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)

Adenosine 3',5'-cyclic monophosphate (cAMP) may be one of the important factors in regulating the expression of many differentiated functions in neuroblastoma cells, but some of these functions can be induced by agents that do not increase the intracellular level of cAMP. An elevation of the intracellular level of guanosine 3',5'-cyclic monophosphate (cGMP) neither induced differentiation nor antagonized the effects of cAMP. Neuroblastoma cells increased the level of cAMP-binding proteins during differentiation, whereas glial cells and L-cells did not. This might have accounted in part for an increase in the intracellular level of cAMP even in the presence of high phosphodiesterase activity in neuroblastoma cells, since the protein-bound with the same proteins, but cAMP had about 10 times higher affinity than did cGMP. cAMP promoted the organization of microtubules and microfilaments necessary for the expression of differentiated phenotypes. The extension of neurites required the synthesis of new protein, but it did not need the synthesis of new RNA. cAMP induced differentiation in neuroblastoma cells by increasing the expression of some genetic information while suppressing the expression of others; e.g., the activities of neural enzymes increased, whereas the synthesis of histone and the phosphorylation of H1-histone markedly decreased in differentiated cells. A hypothesis was offered: An increase in cAMP phosphodiesterase activity as a result of mutation in the regulatory gene for phosphodiesterase in a single, or group of, dividing nerve cell(s) is the primary lesion that leads to malignancy. Based on the concept that selective cytocytoxic drugs should be used with agents that cause differentiation, a new therapeutic approach was suggested for the treatment of neuroblastoma. This involved administration of sodium butyrate followed by L-DOPA or prostaglandin E1 in the presence of cAMP phosphodiesterase inhibitor followed by the less immunosuppressive vincristine and 5-(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide.
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PMID:Cyclic nucleotides in the regulation of expression of differentiated functions in neuroblastoma cells. 1 Apr 49

Activities of monoamine oxidase (MAO), DOPA-decarboxylase (DD), phenoletha-nolamine-N-methyltransferase (PNMT) and phosphodiesterase (PDE) were studied in the brain and its parts, heart, kidneys, adrenals and liver in developing rats. In vitro, the action of nialamid on MAO activity in the liver, RO-4-4602 on DD activity in the liver, and D(-) INPEA on PNMT activity in the adrenals was investigated. The influence of 6-hydroxydopamine (6-OHDA), 200 mg/kg i. p., on MAO activity in the liver of developing rats was also studied. Irregular changes in activities of examined enzymes during development were observed. 6-OHDA, nialamid and RO-4-4602 inhibited enzyme activities in young rats more strongly than in adult animals.
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PMID:Activity of some enzymes which synthesize and metabolize catecholamines in the brain and peripheral organs in developing rats. 16 62

It was shown on albino mice that when DOPA-3H (20 muCi/mouse) was administered before nonradioactive DOPA (1 mg/mouse) tritium accumulation in the tissue of Harding-Passi's melanoma of these mice proved to increase. Melanoma radioactivity in this experimental group was double that in the tumour tissue of the animals to which DOPA-3H alone was administered. Examination of the adenylate cyclase, phosphodiesterase activity and of the level of cAMP in melanoma of mice 2 hours after DOPA administration (1 mg/mouse) showed accumulation of cAMP and an increase in the phosphodiesterase activity; as to adenylate cyclase activity--it fell. It is suggested that DOPA realizes its effect not only as melanin precursor, but also through the cAMP system, influencing the melanogenesis enzymes activity.
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PMID:[Regulatory role of DOPA and components of the cyclic adenosine-3',5'-monophosphate system]. 20 73

The dermal cells in grey, xanthic, and white goldfish integuments were cytochemically characterized for the following enzymatic activities: tyrosinase, DOPA-oxidase, cytochrome oxidase, monoamine oxidase, peroxidase, non-specific esterase, cholinesterase, NAD-diaphorase, NADP-diaphorase, aryl sulfatase, nucleotide phosphodiesterase, beta-glucuronidase, acid phosphatase, alkaline phosphatase, adenosine triphosphatase, thiamine pyrophosphatase, glucose-6-phosphatase, aldolase, as well as succinate, malate, isocitrate, glutamate, glucose-6-phosphate, 6-phosphogluconate, alpha-glycerophosphate, alcohol, lactate, and beta-hydroxybutyrate dehydrogenases. It was found that the epidermis was a significant barrier to the access of cytochemical reaction substrates. Removal of the epidermal barrier provided dermal cell localizations of enzymatic activities which were reproducible. Further, alterations in reaction times and temperatures from the mammalian methodology provided conditions fe various integumental cells were compared for possible interrelationships. The basic foundations for future work with the dermis of poikilothermic vertebrates on an experimental basis were established. In addition, a previously undescribed non-pigmented dermal cell, the "x"-cell, was found to have enzymatic characteristics similar to both melanophores and lipophores. The "x"-cell may be the common precursor of both types of pigment cells.
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PMID:Cytochemical characterization of goldfish (Carassius auratus L.) dermis with special reference to the pigment cells. 82 86

