphatase had higher activity in the 14th day of tissue evolution when compared to Groups I and III . The 5'nucleotide phosphodiesterase activity in Group I was similar in all days checked, although in Group II the enzyme showed higher activity in 7th day and lower in 21st. In Group III the activity was higher after 14 and 7 days and lower after 28 and 21 days. There was no observation of changing in adenosine triphosphatase (ATPase) activity when the three groups were compared. (author)

  17. Mechanisms of action of PDE5 inhibition in erectile dysfunction. (United States)

    Corbin, J D


    A spinal reflex and the L-arginine-nitric oxide-guanylyl cyclase-cyclic guanosine monophosphate (cGMP) pathway mediate smooth muscle relaxation that results in penile erection. Nerves and endothelial cells directly release nitric oxide in the penis, where it stimulates guanylyl cyclase to produce cGMP and lowers intracellular calcium levels. This triggers relaxation of arterial and trabecular smooth muscle, leading to arterial dilatation, venous constriction, and erection. Phosphodiesterase 5 (PDE5) is the predominant phosphodiesterase in the corpus cavernosum. The catalytic site of PDE5 normally degrades cGMP, and PDE5 inhibitors such as sildenafil potentiate endogenous increases in cGMP by inhibiting its breakdown at the catalytic site. Phosphorylation of PDE5 increases its enzymatic activity as well as the affinity of its allosteric (noncatalytic/GAF domains) sites for cGMP. Binding of cGMP to the allosteric site further stimulates enzymatic activity. Thus phosphorylation of PDE5 and binding of cGMP to the noncatalytic sites mediate negative feedback regulation of the cGMP pathway.

  18. Inhibition of Mitochondrial Pyruvate Transport by Zaprinast Causes Massive Accumulation of Aspartate at the Expense of Glutamate in the Retina* (United States)

    Du, Jianhai; Cleghorn, Whitney M.; Contreras, Laura; Lindsay, Ken; Rountree, Austin M.; Chertov, Andrei O.; Turner, Sally J.; Sahaboglu, Ayse; Linton, Jonathan; Sadilek, Martin; Satrústegui, Jorgina; Sweet, Ian R.; Paquet-Durand, François; Hurley, James B.


    Transport of pyruvate into mitochondria by the mitochondrial pyruvate carrier is crucial for complete oxidation of glucose and for biosynthesis of amino acids and lipids. Zaprinast is a well known phosphodiesterase inhibitor and lead compound for sildenafil. We found Zaprinast alters the metabolomic profile of mitochondrial intermediates and amino acids in retina and brain. This metabolic effect of Zaprinast does not depend on inhibition of phosphodiesterase activity. By providing 13C-labeled glucose and glutamine as fuels, we found that the metabolic profile of the Zaprinast effect is nearly identical to that of inhibitors of the mitochondrial pyruvate carrier. Both stimulate oxidation of glutamate and massive accumulation of aspartate. Moreover, Zaprinast inhibits pyruvate-driven O2 consumption in brain mitochondria and blocks mitochondrial pyruvate carrier in liver mitochondria. Inactivation of the aspartate glutamate carrier in retina does not attenuate the metabolic effect of Zaprinast. Our results show that Zaprinast is a potent inhibitor of mitochondrial pyruvate carrier activity, and this action causes aspartate to accumulate at the expense of glutamate. Our findings show that Zaprinast is a specific mitochondrial pyruvate carrier (MPC) inhibitor and may help to elucidate the roles of MPC in amino acid metabolism and hypoglycemia. PMID:24187136

  19. Inhibition of mitochondrial pyruvate transport by zaprinast causes massive accumulation of aspartate at the expense of glutamate in the retina. (United States)

    Du, Jianhai; Cleghorn, Whitney M; Contreras, Laura; Lindsay, Ken; Rountree, Austin M; Chertov, Andrei O; Turner, Sally J; Sahaboglu, Ayse; Linton, Jonathan; Sadilek, Martin; Satrústegui, Jorgina; Sweet, Ian R; Paquet-Durand, François; Hurley, James B


    Transport of pyruvate into mitochondria by the mitochondrial pyruvate carrier is crucial for complete oxidation of glucose and for biosynthesis of amino acids and lipids. Zaprinast is a well known phosphodiesterase inhibitor and lead compound for sildenafil. We found Zaprinast alters the metabolomic profile of mitochondrial intermediates and amino acids in retina and brain. This metabolic effect of Zaprinast does not depend on inhibition of phosphodiesterase activity. By providing (13)C-labeled glucose and glutamine as fuels, we found that the metabolic profile of the Zaprinast effect is nearly identical to that of inhibitors of the mitochondrial pyruvate carrier. Both stimulate oxidation of glutamate and massive accumulation of aspartate. Moreover, Zaprinast inhibits pyruvate-driven O2 consumption in brain mitochondria and blocks mitochondrial pyruvate carrier in liver mitochondria. Inactivation of the aspartate glutamate carrier in retina does not attenuate the metabolic effect of Zaprinast. Our results show that Zaprinast is a potent inhibitor of mitochondrial pyruvate carrier activity, and this action causes aspartate to accumulate at the expense of glutamate. Our findings show that Zaprinast is a specific mitochondrial pyruvate carrier (MPC) inhibitor and may help to elucidate the roles of MPC in amino acid metabolism and hypoglycemia.

  20. Pulsed electromagnetic fields dosing impacts postoperative pain in breast reduction patients. (United States)

    Taylor, Erin M; Hardy, Krista L; Alonso, Amanda; Pilla, Arthur A; Rohde, Christine H


    Pulsed electromagnetic fields (PEMF) reduce postoperative pain and narcotic requirements in breast augmentation, reduction, and reconstruction patients. PEMF enhances both calmodulin-dependent nitric oxide and/or cyclic guanosine monophosphate signaling and phosphodiesterase activity, which blocks cyclic guanosine monophosphate. The clinical effect of these competing responses on PEMF dosing is not known. Two prospective, nonrandomized, active cohorts of breast reduction patients, with 15 min PEMF per 2 h; "Q2 (active)", and 5 min PEMF per 20 min; "5/20 (active)", dosing regimens were added to a previously reported double-blind clinical study wherein 20 min PEMF per 4 h, "Q4 (active)", dosing significantly accelerated postoperative pain reduction compared with Q4 shams. Postoperative visual analog scale pain scores and narcotic use were compared with results from the previous study. Visual analog scale scores at 24 h were 43% and 35% of pain at 1 h in the Q4 (active) and Q2 (active) cohorts, respectively (P PEMF dosing, accelerated postoperative pain reduction compared with historical shams. The 5/20 (active) regimen increases NO 4-fold faster than the Q4 (active) regimen, possibly accelerating phosphodiesterase inhibition of cyclic guanosine monophosphate sufficiently to block the PEMF effect. This study helps define the dosing limits of clinically useful PEMF signals. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Analgesic activity of new 8-methoxy-1,3-dimethyl-2,6-dioxo-purin-7-yl derivatives with carboxylic, ester or amide moieties. (United States)

    Zygmunt, Małgorzata; Chłoń-Rzepa, Grażyna; Sapa, Jacek; Pawłowski, Maciej


    The previous studies in a group of 4-arylpiperazinylalkyl derivatives of purine-2,6-dione and several other heterocyclic systems revealed their analgesic properties. In an effort to establish new analgesic agents we designed and synthesized a series of new 8-methoxy-1,3-dimethyl-2,6-dioxo-purin-7-yl derivatives with terminal carboxylic, ester or amide moieties. The obtained compounds were evaluated pharmacologically in two in vivo models: the writhing syndrome and the formalin tests. The influence of the investigated compounds on the phosphodiesterase (PDE) activity was also determined. Majority of the tested compounds showed significant analgesic activity. The strongest analgesic and anti-inflammatory effect were observed for benzylamide (10) and 4-phenylpiperazinamide (11-14) derivatives which were more active than acetylic acid used as a reference drug (up to 23 and 36 fold increase in activity in writhing and formalin test, respectively). Several active compounds stronger than theophylline inhibited the phosphodiesterase activity. The present study revealed that the presented compounds are new class of analgesic and anti-inflammatory agents and are worthy of the further evaluation regarding to their pharmacological properties. Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  2. From cellulite to smooth skin: is Viagra the new dream cream? (United States)

    Altabas, Karmela; Altabas, Velimir; Berković, Maja Cigrovski; Rotkvić, Vanja Zjacić


    In this article, we provide a hypothesis considering the potential effect of phosphodiesterase 5a inhibitors on cellulite. Cellulite is a significant cosmetic problem for many post-adolescent women. Its pathophysiology is complex and involves the presence of excess subcutaneous fat, the microcirculatory system, lymphatics and the extracellular matrix. Many diverse treatments have been tested to treat cellulite like iontophoresis, ultrasound, thermotherapy, pressotherapy, lymphatic drainage and electrolipophoresis which all enhance skin microcirculation. There have been several attempts to treat cellulite with drugs, but results were insufficient. Phosphodiesterases (PDE) are a superfamily of enzymes degrading adenosine monophosphate (cAMP) and cyclic guanosine monophoshpate (cGMP). Human fat cell lipolysis is mediated by both cAMP- and cGMP-dependent protein kinases. Indeed, high dose sildenafil pretreatment led to increased lipolysis in adipocyte cultures. That effect could not be attributed exclusively to either PDE3b or PDE5a inhibition, since sildenafil inhibited about 50% of the PDE3b activity in pretreated adipocytes. Sildenafil has a potential beneficial effect on skin microcirculation, as well as on tissue hypoxia. Transdermal or local route of administration should be considered.

  3. Practical considerations for the pharmacotherapy of pulmonary arterial hypertension. (United States)

    Bishop, Bryan M; Mauro, Vincent F; Khouri, Samer J


    Pulmonary arterial hypertension is a devastating disease. Before the 1990s, when pharmacologic treatment was finally approved, only supportive therapy was available, consisting of anticoagulation, digoxin, diuretics, and supplemental oxygen. Calcium channel blocker therapy was also an option, but only a small percentage of patients respond to it. However, starting with epoprostenol in 1996, the number of drugs approved to treat pulmonary arterial hypertension increased. Three distinct classes of drugs were developed based on the pathophysiology of the disease: the prostanoids, endothelin-1 receptor antagonists, and phosphodiesterase type 5 inhibitors. The prostanoids are administered either parenterally or by inhalation to replace the lack of prostacyclin within the pulmonary arterial vasculature. The endothelin-1 receptor antagonists were the first class of oral drugs to be developed, but drug interactions and adverse effects are prominent with this class. The phosphodiesterase type 5 inhibitors increase the second messenger cyclic guanosine monophosphate (GMP) that is induced by nitric oxide stimulation. All of the drugs within these three classes are distinct in and of themselves, and their clinical use requires in-depth knowledge of pulmonary arterial hypertension and its pathophysiology. Because these drugs have different mechanisms of action, combination therapy has shown promise in patients with severe disease, although data are still lacking. This article should serve as a practical guide for clinicians who encounter patients with pulmonary arterial hypertension and the drugs used for the treatment of this devastating disease. © 2012 Pharmacotherapy Publications, Inc. All rights reserved.

