抗癌剤の効果増強策に関する実験的研究

第1編抗癌剤の腫瘍塊内侵達性に対する線維素溶解酵素の影響に関する実験的研究.

抄録

It is needless to say that chemotherapy is playing a very important role in the treatment of tumor. However, at present we must admit that no ideal drug specifically killing tumor cells without ill effects on normal cells is available. We therefore must devise some method to make present anti-tumor drugs manifest their effect maximally. Side effects, the sensitivity of tumor cells to the drugs and lack of penetration of drugs into tumor masses and cells are given as factors preventing presently available antitumor drugs from manifesting their maximum effect. Mentioning only the last factor, the route of administration of anti-tumor drugs is very important; for example, injection directly into the blood vessels controling the tumor. Tumor bearing hosts are generaly characterized by a tendency toward coagulability and reduced tendency toward fibrinolytic activity. Fibrin deposition and thrombus formation are apt to occur in tumor masses in relation to these host change s and a barrier is made by fibrin deposition around tumor masses. For such reasons, the anti-tumor drugs in use are thought to be prevented from penetrating tumor masses. Accordingly the skilful manipulation of fibrinolytic phenomena and anticoagulants may be regarded as promising measures. It is desirable to activate fibrinolytic ability as well as to suppress hypercoagulability so that antitumor drugs may penetrate tumor masses easily. We examined the ability of fibrinolytic enzyme to potentiate penetration of anti-tumor drugs into tumor masses. Two interesting findings are presented below: 1) The fibrinolytic enzyme was able to potentiate penetration of the anti-tumor drugs into tumor masses.2) The incorporation of 125I-fibrinogen into tumor masses was greater than in healthy tissues and this could be reduced by fibrinolytic enzyme.