Jak2/Stat1 pathway mediated tetrahydrobiopterin up-regulation contributes to nitric oxide overproduction in high-glucose cultured rat mesangial cells.
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):81-9. doi: 10.1139/cjpp-.Jak2/Stat1 pathway mediated tetrahydrobiopterin up-regulation contributes to nitric oxide overproduction in high-glucose cultured rat mesangial cells.1, , , , , , .1Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical College, 209 Tongshan Road, Xuzhou 221004, Jiangsu, China.AbstractNitric oxide (NO) is crucial for the progression of early diabetic nephropathy (DN). It is important to clarify the mechanism for the production of NO in mesangial cells (MCs). In this study, the amounts/activities of related factors such as reactive oxygen species (ROS), NO, 3 isoforms of nitric oxide synthase (NOS), tetrahydrobiopterin (BH4), GTP cyclohydrolase I (GTPCH I), Jak2, and Stat1 were determined using high-glucose cultured rat MCs. The results showed that the production of BH4 under oxidative stress was strongly stimulated by its rate-limiting enzyme GTP cyclohydrolase, which increased the expression and activity of inducible NOS to facilitate NO synthesis. Furthermore, the relative quantities of activated-Jak2 and activated-Stat1 were increased. Therefore, Jak2/Stat1 pathway mediated BH4 up-regulation can contribute to excessive NO in high-glucose cultured MCs. Our results will be helpful for screening new targets to improve the therapy for early DN. KEYWORDS:
n néphropathie diabé synthase d’oxyde nitriquePMID:
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Kova?evi?, Stana
Tkanje kroz vrijeme( Weaving through time )
TImod 2016
Part of a CC journal:
TImod 2016, Prvi me?unarodni simpozij tekstilnog in?enjerstva i modnog dizajna
Location and date:
Travnik, BiH, 22-24. sije?nja 2016.
Ru?no tkanje, tkala?ki stan, pre?a, tkanina( Hand weaving, weaving loom, yarn, fabric )
Prema nekim literaturama, temeljene prema prona?enim ostacima, mo?e se pretpostaviti da je ?ovjek ve? u prapovijesno vrijeme koristio primitivne alate u lovu, gradnji nastambi, ko?ara i koliba iz pru?a, gdje se zahtijevalo odre?eno umije?e preplitanja kako bi se ostvarila ?vrsto?a i trajnost plo?ne tvorevine. Zbog bolje izolacije prostora koristilo se glineno blato, ko?a, ?ivotinjske kosti, te li??e, ?ime se dobila ?vrsta, dugotrajna i nepropusna. To preplitanje pru?a je vjerojatno bila prete?a u izradi tekstilnih tkanina za odje?u i drugo. Ru?nim uvijanjem pru?a, li??a, a potom ?ivotinjskih dlaka dobila se u po?etku gruba, a kasnije sve finija nit za sve ?ire namijene, kao proizvodnja konopa, torbi za prijenos tereta, le?aljke i sli?no. Prema mnogim saznanjima mo?e utvrditi da su tehni?ke tkanine izra?ene najprije od pru?a a potom tekstilnih vlakana za izradu nastambi zapravo starije od tkanina za odje?u. Tkala?ki stan pojavio se prije Neolitskog razdoblja, odnosno u Epipaleolithicu i to oko 12 000 godina prije Krista (p.K.) Da je vje?tina tkanja i njena primjena, postojala jo? u kameno doba svjedo?e arheolo?ki nalazi, slikovni prikazi, freske, kameni spomenici, arhivski dokumenti, nalazi igala od kostiju i kroja?ki pribor od kamena, kameni utezi za tkala?ke stanove itd. Va?no je napomenuti da je najstarija vunena tkanina u Europi prona?ena 1983. god. na Kupre?kom Polju kao grobni pla?t izva?ena iz prapovijesnog zemljanog tumula Tkanina je upotrijebljena za omatanje pokojnika, njezina procjenjena starost je
godine p.K.
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PP presentation
Type of peer-review:
International peer-review
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Research fields:
Textile technology
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Contrib. to CROSBI by:
Stana Kova?evi? (skovac@ttf.hr), 18. Jul. 2016. u 22:08 satiImage quality, contrast enhancement, and radiation dose of ECG-triggered high-pitch CT versus non-ECG-triggered standard-pitch CT of the thoracoabd...
