Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.4.1 (phosphodiesterase)
 18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The cardiovascular properties of NSP-804 (4,5-dihydro-6-[4-[(2-methyl-3-oxo-1-cyclopentenyl)-amino] phenyl]-3(2H)-pyridazinone) and NSP-805 (4,5-dihydro-5-methyl-6-[4-[(2-methyl-3-oxo-1-cyclopentenyl) amino]phenyl]-3(2H)-pyridazinone), novel cardiotonic agents, were investigated in vitro and in vivo in comparison with those of other cardiotonic agents. In isolated guinea pig left atria, the positive inotropic EC50 values (microM) in order of potency were about 0.18 (NSP-805), 0.39 (indolidan), 1.1 (MCI-154), 1.7 (NSP-804, milrinone), 2.0 (denopamine), 4.0 (papaverine), 4.4 3-isobutyl-1-methylxanthine, IBMX, 6.5 (imazodan), and 27 (amrinone). In anesthetized dogs, intravenous (i.v.) injection of NSP-804 and NSP-805 produced dose-dependent increases in left ventricular VVdp/dtmax and decreases in aortic blood pressure (ABP) with relatively small increases in heart rate (HR). The ED50 values (micrograms/kg) for LVdP/dtmax of NSP-804, NSP-805, denopamine, milrinone, MCI-154, and indolidan were 15, 12, 22, 23, 15, and 7.3, respectively. When the drugs were administered intraduodenally to anesthetized dogs, the ED50 values (micrograms/kg) for LVdP/dtmax of NSP-804, NSP-805, milrinone and indolidan were approximately 30, 10, 200, and 25 respectively. In the propranolol-induced heart failure model, NSP-804 and NSP-805 completely improved the hemodynamic state of heart failure to normal levels. The in vitro positive inotropic effects of NSP-804 and NSP-805 were accompanied by increases in tissue cyclic AMP and abolished by carbachol. NSP-805 was the most potent and selective inhibitor of guinea pig cardiac phosphodiesterase (PDE) III among the agents examined, and NSP-804 was a potent and selective inhibitor of PDE III similar to indolidan. The cardiovascular properties determined in this study suggest that both NSP-804 and NSP-805 may have beneficial effects for treatment of congestive heart failure (CHF).
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PMID:Cardiovascular effects of NSP-804 and NSP-805, novel cardiotonic agents with vasodilator properties. 768 27

The present study was done to identify and characterize the isoenzymes of cyclic nucleotide phosphodiesterase (PDE) and to determine their intracellular distribution in human kidney and heart. The in vitro effects of new cardiotonic agents, namely, NSP-805 (4,5-dihydro-5-methyl-6-[4-[(2-methyl-3-oxo-1-cyclopentenyl)amino] phenyl]-3(2H)-pyridazinone), TZC-5665 (6-[4-[2-[3-(5-chloro-2-cyanophenoxy)-2-hydroxypropylamino]- 2 -methylpropylamino]phenyl]-5-methyl-4,5-dihydro-3(2H)-pyridazinone ) and its metabolites, OPC-18790 ((+/-)-6-[3-(3,4-dimethoxybenzylamino)-2 -hydroxypropoxy]-2-(1H)-quinolinone), MS-857 (4-acetyl-1-methyl-7-(4-pyridyl)-5,6,7,8-tetrahydro-3(2H)-isoquinolinone ) and E-1020 (1,2-dihydro-6-methyl-2-oxo-5-(imidazo[1,2-a]pyridin-6-yl)-3-pyridine carbonitrile hydrochloride monohydrate), on these human PDE isoenzymes were also investigated. PDE isoenzymes were separated from cytosolic and particulate fractions of homogenates of human kidney and heart by DEAE-Sepharose chromatography. PDE isoenzymes were identified by their elution characteristics, substrate specificities, sensitivities to regulation by effectors and by the use of isoenzyme-specific inhibitors. In a cytosolic fraction from kidney, Ca2+/calmodulin-dependent PDE (CaM-PDE), cyclic GMP-stimulated PDE (cGS-PDE), cyclic GMP-inhibited PDE (cGI-PDE) and two forms of cyclic AMP-specific PDE (cAMP-PDE) were resolved. One form of cAMP-PDE (cAMP-PDE alpha), which was eluted at a lower ionic strength than cGI-PDE during DEAE-Sepharose chromatography, was newly recognized in human tissues, though the other form (cAMP-PDE beta), which eluted later than cGI-PDE, had been previously isolated.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Identification and characterization of isoenzymes of cyclic nucleotide phosphodiesterase in human kidney and heart, and the effects of new cardiotonic agents on these isoenzymes. 782 45

