NAKAJIMA Shunichi Niigata University, School of Dentistry, Assistant, 歯学部, 助手 (70143790)
ASHIKAGAYA Misa Niigata University, School of Dentistry, Assistant, 歯学部, 助手 (70212496)
佐藤 正治 新潟大学, 歯学部, 助手 (50215844)
|Budget Amount *help
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1994 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1993 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1992 : ¥800,000 (Direct Cost : ¥800,000)
In vivo 31P-MR spectroscopy was performed on experimental cancers transplantedin animals. 31P-MR spectra of tumors transplanted in the submucosal tissue of the buccal pouch of hamsters were obtained using of a JEOL JMN-GX270 spectrometer with a JEOL NM-G27TSPW surface coil probe. Tumors transplanted were derived from cultured tissues obtained from lymphatic metastatic foci from cancers induced with DMBA in the buccal pouch of hamsters. Following parameters were evaluated. 1) PME/total, 2) Pi/total, 3) PDE/total, 4) PCr/total, 5) ATP/total, 6) PCr/Pi, 7) PCr/ATP,8) PME/ATP,9) PDE/ATP,10)PDE/PME,11) PME/Pi, 12) PDE/Pi, 13) Pi/ATP,14) pHi. Results : In none of 31MR spectroscopy on the buccal pouch mucous membrane of 10 hamsters as the control group, any significant peaks were obtained. In the tumorgroup (12 tumors) ATP (alpha, beta, gamma), PCr, Pi, PME,PDE peaks were obtained. PCr/total, PCr/Pi, PCr/ATP ratios decreased as tumors increaed in size whereas PDE/total ratio increased in proportion to increase in tumors size. There was no sig-nificant correlation between the tumor size and other parameters.
Discussion : PCr definitely decreased with incease in tumor size. This indicated that tumors were evolving into the hypoxic state with tumor growth. There was nosignificant correlation between tumor growth and pHi. This suggested that tumorswere not in the anaerobic state with necrosis but rather in the state where the accumulation of lactic acid as an anaerobic metabolite was not enough to cause areduction in a pH.Increase in PDE suggested an acceleration in membrane metabo-lism. However, in this study the degree of resolution between PDE and PME was not sufficiently sharp to indicate accurate mambrane metabolism.
conclusions : In 31MR spectroscopy of the normal contro group there were no significant peaks obtained. In the tumor group ATP,PCr, Pi, PME,PDE peaks were obtained. PCr/total, PCr/Pi, PCr/ATP ratioes decreased with tumor growth.