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):931-8. doi: 10.2214/AJR.11.6921.Image quality, contrast enhancement, and radiation dose of ECG-triggered high-pitch CT versus non-ECG-triggered standard-pitch CT of the thoracoabdominal aorta.1, , , , , .1Imaging Institute, Cardiovascular Section, Cleveland Clinic, OH 44195, USA. bolenm@ccf.orgAbstractOBJECTIVE: We sought to compare image quality, contrast enhancement, and radiation dose in patients undergoing ECG-triggered high-pitch helical CT or non-ECG-synchronized helical CT of the thoracoabdominal aorta.MATERIALS AND METHODS: We retrospectively assessed data from 101 consecutive patients (81 men, 20 mean age, 71 ± 11 [SD] years) undergoing clinically indicated CT angiography (CTA) of the thoracoabdominal aorta on a dual-source scanner using either the ECG-triggered high-pitch helical mode (group 1, n = 52) or non-ECG-synchronized standard-pitch helical mode (group 2, n = 49) during the arterial phase. Two independent readers assessed image quality, noise, and contrast enhancement throughout the thoracoabdominal aorta. Scanner-reported dose-length product values were used to estimate effective dose values.RESULTS: Image quality at the root-proximal ascending level was higher in group 1 (mean ± SD, 2.81 ± 0.40) than in group 2 (1.22 ± 0.47; p & 0.0001), with similar quality for both groups noted at other levels. Group 1 scans displayed higher image noise at all levels. The groups received a similar volume of contrast material (p = 0.77), and similar percentages of cases with acceptable contrast enhancement (& 250 HU) were noted in the two groups. The estimated radiation burden was significantly lower in group 1 (mean ± SD, 5.4 ± 1.8 mSv) than in group 2 (14.4 ± 5.1 mSv; p & 0.0001).CONCLUSION: Imaging of the thoracoabdominal aorta with ECG-triggered high-pitch CTA provides higher quality images of the aortic root and ascending aorta with sufficient contrast enhancement and decreased estimated radiation dose compared with non-ECG-synchronized standard-pitch helical CT.PMID:
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, December 2014, Pages 349–358
Open Access
Review paperDiversity Storage: Implications for tropical conservation and restoration,
Biological Sciences (m/c 066), University of Illinois at Chicago, Chicago, IL 60607, United StatesThe future of tropical biodiversity in human-dominated landscapes will be conservation and restoration of processes of seed dispersal by birds and mammals. Here the Diversity Storage Hypothesis posits that immense biological diversity resides within skewed species-abundance distributions of tropical trees, and further predicts that many species will adjust to increases of 1.5&3.0&&C anticipated from climate change by 2100. Common and widespread tropical trees (&100,000,000 individuals) may shift ranges but are unlikely to face extinction. Many rare species (e.g.&&1000 individuals) have a more precarious future. The latter may be declining species bound for extinction, incipient species adjusting to environmental changes, or relics of past warmer and more seasonal climates that will be resurrected if processes of seed dispersal allow them to persist and spread. In fragmented agricultural landscapes, preserved or planted corridors, buffers and stepping-stone habitat patches around and between forest remnants are more vital than efforts to preserve or create contemporary forest compositions, dominance relations, and species-abundance distributions. An implication of Diversity Storage is that it is more important to facilitate migration into and out of changing landscapes to allow inherent diversity to adjust and coexist with agricultural economies than to resist change.KeywordsBiodiversity; Conservation; Restoration ecology; Rarity; Seed dispersal; Tropical forest<h2 class="svArticle" id="s. IntroductionChanges in land management and climate will have profound effects on ecosystems worldwide ( and ). With widespread conversion of tropical forests to agriculture over the last 150&years, conservation of dwindling protected areas is insufficient insurance for maintaining tropical biodiversity, or for ensuring re-generation of diverse forests if land is eventually released from agriculture. The challenge is especially acute in more than half of the land areas in tropical biomes that have been cleared for agriculture, logged repeatedly, or intensively hunted (e.g.