Search results for "phosphodiester"

Roflumilast N-oxide, a PDE4 inhibitor, improves cilia motility and ciliated human bronchial epithelial cells compromised by cigarette smoke in vitro

2012

BACKGROUND AND PURPOSEMucociliary malfunction occurs in chronic obstructive pulmonary disease (COPD) and compromised functions of ciliated bronchial epithelial cells may contribute to this. Cigarette smoke, a major risk factor for COPD, impairs ciliary beat frequency (CBF). cAMP augments CBF. This in vitro study addressed, in differentiated, primary human bronchial epithelial cells, whether roflumilast N-oxide, a PDE4 inhibitor, (i) augments CBF; (ii) prevents the reduction in CBF induced by cigarette smoke extract (CSE); and (iii) protects against the loss of the ciliated phenotype following long-term CSE exposure.EXPERIMENTAL APPROACHAir-liquid interface cultured human bronchial epithelia…

Interaction of glutamic-acid-rich proteins with the cGMP signalling pathway in rod photoreceptors.

1999

The assembly of signalling molecules into macromolecular complexes (transducisomes) provides specificity, sensitivity and speed in intracellular signalling pathways. Rod photoreceptors in the eye contain an unusual set of glutamic-acid-rich proteins (GARPs) of unknown function. GARPs exist as two soluble forms, GARP1 and GARP2, and as a large cytoplasmic domain (GARP' part) of the beta-subunit of the cyclic GMP-gated channel. Here we identify GARPs as multivalent proteins that interact with the key players of cGMP signalling, phosphodiesterase and guanylate cyclase, and with a retina-specific ATP-binding cassette transporter (ABCR), through four, short, repetitive sequences. In electron mic…

Mechanism of action of the betalain pigment indicaxanthin, purified from fruits of Opuntia ficus-indica, on mouse ileal motility in vitro.

2010

Cilostazol and atherogenic dyslipidemia: a clinically relevant effect

2011

Cilostazol is a reversible, selective inhibitor of PDE3A able to significantly improve walking distance in patients with intermittent claudication. However, beyond its antiplatelet and vasodilator properties, cilostazol seems to have significant effects on atherogenic dyslipidemia.The effects of cilostazol on plasma lipids, lipoproteins, apolipoproteins and postprandial lipemia are reviewed. A literature search (using Medline and Scopus) was performed up to 24 October 2010. The authors also manually reviewed the references of selected articles for any pertinent material.Cilostazol is able to significantly lower plasma triglyceride levels, with a concomitant increase in high-density lipoprot…

Cyclic AMP-dependent and independent stimulations of ovarian steroidogenesis by brain factors in the blowfly, Phormia regina.

2000

0303-7207 doi: DOI: 10.1016/S0303-7207(00)00312-9; The involvement of cyclic-AMP (cAMP) as a potential second messenger in the neurohormonal control of ovarian steroidogenesis was investigated in the adult female blowfly Phormia regina. Individual measurements of ovarian cAMP concentrations and of ovarian biosynthesis of ecdysteroids, stimulated after a protein meal, demonstrated that steroidogenesis is preceded by a peak of cAMP in the ovaries. In vitro, ovarian steroidogenesis was stimulated by cell-permeable analogues of cAMP and by forskolin. Crude brain extracts were also able to elicit a rise of cAMP in the ovaries in vitro and the secretion of ecdysteroids into the medium: such extra…

Antiproliferative effects of drugs affecting different signalling pathways on rat and human pulmonary artery smooth muscle cells

2015

Current treatments for pulmonary arterial hypertension (PAH) include pulmonary vasodilators which may also inhibit PASMC proliferation. The aim of this study was to compare the antiproliferative effects of multiple drugs on rat and human PASMC (rPASMC and hPMASC, respectively) in vitro. rPASMCs and hPASMC were starved for 24 h, then treated with different inhibitors and incubated for 48 h in 1% foetal calf serum plus endothelin-1, 5-HT and U46619. Cell number was estimated by the MTT test. Viable cells increased by 160-180% in 48 h. Activation of the cGMP pathway with the soluble guanylyl cyclase activators riociguat and YC-1 (≤ 10 µM) or the cAMP pathway by the adenylyl cyclase activator f…

Über die Wirkung von Phosphodiesterase-Hemmstoffen am Herzen / The Influence of Phosphodiesterase Blocking Agents on the Perfused Guinea Pig Heart

1969

Es wurde der Einflus von Phosphodiesterase-Hemmstoffen auf die Funktion und einige Parameter des Kohlenhydratstoffwechsels des Herzens untersucht, um weiteren Aufschlus uber den Zusammenhang zwischen cyclischem AMP und der Regulation dieser Funktionen zu gewinnen. Isolierte Meerschweinchenherzen wurden nach Langendokff bei 37° C mit carbogengesattigter Tyrodelosung perfundiert und konstant mit einer Frequenz von 180/min gereizt. Die Herzen wurden nach einem Kontrollvorlauf 5–20 min mit der pharmakonhaltigen Tyrodelosung durchstromt. Es wurde die Wirkung von Substanzen untersucht, die nach Senft u. Mitarb. [1] in den angegebenen Konzentrationen eine 50% Hemmung der PDE des Rinderherzens in v…

Inhibition of ovarian steroidogenesis by cyclic-GMP in a fly

2003

1479-6805 0022-0795; Previous investigations in the female blowfly Phormia regina have shown that 3-isobutyl-1-methylxanthine (IBMX), a broad spectrum inhibitor of phosphodiesterases (PDEs), fails to mimic the steroidogenic effects of cAMP on ovaries, although it efficiently increases the concentrations of this second messenger. In this study, experiments carried out to clear up this contradiction demonstrated that IBMX, besides its effect on cAMP, also increased cGMP concentrations in blowfly ovary and that these two cyclic nucleotides controlled ovarian steroidogenesis antagonistically. In particular, a selective inhibitor of cGMP-specific PDEs, unlike IBMX, had a very strong negative eff…

Phosphodiesterase-4 inhibition improves corticosteroid insensitivity in pulmonary endothelial cells under oxidative stress.

2012

Several clinical studies have shown that smoking in asthmatics and chronic obstructive pulmonary disease patients is closely associated with corticosteroid refractoriness. In this work, we have analyzed glucocorticoid insensitivity in human pulmonary artery endothelial cells (HPAECs) under cigarette smoke extract (CSE) exposure as well as the possible additive effects of the combination therapy with a phosphodiesterase (PDE)-4 inhibitor. Interleukin (IL)-8 was measured in cell supernatants by ELISA. Histone deacetylase (HDAC), histone acetylase (HAT), and intracellular cAMP levels were measured by colorimetric assays and enzyme immunoassay, respectively. PDE4 isotypes and glucocorticoid rec…

The phototransduction cascade in the isolated chick pineal gland revisited.

2003

It is well established that the isolated chick pineal gland is directly light sensitive and that melatonin synthesis of the gland can be inhibited by exposing the gland to light during scotophase. Since not all the steps of the phototransduction cascade have been clarified to the same extent as in the retina, we have treated isolated chick pineal glands with 90 min of light during scotophase and with drugs that affect key-components of vertebrate phototransduction, i.e., cyclic guanosine monophosphate (cGMP) phosphodiesterase 6 (PDE6), cGMP levels and cGMP-gated calcium channels. The endpoint measured was the activity of the rate-limiting enzyme of melatonin synthesis, arylalkylamine N-acet…