抄録
VX2 carcinoma cells were transplanted onto rabbit tongues to investigate the nature of tumor blood vessels and the effect of anticancer agents on VX2 carcinoma.
Ultrastructural observations, microangiography, and injection replica scanning electron microscopy were performed. Blcomycin (3 mg/kg/day) was given by intravenous injection daily for 15 days.
The results obtained were as follows:
1. The structure of the newly formed tumor blood vessels was different from that of normal vessels.
2. Ultrastructurally, normal blood vessels in the tongue were of a continuous type. On the other hand, fenestration and endothelial discontinuity (gaps) were observed in the tumor blood vessels. Investigation of the vascular resin cast showed that buds arose from host vessels, which then fused to form cross connections and ultimately intricate networks.
3. Application of Bleomycin had remarkable effects on the vessels. Ultratructurally, Bleomycin caused endothelial discontinuities to be enlarged markedly. Protrution of the cytoplasm, degenerative changes of the endothelium, multilayering of the basement membrane were also observed. Microangiographically, destruction and disappearance of vessels, fragmented vascularity, and narrowed vessels were found. Vascular resin casts revealed surface irregularity and intricate network decrease.
4. These results were interpreted to indicate that this anticancer agent damages the vascular system. This obstruction has harmful influence on the localized circulation within the carcinoma.
This harmful effect seemed to be an important factor for controling tumors in the clinical practice.