  4. Treatment of hypertension and renal injury induced by the angiogenesis inhibitor sunitinib: preclinical study. (United States)

    Lankhorst, Stephanie; Kappers, Mariëtte H W; van Esch, Joep H M; Smedts, Frank M M; Sleijfer, Stefan; Mathijssen, Ron H J; Baelde, Hans J; Danser, A H Jan; van den Meiracker, Anton H


    Common adverse effects of angiogenesis inhibition are hypertension and renal injury. To determine the most optimal way to prevent these adverse effects and to explore their interdependency, the following drugs were investigated in unrestrained Wistar Kyoto rats exposed to the angiogenesis inhibitor sunitinib: the dual endothelin receptor antagonist macitentan; the calcium channel blocker amlodipine; the angiotensin-converting enzyme inhibitor captopril; and the phosphodiesterase type 5 inhibitor sildenafil. Mean arterial pressure was monitored telemetrically. After 8 days, rats were euthanized and blood samples and kidneys were collected. In addition, 24-hour urine samples were collected. After sunitinib start, mean arterial pressure increased rapidly by ≈30 mm Hg. Coadministration of macitentan or amlodipine largely prevented this rise, whereas captopril or sildenafil did not. Macitentan, captopril, and sildenafil diminished the sunitinib-induced proteinuria and endothelinuria and glomerular intraepithelial protein deposition, whereas amlodipine did not. Changes in proteinuria and endothelinuria were unrelated. We conclude that in our experimental model, dual endothelin receptor antagonism and calcium channel blockade are suitable to prevent angiogenesis inhibition-induced hypertension, whereas dual endothelin receptor antagonism, angiotensin-converting enzyme inhibitor, and phosphodiesterase type 5 inhibition can prevent angiogenesis inhibition-induced proteinuria. Moreover, the variable response of hypertension and renal injury to different antihypertensive agents suggests that these side effects are, at least in part, unrelated. © 2014 American Heart Association, Inc.

  5. Sleep deprivation impairs cAMP signalling in the hippocampus. (United States)

    Vecsey, Christopher G; Baillie, George S; Jaganath, Devan; Havekes, Robbert; Daniels, Andrew; Wimmer, Mathieu; Huang, Ted; Brown, Kim M; Li, Xiang-Yao; Descalzi, Giannina; Kim, Susan S; Chen, Tao; Shang, Yu-Ze; Zhuo, Min; Houslay, Miles D; Abel, Ted


    Millions of people regularly obtain insufficient sleep. Given the effect of sleep deprivation on our lives, understanding the cellular and molecular pathways affected by sleep deprivation is clearly of social and clinical importance. One of the major effects of sleep deprivation on the brain is to produce memory deficits in learning models that are dependent on the hippocampus. Here we have identified a molecular mechanism by which brief sleep deprivation alters hippocampal function. Sleep deprivation selectively impaired 3', 5'-cyclic AMP (cAMP)- and protein kinase A (PKA)-dependent forms of synaptic plasticity in the mouse hippocampus, reduced cAMP signalling, and increased activity and protein levels of phosphodiesterase 4 (PDE4), an enzyme that degrades cAMP. Treatment of mice with phosphodiesterase inhibitors rescued the sleep-deprivation-induced deficits in cAMP signalling, synaptic plasticity and hippocampus-dependent memory. These findings demonstrate that brief sleep deprivation disrupts hippocampal function by interfering with cAMP signalling through increased PDE4 activity. Thus, drugs that enhance cAMP signalling may provide a new therapeutic approach to counteract the cognitive effects of sleep deprivation.

  6. Malaria parasite cGMP-dependent protein kinase regulates blood stage merozoite secretory organelle discharge and egress.

    Directory of Open Access Journals (Sweden)

    Christine R Collins


    Full Text Available The malaria parasite replicates within an intraerythrocytic parasitophorous vacuole (PV. Eventually, in a tightly regulated process called egress, proteins of the PV and intracellular merozoite surface are modified by an essential parasite serine protease called PfSUB1, whilst the enclosing PV and erythrocyte membranes rupture, releasing merozoites to invade fresh erythrocytes. Inhibition of the Plasmodium falciparum cGMP-dependent protein kinase (PfPKG prevents egress, but the underlying mechanism is unknown. Here we show that PfPKG activity is required for PfSUB1 discharge into the PV, as well as for release of distinct merozoite organelles called micronemes. Stimulation of PfPKG by inhibiting parasite phosphodiesterase activity induces premature PfSUB1 discharge and egress of developmentally immature, non-invasive parasites. Our findings identify the signalling pathway that regulates PfSUB1 function and egress, and raise the possibility of targeting PfPKG or parasite phosphodiesterases in therapeutic approaches to dysregulate critical protease-mediated steps in the parasite life cycle.

  7. The effects of caffeine on sleep in Drosophila require PKA activity, but not the adenosine receptor. (United States)

    Wu, Mark N; Ho, Karen; Crocker, Amanda; Yue, Zhifeng; Koh, Kyunghee; Sehgal, Amita


    Caffeine is one of the most widely consumed stimulants in the world and has been proposed to promote wakefulness by antagonizing function of the adenosine A2A receptor. Here, we show that chronic administration of caffeine reduces and fragments sleep in Drosophila and also lengthens circadian period. To identify the mechanisms underlying these effects of caffeine, we first generated mutants of the only known adenosine receptor in flies (dAdoR), which by sequence is most similar to the mammalian A2A receptor. Mutants lacking dAdoR have normal amounts of baseline sleep, as well as normal homeostatic responses to sleep deprivation. Surprisingly, these mutants respond normally to caffeine. On the other hand, the effects of caffeine on sleep and circadian rhythms are mimicked by a potent phosphodiesterase inhibitor, IBMX (3-isobutyl-1-methylxanthine). Using in vivo fluorescence resonance energy transfer imaging, we find that caffeine induces widespread increase in cAMP levels throughout the brain. Finally, the effects of caffeine on sleep are blocked in flies that have reduced neuronal PKA activity. We suggest that chronic administration of caffeine promotes wakefulness in Drosophila, at least in part, by inhibiting cAMP phosphodiesterase activity.

  8. Update on the clinical utility of sildenafil in the treatment of pulmonary arterial hypertension

    Directory of Open Access Journals (Sweden)

    Gautam V Ramani


    Full Text Available Gautam V Ramani, Myung H ParkUniversity of Maryland, Baltimore, MD, USAAbstract: Sildenafil is an orally administered phosphodiesterase type 5 inhibitor that is approved for the treatment of pulmonary arterial hypertension (PAH. The hemodynamic effects of sildenafil are mitigated primarily via potentiating the effects of endogenous nitric oxide, leading to smooth muscle cell relaxation and reductions in pulmonary arterial pressures and pulmonary vascular resistance. When added to standard background therapy in patients with idiopathic or associated PAH from congenital heart disease, anorexigen use, or connective tissue disease, sildenafil treatment results in improved exercise capacity as measured by 6 minute walk distance, improved hemodynamics, and favorable changes in quality of life. Sildenafil use is contraindicated with concomitant nitrate administration, and caution should be exercised when used in combination with antihypertensive agents due to risks of precipitating hypotension. Side effects are generally mild, and include flushing, headaches, and epistaxis. The combination of sildenafil with intravenous epoprostenol is safe and well tolerated, and further improves exercise capacity. Sildenafil is approved only for treatment of PAH, and although emerging data suggest a potential role in treating other types of pulmonary hypertension, larger trials are required to confirm these findings. Keywords: sildenafil, pulmonary arterial hypertension, phosphodiesterase type 5 inhibitor

  9. cAMP-Signalling Regulates Gametocyte-Infected Erythrocyte Deformability Required for Malaria Parasite Transmission.

    Directory of Open Access Journals (Sweden)

    Ghania Ramdani


    Full Text Available Blocking Plasmodium falciparum transmission to mosquitoes has been designated a strategic objective in the global agenda of malaria elimination. Transmission is ensured by gametocyte-infected erythrocytes (GIE that sequester in the bone marrow and at maturation are released into peripheral blood from where they are taken up during a mosquito blood meal. Release into the blood circulation is accompanied by an increase in GIE deformability that allows them to pass through the spleen. Here, we used a microsphere matrix to mimic splenic filtration and investigated the role of cAMP-signalling in regulating GIE deformability. We demonstrated that mature GIE deformability is dependent on reduced cAMP-signalling and on increased phosphodiesterase expression in stage V gametocytes, and that parasite cAMP-dependent kinase activity contributes to the stiffness of immature gametocytes. Importantly, pharmacological agents that raise cAMP levels in transmissible stage V gametocytes render them less deformable and hence less likely to circulate through the spleen. Therefore, phosphodiesterase inhibitors that raise cAMP levels in P. falciparum infected erythrocytes, such as sildenafil, represent new candidate drugs to block transmission of malaria parasites.

  10. Vasoactive neuropeptides in clinical ophthalmology: An association with autoimmune retinopathy?

    Directory of Open Access Journals (Sweden)

    Donald R Staines


    Full Text Available Donald R Staines1,2, Ekua W Brenu2, Sonya Marshall-Gradisnik21Queensland Health, Gold Coast Population Health Unit, Southport, Gold Coast, Queensland, Australia; 2Faculty of Health Science and Medicine, Population Health and Neuroimmunology Unit, Bond University, Robina, Queensland, AustraliaAbstract: The mammalian eye is protected against pathogens and inflammation in a relatively immune-privileged environment. Stringent mechanisms are activated that regulate external injury, infection, and autoimmunity. The eye contains a variety of cells expressing vasoactive neuropeptides (VNs, and their receptors, located in the sclera, cornea, iris, ciliary body, ciliary process, and the retina. VNs are important activators of adenylate cyclase, deriving cyclic adenosine monophosphate (cAMP from adenosine triphosphate (ATP. Impairment of VN function would arguably impede cAMP production and impede utilization of ATP. Thus VN autoimmunity may be an etiological factor in retinopathy involving perturbations of purinergic signaling. A sound blood supply is necessary for the existence and functional properties of the retina. This paper postulates that impairments in the endothelial barriers and the blood–retinal barrier, as well as certain inflammatory responses, may arise from disruption to VN function. Phosphodiesterase inhibitors and purinergic modulators may have a role in the treatment of postulated VN autoimmune retinopathy.Keywords: retinopathy, autoimmune, vasoactive neuropeptides, phosphodiesterase inhibitors

  11. Torsades de Pointes

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    Richard J Chen, MD


    Full Text Available History of present illness: 70-year-old male with a history ventricular arrhythmia, AICD (automated implantable cardioverter defibrillator, coronary artery disease and cardiac stents presented to the Emergency Department after three AICD discharges with dyspnea but no chest pain. During triage, he was found to have an irregular radial pulse and was placed on a cardiac monitor. Significant findings: The patient was found to be in a polymorphic ventricular tachycardia; he was alert, awake and asymptomatic. A rhythm strip showed a wide complex tachycardia with the QRS complex varying in amplitude around the isoelectric line consistent with Torsades de Pointes. Discussion: Torsades de Pointes (TdP is a specific type of polymorphic ventricular tachycardia. The arrhythmia’s characteristic morphology consists of the QRS complex “twisting” around the isoelectric line with gradual variation of the amplitude, reflecting its literal translation of “twisting of the points.”1 This arrhythmia occurs in the context of prolonged QT. The most common form of acquired QT prolongation is medication induced. Common causes include antiarrhythmics, antipsychotics, antiemetics, and antibiotics.2 Patient specific risk factors include female sex, bradycardia, hypokalemia, hypomagnesemia, hypocalcemia, hypothermia and heart disease.3 In the setting of prolonged QT, the repolarization phase is extended. TdP is initiated when a PVC (premature ventricular contraction occurs during this repolarization, known as an ‘R on T’ phenomenon. TdP is often asymptomatic and self-limited. The danger in TdP is its potential to deteriorate into ventricular fibrillation. A mainstay of management of TdP is prevention of risk factors when possible.4 Unstable patients should be treated with synchronized cardioversion. Magnesium sulfate should be administered in all cases of TdP.1 If a patient is not responsive to magnesium, consider isoproterenol, amiodarone, and overdrive pacing. Since this patient was asymptomatic, he was given 2gm of magnesium sulfate and placed on an amiodarone infusion, after which Tdp terminated with a resulting sinus rhythm. AICD interrogation showed multiple episodes of ventricular fibrillation. The patient was admitted for further management and to determine why his AICD was not functioning properly. Topics: EKG, ECG, cardiology, ventricular tachycardia, arrhythmia, Torsades de Pointes

