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001-es BibID:BIBFORM103106
035-os BibID:(WOS)000228340800003 (Scopus)19544370693
Első szerző:Röszer Tamás (orvos, biológus)
Cím:Seasonal periodicity of enteric nitric oxide synthesis and its regulation in the snail, Helix lucorum / Tamás Röszer, Éva Kiss-Tóth, A. József Szentmiklósi, Gáspár Bánfalvi
Dátum:2005
ISSN:1077-8306
Megjegyzések:The snail Helix lucorum has been used as a model to study the adaptation of a nitric oxide (NO)-forming enteric neural network to the long-term resting period of summer estivation or winter hibernation. Quantification of the NO-derived nitrite established that NO formation is confined to the nitric oxide synthase (NOS)-containing myenteric network of the mid-intestine. In active snails but not in resting snails, NO production could be enhanced by the NOS substrate l-arginine (l-ARG, 1?mM). We followed the enteric NO synthesis in a snail population kept at natural conditions for 1 year. Our findings indicate that NO synthesis was depressed in July during entry to the estivation, had a peak in autumn before hibernation, and finally was reduced during hibernation. Monoamines (histamine, serotonin, and adrenalin) could inhibit the NO liberation in active snails. Cofactors of NOS (?-NADPH, ?-NAD, FAD, FMN, Ca2+, TH4) did not alter the low nitrite production in hibernating snails. We conclude that enteric NO synthesis in H. lucorum has a regular seasonal periodicity following the annual physiological cycles of terrestrial snails. During estivation or hibernation, NOS activity is blocked. Monoamines, the levels of which are elevated during hibernation, can trigger decreased NOS activity. The reduced activity of NOS cannot be restored by the administration of NOS cofactors; therefore, their absence cannot be the cause of the temporarily blocked L-ARG/NO conversion ability of NOS.
Tárgyszavak:Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
NADPH diaphorase
nitric oxide synthase
enteric nervous system
Helix lucorum
Megjelenés:Invertebrate Biology. - 124 : 1 (2005), p. 18-24. -
További szerzők:Kiss-Tóth Éva (1983-) (biológus) Szentmiklósi József András (1948-) (farmakológus, klinikai laboratóriumi szakorvos) Bánfalvi Gáspár (1943-) (sejtbiológus, gyógyszerész)
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DOI
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2.

001-es BibID:BIBFORM012888
035-os BibID:(Wos)000284665200006 (Scopus)78649333360
Első szerző:Röszer Tamás (orvos, biológus)
Cím:Hypothermia translocates nitric oxide synthase from cytosol to membrane in snail neurons / Tamás Rőszer, Éva Kiss-Tóth, Dávid Rózsa, Tamás Józsa, A. József Szentmiklósi, Gáspár Bánfalvi
Dátum:2010
Megjegyzések:Neuronal nitric oxide (NO) levels are modulated through the control of catalytic activity of NO synthase (NOS). Although signals limiting excess NO synthesis are being extensively studied in the vertebrate nervous system, our knowledge is rather limited on the control of NOS in neurons of invertebrates. We have previously reported a transient inactivation of NOS in hibernating snails. In the present study, we aimed to understand the mechanism leading to blocked NO production during hypothermic periods of Helix pomatia. We have found that hypothermic challenge translocated NOS from the cytosol to the perinuclear endoplasmic reticulum, and that this cytosol to membrane trafficking was essential for inhibition of NO synthesis. Cold stress also downregulated NOS mRNA levels in snail neurons, although the amount of NOS protein remained unaffected in response to hypothermia. Our studies with cultured neurons and glia cells revealed that glia-neuron signaling may inhibit membrane binding and inactivation of NOS. We provide evidence that hypothermia keeps NO synthesis "hibernated" through subcellular redistribution of NOS.
Tárgyszavak:Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
nitric oxide synthase
Megjelenés:Cell and Tissue Research. - 342 : 2 (2010), p. 191-203. -
További szerzők:Kiss-Tóth Éva (1983-) (biológus) Rózsa Dávid (1982-) (Ph.D hallgató) Józsa Tamás (1969-) (gyermeksebész, urológus) Szentmiklósi József András (1948-) (farmakológus, klinikai laboratóriumi szakorvos) Bánfalvi Gáspár (1943-) (sejtbiológus, gyógyszerész)
Internet cím:DOI
Intézményi repozitóriumban (DEA) tárolt változat
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3.

001-es BibID:BIBFORM001263
035-os BibID:(Wos)000239248000017 (Scopus)33746435763
Első szerző:Röszer Tamás (orvos, biológus)
Cím:Phe-met-arg-phe (FMRF)-amide is a substrate source of NO synthase in the gastropod nervous system / Tamás Rőszer, Éva Kiss-Tóth, Mihály Petkó, A. József Szentmiklósi, Gáspár Bánfalvi
Dátum:2006
Megjegyzések:The possible involvement of the L-arginine-containing Phe-met-arg-phe (FMRF)-amide (FMRFa) in neuronal nitric oxide (NO) biosynthesis was studied in a gastropod species. We found NADPH-diaphorase-positive neurons and FMRFa-containing fibers in close proximity in the enteric nervous system. Administration of L-arginine and FMRFa induced quantitatively similar nitrite production in both intact intestinal tissues and tissue homogenates. These changes could be prevented by the presence of NOARG (an NO synthase inhibitor). Neither chemically modified FMRFa (D-arginine instead of L-arginine) nor amino acid constituents of FMRFa (methionine, phenylalanine) affected basal nitrite production. FMRFa-induced alterations were reduced in the presence of Na+ channel blockers (tetrodotoxin, amiloride, lidocaine), the Na+/K+ATPase inhibitor ouabain, or protease inhibitors (leupeptine, pepstatine-a). FMRFa and its amino acid constituents were analyzed by paper chromatography. When FMRFa was added to tissue homogenates, the peptide was eliminated within 1-2 min, whereas methionine, phenylalanine, arginine, and citrulline levels were elevated simultaneously. We tested the effects of FMRFa, L-arginine, and NOARG on intestinal contractile activity. FMRFa relaxed the intestine for 1-2 min and then induced contractions for 20-40 min. In the presence of NOARG, no relaxant effect of FMRFa was recorded. As administration of L-arginine strongly inhibits the mechanical activity of the intestinal muscle, NO production presumably plays a substantial role in the action of FMRFa, at least in the initial phase. Our biochemical data indicate a direct involvement of FMRFa in NO biosynthesis. FMRFa might be hydrolyzed by extracellular peptidases and then the locally released arginine might be transported into the cells and broken-down to produce NO. Depolarization-induced NO production attributable to the activation of amiloride-sensitive Na+ channels might also be involved.
Tárgyszavak:Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
neuropeptid NO szintáz szubsztrát
Megjelenés:Cell and Tissue Research. - 325 : 3 (2006), p. 567-575. -
További szerzők:Kiss-Tóth Éva (1983-) (biológus) Petkó Mihály (1943-) (orvos, neurobiológus) Szentmiklósi József András (1948-) (farmakológus, klinikai laboratóriumi szakorvos) Bánfalvi Gáspár (1943-) (sejtbiológus, gyógyszerész)
Internet cím:elektronikus változat
DOI
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