前立腺癌に関する研究 3.抗男性ホルモン療法における血中testosteroneとtestosterne-estradiol binding globulin(TeBG) の変動について

Abstract

For 18 cases of carcinoma of the prostate pathohistologically proved at the Hiroshima University Hospital, castration was performed followed by estrogen therapy or by radiotherapy. Plasma testosterone and testosterone-estradiol binding globulin(TeBG)levels were measured in terms of each treatment. Effects of anti-androgenic agents on the binding of TeBG with testosterone were investigated in in vitro system. The following results were obtained. 1) Castration brought a remarkable reduction of plasma levels of testosterone and a rise of TeBG to 120% of the pre-castration level. After 20 days administration of DES-diphosphate 500 mg per day, some cases showed striking reduction of testosterone level plasma to the non-measurable level, whereas TeBG rose to approximately 2.5 times of pre-treatment level. In the group receiving radiotherapy, plasma testosterone remained at the level of post-castration whereas TeBG also remained at an increased 128% of pre-treatment level, which was almost the same as post-castration level. 2) In vitro study demonstrated an effect of cyproterone acetate on binding of TeBG with testosterone, but no effect of DES-diphosphate, stilbestero1 or spironolactone. Therefore, striking rise of TeBG in prostatic cancer patients on DES-diphosphate administration cannot be explained by binding of TeBG with stilbestrol, an active form of DES-diphosphate. Promoted production of TeBG by liver cells is suggested. Its increased part might bind with unbound testosterone in blood and active form of androgen may decrease. This may explain potent antiandrogenic action.