  12. Actividades Enzimáticas en Consorcios Bacterianos de Suelos Bajo Cultivo de Papa con Manejo Convencional y Bajo Pastizal Enzyme Activities in Bacterial Consortium Isolated from Soils with Potato Crop under Conventional Management and under Grassland

    Directory of Open Access Journals (Sweden)

    Lizeth Manuela Avellaneda-Torres


    Full Text Available Resumen. Se evaluaron las actividades enzimáticas (ureasa, proteasa, fosfatasa ácida y alcalina, fosfodiesterasa, b-glucosidasa y arilsulfatasa en consorcios bacterianos (Bacillus subtilis, Brevundimonas diminuta, Flavimonas oryzihabitants de suelos bajo cultivo de papa variedad Parda Pastusa, con manejo convencional de aplicación de agroinsumos (PCA y en suelos bajo pastizal sin aplicación de agroinsumos (PSA, en fincas de tres localidades del departamento de Cundinamarca (Tausa, Villapinzón y Zipaquirá, Colombia. Se encontraron efectos por la aplicación de insumos de síntesis química y el tipo de uso del suelo, sobre las actividades enzimáticas; sin embargo, estos fueron diferentes para cada una de las enzimas y localidades. Para el municipio de Villapinzón la actividad de ureasa, fosfatasa ácida, fosfodiesterasa y b-glucosidasa, fue mayor en las muestras PCA con respecto a las PSA en un 89, 71, 67 y 75% respectivamente; para el municipio de Zipaquirá se presentó la misma tendencia en la actividad ureasa, b-glucosidasa y arilsulfatasa con un 50, 71 y 68% respectivamente; finalmente en el municipio de Tausa se mantuvo el mismo comportamiento para la actividad de proteasa, fosfatasa ácida, fosfatasa alcalina, fosfodiesterasa, b-glucosidasa, con un 55, 20, 75, 82 y 87% de mayor actividad en las muestras PCA en relación con las de PSA.Abstract. Enzyme activities were evaluated (urease, protease, acid phosphatase and alkaline phosphodiesterase, b-glucosidase and arylsulfatase in bacterial consortia (Bacillus subtilis, Brevundimonas diminuta, Flavimonas oryzihabitants from either soil with potato cropping under conventional management with the application of agrochemicals (PWA or grassland soils without the use of agrochemicals (GNA on farms of three municipalities (Tausa, Villapinzón and Zipaquirá in the department of Cundinamarca, Colombia. The type of land use and the location affected the tested enzymatic activities. In the

  13. Determination of sildenafil by preconcentration on surfactant coated polymeric resin followed by spectrofluorimetry

    Directory of Open Access Journals (Sweden)

    Chien C. Wang


    Full Text Available The illicit addition of phosphodiesterase type-5 (PDE-5 inhibitors like sildenafil (Viagra in product offered as herbal medicine or dietary supplement for male erectile dysfunction has concerned authorities in recent times. In this paper, we proposed a sensitive surfactant-coated Amberlite XAD™ resin for sildenafil preconcentration method with spectrofluorimetric detection. Retention capacity of micellar coated XAD resin for sildenafil was studied and the obtained eluate was measured by spectrofluorometer at excitation and emission wavelengths of 350 and 430nm, respectively. This method allowed the detection of sildenafil at 0.15ng/mL with linear range of 0.0003–7.0μg/mL. The method has been successfully applied to the analysis of some local commercially available herbal medicines and urine. Keywords: Sildenafil, Herbal medicines, Spectrofluorimetric analysis, Surfactant

  14. Total glucosides of peony attenuates experimental autoimmune encephalomyelitis in C57BL/6 mice. (United States)

    Huang, Qiling; Ma, Xiaomeng; Zhu, Dong Liang; Chen, Li; Jiang, Ying; Zhou, Linli; Cen, Lei; Pi, Rongbiao; Chen, Xiaohong


    Total glucosides of peony (TGP), an active compound extracted from the roots of Paeonia lactiflora Pall, has wide pharmacological effects on nervous system. Here we examined the effects of TGP on experimental autoimmune encephalomyelitis (EAE), an established model of multiple sclerosis (MS). The results showed that TGP can reduce the severity and progression of EAE in C57 BL/6 mice. In addition, TGP also down-regulated the Th1/Th17 inflammatory response and prevented the reduced expression of brain-derived neurotrophic factor and 2',3'-cyclic nucleotide 3'-phosphodiesterase of EAE. These findings suggest that TGP could be a potential therapeutic agent for MS. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Roflumilast - A reversible single-crystal to single-crystal phase transition at 50 °C (United States)

    Viertelhaus, Martin; Holst, Hans Christof; Volz, Jürgen; Hummel, Rolf-Peter


    Roflumilast is a selective phosphodiesterase type 4 inhibitor and is marketed under the brand names Daxas®, Daliresp® and Libertec®. A phase transition of the drug substance roflumilast was observed at 50 °C. The low temperature form, the high temperature form and the phase transition were characterised by differential scanning calorimetry, variable temperature powder X-ray diffraction and single crystal X-ray diffraction, Raman spectroscopy and solid state NMR spectroscopy. The phase transition of roflumilast at 50 °C is completely reversible, the high temperature form cannot be stabilised by quench cooling and the phase transition does not influence the quality of the active pharmaceutical ingredient (API) and the drug product. It was observed to be a single crystal to single crystal phase transition.

  16. Effect of the caffeine on treated and non-treated plasmid DNA with stannic chloride; Efeito da cafeina em DNA plasmidial tratado e nao tratado com cloreto estanoso

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Silvana Ramos F. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Biologia. Dept. de Biofisica e Biometria]|[Universidade Federal Fluminense, Niteroi, RJ (Brazil). Faculdade de Ciencias Medicas. Curso de Pos-graduacao em Patologia Experimental; Mattos, Jose C.P. de; Dantas, Flavio; Araujo, Adriano Caldeira de; Bernardo-Filho, Mario [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Biologia. Dept. de Biofisica e Biometria]. E-mail:


    Caffeine, a methilxantine drug is a component of coffee, tea, stimulants and other drinks. Caffeine inhibits phosphodiesterase leading to intracellular accumulation of cyclic AMP, blocks adenosine receptors, and increases the release of Ca{sup 2+}. We have studied the possible effect of caffeine in DNA plasmid treated or not with stannous chloride (SnCl{sub 2}). Previous evaluations of the effect of caffeine on the labeling of red blood cells and plasma proteins with technetium-99m have showed a decrease of % ATI in the insoluble fraction of plasma proteins. Samples of DNA were treated with SnCl{sub 2} (0 and 200{mu}g/ml) in 0.8% agarose. SnCl{sub 2} has induced break on DNA and caffeine has not showed effect on the DNA. This indicates that caffeine does not eliminate the oxidant action of SnCl{sub 2} and does not promote break in isolated DNA plasmid. (author)

  17. Dipyridamole may induce migraine in patients with migraine without aura

    DEFF Research Database (Denmark)

    Kruuse, C; Lassen, L H; Iversen, Helle Klingenberg


    Dipyridamole inhibits phosphodiesterase 5 (PDE5) and adenosine re-uptake. The most prominent side-effect is headache. We examined the migraine-generating effects of dipyridamole as well as the cerebral blood velocity response in a single-blind study, including 10 patients with migraine without aura...... repeatedly. Headache was induced in all migraine patients and in eight of 10 healthy subjects (P = 0.47) with no significant difference in headache intensity (P = 0.53). However, five patients but only one healthy subject experienced the symptoms of migraine without aura, according to ICHD-2 criteria, within....... Thus, dipyridamole induces symptoms of migraine and an initial decrease in V(mca) in migraine patients, but not significantly more than in healthy subjects. This relatively low frequency of migraine induction, compared with nitric oxide donors and sildenafil, is probably due to the less specific action...

  18. Lipopolysaccharide-induced acute renal failure in conscious rats

    DEFF Research Database (Denmark)

    Jonassen, Thomas E N; Graebe, Martin; Promeneur, Dominique


    In conscious, chronically instrumented rats we examined 1) renal tubular functional changes involved in lipopolysaccharide (LPS)-induced acute renal failure; 2) the effects of LPS on the expression of selected renal tubular water and sodium transporters; and 3) effects of milrinone......-alpha and lactate, inhibited the LPS-induced tachycardia, and exacerbated the acute LPS-induced fall in GFR. Furthermore, Ro-20-1724-treated rats were unable to maintain MAP. We conclude 1) PDE3 or PDE4 inhibition exacerbates LPS-induced renal failure in conscious rats; and 2) LPS treated rats develop an escape......, a phosphodiesterase type 3 (PDE3) inhibitor, and Ro-20-1724, a PDE4 inhibitor, on LPS-induced changes in renal function. Intravenous infusion of LPS (4 mg/kg b.wt. over 1 h) caused an immediate decrease in glomerular filtration rate (GFR) and proximal tubular outflow without changes in mean arterial pressure (MAP...

  19. [Female sexual dysfunction: Drug treatment options]. (United States)

    Alcántara Montero, A; Sánchez Carnerero, C I


    Many women will likely experience a sexual problem in their lifetime. Female sexual dysfunction is a broad term used to describe 3 categories of disorders of a multifactorial nature. Effective, but limited pharmacotherapeutic options exist to address female sexual dysfunction. The FDA recently approved the first agent for treatment of hypoactive sexual desire disorder in pre-menopausal women. Off-label use of hormonal therapies, particularly oestrogen and testosterone, are the most widely employed for female sexual dysfunction, particularly in post-menopausal women. Other drugs currently under investigation include phosphodiesterase inhibitors and agents that modulate dopamine or melanocortin receptors. Copyright © 2016 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Synthesis and characterization of polymeric hydrogel containing caffeine for cosmeceutical applications

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Tiago C.; Oliveira, Maria José A.; Lugão, Ademar B., E-mail: [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNE-SP), Sao Paulo, SP (Brazil)


    Caffeine, a substance with belongs to the group of methylxanthines, is alkaloids that penetrate in the human epidermis but is not easily absorbed into the bloodstream. With a dermatological active substance, it exerts action on the subcutaneous adipose tissue causing adipocyte lipolysis through the inhibition of phosphodiesterase. Based on these considerations, the objective of this study was to investigate the behavior of caffeine in a polymeric hydrogel matrix, for possible cosmeceutical applications. The hydrogels were cross-linked and sterilized by Cobalt-60 source gamma irradiation. In the characterization, were used thermogravimetry (TGA), scanning electron microscopy (SEM), differential scanning calorimetry (DSC). It was possible to observe by SEM the presence of crystals in the hydrogel sample. The DSC experiment confirmed a crystallinity of the sample and that caffeine is not degraded by gamma irradiation at 25 kGy. The results were satisfactory, allowing a new investigations that certify the benefits of its application. (author)

  1. The reduction of radiation-induced mitotic delay by caffeine: a test of the cyclic AMP hypothesis

    International Nuclear Information System (INIS)

    Oleinick, N.L.; Brewer, E.N.; Rustad, R.C.


