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 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

An enzymatic cycling procedure for beta-NADP+ generated by the enzyme 3'-phosphodiesterase, 2':3'-cyclic nucleotide (EC 3.1.4.37) from its substrate 2':3'-cyclic NADP+ is described. The enzymes glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and diaphorase (EC 1.8.1.4) are used to cycle the cofactor between its oxidized and reduced forms in the presence of glucose-6-phosphate and p-iodonitrotetrazolium violet (INT) with the concomitant production of colored INT-formazan, monitored at 492 nm. The amplification is about 400-fold per hour and is sensitive enough to detect 6 x 10(-13) mol of NADP(H). A simple procedure for the optimization of this cycling assay is also described. Conjugates to 3'-phosphodiesterase, 2':3'-cyclic nucleotide may be used in heterogeneous enzyme immunoassays for the detection of small quantities of haptens or proteins in biological fluids.
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PMID:An enzymatic cycling procedure for beta-NADP+ generated by 3'-phosphodiesterase, 2':3'-cyclic nucleotide. 132 Mar 51

Previous immunohistochemical staining procedures of the brain and pituitary in Xenopus laevis, using an antiserum against neuronal nitric oxide (NO) synthase (nNOS) and nicotinamide adenine dinucleotide phosphate-diaphorase histochemistry, have revealed NOS activity in neurons and fibers in a number of brain areas, as well as in fibers in the pituitary. In the present study we have localized the target structures of the NOergic system in the Xenopus brain by visualizing the sites of NO-sensitive cyclic 3',5'-guanosine monophosphate (cGMP) accumulation, according to a method for cGMP visualization in rat brain slices. Brain slices of unfixed Xenopus are incubated in the presence of the phosphodiesterase inhibitor isobutylmethylxanthine and the NO donor sodium nitroprusside, followed by fixation and cryosectioning. Sections were then processed for immunohistochemistry using rabbit and sheep antisera against cGMP and a sheep antiserum against nNOS. Visualization of single and double labeling of cGMP immunoreactive and/or nNOS immunoreactive structures was performed with combined CY3/fluorescein isothiocyanate fluorescence microscopy. Following this procedure, we provide immunohistochemical evidence for the distribution of cGMP-accumulating neurons in the brain of adult Xenopus. In most brain areas, the distribution of nNOS and cGMP immunoreactive structures (neuron somata and fibers) is distinct and separate, for instance in the dorsal pallium, the lateral thalamic nuclei, the optic tectum, the locus coeruleus and the reticular formation. However, nNOS and cGMP immunoreactive structures are often found in the vicinity of each other, and in the optic tectum even in adjacent neuron fibers and somata. The present observations are in line with the presence of an NO-dependent soluble guanylate cyclase in distinct brain areas of Xenopus laevis, corroborating similar data in the mammalian brain. Further, our observations may add to the understanding of the anatomical connectivity pattern and functional relevance of the NOergic system in the amphibian brain.
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PMID:Topographical relationship between neuronal nitric oxide synthase immunoreactivity and cyclic 3',5'-guanosine monophosphate accumulation in the brain of the adult Xenopus laevis. 971 Jan 48

Vardenafil hydrochloride (HCl) is a potent and selective phosphodiesterase type-5 (PDE-5) inhibitor that enhances nitric oxide (NO)-mediated relaxation of human corpus cavernosum and NO-induced rabbit penile erection, and enhances erectile function in patients. In the present study, the effect of vardenafil on nitric oxide synthase (NOS) and neuronal NOS expressions in the paraventricular nucleus (PVN) of rats without sexual stimulation was investigated using nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry and neuronal NOS (nNOS) immunohistochemistry and western blot analysis. The present results showed that NOS and nNOS expression in the PVN was increased by vardenafil treatment as the dose- and duration-dependently without sexual stimulation. The phosphodiesterase type-5 inhibitor, vardenafil, augmented NOS expression in the brain without sexual stimulation. The present study suggests that sexual behaviour can be directly modulated by neurotransmitters such as nitric oxide.
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PMID:Effect of vardenafil on nitric oxide synthase expression in the paraventricular nucleus of rats without sexual stimulation. 2195 Feb 84

This study examines the role of the unconventional gaseous signaling molecule nitric oxide (NO) on the regulation of heart rate in the Vietnamese stick insect, Baculum extradentatum. Using nicotinamide dinucleotide hydrogen phosphate (NADPH)-diaphorase histochemistry, as well as immunohistochemistry and Western blotting with an antibody against NO synthetase (NOS), we identified the presence of NOS in hemocytes present throughout the lumen of the dorsal vessel. We propose that NO is delivered to heart muscle tissue via hemocytes circulating within the hemolymph. In the present study, stimulation of NO levels by the application of the NO donor MAHMA-NONOate and l-arginine led to a dose-dependent decrease in heart rate. Treatment of tissues with the NOS inhibitor, L-NAME, in equimolar concentrations with l-arginine, led to a recovery of heart rate, without modifying heart rate on its own. Finally guanosine 3',5'-cyclic monophosphate (cGMP) analog, 8-bromo-cGMP, elicited similar inhibitory effects on stick insect heart rate as did the guanylate cyclase activator, YC-1, and the phosphodiesterase inhibitor, dipyridamole, indicating that cGMP is most likely the second messenger in the stick insect NO signaling pathway. Contrary to the cardioexcitatory effect of NO on other insect hearts, we have found that NO inhibits stick insect heart rate independently from any nervous system input, in a similar inhibitory fashion as that of vertebrate hearts.
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PMID:The regulation of cardiac activity by nitric oxide (NO) in the Vietnamese stick insect, Baculum extradentatum. 2230 70

Calf and human thyroids have been disrupted by nitrogen microcavitation, and the thyroid membranes prepared by repeated centrifugation in low ionic strength buffers. Two classes of membranes were prepared by centrifugation on a discontinuous gradient of ficoll. A lighter fraction was comprised of somewhat larger vesicles; they were higher in Na(+)-K(+)-activated ATPase, phosphodiesterase, and 5'-nucleotidase than was the heavier fraction. The heavier fraction had a higher nicotinamide adenine nucleotide dehydrogenase-diaphorase activity. Thus the lighter fraction appears to have been enriched in fragments derived from the plasma membrane.
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PMID:Preparation and properties of thyroid cell membranes. 2417 60