1. The present study has examined the influence of alpha-human atrial natriuretic peptide (alpha-hANP) on the synthesis of dopamine and its deamination into 3,4-dihydroxyphenylacetic acid (DOPAC) in rat kidney slices loaded with exogenous L-dihydroxyphenylalanine (L-DOPA). 2. alpha-hANP (3.3 and 330 nM) was found to produce a marked reduction (63-78% reduction) in the time-dependent accumulation of newly-formed dopamine and of its deaminated metabolite DOPAC in kidney slices loaded with 10 microM L-DOPA. alpha-hANP (330 nM) was also found to decrease the accumulation of newly-formed dopamine (45-66% reduction) and DOPAC (38-61% reduction) in experiments in which increasing concentrations (1-100 microM) of L-DOPA were used. This inhibitory effect was found to be potentiated by zaprinast (M&B 22,948; 10 microM), a guanosine cyclic 3',5'-monophosphate (cyclic GMP) phosphodiesterase inhibitor. Alone, zaprinast also decreased the accumulation of both dopamine (54-71% reduction) and DOPAC (73-92% reduction). 3. In kidney homogenates, alpha-hANP (330 nM) was found to affect neither the formation of dopamine nor its deamination to DOPAC. 4. Both alpha-hANP (330 nM) and zaprinast (10 microM) were found not to affect the formation of dopamine and DOPAC in kidney slices obtained from rats on a high salt diet during the previous 6 weeks. A similar situation was also found to occur when kidney slices obtained from 24-months old rats were used.5. The results obtained suggest that the inhibitory effect of alpha-hANP on the renal synthesis of dopamine is dependent on the activation of a membrane-operated mechanism, coupled to the enzyme guanylate cyclase, controlling the entry of L-DOPA into the cells.
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PMID:Effect of alpha-human atrial natriuretic peptide on the synthesis of dopamine in the rat kidney. 132 52

1. In the present study the effects of M&B 22,948, a guanosine 3':5'-cyclic monophosphate (cyclic GMP) selective phosphodiesterase inhibitor and of 8-bromo cyclic GMP were examined on the synthesis of dopamine from L-3,4-dihydroxyphenylalanine (L-DOPA) in rat cortical slices and in whole kidney homogenates. The deamination of newly-formed dopamine into 3,4-dihydroxyphenylacetic acid (DOPAC) was also studied. The assay of L-DOPA, dopamine, noradrenaline and DOPAC was performed by high performance liquid chromatography (h.p.l.c.) with electrochemical detection. 2. Incubation of renal slices and homogenates of whole kidney with exogenous L-DOPA (0.1-10.0 microM) resulted in a concentration-dependent formation of both dopamine and DOPAC. 3. The addition of M&B 22,948 (10 microM) to the incubation medium resulted in a marked reduction in the accumulation of both newly-formed dopamine and DOPAC in kidney slices; the inhibitory effect of M&B 22,948 on DOPAC formation was greater than that on dopamine. 8-Bromo cyclic GMP (250 microM) produced only a slight decrease in the tissue levels of newly-formed dopamine (5-13% reduction), but was found to decrease significantly (51-68% reduction) the formation of DOPAC in kidney slices. The addition of 8-bromo cyclic GMP plus M&B 22,948 to the incubation medium resulted in similar effects to those described for M&B 22,948 alone. 4. In kidney homogenates, in contrast to results observed in kidney slices, M&B 22,948 (10 microM) and 8-bromo cyclic GMP (250 microM) were found to affect neither the formation of dopamine nor its deamination to DOPAC. 5. In conclusion, the results presented here suggest that cyclic GMP may be involved in the regulation of dopamine synthesis, probably through the control of the entry of L-DOPA into the tubular epithelial cells.
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PMID:Inhibitory effects of guanosine 3':5'-cyclic monophosphate on the synthesis of dopamine in the rat kidney. 165 48

