Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.4.1 (phosphodiesterase)
18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cyclosporine stimulates vasoconstrictor endothelin-1 (ET-1) synthesis. This study examined the effect of heparin on cyclosporine-induced ET-1 synthesis in Wistar rat aortic endothelial cells in culture. Cyclosporine (0.01-5 mumol/L) stimulated ET-1 mRNA expression in a dose-dependent manner. A nitric oxide synthesis inhibitor, NG-monomethyl-L-arginine (L-NMMA) (10(-5) mol/L), did not affect cyclosporine-induced ET-1 mRNA expression. Heparin (1-20 U/ml) suppressed cyclosporine-induced ET-1 mRNA expression in a dose-dependent manner. The inhibitory effect of heparin was blunted in the presence of either L-NMMA (10(-5) mol/L) or calmodulin inhibitors such as N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) (5 x 10(-5) mol/L) or calmidazolium (5 x 10(-5) mol/L) in the presence of the phosphodiesterase inhibitor 3-isobutyl 1-methylxanthine (0.1 mmol/L). These results suggest that heparin suppresses cyclosporine-induced ET-1 mRNA expression via both NO- and calmodulin-dependent pathways.
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PMID:Heparin suppresses cyclosporine-induced endothelin-1 synthesis in rat endothelial cells. 959 12

We evaluated the effects of oral administration of E4021 (100 mg/kg/day), a type V phosphodiesterase inhibitor, on immunoreactivities of endothelin-1, endothelin receptors, and nitric oxide synthases in pulmonary arteries in a rat model of pulmonary hypertension. Immunoreactivities of endothelin-1 and endothelial nitric oxide synthase were observed significantly less frequently, together with significant reduction of right ventricular overload and medial thickening in rats treated with E4021 than in the control with monocrotaline on day 28. The levels of plasma endothelin-1 and serum nitrite and nitrate were significantly lower in rats that received E4021 than in the control with monocrotaline. Oral administration of E4021 modulates endogenous immunoreactivities of endothelin-1 and endothelial nitric oxide synthase with the improvement or right ventricular overload and medial thickening.
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PMID:Type V phosphodiesterase inhibition modulates endogenous immunoreactivities of endothelin-1 and endothelial nitric oxide synthase in pulmonary arteries in rats with monocrotaline-induced pulmonary hypertension. 963 94

Ligation of the ductus arteriosus in utero produces fetal and neonatal pulmonary hypertension and alterations in the hemodynamic responses to nitric oxide and endothelin-1 in fetal and newborn lambs. To determine whether fetal pulmonary hypertension alters the expression of the genes of the nitric oxide and endothelin-1 pathways, seven fetal lambs (123-126-d gestation) underwent ligation of the ductus arteriosus. Near-term (138-139-d gestation), total lung RNA, and protein were prepared from control and ductal ligation fetal lambs for RNase protection assays and Western blotting. Ligation of the ductus arteriosus was associated with decreased expression of endothelial nitric oxide synthase mRNA and protein, and the alpha1 and the beta1 subunits of soluble guanylate cyclase protein; and with increased expression of phosphodiesterase V mRNA. Ligation of the ductus arteriosus was also associated with increased expression of preproendothelin-1 mRNA and with decreased expression of endothelin B receptor (ET(B)) mRNA. These results suggest that there is coordinated regulation of genes of the nitric oxide pathway, which would decrease nitric oxide and cGMP concentration, thereby decreasing pulmonary vasodilator activity. There is also coordinated regulation of genes of the endothelin-1 pathway, which would increase endothelin-1 concentration and limit ET(B) receptor activation, thereby increasing pulmonary vasoconstrictor activity. These alterations in gene expression would increase fetal pulmonary vascular resistance, contributing to the development of pulmonary hypertension after birth.
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PMID:Coordinated regulation of genes of the nitric oxide and endothelin pathways during the development of pulmonary hypertension in fetal lambs. 985 13

In the coronary circulation, endothelin-1 (ET-1) evokes spasms which are difficult to treat when the endothelial integrity is compromised. This study compares several classes of relaxing agents on already established contractions to ET-1 in an in vitro model using ring segments of the porcine left descending coronary artery (pLAD). All segments were precontracted with 10 nmol/L ET-1. The calcium channel blocker isradipine was 300 times more potent than verapamil, but was only a partial relaxant; the maximal relaxation obtained was 52 +/- 2% (n = 6). Atrial natriuretic peptide (ANP) was an equally potent relaxant of the ET-1 contraction; however, it too was an incomplete relaxant, maximal relaxation being < 60%. A 50% relaxation of the ET-1 contraction was obtained with 0.28 +/- 0.24 mumol/L ANP, n = 4 (IC50). Comparison of cyclic nucleotide analogues revealed a 30 times higher potency for 8-bromo-cyclic guanosine monophosphate (8-Br-cGMP)(IC50 44 +/- 11 mumol/L, n = 6) than for 8-bromo-cyclic adenosine monophosphate (8-Bi-cAMP) (IC50 1600 mumol/L, n = 6). The cyclic nucleotide phosphodiesterase (PDE) inhibitor milrinone, a PDE 3-inhibitor with an IC50 2.4 +/- 1.8 mumol/L, (n = 6) was 10 times more potent than rolipram (PDE 4-inhibitor), zaprinast (PDE 5-inhibitor) and vinpocentine (PDE 1-inhibitor). Withdrawal of these analogues and inhibitors from segments continuously exposed to 10 nmol/l ET-1 revealed that vinpocentine and 8-Br-cGMP were irreversible relaxants, in contrast to milrinone and 8-Br-cAMP. In conclusion, this study has demonstrated that cGMP-enhancing agents, such as the naturally occurring ANP, the calcium channel blocker isradipine, and the synthetic inhibitor of PDE 3, were the most effective relaxants of ET-1 evoked contractions in pLAD in vitro.
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PMID:Relaxing effects of cyclic GMP and cyclic AMP-enhancing agents on the long-lasting contraction to endothelin-1 in the porcine coronary artery. 1008 99