&& ). The best hope in degraded landscapes is to strategically preserve forest remnants (,  and ), and to determine where and how vegetation can be restored with assisted or unassisted secondary succession ( and ). Efforts should emphasize preservation or creation of mixed-species corridors, planted-tree buffers and stepping-stone habitat patches that permit movement of plant populations in response to environmental change. Because most tropical trees are dispersed by animals, conservation and restoration of the 21st Century must emphasize protection or reintroduction of birds and mammals that actually mediate tree dispersal on local scales, and allow tree migration on regional scales. For long-term resilience of landscapes that remain under cultivation or grazing, it is more important to maintain or create patches and corridors of forest cover and encourage the dispersal agents that use them than to attempt to re-establish contemporary forest composition, as defined by dominance and species-abundance distributions, that are or will soon become ecologically obsolete.Implications of processes and consequences of species turnover for both conservation and ecological restoration do not receive the attention they deserve. The Diversity Storage Hypothesis proposes: (1) tropical communities will change dramatically in species composition as land use and climates change, (2) for projected increases of 1.5&3& C this century, some or even many taxa in species-rich communities will respond positively to climate change, and (3) others will not. One unusual emphasis in this paper is in suggesting rare tree species, the source of most tree diversity in the tropics, as potential sources of species capable of responding positively to climate change. Another unusual emphasis is that the successful migration of common tree species and expansion of adapting species to new sites requires protection or re-introduction of dispersal agents responsible for tree movement across landscapes.Turnover could result in net loss of taxa to landscape or global extinction, or replacement or even increases in richness due to range shifts and&in the longer term&speciation (e.g. ; ; in decades, , in millennia or longer,& ). Positive responses may occur among widespread and abundant species with high genetic diversity, as well as spread of incipient species that by chance are pre-adapted, or are continually adapting, to developing conditions. It is uncertain what the future role of currently rare species (&1 ha&1) will be. Because they comprise most tree species in diverse contemporary tropical forests, their fates are important (,  and ). Rare tree species that are relics of past climate regimes may be resurrected by return of conditions to which they are adapted. Or, lacking the genetic diversity of more common species with much larger populations, rare species may become extinct. Whether by range shifts, speciation, or resurrection in situ, species fortunes over centuries in a given landscape are virtually certain to reflect competitive gains by many species and ultimately genera that are now infrequent or rare, at the expense of those that are now common.The Diversity Storage Hypothesis is developed for tropical trees. This is feasible because quantitative inventories exist for relative tree abundances at multiple scales in multiple tropical sites (e.g.& ,  and ), and paleobotanical records calibrated with geological and biogeochemical proxies are the basis of ecological interpretations of climate change in the past (e.g.& ,  and ). Diversity Storage is directly relevant to other species-rich taxa that are strongly associated with trees, such as herbivorous insects. Relevance is indirect for taxa with few species, including vertebrates that pollinate flowers or disperse seeds.This Diversity Storage Hypothesis predicts that strong positive responses by a subset of currently common, infrequent or rare tree species will reflect adaptive responses to changes in land use or climate. This is not the storage effect of rare species in some community-drift models in which frequency-dependent advantages for rare species occur if density-dependent mortality of seedlings reduces abundances of common species&(). Rare-species advantages exist (e.g.