    A study has been made of the reduction in γ-radiation-induced mitotic delay by caffeine in the naturally-synchronous plasmodial slime mould. Physarum polycephalum during late G 2 and early prophase, and the results compared with those obtained with other compounds of similar structure and/or physiological function. The reduction of radiation-induced mitotic delay was related to increasing concentrations of caffeine over at least two orders of magnitude. Pre-irradiation treatment with caffeine had no detectable effect. Caffeine had to be present for most, if not all, of the post-irradiation pre-mitotic period. Other chemicals which are reported to inhibit cyclic AMP phosphodiesterase either reduce or increase radiation-induced mitotic delay. The results therefore indicate that the reduction of mitotic delay by caffeine is not a result of altered cyclic AMP levels. (UK)

  2. Phosphorylation of proteins in hippocampal slices: effects of noradrenaline and of pretreatment with kainic acid

    Energy Technology Data Exchange (ETDEWEB)

    Hofstein, R.; Segal, M.


    Hippocampal slices were incubated in the presence of (/sup 32/P)P1, and protein phosphorylation was examined by means of sodium dodecyl sulfate-gel electrophoresis. Incubation for at least 30 min with 300 muCi of (/sup 32/P)P1/brain slice gave rise to the phosphorylation of 8-10 protein bands. Most of these bands showed enhanced phosphorylation in response to noradrenaline. The basal phosphorylation of kainic acid-pretreated hippocampal slices was enhanced two- to threefold compared with controls. There was also an additional increase in kainic acid-pretreatment slices in the response to noradrenaline. 8-Br-Cyclic AMP and phosphodiesterase inhibitors, such as papaverine or isobutylmethylxanthine, had no effect on the phosphorylation patterns.

  3. Chloride transport in toad skin (Bufo viridis). The effect of salt adaptation

    DEFF Research Database (Denmark)

    Katz, U; Larsen, Erik Hviid


    The steady-state Cl- current across the skin of Bufo viridis adapted to tap water was found to be rectified. In skins bathed with NaCl Ringer on both sides, a large outward current, carried by influx of Cl-, was observed at a clamping voltage (V) of less than -50 mV (outside of the skin negative......, and apparent leakage conductance was reduced. Application of the phosphodiesterase inhibitor 3-isobutyl-1-methyl-xanthine to skin of fully salt-adapted toads increased the transepithelial Cl- conductance, and the time courses of voltage clamp currents became more like those of water-adapted toads. Apparent...... leakage conductance was increased.(ABSTRACT TRUNCATED AT 400 WORDS)...

  4. Treatment of psoriatic arthritis with traditional DMARD's and novel therapies: approaches and recommendations. (United States)

    Maharaj, Ajesh B; Chandran, Vinod


    Recent advances in the therapeutics of psoriatic arthritis (PsA) have provided more options to clinicians managing PsA. The purpose of this review is to update the reader on treatment options for PsA using conventional synthetic disease modifying agents (csDMARDs) and novel therapies including tumour necrosis factor alpha inhibitors, interleukin 12/23 inhibitor (ustekinumab), the interleukin 17 antagonists including secukinumab, brodalumab, ixekizumab, and the phosphodiesterase-4 inhibitor, apremilast. Areas covered: We reviewed published articles on the treatment of PsA. Our main sources of data included treatment recommendations, registry studies, systematic literature reviews, major randomised controlled trials for more recently approved drugs, and abstracts from the American College of Rheumatology and EULAR meetings. Expert commentary: An overview of the evidence for the use of various pharmacotherapeutic agents for treatment of this heterogeneous disease was compiled. Treatment options for the various domains of PsA are also discussed.

  5. Coadjuvants in the Diabetic Complications: Nutraceuticals and Drugs with Pleiotropic Effects (United States)

    Pereira, Thiago Melo Costa; Pimenta, Fabio Silva; Porto, Marcella Lima; Baldo, Marcelo Perim; Campagnaro, Bianca Prandi; Gava, Agata Lages; Meyrelles, Silvana Santos; Vasquez, Elisardo Corral


    Because diabetes mellitus (DM) is a multifactorial metabolic disease, its prevention and treatment has been a constant challenge for basic and clinical investigators focused on translating their discoveries into clinical treatment of this complex disorder. In this review, we highlight recent experimental and clinical evidences of potential coadjuvants in the management of DM, such as polyphenols (quercetin, resveratrol and silymarin), cultured probiotic microorganisms and drugs acting through direct/indirect or pleiotropic effects on glycemic control in DM. Among several options, we highlight new promising therapeutic coadjuvants, including chemical scavengers, the probiotic kefir and the phosphodiesterase 5 inhibitors, which besides the reduction of hyperglycemia and ameliorate insulin resistance, they reduce oxidative stress and improve endothelial dysfunction in the systemic vascular circulation. In the near future, experimental studies are expected to clear the intracellular pathways involving coadjuvants. The design of clinical trials may also contribute to new strategies with coadjuvants against the harmful effects of diabetic complications. PMID:27527163

  6. The effect of in vitro procedures on cyclic AMP accumulation in human leucocytes

    DEFF Research Database (Denmark)

    Johansen, Torben; Friis, U G; Rasmussen, A K


    The aim of this study was to investigate the effect of various methodological procedures or protocols on cyclic AMP formation in human leucocytes. The data showed that: (1) ATP content and lactate production was unaffected by hypotonic lysis during leucocyte isolation; (2) there was a linear...... relation between cell number/sample and the production of cyclic adenosine 3':5'-monophosphate (cAMP); (3) the interindividual variation markedly affected cAMP production during long observation periods (years), whereas day-to-day variation within a week was less important; (4) whole blood could be stored...... for up to 4 h (at 4 degrees C or 23 degrees C) without affecting cAMP accumulation; (5) isolated MNL could be stored for up to 2 h (at 4 degrees C) without affecting cAMP accumulation; and finally that (6) choice and concentration of phosphodiesterase inhibitors markedly influenced the basal...

  7. A comparison of the inhibitory activity of selective PDE4 inhibitors on eosinophil recruitment in guinea pig skin

    Directory of Open Access Journals (Sweden)

    Mauro M Teixeira


    Full Text Available The elevation of intracellular cyclic AMP by phosphodiesterase (PDE4 inhibitors in eosinophils is associated with inhibition of the activation and recruitment of these cells. We have previously shown that systemic treatment with the PDE4 inhibitor rolipram effectively inhibt eosinophil migration in guinea pig skin. In the present study we compare the oral potency and efficacy of the PDE4 inhibitors rolipram, RP 73401 and CDP 840 on allergic and PAF-induced eosinophil recruitment. Rolipram and RP 73401 were equally effective and potent when given by the oral route and much more active than the PDE4 inhibitor CDP 840. We suggest that this guinea pig model of allergic and mediator-induced eosinophil recruitment is both a sensitive and simple tool to test the efficacy and potency of PDE4 inhibitors in vivo.

  8. Antidepressant effects of total tertiary alkaloid fraction of Cissampelos sympodialis Eichler in rodents

    Directory of Open Access Journals (Sweden)

    Sueli Mendonça-Netto

    Full Text Available The purpose of the present study was to evaluate the effects of total tertiary alkaloid fraction (TTAF of Cissampelos sympodialis Eichler (Menispermaceae on two animal models of depression: a forced swim test and b reserpine test. Treatment of mice with TTAF (12.5 mg/kg reduced the total immobility time. It also reversed the reserpine-induced hypothermia, demonstrating an antidepressant effect in both models. Additionally, TTAF treatment did not modify the ambulation and rearing evaluated in open field test in order to investigate if the immobility time reduction found in the forced swimming test was caused by locomotive activity stimulation. Since warifteine is one of the main alkaloids present in the TTAF of C. sympodialis, and it has inhibitory activity of the phosphodiesterase enzyme, it may be responsible by the antidepressant effect found in the fraction studied.

  9. Caffeine and adenosine. (United States)

    Ribeiro, Joaquim A; Sebastião, Ana M


    Caffeine causes most of its biological effects via antagonizing all types of adenosine receptors (ARs): A1, A2A, A3, and A2B and, as does adenosine, exerts effects on neurons and glial cells of all brain areas. In consequence, caffeine, when acting as an AR antagonist, is doing the opposite of activation of adenosine receptors due to removal of endogenous adenosinergic tonus. Besides AR antagonism, xanthines, including caffeine, have other biological actions: they inhibit phosphodiesterases (PDEs) (e.g., PDE1, PDE4, PDE5), promote calcium release from intracellular stores, and interfere with GABA-A receptors. Caffeine, through antagonism of ARs, affects brain functions such as sleep, cognition, learning, and memory, and modifies brain dysfunctions and diseases: Alzheimer's disease, Parkinson's disease, Huntington's disease, Epilepsy, Pain/Migraine, Depression, Schizophrenia. In conclusion, targeting approaches that involve ARs will enhance the possibilities to correct brain dysfunctions, via the universally consumed substance that is caffeine.

  10. Current views on the pharmacotherapy of psoriatic arthritis

    Directory of Open Access Journals (Sweden)

    G. G. Taradin


    Full Text Available The review deals with current pharmacological approaches to treating psoriatic arthritis (PsA. It gives data on the prevalence of psoriasis and psoriatic joint injury that is a common cause of early patient disability. Approaches to evaluating the efficacy of drugs are given on the basis of developed and used criteria with regard to the standardized assessment of the dynamics of joint injury in rheumatic diseases and PSA in particular. The review gives brief information on the mechanism of drug actions and the results of clinical trials evaluating the efficacy and safety of different medicaments in PsA. It also covers the experience in using nonsteroidal antiinflammatory drugs, glucocorticoids, synthetic diseasemodifying antirheumatic drugs (methotrexate, cyclosporine, leflunomide, sulfasalazine, and also a promising group of biologicals. Particular emphasis is placed on the results of using tumor necrosis factor inhibitors (etanercept, infliximab, golimumab, certolizumab pegol, adalimumab, interleukin inhibitors (ustekinumab, brodalumab, and phosphodiesterase 4 inhibitors (apremilast.

  11. Premature ejaculation. 3. Therapy. (United States)

    Piediferro, Guido; Colpi, Elisabetta M; Castiglioni, Fabrizio; Scroppo, Fabrizio I


    Serotonergic drugs (SSRIs) are the most commonly used, but they are characterized by relapse some time after medication interruption as well as by sexual side effects. The efficacy of phosphodiesterase-5 inhibitors seems excellent, but the risk of tachyphylaxis has been reported. The former (fluoxetine, paroxetine, sertraline, clomipramine) should be used in young patients with hyper-orgasmic forms, while the latter (sildenafil, tadalafil, vardenafil) should be used in hypo-orgasmic forms, in old age or when PE is associated with erectile dysfunction. Topical anesthetics provide satisfactory results in premature ejaculation due to hypersensitivity of the glans, and physiotherapy of the pelvic floor muscles proves successful in cases associated with pelvic floor dysfunction. Therapeutic associations and psycho-sexual therapy techniques may improve results, particularly in the long term.

  12. Sarafotoxin, a novel vasoconstrictor peptide: phosphoinositide hydrolysis in rat heart and brain. (United States)

    Kloog, Y; Ambar, I; Sokolovsky, M; Kochva, E; Wollberg, Z; Bdolah, A


    Sarafotoxins, a group of 21-residue cardiotoxic peptides from snake venom that induce coronary vasoconstriction, show high-affinity binding to rat atrial and brain membranes and activate the hydrolysis of phosphoinositides. Neither their binding nor their activity is affected by blockers or activators of known receptors and ion channels, suggesting that sarafotoxins act either directly on the phosphoinositide phosphodiesterase system or on a novel receptor. Their amino acid sequence shows a high degree of homology with that of endothelin, a recently described 21-residue vasoconstrictor peptide found in porcine aortic endothelium. This is remarkable, since endothelin is a natural compound of the mammalian vascular system while sarafotoxins are highly toxic components of snake venom.

