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Assessment of tumor redox status in mice with magnetic resonance imaging: Nitroxides as functional redox-sensitive contrast agents
https://repo.qst.go.jp/records/68594
https://repo.qst.go.jp/records/685949d02e1b1-e0d5-47b3-9015-0ab15297609a
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2006-07-19 | |||||
| タイトル | ||||||
| タイトル | Assessment of tumor redox status in mice with magnetic resonance imaging: Nitroxides as functional redox-sensitive contrast agents | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Matsumoto, Kenichiro
× Matsumoto, Kenichiro× et.al× 松本 謙一郎 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | The pharmacokinetic behavior of the nitroxide paramagnetic contrast agent 3-carbamoyl Proxyl (3CP) in squamous cell carcinoma (SCCVII tumor) implanted in a hind leg of C3H mice was measured using electron paramagnetic resonance imaging (EPRI) and magnetic resonance imaging (MRI). Nitroxides have, in general lower relaxivity (~ 0.2 mM-1s-1) than the widely used gadolinium complexes (4.0 mM-1s-1). Relatively lower relaxivity of nitroxides in MRI gives a reliable linear response between the concentration and intensity enhancement compared to agents with higher contrast. Phantom studies showed that the nitroxide, 3CP undergoes time-dependent reduction to the corresponding diamagnetic hydroxylamine in the presence of a chemical reducing agent such as ascorbic acid. The reduction rates of 3CP obtained by both EPRI and MRI from phantom studies were in good agreement suggesting the feasibility of using MRI to monitor the nitroxide levels in tissues. In vivo experiments showed a T1-dependent image intensity enhancement afforded by 3CP that decreased in a time-dependent manner. Though reduction and clearance can contribute to loss in contrast-mediated image intensity, reduction of the 3CP was found to be the dominant mechanism of contrast loss over the imaging times. In both EPRI and MRI, the reduction rates of 3CP computed from a sequence of images obtained as a function of time, the tumor-bearing leg exhibited a faster decay of the nitroxide compared to the normal leg. The reduction rates of the 3CP determined by both EPRI and MRI from in vivo experiments were in agreement. The combination of T1-weighted SPGR based MRI and redox-sensitive nitroxide contrast agents can provide tissue redox mapping with improved spatial and temporal resolutions compared to EPRI. The tissue redox status derived from MRI/nitroxide studies can be co-registered with anatomic images providing potentially valuable biochemical information from the tissue of interest. | |||||
| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | アメリカ癌学会第９７回年会 | |||||
| 発表年月日 | ||||||
| 日付 | 2006-04-05 | |||||
| 日付タイプ | Issued | |||||