&& ), but density-dependent seedling mortality may not be involved. On Barro Colorado Island (BCI) in Panama, for instance, survival of seedlings of 180 tree species shows that density-dependent mortality among conspecifics varies widely among species, but is much more pronounced in rare than common species&(). For most species in that sample, proximity of heterospecifics has a negligible effect on growth and mortality, suggesting that rare species may hold on, but are maladapted to current biotic or abiotic conditions. Diversity Storage predicts replacement of taxa that are now common with relic or novel species better adapted to or by chance more tolerant of environments as they change, not because of community drift reflecting random processes.<h2 class="svArticle" id="s. Short and long viewConservation and restoration planning must accommodate both the short term of decades and the longer term of centuries or more. Imminent threats to tropical forests remain hunting, deforestation, forest fragmentation and complications of fire (,  and ). Deforestation affects local weather, often resulting in higher temperatures, decreased humidity and lower soil moisture tens to hundreds of meters inside fragment edges&(). Fragmented forests in agricultural landscapes are not small-scale replicas of they are developing communities adjusting to changing biotic and abiotic realities. For reasons that will become apparent, pre-occupation with preservation of forest integrity defined by contemporary tree-species composition and dominance relations will become increasingly counterproductive with time in &permanent& agricultural landscapes. Forest composition and dominance will change with local, regional and global climates, as they always have. Long-term resilience of tropical biodiversity in highly altered agricultural landscapes must expedite dispersal processes for birds and mammals and the tree species that they disperse to ensure that such changes take place, rather than leave current dominants trapped in environments in which they are unlikely to survive.The key problem is that much of the ecology of existing tropical communities is the ecology of common species, which arguably are those best adapted to current climatic conditions. Over time scales of centuries, millennia and longer, species move, evolve or disappear with changing environments. As in the past, natural climate change alone will result in no-analog communities unlike those that exist today ( and ). In a future in which human influences on rates of climate change are compounded by human domination of landscapes, priorities for conservation and restoration must adapt. Changes in temperature, precipitation and seasonality in agricultural landscapes may even preview conditions projected over much of Africa, Asia and Central and South America by the end of this century (e.g.&scenarios RCP 4.5 and RCP 8.5, , p. 89). Fragmented forests of the present may become nurseries of relic or incipient species that can better coexist with human-dominated landscapes of a hotter future than common species of the present. For most, that future will be aborted if dispersal agents are not present to carry seeds across landscapes.
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No articles found.Cytokine-induced S-nitrosylation of soluble guanylyl cyclase and expression of phosphodiesterase 1A contribute to dysfunction of longitudinal smoot...
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):509-18. doi: 10.1124/jpet.114.221929. Epub
2014 Dec 30.Cytokine-induced S-nitrosylation of soluble guanylyl cyclase and expression of phosphodiesterase 1A contribute to dysfunction of longitudinal smooth muscle relaxation.1, 1, 1, 1, 1, 1, 1, 2.1Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia.2Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia skarnam@vcu.edu.AbstractThe effect of proinflammatory cytokines on the expression and activity of soluble guanylyl cyclase (sGC) and cGMP-phosphodiesterases (PDEs) was determined in intestinal longitudinal smooth muscle. In control muscle cells, cGMP levels are regulated via activation of sGC and PDE5; the activity of the latter is regulated via feedback phosphorylation by cGMP-dependent protein kinase. In muscle cells isolated from muscle strips cultured with interleukin-1β (IL-1β) or tumor necrosis factor α (TNF-α) or obtained from the colon of TNBS (2,4,6-trinitrobenzene sulfonic acid)-treated mice, expression of inducible nitric oxide synthase (iNOS) was induced and sGC was