  13. Therapeutic options for severe asthma (United States)

    Mathew, Jilcy; Chandy, Dipak


    As the overall prevalence of asthma has escalated in the past decades, so has the population of patients with severe asthma. This condition is often difficult to manage due to the relative limitation of effective therapeutic options for the physician and the social and economic burden of the disease on the patient. Management should include an evaluation and elimination of modifiable risk factors such as smoking, allergen exposure, obesity and non-adherence, as well as therapy for co-morbidities like gastro-esophageal reflux disease and obstructive sleep apnea. Current treatment options include conventional agents such as inhalational corticosteroids, long acting β2 agonists, leukotriene antagonists, and oral corticosteroids. Less conventional treatment options include immunotherapy with methotrexate, cyclosporine and tacrolimus, biological drugs like monoclonal antibodies, tumor necrosis factor-α blockers and oligonucleotides, phosphodiesterase inhibitors, antimicrobials and bronchial thermoplasty. PMID:23056066

  14. Vascular Alterations and Sexual Function in Systemic Sclerosis

    Directory of Open Access Journals (Sweden)

    Ann Julie Impens


    Full Text Available Sexual dysfunction is common in systemic sclerosis (SSc. Male erectile dysfunction (MED has been reported in around 80% of subjects and more than half of female patients fulfill criteria for diagnosis as female sexual arousal Disorder (FSAD. While some evidence supports a role for cavernosal fibrosis, abundant data suggest that MED is yet another clinical feature of SSc related to vasculopathy. The contribution of vasculopathy to the more complex issues of female sexual dysfunction is less clear. Inhibitors of Type V phosphodiesterase are effective in men with MED secondary to SSc. Limited study in women suggests inconsistent effects on behavior (frequency but not on measures related to perfusion. Sexual activity is an important component of quality of life and an important domain for the caregiver to address; it is not clear that it warrants primary consideration as a consistent measure of scleroderma-related vasculopathy.

  15. Relaxation of soman-induced contracture of airway smooth muscle in vitro. (Reannouncement with new availability information)

    Energy Technology Data Exchange (ETDEWEB)

    Filbert, M.G.; Moore, D.H.; Adler, M.


    A possible role for beta-adrenergic agonists in the management of bronchoconstriction resulting from exposure to anticholinesterase compounds was investigated in vitro in canine tracheal smooth muscle. Norepinephrine, salbutamol and isoproterenol produced partial relaxation of soman-induced contractures. However, the relaxation induced was not sustained; muscle tensions returned to pretreatment levels within minutes despite the continued presence of beta-agonists. Increasing cAMP levels with the non beta-agonist bronchodilators such as thoophylline, a phosphodiesterase inhibitor, or forskolin, a specific stimulator of adenylate cyclase, resulted in more complete and longer lasting relaxation, suggesting that beta-adrenoceptor desensitization may contribute to the failure by beta-agonists to produce sustained relaxation. Nerve agents, Soman, Toxicity, Airway smooth muscle, In vitro, Physiology, Effects.

  16. Survey of treatment practices for sexual dysfunction(s) associated with anti-depressants. (United States)

    Balon, Richard; Segraves, R Taylor


    There are many management strategies and antidotes available for sexual dysfunction associated with antidepressants available. However, only a few of these strategies and antidotes were tested in rigorous trials and most of them probably will not be rigorously tested. Surveying the prescribing practices of experts in this area provides another opportunity to evaluate these strategies and antidotes. The authors surveyed 29 (of 50) "expert" psychiatrists in the area of sexual dysfunction associated with antidepressants. Switching to another antidepressant, decreasing the dose of an antidepressant, and adding oral agents such as bupropion, phosphodiesterase-5 inhibitors, and some dopaminergic agents (dextroamphetamine, methylphenidate) and a testosterone patch in some dysfunctions (libido, orgasm) are management strategies most frequently used by the experts. The experts also consider these strategies as the most effective ones. These findings are compared with other studies and discussed with regard to the evidence from clinical trials.

  17. Pulmonary Arterial Hypertension in Adults: Novel Drugs and Catheter Ablation Techniques Show Promise? Systematic Review on Pharmacotherapy and Interventional Strategies

    Directory of Open Access Journals (Sweden)

    Salvatore Rosanio


    Full Text Available This systematic review aims to provide an update on pharmacological and interventional strategies for the treatment of pulmonary arterial hypertension in adults. Currently US Food and Drug Administration approved drugs including prostanoids, endothelin-receptor antagonists, phosphodiesterase type-5 inhibitors, and soluble guanylate-cyclase stimulators. These agents have transformed the prognosis for pulmonary arterial hypertension patients from symptomatic improvements in exercise tolerance ten years ago to delayed disease progression today. On the other hand, percutaneous balloon atrioseptostomy by using radiofrequency perforation, cutting balloon dilatation, or insertion of butterfly stents and pulmonary artery catheter-based denervation, both associated with very low rate of major complications and death, should be considered in combination with specific drugs at an earlier stage rather than late in the progression of pulmonary arterial hypertension and before the occurrence of overt right-sided heart failure.

  18. Synthesis and characterization of polymeric hydrogel containing caffeine for cosmeceutical applications

    International Nuclear Information System (INIS)

    Santos, Tiago C.; Oliveira, Maria José A.; Lugão, Ademar B.


    Caffeine, a substance with belongs to the group of methylxanthines, is alkaloids that penetrate in the human epidermis but is not easily absorbed into the bloodstream. With a dermatological active substance, it exerts action on the subcutaneous adipose tissue causing adipocyte lipolysis through the inhibition of phosphodiesterase. Based on these considerations, the objective of this study was to investigate the behavior of caffeine in a polymeric hydrogel matrix, for possible cosmeceutical applications. The hydrogels were cross-linked and sterilized by Cobalt-60 source gamma irradiation. In the characterization, were used thermogravimetry (TGA), scanning electron microscopy (SEM), differential scanning calorimetry (DSC). It was possible to observe by SEM the presence of crystals in the hydrogel sample. The DSC experiment confirmed a crystallinity of the sample and that caffeine is not degraded by gamma irradiation at 25 kGy. The results were satisfactory, allowing a new investigations that certify the benefits of its application. (author)


    Directory of Open Access Journals (Sweden)

    A. V. Govorov


    Full Text Available Erectile dysfunction is a frequent complication of radical prostatectomy despite numerous modifications in surgical technique. The term «penile rehabilitation» refers usually to treatments intended to restore functional penile erection after radical prostatectomy. Selective phosphodiesterase type 5 inhibitors are the mainstay of this rehabilitation at present. Tadalafil seems a logical choice for recovering of erectile functionafter radical prostatectomy given its prolonged duration of action. The once-daily dose of tadalafil has the theoretical benefit in terms of safety and separation of medication from sexual activity. In this paper we review the published clinical and basic science research studies on the role of tadalafil in patients with postprostatectomy erectile dysfunction.

  20. Prevention of erectile dysfunction after radiotherapy for prostate cancer

    Directory of Open Access Journals (Sweden)

    Izak Faiena


    Full Text Available With increasing scrutiny of prostate cancer (PCa diagnosis and treatment, much attention has been given to the morbidity caused by radical prostatectomy (RP and/or radiotherapy (RT. One of the most common side-effects of either treatment is erectile dysfunction (ED. [1] Approximately, 40% of patients will experience ED after RT for PCa. The post-RT ED causes significant patient dissatisfaction with cancer treatment as well as decrease in patient and partner psychosocial function. [2] To address this issue in patients undergoing RT, Pisansky et al. [3] conducted a prospective, randomized, double-blinded, placebo-controlled trial to assess the efficacy of a phosphodiesterase enzyme-5 inhibitor (PDE5i, tadalafil, as a preventive measure for patients undergoing RT for PCa and found no difference in erectile function between the control and treatment groups.


    Directory of Open Access Journals (Sweden)

    A. V. Govorov


    Full Text Available Erectile dysfunction is a frequent complication of radical prostatectomy despite numerous modifications in surgical technique. The term «penile rehabilitation» refers usually to treatments intended to restore functional penile erection after radical prostatectomy. Selective phosphodiesterase type 5 inhibitors are the mainstay of this rehabilitation at present. Tadalafil seems a logical choice for recovering of erectile functionafter radical prostatectomy given its prolonged duration of action. The once-daily dose of tadalafil has the theoretical benefit in terms of safety and separation of medication from sexual activity. In this paper we review the published clinical and basic science research studies on the role of tadalafil in patients with postprostatectomy erectile dysfunction.

  2. Milrinone in Enterovirus 71 Brain Stem Encephalitis

    Directory of Open Access Journals (Sweden)



    Full Text Available Enterovirus 71 (EV71 was implicated in a widespread outbreak of hand-foot-and-mouth disease (HFMD across the Asia Pacific area since 1997 and has also been reported sporadically in patients with brain stem encephalitis. Neurogenic shock with pulmonary edema (PE is a fatal complication of EV71 infection. Among inotropic agents, milrinone is selected as a therapeutic agent for EV71- induced PE due to its immunopathogenesis. Milrinone is a type III phosphodiesterase inhibitor that has both inotropic and vasodilator effects. Its clinical efficacy has been shown by modulating inflammation, reducing sympathetic over-activity, and improving survival in patients with EV71-associated PE. Milrinone exhibits immunoregulatory and anti-inflammatory effects in the management of systemic inflammatory responses in severe EV71 infection.

  3. Nitric oxide-related drug targets in headache

    DEFF Research Database (Denmark)

    Olesen, Jes


    SUMMARY: Nitric oxide (NO) is a very important molecule in the regulation of cerebral and extra cerebral cranial blood flow and arterial diameters. It is also involved in nociceptive processing. Glyceryl trinitrate (GTN), a pro-drug for NO, causes headache in normal volunteers and a so-called del......SUMMARY: Nitric oxide (NO) is a very important molecule in the regulation of cerebral and extra cerebral cranial blood flow and arterial diameters. It is also involved in nociceptive processing. Glyceryl trinitrate (GTN), a pro-drug for NO, causes headache in normal volunteers and a so...... another very likely new treatment. It is more unlikely that antagonism of cGMP or its formation will be feasible, but augmenting its breakdown via phosphodiesterase activation is a possibility, as well as other ways of inhibiting the NO-cGMP pathway....

  4. MEK Inhibitors Reverse cAMP-Mediated Anxiety in Zebrafish

    DEFF Research Database (Denmark)

    Lundegaard, Pia R.; Anastasaki, Corina; Grant, Nicola J.


    Altered phosphodiesterase (PDE)-cyclic AMP (cAMP) activity is frequently associated with anxiety disorders, but current therapies act by reducing neuronal excitability rather than targeting PDE-cAMP-mediated signaling pathways. Here, we report the novel repositioning of anti-cancer MEK inhibitors...... as anxiolytics in a zebrafish model of anxiety-like behaviors. PDE inhibitors or activators of adenylate cyclase cause behaviors consistent with anxiety in larvae and adult zebrafish. Small-molecule screening identifies MEK inhibitors as potent suppressors of cAMP anxiety behaviors in both larvae and adult...... zebrafish, while causing no anxiolytic behavioral effects on their own. The mechanism underlying cAMP-induced anxiety is via crosstalk to activation of the RAS-MAPK signaling pathway. We propose that targeting crosstalk signaling pathways can be an effective strategy for mental health disorders, and advance...

  5. Advances in the treatment of erectile dysfunction: what’s new and upcoming? [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Chintan K. Patel


    Full Text Available Erectile dysfunction adversely affects up to 20% of all men and is the most commonly treated sexual disorder. The public health implications of this condition are significant and represent a challenge for our healthcare system. The physiological pathways responsible for erections have been extensively studied, and much advancement has been made since the introduction of phosphodiesterase 5 inhibitors. Newer agents, such as dopaminergic and melanocortin receptor agonists, which target central erectogenic pathways, are under investigation. Newer formulations and delivery methods of existing medications such as alprostadil will also be introduced in the near future. Furthermore, low-intensity shockwave lithotripsy and stem cell regenerative techniques are innovative approaches to the treatment of erectile dysfunction.