The effects of transfer of the endothelial nitric oxide synthase (eNOS) gene to the lung were studied in mice. After intratracheal administration of AdCMVbetagal, expression of the beta-galactosidase reporter gene was detected in pulmonary airway cells, in alveolar cells, and in small pulmonary arteries. Gene expression with AdCMVbetagal peaked 1 day after administration and decayed over a 7- to 14-day period, whereas gene expression after AdRSVbetagal transfection peaked on day 5 and was sustained over a 21- to 28-day period. One day after administration of AdCMVeNOS, eNOS protein levels were increased, and there was a small reduction in mean pulmonary arterial pressure and pulmonary vascular resistance. The pressure-flow relationship in the pulmonary vascular bed was shifted to the right in animals transfected with eNOS, and pulmonary vasodepressor responses to bradykinin and the type V cGMP-selective phosphodiesterase inhibitor zaprinast were enhanced, whereas systemic responses were not altered. Pulmonary vasopressor responses to endothelin-1 (ET-1), angiotensin II, and ventilatory hypoxia were reduced significantly in animals transfected with the eNOS gene, whereas pressor responses to norepinephrine and U46619 were not changed. Systemic pressor responses to ET-1 and angiotensin II were similar in eNOS-transfected mice and in control mice. Intratracheal administration of AdRSVeNOS attenuated the increase in pulmonary arterial pressure in mice exposed to the fibrogenic anticancer agent bleomycin. These data suggest that transfer of the eNOS gene in vivo can selectively reduce pulmonary vascular resistance and pulmonary pressor responses to ET-1, angiotensin II, and hypoxia; enhance pulmonary depressor responses; and attenuate pulmonary hypertension induced by bleomycin. Moreover, these data suggest that in vivo gene transfer may be a useful therapeutic intervention for the treatment of pulmonary hypertensive disorders.
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PMID:Gene transfer of endothelial nitric oxide synthase to the lung of the mouse in vivo. Effect on agonist-induced and flow-mediated vascular responses. 1038 95

Tyrphostin-23 is commonly used as inhibitor of tyrosine kinase (TK). We found that tyrphostin-23 concentration-dependently increased basal steroid-hormone secretion from dispersed human and rat adrenocortical cells, the maximal effective concentration being 10(-5) M. Tyrphostin-23 (10(-5) M) enhanced 10(-9) M angiotensin-II- and endothelin-1-stimulated secretion of human and rat adrenocortical cells, but not the secretory response to 10(-9) M ACTH However, it increased the response to lower concentrations (10(-12) or 10(-11) M) of ACTH. The secretagogue effect of tyrphostin-23 on dispersed rat adrenocortical cells was abolished by either the adenylate cyclase inhibitor SQ-22536 (10(-4) M) or the protein kinase A (PKA) inhibitor H-89 (10(-5) M). Tyrphostin-23 (10(-5) M) raised basal cyclic-AMP release by dispersed rat adrenocortical cells, but in the presence of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX, 10(-3) M) it was ineffective. Both tyrphostin-23 and IBMX increased cyclic-AMP release by rat adrenocortical cells in response to 10(-10) M ACTH, and their effects were not additive. Taken together, our findings suggest that tyrphostin-23, acting as an inhibitor of phosphodiesterases in adrenocortical cells, increases the intracellular concentration of cyclic-AMP available for PKA activation thereby stimulating steroid-hormone secretion. They also stress that caution must be used in interpreting the results of studies aimed at investigating the possible cross-talk between adenylate cyclase- and TK-dependent signaling cascades.
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PMID:Tyrphostin-23 enhances steroid-hormone secretion from dispersed human and rat adrenocrotical cells. 1101 98

