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Astronomische Nachrichten, t. 189, nos 4513-4536
No full textF. G. Astronomische Nachrichten, t. 189, nos 4513-4536. In: Bulletin astronomique, tome 30, 1913. pp. 510-536
RADIOLYSIS OF C-11-Ro 15-4513 IN AN AQUEOUS SOLUTION
No full textAIMS: Recent development of PET radiopharmaceutical production technique has made it possible to prepare C-11 labelled compounds with extremely high specific activity (more than 10 Ci/_mol). C-11-Ro 15-4513 has been used for benzodiazepine receptor imaging and recently is needed to be labelled with such an extremely high specific activity to image high affinity binding site. However, large amount of radioactivity and extremely high specific activity might cause the possibility of radiolysis. Therefore we investigated the mechanism of radiolysis of C-11-Ro 15-4513 to suppress the decomposition of C-11-Ro 15-4513 in aqueous solution.
METHODS: C-11-Ro 15 4513 was prepared by C-11 methylation of desmethy precursor with C-11-CH3I. After purification with HPLC system (column: C-18, mobile phase: 40% CH3CN), C-11-Ro 15-4513 fraction was evaporated to dryness and C-11-Ro 15-4513 was dissolved in pure H2O. C-11-Ro 15-4513 solution was allowed to stand to give degradation product. And the degradation products were estimeted with decomposed samples of authentic Ro 15-4513 solution by Co-60 or UV photolysis by comparing with those retention time. Chemical structure of degrdation products was estimeted with LC/MS. Effect of additives (MeOH, EtOH, HCOONH4, NaNO3, etc) on radiolysis of Ro 15-4513 was also examined.
RESULTS: C-11-Ro 15-4513 solution underwent radiolysis to give one major and another minor radioactive degradation product. The major degradation product had same retention time with that of degradation product with Co-60. And minor degradation product was corresponded to degradation product by UV photolysis. The structure of degradation product by radiolysis and photolysis was estimated that azido group in Ro 15-4513 was displaced by amine and hydroxylamine group respectively from mass spectra. From the examination of radiolysis with Co-60 and radiolysis of C-11-Ro 15-4513 in the presence of additives, addition of selective hydroxyradical scavenger such as MeOH and EtOH accelerated the radiolysis of Ro 15-4513. In contrast the radiolysis was effectively suppressed by addition of selective hydrated electron scavenger (e.g. NaNO3), suggesting a possibility that hydrated electron would play important role to the radiolysis of C-11-Ro 15-4513.
CONCLUSION: From this investigation addition of selective hydroxyl radical scavenger accelerated the radiolysis of C-11-Ro 15-4513, in contrast the radiolysis was suppressed perfectly by addition of selective hydrated electron scavenger. These results would suggest the participation of hydrated electron to the radiolysis of Ro-15-4513.Ninth International Worksshop on Targetry and TargetChemistryconference objec
Block Card 4513 Willys Parkway
No full textThis image was produced by the Auditor's Office in Lucas County, Ohio for tax assessment purposes. Associated dates are approximate. Descriptive terms related to this photograph include: Dwelling (Toledo, Ohio) | Tudor Revival | Homeville Subdivision (Toledo, Ohio) | Willys Park area (Toledo, Ohio) | West Toledo (Toledo, Ohio) | 4513 Willys Parkway (Toledo, Ohio
Decomposition of an aqueous solution of [11C]Ro 15-4513: implication of hydrated electrons in the radiolysis of[11C]Ro 15-4513
No full textAn aqueous solution of [11C]Ro 15-4513 underwent decomposition to give a few radioactive degradation products. The major degradation product corresponded to that of authentic Ro 15-4513 with 60Co radiolysis, which showed a molecular weight of 301(M+H). The structure of this degradation product was estimated to have an amine group instead of an azido group on Ro 15-4513. Radiolysis of Ro15-4513 was not suppressed by the addition of selective hydroxyl radical scavenger (MeOH,HCOO-), in contrast,it was suppressed effectively in the presence of a selective hydrated electron scavenger (NaNO3), suggesting that hydrated electrons would play an important role in the radiolysis of [11C]Ro 15-4513.journal articl
Block Card 4513 McKain Drive
No full textThis image was produced by the Auditor's Office in Lucas County, Ohio for tax assessment purposes. Associated dates are approximate. Descriptive terms related to this photograph include: Ranch houses | 4513 McKain Drive (Toledo, Ohio) | Dwelling | Greenbush Knolls Addition (Toledo, Ohio) | Trilby Area (Toledo, Ohio)
Ro 15-4513 antagonizes alcohol-induced sedation in mice through alpha-beta-gamma2-type GABAA receptors