  6. To the mechanism of spermine-FBS cytotoxicity toward K562 human myelogenous leukemia cells. (United States)

    Juranić, Z; Joksimović, J; Spuzić, I; Sami, I; Juranić, I


    The effects of several compounds acting through adenylate cyclase system and/or influencing prostaglandin biosynthesis on spermine-FBS cytotoxicity to human myelogenous leukemia K562 cells were studied. Salbutamol, a beta 2-adrenoceptor agonist inhibited to a certain extent spermine-FBS cytotoxic action to K562 cells, and propranolol, a beta 2-adrenoceptor antagonist, did not affect this inhibition. Aminophylline, an inhibitor of cyclic nucleotide phosphodiesterase, acted suppressing spermine-FBS cytotoxicity to K562 cells. Pretreatment of the cells with dexamethasone did not significantly alter salbutamol-related inhibition of spermine-FBS cytotoxicity. Indomethacin, an inhibitor of cyclooxygenases directly involved in prostaglandin biosynthesis, did not interfere with protective terbutaline effects against spermine-FBS cytotoxicity to K562 cells during the 24-hour period.

  7. Studies on the role of histamine and 5-hydroxytryptamine in immunity against the nematode Trichostrongylus colubriformis. IV. Inhibition of the expulsion of worms transplanted into the duodenum of immune guinea pigs. (United States)

    Rothwell, T L; Love, R J; Evans, D P


    Significant numbers of fourth larval stage Trichostrongylus colubriformis from sheep donors are expelled from the small intestine of T. colubriformis-immune guinea pigs within 8 h of transplantation into this organ. This model system for the immune expulsion of gastrointestinal nematode parasites was used in the current experiments to examine the effect of drugs recently shown to modify the release of histamine. The experiments showed that worm expulsion was inhibited by the beta-adrenergic agonists salbutamol and isoprenaline, the phosphodiesterase inhibitors aminophylline and ICI 63,197, the antiallergic drug ICI 74,917 and the antihistamine mepyramine. The beta-blocker propranolol prevented inhibition of worm expulsion following salbutamol treatment and there was some evidence of synergistic action between salbutamol and ICI 63,197. The results support previous findings suggesting an important role for histamine release in the effector mechanism of the immune response of guinea pigs against the parasitic nematode T.colubriformis.

  8. Palmoplantar Psoriasis and Palmoplantar Pustulosis: Current Treatment and Future Prospects. (United States)

    Raposo, Inês; Torres, Tiago


    Palmoplantar psoriasis and palmoplantar pustulosis are chronic skin diseases with a large impact on patient quality of life. They are frequently refractory to treatment, being generally described as a therapeutic challenge. This article aims to review the definitions of palmoplantar psoriasis and palmoplantar pustulosis, highlighting the similarities and differences in terms of epidemiology, clinical presentation, genetics, histopathology, and pathogenesis, as well as treatment options for both entities. Classical management of mild to moderate palmoplantar pustulosis and palmoplantar psoriasis relies on use of potent topical corticosteroids, phototherapy, and/or acitretin. Nevertheless, these drugs have proven to be insufficient in long-term control of extensive disease. Biologic therapy-namely, anti-interleukin-17 agents and phosphodiesterase type 4 inhibitors-has recently shown promising results in the treatment of palmoplantar psoriasis. Knowledge of the pathophysiologic pathways of both entities is of utmost importance and may, in the future, allow development of molecularly targeted therapeutics.

  9. Turning Failure into Success: Trials of the Heart Failure Clinical Research Network. (United States)

    Joyce, Emer; Givertz, Michael M


    The Heart Failure Clinical Research Network (HFN) was established in 2008 on behalf of the NIH National Heart, Lung and Blood Institute, with the primary goal of improving outcomes in heart failure (HF) by designing and conducting high-quality concurrent clinical trials testing interventions across the spectrum of HF. Completed HFN trials have answered several important and relevant clinical questions concerning the safety and efficacy of different decongestive and adjunctive vasodilator therapies in hospitalized acute HF, phosphodiesterase-5 inhibition and nitrate therapies in HF with preserved ejection fraction, and the role of xanthine oxidase inhibition in hyperuricemic HF. These successes, independent of the "positive" or "negative" result of each individual trial, have helped to shape the current clinical care of HF patients and serve as a platform to inform future research directions and trial designs.

  10. GDE2 regulates subtype-specific motor neuron generation through inhibition of Notch signaling. (United States)

    Sabharwal, Priyanka; Lee, Changhee; Park, Sungjin; Rao, Meenakshi; Sockanathan, Shanthini


    The specification of spinal interneuron and motor neuron identities initiates within progenitor cells, while motor neuron subtype diversification is regulated by hierarchical transcriptional programs implemented postmitotically. Here we find that mice lacking GDE2, a six-transmembrane protein that triggers motor neuron generation, exhibit selective losses of distinct motor neuron subtypes, specifically in defined subsets of limb-innervating motor pools that correlate with the loss of force-generating alpha motor neurons. Mechanistically, GDE2 is expressed by postmitotic motor neurons but utilizes extracellular glycerophosphodiester phosphodiesterase activity to induce motor neuron generation by inhibiting Notch signaling in neighboring motor neuron progenitors. Thus, neuronal GDE2 controls motor neuron subtype diversity through a non-cell-autonomous feedback mechanism that directly regulates progenitor cell differentiation, implying that subtype specification initiates within motor neuron progenitor populations prior to their differentiation into postmitotic motor neurons. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Diverse Regulation of Temperature Sensation by Trimeric G-Protein Signaling in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Tomoyo Ujisawa

    Full Text Available Temperature sensation by the nervous system is essential for life and proliferation of animals. The molecular-physiological mechanisms underlying temperature signaling have not been fully elucidated. We show here that diverse regulatory machinery underlies temperature sensation through trimeric G-protein signaling in the nematode Caenorhabditis elegans. Molecular-genetic studies demonstrated that cold tolerance is regulated by additive functions of three Gα proteins in a temperature-sensing neuron, ASJ, which is also known to be a light-sensing neuron. Optical recording of calcium concentration in ASJ upon temperature-changes demonstrated that three Gα proteins act in different aspects of temperature signaling. Calcium concentration changes in ASJ upon temperature change were unexpectedly decreased in a mutant defective in phosphodiesterase, which is well known as a negative regulator of calcium increase. Together, these data demonstrate commonalities and differences in the molecular components concerned with light and temperature signaling in a single sensory neuron.

  12. Diverse Regulation of Temperature Sensation by Trimeric G-Protein Signaling in Caenorhabditis elegans (United States)

    Ujisawa, Tomoyo; Ohta, Akane; Uda-Yagi, Misato


    Temperature sensation by the nervous system is essential for life and proliferation of animals. The molecular-physiological mechanisms underlying temperature signaling have not been fully elucidated. We show here that diverse regulatory machinery underlies temperature sensation through trimeric G-protein signaling in the nematode Caenorhabditis elegans. Molecular-genetic studies demonstrated that cold tolerance is regulated by additive functions of three Gα proteins in a temperature-sensing neuron, ASJ, which is also known to be a light-sensing neuron. Optical recording of calcium concentration in ASJ upon temperature-changes demonstrated that three Gα proteins act in different aspects of temperature signaling. Calcium concentration changes in ASJ upon temperature change were unexpectedly decreased in a mutant defective in phosphodiesterase, which is well known as a negative regulator of calcium increase. Together, these data demonstrate commonalities and differences in the molecular components concerned with light and temperature signaling in a single sensory neuron. PMID:27788246

  13. Overcoming of P-glycoprotein mediated vincristine resistance of L1210/VCR mouse leukemic cells could be induced by pentoxifylline but not by theophylline and caffeine

    International Nuclear Information System (INIS)

    Stefankova, Z.; Barancik, M.; Breier, A.


    Effects of xanthine derivatives (pentoxifylline (PTX), caffeine, theophylline, 1-methyl-3-isobutylxanthine) on P-glycoprotein mediated vincristine resistance of L1210/VCR mouse leukemic cell sub-line were studied. From the applied xanthines only PTX was found to reverse the vincristine resistance of the above cells. Moreover, only PTX, but not other xanthine, increased the accumulation of [ 3 H]vincristine by L1210/VCR cells. Thus it may be concluded that PTX-induced reversal of vincristine (VCR) resistance could not be explained from the point of known pharmacological effects of PTX that are common for other xanthines such as inhibition of phosphodiesterase activity, calcium mobilizing effect, inhibition of tumor necrosis factor α (TNF), etc. (author)

  14. Nucleoside composition of Heloderma venoms. (United States)

    Aird, Steven D


    Venoms of Heloderma horridum and Heloderma suspectum were analyzed for the possible presence of purine and pyrimidine nucleosides. Adenosine, cytidine, guanosine, hypoxanthine, inosine, and uridine were found in mug quantities. These amounts are much smaller than those seen in many elapid or viperine venoms, but greater and more varied than those found in crotaline venoms. While their contribution to the hypotension induced by Heloderma venoms may be minor, venom nucleosides nonetheless act in concert with kallikreins/hemorrhagins, alkaline phosphomonoesterase, 5'-nucleotidase, helodermin, helospectins, helothermine, and serotonin. The use of nucleosides as toxins is therefore a generalized squamate strategy, rather than the exclusive province of snakes. Both Heloderma venoms were found to be devoid of NADase and phosphodiesterase activities. Enzymes to release endogenous purines in the prey, are not significant components of Heloderma venoms.

  15. Fragment-Based Screening by Protein Crystallography: Successes and Pitfalls

    Directory of Open Access Journals (Sweden)

    Aaron J. Oakley


    Full Text Available Fragment-based drug discovery (FBDD concerns the screening of low-molecular weight compounds against macromolecular targets of clinical relevance. These compounds act as starting points for the development of drugs. FBDD has evolved and grown in popularity over the past 15 years. In this paper, the rationale and technology behind the use of X-ray crystallography in fragment based screening (FBS will be described, including fragment library design and use of synchrotron radiation and robotics for high-throughput X-ray data collection. Some recent uses of crystallography in FBS will be described in detail, including interrogation of the drug targets β-secretase, phenylethanolamine N-methyltransferase, phosphodiesterase 4A and Hsp90. These examples provide illustrations of projects where crystallography is straightforward or difficult, and where other screening methods can help overcome the limitations of crystallography necessitated by diffraction quality.

  16. Novel potential for the management of Alzheimer disease. (United States)

    Ginter, E; Simko, V; Weinrebova, D; Ladecka, Z


    Pathologic characteristics of Alzheimer disease (AD) are β-amyloid (Aβ) plaques, neurofibrillary tangles (NFT) and neurodegeneration. Currently, there is no cure for AD. Cilostazol, a selective inhibitor of type 3 phosphodiesterase, is likely to be a promising agent for AD. In the brain of the experimental animals it significantly reduced the Aβ amyloid plaques. Initial clinical reports on the effect of Cilostazol in AD patients are promising. In mice, stem cells favourably influence the pathogenetic process critical in AD, by reducing deposits of Aβ plaques. Clinical trials of the drug, called Betablock, are already underway in Britain. Successful management and resolution of AD in man will still require further intensive research (Fig. 4, Ref. 11).