Exposure of human vascular smooth muscle cells (HVSMCs) to cytokines markedly elevates endothelin-1 (ET-1) mRNA expression and peptide production. Cyclic AMP is a key regulator of many physiological processes. The aim of this study was to determine whether an elevation of intracellular cAMP may affect cytokine-induced production of ET-1 in HVSMCs. Cicaprost, a prostacyclin analogue, forskolin, an activator of adenylate cyclase, and Ro-20-1724, a phosphodiesterase type IV inhibitor, inhibited cytokine-stimulated ET-1 release in a concentration-dependent manner. Ro-20-1724 also inhibited cytokine-induced upregulation of preproendothelin-1 mRNA expression in saphenous vein (SV) vascular smooth muscle cells (VSMCs). These findings demonstrate that ET-1 mRNA expression and peptide production is modulated by elevations in cAMP levels. Further studies are necessary to elucidate which other pathways may be involved in the regulation of cytokine-stimulated ET-1 release from HVSMCs.
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PMID:Cyclic AMP regulates cytokine stimulation of endothelin-1 release in human vascular smooth muscle cells. 1107 34

We report for the first time that penile smooth muscle cells (SMC) not only respond to, but also synthesize, endothelin-1 (ET-1), one of the main regulators of SMC activity. Immunohistochemical studies indicated that, beside endothelial cells (EC), SMC of the human adult and fetal penis also express ET-1 and its converting enzyme, ECE-1. Accordingly, cultures of adult penile stromal cells express these genes. We also prepared and characterized penile SMC from human fetuses. These cells express SMC specific markers such as alpha smooth muscle actin and phosphodiesterase type 5A3 along with hallmarks of androgen-dependent cells (androgen receptor and 5alpha reductase type 2). Human fetal penile SMC (hfPSMC) are immunopositive for ET-1 and release ET-1. ET-1 expression in hfPSMC was strongly increased by several factors such as transforming growth factor-beta1 (TGF-beta1), interleukin-1alpha (IL-1alpha), ET-1 itself and prolonged (24 h) hypoxia. This latter condition not only affected ET-1 expression but also responsiveness. While at normal oxygen tension, hfPSMC responded to ET-1 with a decreased proliferation mediated by the endothelin-A receptors and TGF-beta1; however, during hypoxia, ET-1 stimulated cell growth. Accordingly, prolonged hypoxia up-regulated endothelin-B receptor mRNA expression. In conclusion, our results indicate that in penile tissues SMC produce ET-1 and that such production is modulated by factors involved in penile physiology and tissue remodelling. In addition, the hfPSMC we have characterized might be a useful model for studying biochemical aspects of the human erectile process in vitro.
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PMID:Expression and regulation of endothelin-1 and its receptors in human penile smooth muscle cells. 1246 37

We investigated the short-term effects of a phosphodiesterase III inhibitor (Olprinone) on hemodynamics and thoracic duct lymph flow in anesthetized open-chest sheep with heart failure induced by endothelin-1 (cardiogenic shock). Ultrasound transit-time flow probes were attached to the thoracic duct, the ascending aorta and the renal artery. Arterial, pulmonary and central venous pressures were monitored. Endothelin-1 was infused intravenously at a dosage that reduced cardiac output to 50% or more of baseline (n=11). The effects of Olprinone were examined (n=5) by intravenous infusion after endothelin-1 administration. Other sheep (n=6) were used as controls. Olprinone significantly increased cardiac output that had been decreased by endothelin-1 and further increased thoracic duct flow that had been increased by endothelin-1. Increased arterial and pulmonary pressures induced by endothelin-1 administration were rapidly decreased by Olprinone. Renal arterial flow and central venous pressure were, however, unchanged by Olprinone. Overall, Olprinone acutely improved experimental cardiogenic shock (heart failure) induced by endothelin-1, and maintained thoracic duct lymph flow at a high level after endothelin-1 administration.
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PMID:Effect of phosphodiesterase III inhibitor (Olprinone) on thoracic duct lymph flow in anesthetized sheep with experimentally induced heart failure by endothelin-1. 1257 Mar 23

Human BNP serves to compensate for deteriorating cardiac function causing preload and afterload reductions, natriuresis, diuresis, suppression of the renin-angiotensin-aldosterone system (RAAS) and endothelin-1, and lowering of norepinephrine. Based on its unique pharmacologic profile, nesiritide results in clinically significant balanced vasodilation of arteries and veins, and may be well suited for patients presenting with various scenarios of decompensated CHF usually due to volume overload (NYHA classes II-IV). More than 1000 subjects have participated in clinical trials with nesiritide and more than 55,000 patients have been treated with nesiritide since it was approved for use in August 2001. Unlike nitroglycerin, tachyphylaxis did not appear to occur with Natrecor. The complete efficacy profile of nesiritide included preload reduction (PCWP and RAP), reductions in pulmonary artery pressures, afterload reduction (systemic vascular resistance), and increases in cardiac index and stroke volume index (which are dose-dependent and not the result of a direct inotropic effect), without increasing heart rate. Unlike inotropes, the beneficial hemodynamic effects produced by nesiritide do not cause an increase in myocardial oxygen consumption (MVO(2)), an important consideration for patients with acutely decompensated heart failure. Because Nesiritide is not an inotrope, it does not affect myocardial contractility, as does a beta-adrenergic receptor agonist, or a phosphodiesterase III inhibitor. As a result, nesiritide is not arrhythmogenic. Nesiritide should be considered for patients presenting with acutely typical or useful decompensated heart failure, especially those with dyspnea at rest or with minimal activity.
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PMID:Nesiritide: a new therapy for the treatment of heart failure. 1266 89


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