SUYAMA Kazuho Kitasato Univ. Med. Assistant, 医学部, 助手 (70226611)
MUKAI Nobuya Kitasato Univ. Med. Assistant, 医学部, 助手 (30200231)
GO Mikitoshi Kitasato Univ. Med. Assistant, 医学部, 助手 (10195919)
KAWAKAMI Tatsuo Kitasato Univ. Med. Assistant, 医学部, 助手 (80195049)
AO Teruaki Kitasato Univ. Med. Assistant, 医学部, 助手 (30150907)
|Budget Amount *help
¥6,500,000 (Direct Cost : ¥6,500,000)
Fiscal Year 1992 : ¥300,000 (Direct Cost : ¥300,000)
Fiscal Year 1991 : ¥6,200,000 (Direct Cost : ¥6,200,000)
We established LNCaP tumor in male nude mice after inoculation of LNCaP cells (American Type Culture Collection). The tumor produces the organ-specific glycoproteins in the human prostate, prostatic acid phosphatase (PAP) and gamma seminoprotein, which were verified by immunohistochemistry and by enzyme immuno assay.
The monoclonal antibody to PAP (Cosmo Bio.) was radio-labeled with iodine-125 (I-125) by lactoperoxidase method and free I-125 was separated by passage over column chromatography (Sephadex G-75). The I-125 labeled antibody (1043 KBq/30 mug) was injected into the tail vein. The mice were sacrificed 2, 3, 4, 6 and 7 days after injection. Then the whole-body autoradiograms were obtained by slicing the mice into 40 mum using an autoradiography cryostat OT/SEA (Bright). In addition, the radioactivities of various organs, including the tumor, blood, liver, kidney, spleen, were determined by the well type gamma counter (ARC601, Aloka). The label uptakes by organs were expressed as F-value (%), which was calculated by the following formula: F= radioactivity per gram of organ (dpm/g) * injected dose per gram of animal (dpm/g) X 100.
Specific uptake in the LNCaP tumors was observed on whole-body autoradiograms, with optimal images of the tumors evaluated at 6 and 7 days after administration. Significantly high radioactivity in the background (blood, liver, kidneys) at 2 days and relatively high radioactivity in the background were observed at 3, 4 days after injection. The F-values evaluated at 3 days after injection were 33.6 for tumor, 13.1 for blood, 5.8 for liver and 9.3 for kidney, while those evaluated at 6 days were 7.7 for tumor, 5.2 for blood, 4.0 for liver and 3.8 for kidney respectively. Further studies are being undertaken now and the results will be published.