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

---

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

Isoenzyme V of 5'-nucleotide phosphodiesterase (5'-NPD-V) is present in the peripheral sera of patients with hepatic metastases. A total of 122 patients underwent prospective serologic analysis followed by operation for primary tumors of the gastrointestinal tract and careful evaluation of the liver. A positive 5'-NPD-V assay was found in fifty-nine of sixty patients with liver metastases. A negative 5'-NPD-V assay was found in forty-three of sixty-two patients with no evidence of hepatic metastases. The accuracy of the test was 84 per cent, and the predictive value was 75 per cent. Serum 5'-NPD-V was abnormal significantly more frequently in patients with metastatic liver disease than were liver scans or carcinoembryonic antigen (CEA), alpha fetoprotein, serum glutamic oxalacetic transaminase (SGOT), and total serum bilirubin or serum alkaline phosphatase levels.
...
PMID:Serum 5'-nucleotide phosphodiesterase as a predictor of hepatic metastases in gastrointestinal cancer. 21 45

Phosphodiesterase III inhibitors have been established in recent years in the therapy of congestive heart failure. Many disadvantages, such as extensive vasodilation and the lack of proven positive inotropic properties combined with thrombepenia and elevation of transaminases, have complicated the handling of the drug in clinical practice. Enoximone, an imidazole derivative, has been demonstrated to be more cardioselective and vasodilation has been found to be less pronounced than with amrinone. As a consequence, research was performed to enhance the cardioselectivity of phosphodiesterase III inhibitors by reduction of non-specific cross-reactivity with other phosphodiesterases, and R80122 (Janssen Pharmaceutics, Belgium) was introduced into clinical practice. R80122 ((E)-Ncyclohexal-N-methyl-2[[[phenyl (1,2,3,5-tetrahydro-2 oxoimidazo [2,1b]-quinazolin-7-yl)methylene] amino] oxy] acetamide) is a selective inhibitor of phosphodiesterase (PDE) IIIc, which is localized in the myocardium. Thus, its inhibition leads to a positive inotropic effect, whereas phosphodiesterase IIIRo is found in the vessel wall and causes vasodilation. This study was performed to investigate the hemodynamic profile of R80122 under clinical conditions. Additionally, the intestinal hemodynamics were recorded and changes in intestinal perfusion compared with changes in global hemodynamics. METHODS. The study was thoroughly discussed and approved by the local ethics committee; all patients gave written informed consent. The investigation was performed on ten male patients who were about to undergo elective coronary artery bypass surgery. History, physical examination and laboratory results were within the normal limits and revealed no evidence of liver disease. The usual medication was continued until the day before the operation. Premedication consisted of 2 mg flunitrazepam p.o. in the evening before the operation and 1.5 h before induction of anaesthesia. The determination of hepatic plasma flow was performed by the indocyanine green (ICG) infusion extraction technique using liver vein catheterization. After induction of anaesthesia (MP1), after application of a bolus dose of R80122 (0.3 mg/kg BW) (MP2) and at sternotomy (MP3), hemodynamic data (heart rate, arterial pressure, cardiac output) were recorded and blood samples for the determination of hepatic plasma flow by the concentration of ICG were collected. Anaesthesia was induced with a bolus dose of 0.2 mg/kg BW etomidate, 7 micrograms/kgBW fentanyl and 0.1 mg/kgBW pancuronium and maintained with a continuous infusion of 20 micrograms/min fentanyl, 300 micrograms/min midazolam and mechanical ventilation with O2/N2O at an FiO2 of 0.5. Statistical analysis was performed using the Wilcoxon-Mann-Whitney U test comparing the results after induction of anesthesia (MPI) with those after application of R80122 (MPII) and the results of MPII with those at sternotomy (MPIII). Statistical significance was assumed at P less than 0.05. RESULTS. After the induction of anaesthesia, the median heart rate (HR) was 56/min and did not change after administration of R80122. During sternotomy there was a significant increase in the HR from 64 to 78/min (P less than 0.05). Median arterial blood pressure (MAP) tended to decreased from 91 mm Hg after induction of 77 mm Hg after administration of R80122, although there was no statistical significance because of interindividual differences in the tendencies. At sternotomy, MAP remained unchanged. Cardiac output (CO) increased by 60% after administration of R80122 (P less than 0.01) and did not change during sternotomy. As a consequence of the changes in HR and CO, stroke volume (SV) increased by 22% after administration of R80122 (P less than 0.025) and decreased to control values during sternotomy.
...
PMID:[Effects of R80122. The influence of a new phosphodiesterase inhibitor on global and intestinal hemodynamics in coronary surgery patients]. 152 59