NSP-513, a novel potent and selective phosphodiesterase 3 (PDE 3) inhibitor, and cilostazol, a previously developed PDE 3 inhibitor, were compared with respect to antiplatelet, antithrombotic, and hemodynamic effects. In the in vitro antiplatelet aggregation studies, NSP-513 and cilostazol inhibited collagen-induced canine platelet aggregation with median inhibitory concentration (IC50) values of 0.093 and 3.1 miccroM, respectively, and inhibited adenosine diphosphate (ADP)-induced canine platelet aggregation with IC50 values of 0.15 and 12 microM, respectively. For ADP-induced platelet aggregation, the presence of prostaglandin E1 (PGE1; 3 and 10 nM) further decreased the IC50 values for NSP-513 to 0.11 and 0.032 microM, respectively. In ex vivo antiplatelet aggregation studies, orally administered NSP-513 (0.03-1 mg/kg) and cilostazol (50 mg/kg) inhibited collagen-induced canine platelet aggregation. In an in vivo canine femoral arterial thrombosis model, intraduodenally administered NSP-513 (0.01-0.03 mg/ kg) dose-dependently prevented thrombus formation without any changes in blood pressure, heart rate, or bleeding time. In conscious dogs, NSP-513 at oral doses of > or =0.3 mg/kg produced hemodynamic changes such as decreased blood pressure and increased heart rate and LVdP/dt(max). Thus the minimal hemodynamically effective dose of NSP-513 was 0.3 mg/kg, and the hemodynamic effects of this dose were comparable to those of 50 mg/kg of cilostazol. In conclusion, these data suggest that NSP-513 has in vivo selectivity for antiplatelet and antithrombotic activities over hemodynamic activity, and that the selectivity of NSP-513 is higher than that of cilostazol in dogs.
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PMID:Antithrombotic activity of NSP-513, a novel selective phosphodiesterase 3 inhibitor, on femoral arterial thrombosis induced by physical stenosis and electrical current: comparison of antithrombotic and hemodynamic effects. 1077 90

We investigated the effects of NSP-513, (R)-4,5-dihydro-5-methyl-6-[4-(2-propyl-3-oxo-1-cyclohexenyl)amino] phenyl-3(2H)-pyridazinone, on phosphodiesterase (PDE) isozyme activities, in vitro platelet aggregation and in vivo thrombus formation. NSP-513 selectively inhibited human platelet PDE 3 isozyme with an IC50 value of 0.039 microM. In an in vitro human platelet aggregation assay, the IC50 values (microM) of NSP-513 for platelet aggregation induced by collagen, U-46619, arachidonic acid, adenosine diphosphate (ADP), epinephrine and thrombin were 0.31, 0.25, 0.082, 0.66, 0.23 and 0.73, respectively. In a mouse pulmonary thromboembolism model, orally administered NSP-513 showed in vivo antithrombotic effects that were 320 to 470 times more potent than those of cilostazol. In a rat carotid arterial thrombosis model, intraduodenally administered NSP-513 (0.1 mg/kg), cilostazol (30 mg/kg) and aspirin (30 mg/kg) reduced thrombus formation by 75%, 66% and 48%, respectively. However, intravenously administered dipyridamole (10 mg/kg) did not significantly prevent thrombus formation. These results demonstrate that NSP-513 has the potential to prevent not only in vitro platelet aggregation but also in vivo thrombus formation and indicate that the highly selective PDE 3 inhibitory effect of NSP-513 may make this compound useful for assessing the physiological role of PDE 3.
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PMID:Antiplatelet and antithrombotic effects of a novel selective phosphodiesterase 3 inhibitor, NSP-513, in mice and rats. 1088 49