  17. Multiple diguanylate cyclase-coordinated regulation of pyoverdine synthesis in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Chen, Yicai; Yuan, Mingjun; Mohanty, Anee


    intrinsic feature of c-di-GMP signalling is the abundance of DGCs and PDEs encoded by many bacterial species. It is unclear whether the different DGCs or PDEs coordinately establish the c-di-GMP regulation or function independently of each other. Here, we provide evidence that multiple DGCs are involved......The nucleotide signalling molecule bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) plays an essential role in regulating microbial virulence and biofilm formation. C-di-GMP is synthesized by diguanylate cyclase (DGC) enzymes and degraded by phosphodiesterase (PDE) enzymes. One...... in regulation of c-di-GMP on synthesis of the major iron siderophore pyoverdine in Pseudomonas aeruginosa. Constitutive expression of the WspG or YedQ DGC in P.aeruginosa is able to induce its pyoverdine synthesis. Induction of pyoverdine synthesis by high intracellular c-di-GMP depends on the synthesis...

  18. Bosentan and sildenafil: successful treatment in a sclerodermic patient with refractory ulcers

    Directory of Open Access Journals (Sweden)

    E. Catarsi


    Full Text Available Systemic sclerosis is an inflammatory disease of the connective tissue characterized by vasculopathy and accumulation of collagen and other components of the connective matrix, affecting the skin and internal organs. The appearance of skin ulcers as a result of vascular damage is very common in the history of the disease. Skin ulcers, painful and slow healing due to atrophy and local ischemia, get worse the quality of life of patients. Often, the use of conventional therapies (such as calcium channel blockers and prostanoids does not cause the complete healing of the lesions. We report the case of a patient in whom therapeutic association between endothelin antagonist (bosentan and phosphodiesterase-V inhibitor (sildenafil resulted in complete healing of old ulcers both to upper and lower limbs and allowed the interruption of intravenous therapies.

  19. Effects of drugs on platelet function. (United States)

    Morse, E E


    Numerous drugs and chemicals affect the function of human blood platelets. The mechanism of action of some medications is partly understood. Aspirin is the most frequently involved drug. It appears to interfere with the platelet release reaction by acetylation of a platelet membrane protein which may be involved in the synthesis of prostaglandins. Other anti-inflammatory drugs, including indomethacin, phenylbutazone, ibuprophen (Motrin) and clonixin, also interfere with the release reaction but have a shorter acting course than aspirin. Some drugs stimulate adenylcyclase (gliclazide) or block phosphodiesterase, (dipyridamole, caffeine) both of which actions lead to an increase in adenosine cyclic 3':5' monophosphate (cAMP) and decrease aggregation by adenosine diphosphate (ADP). These interactions should be known to clinical scientists since patients using these medicaments may manifest abnormal platelet function tests in the laboratory and mild hemorrhagic syndromes in the clinic.

  20. Ultraviolet light induction of skin carcinoma in the mouse; influence of cAMP modifying agents

    International Nuclear Information System (INIS)

    Zajdela, F.; Latarjet, R.


    A short review of pathogenic factors in U.V. light skin carcinogenesis in the mouse is presented. Caffeine and theophylline applied locally during U.V. irradiation caused a 50% reduction of skin tumour induction in Swiss mice. These two chemicals are inhibitors of DNA postreplication repair, but they also raise the intracellular level of cyclic AMP by inhibiting cAMP phosphodiesterase with, as a consequence, a possible slowing down of cellular growth. Control experiments using three different chemicals capable of raising the cAMP level in epidermal cells gave negative results. These experimental data are compatible with our original hypothesis according to which production of skin cancers by U.V. radiation is in same way related to DNA repair which helps the cell to survive but allows or favours the occurence of errors in cellular DNA

  1. Insulin release by glucagon and secretin

    DEFF Research Database (Denmark)

    Kofod, Hans; Andreu, D; Thams, P


    Secretin and glucagon potentiate glucose-induced insulin release. We have compared the effects of secretin and glucagon with that of four hybrid molecules of the two hormones on insulin release and formation of cyclic AMP (cAMP) in isolated mouse pancreatic islets. All six peptides potentiated...... the release of insulin at 10 mM D-glucose, and their effects were indistinguishable with respect to the dynamics of release, dose-response relationship, and glucose dependency. However, measurements of cAMP accumulation in the presence of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (10(-4) M...... potentiating effects of secretin and glucagon on glucose-induced insulin release, their modes of action may be different....

  2. Alleged Detrimental Mutations in the SMPD1 Gene in Patients with Niemann-Pick Disease

    Directory of Open Access Journals (Sweden)

    Cosima Rhein


    Full Text Available Loss-of-function mutations in the sphingomyelin phosphodiesterase 1 (SMPD1 gene are associated with decreased catalytic activity of acid sphingomyelinase (ASM and are the cause of the autosomal recessive lysosomal storage disorder Niemann-Pick disease (NPD types A and B. Currently, >100 missense mutations in SMPD1 are listed in the Human Gene Mutation Database. However, not every sequence variation in SMPD1 is detrimental and gives rise to NPD. We have analysed several alleged SMPD1 missense mutations mentioned in a recent publication and found them to be common variants of SMPD1 that give rise to normal in vivo and in vitro ASM activity. (Comment on Manshadi et al. Int. J. Mol. Sci. 2015, 16, 6668–6676.

  3. Raynaud’s phenomenon as an interdisciplinary problem

    Directory of Open Access Journals (Sweden)

    Karolina Górska


    Full Text Available Raynaud’s phenomenon is one of the most common disorders of the blood vessels, which usually affects fingers and toes. Raynaud’s disease, also called primary Raynaud’s phenomenon, is diagnosed when the cause is unknown, whereas Raynaud’s syndrome or secondary Raynaud’s phenomenon occurs as a skin manifestation of concomitant disease. The most common trigger is exposure to cold. Specific clinical features allow a quick diagnosis. Raynaud’s phenomenon usually does not require pharmacologic treatment, but in some cases symptoms are severe and pharmacotherapy is necessary. Calcium channel blockers are usually used as a first-line treatment. Alternative forms of therapy include angiotensin-converting-enzyme inhibitors, 1-adrenergic blockers, phosphodiesterase-5 inhibitors, endothelin antagonists, nitrates, antioxidants, statins, botulinum toxin, and even autologous fat grafting.

  4. Static magnetic field changes the activity of venom phospholipase of Vipera Lebetina snakes

    International Nuclear Information System (INIS)

    Garibova, L.S.; Avetisyan, T.O.; Ajrapetyan, S.N.


    The effect of the static magnetic field (SMF) on the phospholipid activity of the class-A snake venom is studied. The Vipera Lebetina snake venom was subjected during 10 days to 30 minute impact of the CMF daily. It is established that increase in the phospholipase A 1 and A 2 approximately by 21 and 32 % correspondingly and in the phosphodiesterase C - by 33 % was observed. The decrease in the total protein level of the snake venom by 31.6 ± 2.2 % was noted thereby. It may be assumed that the described phospholipase and phosphoesterase changes may lead to essential shifts in the total metabolic activity of cells and organism as a whole. The activity index of these ferments may serve as an indicator of changes in the environmental magnetic field [ru

  5. Unveiling the nature of black mamba (Dendroaspis polylepis) venom through venomics and antivenom immunoprofiling: Identification of key toxin targets for antivenom development

    DEFF Research Database (Denmark)

    Laustsen, Andreas Hougaard; Lomonte, Bruno; Lohse, Brian


    The venom proteome of the black mamba, Dendroaspis polylepis, from Eastern Africa, was, for the first time, characterized. Forty- different proteins and one nucleoside were identified or assigned to protein families. The most abundant proteins were Kunitz-type proteinase inhibitors, which include...... the unique mamba venom components ‘dendrotoxins’, and α-neurotoxins and other representatives of the three-finger toxin family. In addition, the venom contains lower percentages of proteins from other families, including metalloproteinase, hyaluronidase, prokineticin, nerve growth factor, vascular...... endothelial growth factor, phospholipase A2, 5′-nucleotidase, and phosphodiesterase. Assessment of acute toxicity revealed that the most lethal components were α-neurotoxins and, to a lower extent, dendrotoxins. This venom also contains a relatively high concentration of adenosine, which might contribute...

  6. Use of gamma irradiated viper venom as the toxoid against viper venom poisoning in mice and rabbits

    International Nuclear Information System (INIS)

    Hati, A.K.; Mandal, M.; Hati, R.N.; Das, S.


    The present paper deals with detoxification of the crude viper (Vipera russelli) venom by gamma irradiation and its effective immunogenic role in Balb/C mice, used as a toxoid. The successful immunization of rabbits with irradiated viper venom toxoid is also reported. Certain biochemical changes of the venom due to radiation exposure and neutralization capacity of the immune sera against phosphodiesterase and protease activity of the crude viper venom have also been studied. The neutralizing potency of Russell's viper venom (RVV) toxoid anti venom (anti venom raised in rabbits against γ-irradiated RVV toxoid adsorbed on aluminium phosphate), in comparison with a commercial bivalent anti venom (as a standard reference) with reference to haemorrhagic, necrotic and lethal effects of Russell's viper envenomation are reported. 25 refs

  7. Peyronie's Reconstruction for Maximum Length and Girth Gain: Geometrical Principles

    Directory of Open Access Journals (Sweden)

    Paulo H. Egydio


    Full Text Available Peyronie's disease has been associated with penile shortening and some degree of erectile dysfunction. Surgical reconstruction should be based on giving a functional penis, that is, rectifying the penis with rigidity enough to make the sexual intercourse. The procedure should be discussed preoperatively in terms of length and girth reconstruction in order to improve patient satisfaction. The tunical reconstruction for maximum penile length and girth restoration should be based on the maximum length of the dissected neurovascular bundle possible and the application of geometrical principles to define the precise site and size of tunical incision and grafting procedure. As penile rectification and rigidity are required to achieve complete functional restoration of the penis and 20 to 54% of patients experience associated erectile dysfunction, penile straightening alone may not be enough to provide complete functional restoration. Therefore, phosphodiesterase inhibitors, self-injection, or penile prosthesis may need to be added in some cases.

  8. Association study of PDE4B gene variants in Scandinavian schizophrenia and bipolar disorder multicenter case-control samples

    DEFF Research Database (Denmark)

    Kähler, Anna K; Otnæss, Mona K; Wirgenes, Katrine V


    The phosphodiesterase 4B (PDE4B), which is involved in cognitive function in animal models, is a candidate susceptibility gene for schizophrenia (SZ) and bipolar disorder (BP). Variations in PDE4B have previously been associated with SZ, with a suggested gender-specific effect. We have genotyped......SNPs were nominally associated (0.0005 gender-specific subgroups. None of these findings remained significant after correction for multiple testing. However, a number of tagSNPs found to be nominally associated with SZ and BP...... were located in a high LD region spanning the splice site of PDE4B3, an isoform with altered brain expression in BP patients. Four tagSNPs were associated with SZ in women, but none in men, in agreement with the previously reported gender-specific effect. Proxies of two nominally associated SNPs...

  9. Safety of Intravenous Methamphetamine Administration During Ibudilast Treatment. (United States)

    DeYoung, Dustin Z; Heinzerling, Keith G; Swanson, Aimee-Noelle; Tsuang, John; Furst, Benjamin A; Yi, Yi; Wu, Ying Nian; Moody, David E; Andrenyak, David M; Shoptaw, Steven J


    Methamphetamine dependence is a significant public health concern without any approved medications for treatment. We evaluated ibudilast, a nonselective phosphodiesterase inhibitor, to assess the safety and tolerability during intravenous methamphetamine administration. We conducted a randomized, double-blind, placebo-controlled, within-subjects crossover clinical trial. Participants received ibudilast (20 mg twice daily followed by 50 mg twice daily) and placebo, with order determined by randomization, and then underwent intravenous methamphetamine challenges (15 and 30 mg). We monitored cardiovascular effects, methamphetamine pharmacokinetics, and reported adverse events. Ibudilast treatment had similar rates of adverse events compared with placebo, and there was no significant augmentation of cardiovascular effects of methamphetamine. Pharmacokinetic analysis revealed no clinically significant change in maximum concentration or half-life of methamphetamine with ibudilast. Methamphetamine administration during ibudilast treatment was well tolerated without additive cardiovascular effects or serious adverse events, providing initial safety data to pursue ibudilast's effectiveness for the treatment of methamphetamine dependence.