Enoximone, a new phosphodiesterase-inhibitor with positive inotropic and vasodilating activities is available for intravenous use in patients with severe heart failure. A review of the current knowledge regarding the adverse effects of this substance reveals that they are characterized by cardiovascular, central nervous, and gastrointestinal side effects. Adverse effects occurred in 20% of patients and were mostly due to the pharmacological properties of enoximone. Cardiovascular side effects (10%) were the most frequent; ventricular and supraventricular arrhythmias were most common. Two to three percent of the patients experienced hypotension due to the vasodilator activity of enoximone. Headache, insomnia, and anxiety were the most frequent adverse effects on the central nervous system. Three percent of the patients treated experienced vomiting, nausea, abdominal pain, and diarrhea. An increase of liver enzymes and serum glucose could be observed, mostly in patients with previous liver disease or diabetes. Pharmacokinetic drug interactions are not known; possible pharmacodynamic interactions result from the pharmacological properties of the drugs. Intravenous therapy with enoximone causes a few serious side effects that can only be controlled by careful observation of the patients treated.
...
PMID:[Tolerance of enoximone in patients with heart failure]. 183 4

The levels of 5'-nucleotide phosphodiesterase isoenzymes (5'-NPD; EC 3.1.4.1) in sera of 54 healthy donors and 201 inpatients were measured. Isozymes were separated electrophoretically and designated as 5'-NPD-0, -I, -II, -III, -IV and -V in the reverse order of their electrophoretic mobility. In healthy donors all isozymes except 5'-NPD-V were detectable. In pathological sera isozymes 0 to V were elevated in 26.0%, 20.5%, 14.0%, 30.5%, 7.0% and 15.0% of the cases, respectively. Decreased values were found in 6-7%, with the exception of 5'-NPD-IV showing decreased activities in 23.5% of the patients. This average distribution pattern was found in many disorders. However, in diseases of the liver and the pancreas a remarkable accumulation of cases with elevated levels of all isozymes, except 5'-NPD-IV, was observed. All isozymes, except 5'-NPD-IV, showed many significant correlations with other laboratory parameters indicating liver disease. Isozyme IV was not related to these parameters but exhibited a strong correlation with serum albumin. 5'-NPD-II was unproportionally often increased in patients with liver cirrhosis and was the only isozyme with on the average higher levels in women than in men.
...
PMID:Levels of 5'-nucleotide phosphodiesterase isoenzymes in normal and pathological sera. 285 13

Nucleotide pyrophosphatase and phosphodiesterase I activities were determined in sera from 126 patients with different types of liver disease and in two additional groups of patients with intra- and extrahepatic cholestasis, respectively. Both activities probably represent the same enzyme, and were positively correlated with alkaline phosphatase, lipoprotein X, and several other tests reflecting cholestasis. Also, we found by discriminant analysis that tests for cholestasis frequently replaced the results of both enzymes. In some groups of liver disease, nucleotide pyrophosphatase and phosphodiesterase I were correlated with the concentrations of prealbumin and albumin. The sensitivity of phosphodiesterase I (and nucleotide phosphatase) is rather low when compared with alkaline phosphatase, and we do not recommend it for use in the clinical routine. Nevertheless, it appears to be of potential value for studies on classification of liver diseases, adding information to a panel of 20 commonly used "liver tests" by appearing in some of the best four test-sets for distinguishing between groups of liver disease by discriminant analysis.
...
PMID:Usefulness of serum nucleotide pyrophosphatase and phosphodiesterase I activities in classifying liver disease. 611 26

The results of determination of the serum 5'-NPDase isozymes in 95 cases of primary liver carcinoma and other kinds of disease are presented. The 5'-NPDase-V was positive in 83.2% of primary liver cancer cases. This test might be a useful supplement to AFP determination, especially in AFP-negative liver cancer patients. In most patients who had undergone successful liver resection for primary carcinoma, the test became negative. A positive 5'NPDase-V test in patients with cancer elsewhere in the body may suggest liver metastasis. In addition, this test may be of some help in the differentiation of primary liver cancer from other kinds of liver disease. The problem of "false-positive" results of this test is discussed.
...
PMID:The significance of 5'-nucleotide phosphodiesterase isozymes in the diagnosis of liver carcinoma. 626 4

Resistance to the natriuretic action of atrial natriuretic peptide (ANP) is a hallmark of states of pathological sodium retention including congestive heart failure, cirrhosis of the liver, and nephrotic syndrome. A variety of mechanisms including reduced delivery of filtrate to ANP-sensitive sites in the inner medullary collecting duct and diminished receptor density in this tubular segment have been offered to account for this resistance. Recent studies in experimental nephrotic syndrome and in liver disease produced by ligation of the common bile duct in rats suggest that increased activity of cyclic guanosine 3',5'-monophosphate (cGMP) phosphodiesterase may be an important mediator of renal resistance to ANP. Such increased enzyme activity rapidly catabolizes the second messenger cGMP, normally formed when ANP interacts with its biologically active natriuretic peptide. A receptors, thereby leading to blunted ANP responsiveness. This increased phosphodiesterase activity offers a novel approach to the management of clinical conditions associated with sodium retention and edema formation.
...
PMID:Phosphodiesterases (PDEs) hydrolyze the 3' phosphoester bond of the purine 3',5'-cyclic monophosphates, cAMP and cGMP. 876 Feb 35