S-nitrosylated, resulting in attenuation of nitric oxide (NO)-induced sGC activity and cGMP formation. The effect of cytokines on sGC S-nitrosylation and activity was blocked by the iNOS inhibitor 1400W [N-([3-(aminomethyl)phenyl]methyl)ethanimidamide dihydrochloride]. The effect of cytokines on cGMP levels measured in the absence of IBMX (3-isobutyl-1-methylxanthine), however, was partly reversed by 1400W or PDE1 inhibitor vinpocetine and completely reversed by a combination of 1400W and vinpocetine. Expression of PDE1A was induced and was accompanied by an increase in PDE1A activity in muscle cells isolated from muscle strips cultured with IL-1β or TNF-α or obtained from the colon of TNBS- the effect of cytokines on PDE1 expression and activity was blocked by MG132 (benzyl N-[(2S)-4-methyl-1-[[(2S)-4-methyl-1-[[(2S)-4-methyl-1-oxopentan-2-yl]amino]-1-oxopentan-2-yl]amino]-1-oxopentan-2-yl]carbamate), an inhibitor of nuclear factor κB activity. NO-induced muscle relaxation was inhibited in longitudinal muscle cells isolated from muscle strips cultured with IL-1β or TNF-α or obtained from the colon of TNBS-treated mice, and this inhibition was completely reversed by the combination of both 1400W and vinpocetine. Inhibition of smooth muscle relaxation during inflammation reflects the combined effects of decreased sGC activity via S-nitrosylation and increased cGMP hydrolysis via PDE1 expression. Copyright (C) 2015 by The American Society for Pharmacology and Experimental Therapeutics.PMID:
[PubMed - indexed for MEDLINE] Expression of sGC and cGMP-hydrolyzing PDEs in circular and longitudinal smooth muscle and SNAP-induced stimulation of sGC and PDE5 activity. (A) Expression of sGC β1 subunit and PDE isoforms were analyzed in freshly prepared dispersed circular (CM) and longitudinal (LM) smooth muscle of colon and brain (b). Lysates containing equal amounts of total proteins were separated with SDS-PAGE, and expression of sGC β1 subunit, PDE1A, PDE2A, PDE3A, and PDE5A was analyzed using selective antibody. Membranes were reblotted to measure β-actin. Protein bands were visualized with enhanced chemiluminescence. (B) Longitudinal muscle cells were treated with different concentrations of SNAP for 5 minutes. sGC activity was measured as described in . Results are expressed as pmol cGMP/mg protein above basal levels (2.82 pmol/mg protein). Values are the means ± S.E.M. of five experiments. **P & 0.01, significant increase in sGC activity. (C) Longitudinal muscle cells were treated with different concentrations of SNAP in the presence or absence of PKG inhibitor, Rp-cGMPS (10 uM), for 5 minutes, and PDE5 activity was measured in PDE5A immunoprecipitates as described in
and expressed as cpm/mg protein above basal values (295 ± 42 cpm/mg protein). Values are the means ± S.E.M. of five experiments. **P & 0.01, significant inhibition of SNAP-stimulated PDE5 activity by Rp-cGMPS. Inset: Representative immunoblot of four different experiments. Longitudinal muscle cells were treated with different concentrations of SNAP, and PDE5A immunoprecipitates were separated on SDS-PAGE and analyzed with phospho-specific (Ser92) antibody in the Western blot.J Pharmacol Exp Ther. ):509-518.SNAP-induced cGMP generation and muscle relaxation. (A) Longitudinal muscle cells were treated with different concentrations of SNAP in the presence or absence of Rp-cGMPS (10 uM) for 5 minutes. cGMP was measured in the presence of 100 uM IBMX by radioimmunoassay and expressed as pmol/mg protein above basal levels (0.22 ± 0.04 pmol/mg protein). Values are the means ± S.E.M. of four experiments. **P & 0.01, significant increase in SNAP-induced cGMP generation by Rp-cGMPS. (B) Longitudinal muscle cells isolated from colon were treated with different concentrations of SNAP in the presence or absence of Rp-cGMPS (10 uM) for 5 minutes followed by carbachol for 30 seconds to measure initial Ca2+-dependent contraction. Smooth muscle cell contraction was measured by scanning micrometry, and relaxation was expressed as the percent inhibition of carbachol-induced contraction (basal cell length: 95 ± 4 um; carbachol-induced contraction: 31 ± 3% decrease in cell length). Values are the means ± S.E.M. of five to six experiments. **P & 0.01 significant inhibition in SNAP-induced relaxation by Rp-cGMPS.J Pharmacol Exp Ther. ):509-518.Suppression of SNAP-induced sGC activity via iNOS-mediated