3 0 0 0 OA 空間ガンマ線量率への黄砂の影響
- 著者
- 河野 彬 原 泰寛 菅田 節朗 加留部 善晴 松島 美一 石塚 秀夫
- 出版者
- The Pharmaceutical Society of Japan
- 雑誌
- Chemical and Pharmaceutical Bulletin (ISSN:00092363)
- 巻号頁・発行日
- vol.31, no.1, pp.175-178, 1983-01-25 (Released:2008-03-31)
- 参考文献数
- 20
- 被引用文献数
- 77 93
Activities of pyrimidine nucleoside phosphorylases were assayed in extracts of human tumors, normal tissues of the same organs and tumors of mice (Sarcoma-180) and guinea pigs (Line-10), with thymidine (dThd), uridine (Urd), and 5'-deoxy-5-fluorouridine (5'-DFUR) as substrates. The nucleoside cleaving activities were higher in extracts of human tumor tissues than in those of normal tissues of the same organs. In human tissues, phosphorolytic activitiy towards dThd was high, while that towards Urd was low. In animal tumors, Urd was the best substrate. 1-(2'-Deoxy-β-D-glucopyranosyl)-thymine (GPT), a specific inhibitor of uridine phosphorylase, inhibited the phosphorolysis of Urd and 5'-DFUR in extracts of animal tumors, but not that of dThd and 5'-DFUR in extracts of human tumors. A thymidine phosphorylase preparation was partialy purified from human lung cancer. Km values of the preparation were 2.43×10-4 M and 1.69×10-3 M for dThd and 5'-DFUR, respectively. We conclude that in human tumors a thymidine phosphorylase activity converts 5'-DFUR to 5-fluorouracil, an activated form.
- 著者
- 菅田 節郎 河野 彬 原 泰寛 加留部 善晴 松島 美一
- 出版者
- The Pharmaceutical Society of Japan
- 雑誌
- Chemical and Pharmaceutical Bulletin (ISSN:00092363)
- 巻号頁・発行日
- vol.34, no.3, pp.1219-1222, 1986-03-25 (Released:2008-03-31)
- 参考文献数
- 16
- 被引用文献数
- 5 11
A thymidine phosphorylase (TP) preparation was partially purified from human gastric cancer (poorly differentiated adenocarcinoma). The specific activity of the final preparation represented a 379-fold purification of the 7000g supernatant of tissue homogenate. The phosphorolytic activities toward thymidine (dThd), 5'-deoxy-5-fluorouridine (5'-DFUR), and 1-(tetrahydro-2-furanyl)-5-fluorouracil (Tegafur) remained closely in parallel during the whole purification procedure. The results provide evidence in support of the assumption that 5'-DFUR and Tegafur are converted into 5-fluorouracil, an activated form of the antitumor agents, in humn tumor tissues by a TP activity. The values of Km of the TP preparation were 1.68×10-4, 1.72×10-3, 1.33×10-2, and 4.76×10-2M for dThd, 5'-DFUR, Tegafur, and uridine, respectively.