Resistance to the natriuretic action of atrial natriuretic peptide (ANP) is a hallmark of states of pathological sodium retention including congestive heart failure, cirrhosis of the liver, and nephrotic syndrome. A variety of mechanisms including reduced delivery of filtrate to ANP-sensitive sites in the inner medullary collecting duct and diminished receptor density in this tubular segment have been offered to account for this resistance. Recent studies in experimental nephrotic syndrome and in liver disease produced by ligation of the common bile duct in rats suggest that increased activity of cyclic guanosine 3',5'-monophosphate (cGMP) phosphodiesterase may be an important mediator of renal resistance to ANP. Such increased enzyme activity rapidly catabolizes the second messenger cGMP, normally formed when ANP interacts with its biologically active natriuretic peptide A receptors, thereby leading to blunted ANP responsiveness. This increased phosphodiesterase activity offers a novel approach to the management of clinical conditions associated with sodium retention and edema formation.
...
PMID:Phosphodiesterase activity as a mediator of renal resistance to ANP in pathological salt retention. 876 Feb 36

Long-term potentiation (LTP) is a long-lasting enhancement of synaptic transmission efficacy and is considered the base for some forms of learning and memory. Nitric oxide (NO)-induced formation of cGMP is involved in hippocampal LTP. We have studied in hippocampal slices the effects of application of a tetanus to induce LTP on cGMP metabolism and the mechanisms by which cGMP modulates LTP. Tetanus application induced a transient rise in cGMP, reaching a maximum at 10s and decreasing below basal levels 5 min after the tetanus, remaining below basal levels after 60 min. Soluble guanylate cyclase (sGC) activity increased 5 min after tetanus and returned to basal levels at 60 min. The decrease in cGMP was due to sustained tetanus-induced increase in cGMP-degrading phosphodiesterase activity, which remained activated 60 min after tetanus. Tetanus-induced activation of PDE and decrease of cGMP were prevented by inhibiting protein kinase G (PKG). This indicates that the initial increase in cGMP activates PKG that phosphorylates (and activates) cGMP-degrading PDE, which, in turn, degrades cGMP. Inhibition of sGC, of PKG or of cGMP-degrading phosphodiesterase impairs LTP, indicating that proper induction of LTP involves transient activation of sGC and increase in cGMP, followed by activation of cGMP-dependent protein kinase, which, in turn, activates cGMP-degrading phosphodiesterase, resulting in long-lasting reduction of cGMP content. Hyperammonemia is the main responsible for the neurological alterations found in liver disease and hepatic encephalopathy, including impaired intellectual function. Hyperammonemia impairs LTP in hippocampus by altering the modulation of this sGC-PKG-cGMP-degrading PDE pathway. Exposure of hippocampal slices to 1 mM ammonia completely prevents tetanus-induced decrease of cGMP by impairing PKG-mediated activation of cGMP-degrading phosphodiesterase. This impairment is responsible for the loss of the maintenance of LTP in hyperammonemia, and may be also involved in the cognitive impairment in patients with hyperammonemia and hepatic encephalopathy.
...
PMID:Sequential activation of soluble guanylate cyclase, protein kinase G and cGMP-degrading phosphodiesterase is necessary for proper induction of long-term potentiation in CA1 of hippocampus. Alterations in hyperammonemia. 1531 84

Patients with liver disease with overt or minimal hepatic encephalopathy show impaired intellectual capacity. The underlying molecular mechanism remains unknown. Rats with portacaval anastomosis or with hyperammonemia without liver failure also show impaired learning ability and impaired function of the glutamate-nitric oxide-cyclic guanine monophosphate (glutamate-NO-cGMP) pathway in brain. We hypothesized that pharmacological manipulation of the pathway in order to increase cGMP content could restore learning ability. We show by in vivo brain microdialysis that chronic oral administration of sildenafil, an inhibitor of the phosphodiesterase that degrades cGMP, normalizes the function of the glutamate-NO-cGMP pathway and extracellular cGMP in brain in vivo in rats with portacaval anastomosis or with hyperammonemia. Moreover, sildenafil restored the ability of rats with hyperammonemia or with portacaval shunts to learn a conditional discrimination task. In conclusion, impairment of learning ability in rats with chronic liver failure or with hyperammonemia is the result of impairment of the glutamate-NO-cGMP pathway. Moreover, chronic treatment with sildenafil normalizes the function of the pathway and restores learning ability in rats with portacaval shunts or with hyperammonemia. Pharmacological manipulation of the pathway may be useful for the clinical treatment of patients with overt or minimal hepatic encephalopathy.
...
PMID:Oral administration of sildenafil restores learning ability in rats with hyperammonemia and with portacaval shunts. 1566 Apr 36


1 2 3 Next >>

---