nitrosylation of sGC. Longitudinal muscle cells isolated from colons of control and TNBS-treated mice (A) or from muscle strips cultured in the presence of IL-1β (10 ng/ml) (B) or TNF-α (1 nM) (C) for 48 hours were treated with different concentrations of SNAP, and sGC activity was measured as described in . In some experiments, muscle strips were cultured in the presence of IL-1β (10 ng/ml) (B) or TNF-α (1 nM) (C) plus iNOS inhibitor 1400W (10 uM) for 48 hours. Basal sGC activity was not significantly different between control and TNBS-treated mice (2.61 ± 0.32 versus 2.54 ± 0.36 pmol/mg protein) or between control and cytokine-treated muscle strips (2.48 ± 0.36 versus 2.62 ± 0.36 pmol/mg protein). Values are the means ± S.E.M. of five experiments. **P & 0.01, significant inhibition of SNAP-induced sGC activity. (D) Representative immunoblot of four to five different experiments. Longitudinal muscle cells isolated from colons of control and TNBS-treated mice or from muscle strips cultured in the presence of IL-1β (10 ng/ml) or TNF-α (1 nM) for 48 hours. In some experiments, muscle strips were cultured with IL-1β (10 ng/ml) or TNF-α (1 nM) in the presence of iNOS inhibitor 1400W (10 uM) for 48 hours. Lysates were used to measure iNOS expression and S-nitrosylation of sGC (sn-sGC) as described in .J Pharmacol Exp Ther. ):509-518.Suppression of SNAP-induced cGMP levels via iNOS. Longitudinal muscle cells isolated from colons of control and TNBS-treated mice (A) or from muscle strips cultured in the presence of IL-1β (10 ng/ml) (B) or TNF-α (1 nM) (C) for 48 hours were treated with different concentrations of SNAP. In some experiments, muscle strips were cultured with IL-1β (10 ng/ml) or TNF-α (1 nM) in the presence of iNOS inhibitor 1400W (10 uM) for 48 hours. cGMP levels were measured in the presence of 100 uM IBMX as described in . Basal cGMP levels were not significantly different between control and TNBS-treated mice (0.24 ± 0.05 versus 0.21 ± 0.04 pmol/mg protein) or between control and cytokine-treated muscle strips (0.22 ± 0.04 versus 0.26 ± 0.05 pmol/mg protein). Values are the means ± S.E.M. of five experiments. **P & 0.01, significant inhibition in SNAP-induced cGMP formation.J Pharmacol Exp Ther. ):509-518.Upregulation of PDE1A expression via NF-κB and suppression of SNAP-induced cGMP levels. Longitudinal muscle cells isolated from colons of control and TNBS-treated mice (A) or from muscle strips cultured in the presence of IL-1β (10 ng/ml) or TNF-α (1 nM) (B) for 48 hours were treated with different concentrations of SNAP. Cyclic GMP levels were measured in the absence of IBMX as described in . Basal cGMP levels were not significantly different between control and TNBS-treated mice or between control and cytokine-treated muscle strips. Values are the means ± S.E.M. of five experiments. **P & 0.01, significant inhibition of SNAP-induced cGMP formation. (C) Longitudinal muscle cells in culture were treated with IL-1β for 48 hours, and expression of PDE1 isoforms was measured by real-time PCR as described in . Values are the means ± S.E.M. of five experiments. **P & 0.01, significant increase in PDE1A expression. (D) Representative immunoblot of four to five different experiments. Longitudinal muscle cells were isolated from colons of control and TNBS-treated mice or from muscle strips cultured in the presence of IL-1β (10 ng/ml) or TNF-α (1 nM) for 48 hours. In some experiments, muscle strips were cultured with IL-1β (10 ng/ml) or TNF-α (1 nM) in the presence of NF-κB inhibitor MG132 (10 uM) for 48 hours. Expression of PDE1A and PDE5 was analyzed by Western blot.J Pharmacol Exp Ther. ):509-518.Suppression of SNAP-induced cGMP formation by proinflammatory cytokines via iNOS- and NF-κB–mediated PDE1A activity. Longitudinal muscle cells were isolated from muscle strips cultured in the presence of IL-1β (10 ng/ml) or TNF-α (1 nM) for 48 hours. In some experiments, muscle strips were cultured with IL-1β (10 ng/ml) or TNF-α (1 nM) in the presence of NF-κB inhibitor MG132 (10 uM), iNOS inhibitor 1400W (10 uM), PDE1 inhibitor vinpocetine (50 uM), or 1400W in combination with MG132 or vinpocetine for 48 hours. cGMP levels in response to SNAP (10 uM) were measured in the absence of IBMX by radioimmunoassay. Values are the means ± S.E.M. of five experiments. **P & 0.01, significant inhibition compared with control SNAP-induced cGMP formation (solid