[Fundamental study of subrenal capsule assay by measuring specific activity of succinate dehydrogenase]

It may not show accurate results if subrenal capsule assay (SRCA) is made only by measuring tumor size, because of infiltration of host inflammation cells resulted from host immune reaction. We developed a new method which make possible an accurate determination of chemosensitivity by measuring specific activity of succinate dehydrogenase (SD) of the tumor cells implanted in the subrenal capsular space. With reference to SDI test, the assay condition for measuring specific activity of SD was determined. A comparative study was carried out in which malignant tumors of the oral cavity serially transplanted in nude mice were tested with SRCA and subcutaneous transplantation assay in nude mice. Chemosensitivity to peplomycin (PEP), CDDP and 5-fluorouracil (5-FU) evaluated SSDI method and nude mouse assay showed a high correlation than those evaluated by TGIR method and nude mouse assay. The overall predictive accuracy compared with nude mouse assay was 72.2% by TGIR method and 88.9% by SSDI method. SSDI method seemed to be a useful method to evaluate the chemosensitivity in SRCA.