Effects of three phosphodiesterase (PDE) inhibitors (rolipram, IBMX, and Ro 20-1724) were studied in mice in some tests predictive for antidepressant activity. All the drugs antagonized reserpine-induced hypothermia and slightly antagonized reserpine-evoked hypoactivity. Rolipram and IBMX were also effective in behavioral despair test. On the other hand, the examined PDE inhibitors did not affect apomorphine-induced hypothermia and did not potentiate the central action of L-DOPA. These results show that psychopharmacological profile of the PDE inhibitors differs from that of classical imipramine-like antidepressants.
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PMID:Antidepressant properties of some phosphodiesterase inhibitors. 619 18

Glaucine and two of its structural analogues exerted an inhibitory effect on phosphodiesterase activity in different tissue homogenates. In experiments on rats glaucine applied intraperitoneally significantly increased the brain level of dopamine (DA) and did not change the content of noradrenaline and serotonin (5-HT). The combined application of L-DOPA and glaucine or glaucine derivatives produced a higher increase in brain DA than the increase which would be expected by simple summation of the effects of L-DOPA and glaucine and of the glaucine derivatives respectively. At the same time L-DOPA and glaucine, applied together, caused a slighter decrease of brain 5-HT than the decrease produced by the same dose of L-DOPA when the latter was applied alone. It is suggested that the higher increase of brain DA produced by the combination of L-DOPA and the phosphodiesterase inhibitor glaucine or its structural analogues is mainly due to the increased cAMP level.
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PMID:Effects of glaucine and some glaucine derivatives and of their combination with L-DOPA on the brain level of biogenic monoamines. 718 77

The present investigation was undertaken to study effects of methylxanthine derivatives on rotational behaviour produced by dopamine receptor stimulating drugs and properties of methylxanthine-induced rotation in mice with unilateral 6-hydroxydopamine (6-OHDA)-induced lesions of the striatum. L-Dopa 10mg/kg, i.p., produced contralateral turning which lasted for about 40 min. When L-dopa 10mg/kg was given to mice in combination with theophylline 25 mg/kg, total turns for 2 hr were significantly higher than those of L-dopa and theophylline alone. Caffeine and theophylline in doses of 25 and 50 mg/kg, i.p., respectively, produced marked increase in contralateral rotation in a dose-dependent manner in mice with lesions. Theobromine 100 mg/kg, i.p., also produced a moderate contralateral rotation. Total turns of ipsilateral rotation produced by methylxanthine derivatives were less than 10% of those of contralateral circling. Theophylline-induced contralateral rotation was reduced to nearly 30% of the control by alpha-methyl-p-tyrosine (alpha-MPT). It was also suppressed by spiroperidol, at a dose higher than that to apomorphine or methamphetamine. These results suggest that methylxanthine derivatives produce contralateral rotational behaviour due to not only phosphodiesterase inhibition but also dopamine receptor stimulation.
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PMID:Properties of rotational behaviour produced by methylxanthine derivatives in mice with unilateral striatal 6-hydroxydopamine-induced lesions. 719 46

In the striatum, dopamine release is inhibited by activation of dopamine D(2) autoreceptors. Changes in dopamine release have been attributed to changes in the synthesis of dopamine, which is regulated via phosphorylation of tyrosine hydroxylase (TH), the rate-limiting enzyme in the synthesis of catecholamines. Here, we have studied the involvement of dopamine D(2) receptors in the regulation of TH phosphorylation at distinct seryl residues, using phosphorylation site-specific antibodies and a preparation of rat striatal slices. The D(2) receptor agonist, quinpirole, reduced basal TH phosphorylation at Ser40 but not at Ser19 or Ser31. Quinpirole was also able to reduce the increase in Ser40 phosphorylation caused by forskolin, an activator of adenylyl cyclase, without affecting the increase in Ser19 phosphorylation produced by the glutamate receptor agonist, N-methyl-D-aspartate (NMDA). In addition, the dopamine D(2) receptor agonist reduced both basal and forskolin-stimulated activity of TH, measured as 3,4-dihydroxyphenylalanine (DOPA) accumulation. Quinpirole decreased phosphorylation of Ser40 induced by okadaic acid, an inhibitor of protein phosphatase 1 and 2A and Ro-20-1724, a phosphodiesterase inhibitor. In contrast, quinpirole did not affect the increase in Ser40 phosphorylation caused by the cAMP analogue, 8-Br-cAMP. These data indicate that, in the striatum, activation of dopamine D(2) receptors results in selective inhibition of TH phosphorylation at Ser40 via reduction of the activity of adenylyl cyclase. They also provide a molecular mechanism accounting for the ability of dopamine D(2) autoreceptors to inhibit dopamine synthesis and release from nigrostriatal nerve terminals.
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PMID:Dopamine D(2) receptors regulate tyrosine hydroxylase activity and phosphorylation at Ser40 in rat striatum. 1120 12


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