No full textEthyl alcohol (ethanol) has many molecular targets in the nervous system, its potency at these sites being low compared with those of sedative drugs. This has made it difficult to discover ethanol’s binding site(s). There are two putative binding sites at gamma-aminobutyric acid (GABA) type A receptor subtypes for the proposed ethanol antagonist Ro 15-4513, the established gamma2 subunit-dependent benzodiazepine site and the recently reported delta subunit-dependent Ro 15-4513/ethanol binding site. Here, we aimed at clarifying the in vivo role of Ro 15-4513 at these two sites. We found that the antagonism of ethanol actions by Ro 15-4513 in wildtype mice was dependent on the test: an open field test showed that light sedation induced by 1.5-1.8 g/kg ethanol was sensitive to Ro 15-4513, whereas several tests for ethanol-induced anxiolytic effects showed that the ethanol-induced effects were insensitive to Ro 15-4513. Antagonism of ethanol-induced sedation by Ro 15-4513 was unaffected in GABAA receptor delta subunit knockout mice. By contrast, when testing the GABAA receptor gamma2 subunit F77I knock-in mouse line (gamma2I77 mice) with its strongly reduced affinity of the benzodiazepine sites for Ro 15-4513, we found that the ethanol-induced sedation was no longer antagonized by Ro 15-4513. Indeed, gamma2I77 mice had only a small proportion of high-affinity binding of [3H]Ro 15-4513 left as compared to wildtype mice, especially in the caudate-putamen and septal areas, but these residual sites are apparently not involved in ethanol antagonism. In conclusion, we found that Ro 15-4513 abolished the sedative effect of ethanol by an action on gamma2 subunit-dependent benzodiazepine sites
Mechanistic and Functional Divergence Between Thyrotropin-releasing Hormone and RO 15-4513 Interactions with Ethanol
Get PDFBoth thyrotropin-releasing hormone (TRH) and RO 15-4513 antagonize ethanol-induced depression, but this common property does not infer that both compounds share similar mechanisms of action. In the present studies, both TRH (30 mg/kg, i.p.) and RO 15-4513 (10 mg/kg, i.p.) reversed ethanol-induced depression of locomotor activity, in accord with previous reports. However, the benzodiazepine antagonist, RO 15-1788, blocked this action of RO 15-4513, while exerting no effect on the analeptic action of TRH. Using a model of seizure activity electrically elicited from the inferior colliculus, ethanol exerted a dose-related attenuation of seizure activity. This anticonvulsant action of ethanol was not altered by TRH (30 mg/kg, i.p.), but RO 15-4513 (3 mg/kg) reversed the effect of the 0.5, but not the 1.0 g/kg, dose of ethanol. In addition, pretreatment with RO 15-4513 (1 or 3 mg/kg, i.p.), but not TRH (30 mg/kg, i.p.), caused seizure generalization into the forebrain following inferior collicular stimulation, further verifying the proconvulsant properties of RO 15-4513. In conclusion, the analeptic action of TRH appears independent of benzodiazepine activity, and in contrast to RO 15-4513, TRH does not exhibit proconvulsant properties. Furthermore, because TRH did not antagonize both depressant actions of ethanol studied, it appears unlikely that TRH directly interacts with the molecular basis of ethanol action
Using [11C]Ro15 4513 PET to characterise GABA-benzodiazepine receptors in opiate addiction: Similarities and differences with alcoholism
Get PDFThe importance of the GABA-benzodiazepine receptor complex and its subtypes are increasingly recognised in
addiction. Using the α1/α5 benzodiazepine receptor PET radioligand [ 23 11C]Ro15 4513, we previously showed reduced
binding in the nucleus accumbens and hippocampus in abstinent alcohol dependence. We proposed that 24
reduced [ 25 11C]Ro15 4513 binding in the nucleus accumbens was a marker of addiction whilst the reduction in hippocampus
and positive relationship with memory was a consequence of chronic alcohol abuse. To examine this 26
further we assessed [ 27 11C]Ro15 4513 binding in another addiction, opiate dependence, and used spectral analysis
to estimate contributions of α1 and α5 subtypes to [ 28 11C]Ro15 4513 binding in opiate and previously acquired alcohol-dependent
groups. Opiate substitute maintained opiate-dependent men (n = 12) underwent an [ 29 11C]Ro15
4513 PET scan and compared with matched healthy controls (n = 13). We found a significant reduction in 30
[ 31 11C]Ro15 4513 binding in the nucleus accumbens in the opiate-dependent compared with the healthy control
group. There was no relationship between [ 32 11C]Ro15 4513 binding in the hippocampus with memory. We
found that reduced [ 33 11C]Ro15 4513 binding was associated with reduced α5 but not α1 subtypes in the opiate-dependent
group. This was also seen in an alcohol-dependent group where an association between memory 34
performance and [ 35 11C]Ro15 4513 binding was primarily driven by α5 and not α1 subtype. We suggest that reduced
α5 levels in the nucleus accumbens are associated with addiction since we have now shown this in depen- 36
dence to two pharmacologically different substances, alcohol and opiates
Linked collectors and determiners for: University of Lethbridge Herbarium (LEA).
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