  10. Caffeine's Vascular Mechanisms of Action

    Directory of Open Access Journals (Sweden)

    Darío Echeverri


    Full Text Available Caffeine is the most widely consumed stimulating substance in the world. It is found in coffee, tea, soft drinks, chocolate, and many medications. Caffeine is a xanthine with various effects and mechanisms of action in vascular tissue. In endothelial cells, it increases intracellular calcium stimulating the production of nitric oxide through the expression of the endothelial nitric oxide synthase enzyme. Nitric oxide is diffused to the vascular smooth muscle cell to produce vasodilation. In vascular smooth muscle cells its effect is predominantly a competitive inhibition of phosphodiesterase, producing an accumulation of cAMP and vasodilation. In addition, it blocks the adenosine receptors present in the vascular tissue to produce vasoconstriction. In this paper the main mechanisms of action of caffeine on the vascular tissue are described, in which it is shown that caffeine has some cardiovascular properties and effects which could be considered beneficial.

  11. Roflumilast: clinical benefit in patients suffering from COPD

    DEFF Research Database (Denmark)

    Ulrik, Charlotte Suppli; Calverley, Peter Michael Anthony


    in the treatment of COPD, new treatment options for COPD are clearly necessary. The oral phosphodiesterase-4 (PDE4) inhibitor roflumilast represents a new class of drugs that has shown efficacy and acceptable tolerability in preclinical and short-term clinical studies in patients with COPD. METHODS AND RESULTS......: The available long-term clinical studies reviewed here suggest that the clinical efficacy of roflumilast is likely because of the suppression of airway inflammation and not through bronchodilation. Furthermore, the clinical studies have shown a modest improvement in airway function, including FEV(1......) , and a reduction in frequency and severity of COPD exacerbations, as well as a positive effect on several patient-reported outcomes. The clinical benefit of roflumilast appears to be greatest in patients with more symptomatic and severe disease who experience exacerbations. The most common adverse effects...

  12. Roflumilast: clinical benefit in patients suffering from COPD

    DEFF Research Database (Denmark)

    Ulrik, Charlotte Suppli; Calverley, Peter Michael Anthony


    in the treatment of COPD, new treatment options for COPD are clearly necessary. The oral phosphodiesterase-4 (PDE4) inhibitor roflumilast represents a new class of drugs that has shown efficacy and acceptable tolerability in preclinical and short-term clinical studies in patients with COPD. METHODS AND RESULTS......: The available long-term clinical studies reviewed here suggest that the clinical efficacy of roflumilast is likely because of the suppression of airway inflammation and not through bronchodilation. Furthermore, the clinical studies have shown a modest improvement in airway function, including FEV(1......) , and a reduction in frequency and severity of COPD exacerbations, as well as a positive effect on several patient-reported outcomes. The clinical benefit of roflumilast appears to be greatest in patients with more symptomatic and severe disease who experience exacerbations. The most common adverse effects...

  13. Silencing the alarms: innate immune antagonism by rotavirus NSP1 and VP3 (United States)

    Morelli, Marco; Ogden, Kristen M.; Patton, John T.


    The innate immune response involves a broad array of pathogen sensors that stimulate the production of interferons (IFN) to induce an antiviral state. Rotavirus, a significant cause of childhood gastroenteritis and a member of the Reoviridae family of segmented, double-stranded RNA viruses, encodes at least two direct antagonists of host innate immunity: NSP1 and VP3. NSP1, a putative E3 ubiquitin ligase, mediates the degradation of cellular factors involved in both IFN induction and downstream signaling. VP3, the viral capping enzyme, utilizes a 2H-phosphodiesterase domain to prevent activation of the cellular oligoadenylate synthase (OAS)-RNase L pathway. Computational, molecular, and biochemical studies have provided key insights into the structural and mechanistic basis of innate immune antagonism by NSP1 and VP3 of group A rotaviruses (RVA). Future studies with non-RVA isolates will be essential to understand how other RV species evade host innate immune responses. PMID:25724417

  14. The Siblings With Ischemic Stroke Study (SWISS): A Progress Report (United States)

    Meschia, James F.; Kissela, Brett M.; Brott, Thomas G.; Brown, Robert D.; Worrall, Bradford B.; Beck, Jeanne; Skarp, Alexa N.


    There is increasing evidence that genetic factors are associated with ischemic stroke, including multiple recent reports of association with the gene PDE4D, encoding phosphodiesterase 4D, on chromosome 5q12. Genetic studies of stroke are important but can be logistically difficult to perform. This article reviews the design of the Siblings With Ischemic Stroke Study (SWISS) and discusses problems in performing a sibling-based pedigree study where proband-initiated consent is used to enroll pedigree members. Proband-initiated enrollment optimizes privacy protections for family members, but it is associated with a substantial pedigree non-completion rate such that 3 to 4 probands must be identified to obtain one completed sibling pedigree. This report updates the progress of enrollment in the SWISS protocol, discusses barriers to pedigree completion and describes innovative approaches used by the SWISS investigators to enhance enrollment. PMID:16595789

  15. Effects of caffeine on protein phosphorylation and cell cycle progression in X-irradiated two-cell mouse embryos

    International Nuclear Information System (INIS)

    Jung, Th.; Streffer, C.


    To understand the mechanism of the caffeine-induced uncoupling of mitosis and the cellular reactions to DNA-damaging agents, the authors studied the effects of caffeine treatment on cell cycle progression and protein phosphorylation in two-cell mouse embryos after X-irradiation. Caffeine alone had no effect on timing of and changes in phosphorylation associated with the embryonic cell cycle. In combination with X-rays, caffeine was able to override the radiation induced G 2 block and restored normal timing of these phosphorylation changes after X-irradiation. New additional changes in protein phosphorylation appeared after the combined treatment. Isobutyl-methylxanthine (IBMX), a substance chemically related to caffeine but a more specific inhibitor of the phosphodiesterase that breaks down cyclic AMP, reduced radiation induced G 2 block from 4 to 5 h to about 1 h and restored the cell cycle associated changes in protein phosphorylation. (author)

  16. Recent strategies in treatment of pulmonary arterial hypertension, a review. (United States)

    Fallah, Flora


    Pulmonary arterial hypertension (PAH) is a disease characterized by an elevation in pulmonary artery pressure that can lead to right ventricular failure and death. The pulmonary circulation has to accommodate the entire cardiac output in each cardiac cycle and evolution has adapted to this by making it a low-pressure high-flow system. However, pathology can affect both the arterial and venous components of this system. Pulmonary venous hypertension mainly refers to diseases that result in elevated venous pressure and occurs mainly from mitral valve and left-sided heart disease. Standard treatment options include oral anticoagulation, diuretics, oxygen supplementation, and for a small percentage of patients, calcium channel blockers. Newer treatments include prostacyclin analogues, endothelin receptor antagonists, and phosphodiesterase type 5 inhibitors. This article reviews the current treatments strategies for PAH and provides guidelines for its management.

  17. [Pulmonary arterial hypertension: changing approaches to management]. (United States)

    Sidorenko, B A; Preobrazhenskiĭ, D V; Batyraliev, T A; Belenkov, Iu N


    The review is devoted to different aspects of pulmonary arterial hypertension (PAH); new classification of PAH is published in 2010. There are idiopathic PAH and PAH associated with other diseases. Current guidelines recommend to treat PAH only after the verification of diagnosis with right heart catheterization and acute tests with vasodilators. Patients-reactors should be treated with calcium antagonists. The following drugs related to one of three categories should be used in PAH: (1) prostanoids (epoprostenol, iloprost et al.); (2) blockers of endothelin receptors (bosentan, ambrisentan, sitaxsentan); (3) phosphodiesterase 5 type inhibitors (sildenafil, tadalafil et al.) In majority of cases the combined treatment is used, usually the combination of bosentan and sildenafil is used.

  18. Preoperative preparation of patients with arterial or pulmonary hypertension in noncardiac surgery. (United States)

    Ivanović, Branislava; Tadić, Marijana; Marković, Dejan; Bradi, Zeljko; Janković, Radmilo; Kalezić, Nevena


    Arterial hypertension is not an independent risk factor in cardiovascular complications in noncardiac surgery. Nevertheless, preoperative evaluation is necessary and includes estimation of arterial hypertension grade and possible damage of target organs. In patients with first and second grade of arterial hypertension postponement of elective intervention is not necessary, only optimization of therapy. On the other hand, patients with third level arterial hypertension have benefit if intervention is postponed till the reduction of arterial pressure. There is no indication that any of the antihypertensive drug groups has advantage in the preoperative treatment of hypertension. Unlike arterial hypertension pulmonary hypertension increases the risk of cardiac morbidity and mortality in the perioperative period. In patients with pulmonary hypertension, anesthesia and surgery may be complicated with heart failure, hypoxia and arrhythmias. Preoperative and postoperative treatments include calcium channel blockers, prostanoids, endothelin receptor antagonists and inhibitors of phosphodiesterase type 5.

  19. Pathways and Drugs in Pulmonary Arterial Hypertension - Focus on the Role of Endothelin Receptor Antagonists. (United States)

    Madonna, Rosalinda; Cocco, Nino; De Caterina, Raffaele


    Pulmonary arterial hypertension (PAH) is a group of diseases characterized by a progressive increase of pulmonary vascular resistance (PVR), initially due to abnormal pulmonary vasoconstriction in response to endothelial injury. Recent studies have here confirmed the prominent role of endothelin (ET)-1 in vasoconstriction and remodelling of the pulmonary microcirculation. In patients who are acute-vasoreactive, classical treatments for PAH are calcium channels blockers (CCBs), while drugs targeting the prostacyclin, nitric oxide and endothelin pathways, i.e., prostanoids, phosphodiesterase (PDE)-5 inhibitors and endothelin receptor antagonists (ERAs), respectively, are indicated in non-vasoreactive patients or in vasoreactive patients not responding to initial CCB therapy. Randomised, placebo-controlled trials have shown that ERAs improve pulmonary haemodynamics, exercise capacity, functional status and clinical outcome in patients with PAH. Here we provide an overview of the currently recommended diagnostic and therapeutic work-up in PAH, with special emphasis on ERAs.

  20. Pulmonary arterial hypertension: an update on diagnosis and treatment. (United States)

    Stringham, Richard; Shah, Nipa R


    Pulmonary arterial hypertension is defined as a mean pulmonary arterial pressure greater than 25 mm Hg at rest or 30 mm Hg during physical activity. Pulmonary arterial hypertension is classified into subgroups, including idiopathic, heritable, and pulmonary arterial hypertension associated with other conditions. A detailed history, thorough physical examination, and most importantly, a high index of suspicion are essential to diagnosis. Evaluation includes echocardiography and exclusion of other causes of symptoms. Targeted laboratory testing can help identify the subgroup of pulmonary arterial hypertension. Right heart catheterization is required to confirm the diagnosis. Standard treatment options include oral anticoagulation, diuretics, oxygen supplementation, and for a small percentage of patients, calcium channel blockers. Newer treatments include prostacyclin analogues, endothelin receptor antagonists, and phosphodiesterase type 5 inhibitors. Combination therapy has been shown to improve pulmonary arterial pressure, but more research is needed. Interventional procedures for patients with pulmonary arterial hypertension include balloon atrial septostomy and lung transplantation.