Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.6.99.1 (NADPH-diaphorase)
 3,903 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nitric oxide (NO) produces rapid osteoclast detachment and contraction in vitro, and this effect is accompanied by a profound inhibition of bone resorption. Work by others has confirmed these findings in vivo: inhibition of NO synthase [NOS; L-arginine, NADPH: oxygen oxidoreductase (NO-forming), EC 1.14.13.39] in normal rats is followed by increased bone resorption reflected by a marked loss in bone mineral density. In our present study, immunocytochemistry and Northern blotting show the presence of the constitutive calcium-sensitive NOS isoform (cNOS) in normal rat osteoclasts and in the human preosteoclast cell line (FLG 29.1). The inducible NOS isoform (iNOS) was also clearly demonstrable in the rat cells especially after treatment with gamma interferon (IFN-gamma) and bacterial wall products [lipopolysaccharide (LPS)], while a basal level of transcript was detected in the untreated human preosteoclast line. However NADPH-diaphorase activity was intense only in neonatal rat osteoclasts attached to bone, perhaps reflecting either enhancement of cNOS activity by calcium or increased amounts of the inducible isoform in activated osteoclasts in situ compared with isolated neonatal rat osteoclasts. These actively resorb devitalized bone but the untreated cells contain relatively low levels of NOS; they are extremely sensitive to inhibition by NO. The iNOS inhibitor aminoguanidine markedly enhances in vitro resorption by activated NOS-rich chick osteoclasts and by normal rat osteoclasts treated with LPS or IFN-gamma. In contrast, the nonselective NOS inhibitor NG-monomethyl-L-arginine inhibits resorption by untreated neonatal rat osteoclasts. Thus, osteoclast function may require intermittent calcium-stimulated increases in NO production by cNOS against a basal inhibitory background activity of the iNOS isoform. However, bone resorption depends on precursor replication and on the activity of the mature cells, and we found that the NO donor 3-morpholinosydnonimine (SIN-1) (50 microM) profoundly depressed replication in the human preosteoclast line. Taken together, these results strongly suggest that NO maintains a central control of bone resorption in both avian and mammalian species by exerting a powerful tonic restraint of osteoclast numbers and activity. The presence of NOS in human cells implies a similar function in man and that conventional views of calcium homoeostasis and skeletal metabolism will need substantial revision. Since NO also influences behavior of the osteoblast, the bone-forming cell, in vitro, a similar effect in vivo might imply a general influence on bone remodeling.
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PMID:Bidirectional regulation of osteoclast function by nitric oxide synthase isoforms. 753 33

While considerable progress has been made in elucidating nitric oxide (NO) regulatory mechanisms in the later stages of gestation, much less is known about its synthesis and role during embryo implantation. Thus, to evaluate the participation of the trophoblast in the production of NO during this phase, this study focused on NADPH-diaphorase activity and the distribution of NO synthase isoforms (NOS) using immunohistochemistry in pre- and postimplantation mouse embryos in situ and in vitro, as well as on NO production itself, measured as total nitrite, in trophoblast culture supernatants (Griess reaction). No NADPH-diaphorase activity was found in preimplanting embryos except after culturing for at least 48 h, when a few trophoblastic giant cells were positive. Conversely, postimplantation trophoblast cells either lodged into the implantation chamber (in situ) or after culturing (in vitro) showed intense NADPH-diaphorase activity. Also in the postimplantation trophoblast, the endothelial and inducible NOS (eNOS and iNOS) isoforms were immunodetected, under both in situ and in vitro conditions, although in different patterns. Extracts of ectoplacental cone also revealed bands of 135 and 130 kDa on SDS-PAGE that reacted with anti-eNOS and anti-iNOS, respectively, on Western blot. Analysis of the culture supernatant demonstrated that the nitrite concentration was 1) proportional to the number of cultured trophoblast cells, 2) almost completely abolished in the presence of N(omega)-nitro-L-arginine methyl ester, and 3) increased 2-fold in cultures stimulated with gamma-interferon. These results strongly suggest the production of NO from constitutive and inducible isoforms of NOS by the implanting mouse trophoblast. They also emphasize the possibility of the participation of these cells in vasodilatation and angiogenesis, and in cytotoxic mechanisms involved in the intense phagocytosis of injured maternal cells, which occur during the implantation process.
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PMID:Participation of the mouse implanting trophoblast in nitric oxide production during pregnancy. 1064 61

Clinicopathogenetic impact of cycloferon, an endogenous interferon inductor, on the process of Astrakhan rikettsial fever, its complications and outcomes was analysed. The treatment scheme with addition of cycloferon to the complex therapy was optimized. The specificity of the disease clinical process and the level of the interferon status in the patients treated with cycloferon alone or with combination of the standard therapy and cycloferon was shown. It was observed that in the patients with moderate severity of the disease the combined use of the standard therapy and cycloferon was in favour of arresting the disease clinical signs (fever, headache, weakness, eruption, hepatomegaly, arthralgia and myalgia, lymphatic gland inflammation, primary affect) and lowered the hospitalization term vs. the standard therapy alone. In the patients with moderate severity of the disease the levels of the serous interferon-alpha before the treatment were found lower, while those of interferon-gamma were higher. The use of cycloferon in the treatment scheme resulted in increase of the interferon-alpha levels and decrease of the higher levels of interferon-gamma. The standard therapy in combination with cycloferon in the patients with moderate severity of the disease provided changes in the immune status: increase of the relative content of T- and B-lymphocytes and normalization of their absolute number. Normalization of the phagocytic activity and the coefficient of the active phagocytes, as well as increase of the phagocytic index, the levels of immunoglobulins G, A and M and the number of the circulating immune cells were stated. The standard therapy with addition of cycloferon resulted in normalization of the levels not only of succinic denydrogenase, lactate dehydrogenase and glucose-6-dehydrogenase but also of alpha-naphthylacetate esterase and alpha-naphthylbutirate esterase in the neutrophils, as well as of the whole spectrum of the monocyte enzymes, except NAD-diaphorase. The adverse reactions were observed in 2.5% of the cases (9 subjects). All of them were mild and did not require discontinuation of the drugs use.
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PMID:[Evaluation of safety and pharmacotherapeutic efficacy of cycloferon in treatment of Astrakhan rickettsial fever]. 2274 Nov 99