bar).J Pharmacol Exp Ther. ):509-518.Increase in PDE1A activity by inflammation. (A) Longitudinal muscle cells isolated from colons of control and TNBS-treated mice or from muscle strips cultured in the presence of IL-1β (10 ng/ml) or TNF-α (1 nM) for 48 hours were used to measure PDE1A activity as described in . In some experiments, muscle strips were cultured with IL-1β (10 ng/ml) or TNF-α (1 nM) in the presence of NF-κB inhibitor MG132 (10 uM) for 48 hours. Values are the means ± S.E.M. of five experiments. **P & 0.01, significant increase in PDE1A activity compared with control. (B) Longitudinal muscle cells isolated from colons of control and TNBS-treated mice or from muscle strips cultured in the presence of IL-1β (10 ng/ml) or TNF-α (1 nM) for 48 hours were used to measure cGMP-hydrolyzing activity in the presence or absence of PDE1 inhibitor vinpocetine (50 uM). Total cGMP-hydrolyzing activity reflects the activity in the absence of vinpocetine. PDE1A activity was calculated as the percentage of total cGMP-hydrolyzing activity that was inhibited by vinpocetine. Values are the means ± S.E.M. of five experiments. **P & 0.01, significant increase in PDE1A activity compared with control.J Pharmacol Exp Ther. ):509-518.Suppression of SNAP-induced relaxation by proinflammatory cytokines and reversal of inhibition by blockade of iNOS, NF-κB, or PDE1 activity. Longitudinal muscle cells were isolated from muscle strips cultured in the presence of IL-1β (10 ng/ml) or TNF-α (1 nM) for 48 hours. In some experiments, muscle strips were cultured with IL-1β or TNF-α in the presence of 1400W (10 uM), vinpocetine (50 uM), or MG132 (10 uM) for 48 hours. Cells were treated with 10 uM SNAP for 5 minutes followed by carbachol for 30 seconds to measure initial Ca2+-dependent contraction. Smooth muscle cell contraction was measured by scanning micrometry, and relaxation was expressed as the percent inhibition of carbachol-induced contraction. Values are the means ± S.E.M. of five to six experiments. **Significant inhibition in SNAP-induced relaxation by IL-1β or TNF-α compared with control SNAP-induced relaxation (solid bar). #P & 0.05, significant reversal of inhibition by 1400W, vinpocetine, or MG132.J Pharmacol Exp Ther. ):509-518.Suppression of SNAP-induced relaxation by inflammation and complete reversal of inhibition by blockade of iNOS and PDE1 activity. Longitudinal muscle cells isolated from colons of control and TNBS-treated mice (A) or from muscle strips cultured in the presence of IL-1β (10 ng/ml) (B) or TNF-α (1 nM) (C) for 48 hours were treated with different concentrations of SNAP for 5 minutes and carbachol for 30 seconds to measure initial Ca2+-dependent contraction. In some experiments, muscle strips were cultured with IL-1β or TNF-α in the presence of both iNOS (1400W, 10 uM) and PDE1 (vinpocetine, 50 uM) inhibitors. Smooth muscle cell contraction was measured by scanning micrometry, and relaxation was expressed as the percent inhibition of carbachol-induced contraction. Values are the means ± S.E.M. of five to six experiments. **P & 0.01, significant inhibition of SNAP-induced relaxation. (D) Longitudinal muscle cells isolated from colons of control and TNBS-treated mice or from muscle strips cultured in the presence of IL-1β (10 ng/ml) or TNF-α (1 nM) for 48 hours were treated with PDE-resistant 8-Bromo-cGMP (10 uM) for 5 minutes and carbachol (1 uM) for 30 seconds to measure initial Ca2+-dependent contraction. Smooth muscle cell contraction was measured by scanning micrometry, and relaxation was expressed as the percent inhibition of carbachol-induced contraction. Values are the means ± S.E.M. of four experiments.J Pharmacol Exp Ther. ):509-518.Schematic diagram demonstrating the effects of proinflammatory cytokines on pathways that regulate cGMP levels in colonic longitudinal smooth muscle cells. In longitudinal smooth muscle, cGMP levels are regulated by the activities of sGC and PDE5; the activity of the latter is stimulated via PKG-mediated phosphorylation. Proinflammatory cytokines inhibited sGC activity via iNOS-mediated S-nitrosylation, induced PDE1A expression via NF-κB, and stimulated cGMP hydrolysis, leading to suppression of cGMP formation and a decrease in muscle relaxation.J Pharmacol Exp Ther. ):509-518.Publication TypesMeSH TermsSubstancesGrant SupportFull Text Sources
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