[Effect of chemotherapy on the interstitial tissue of a malignant human tumor transplanted into nude mice, with reference to microvessels].
Experimental chemotherapy of cyclophosphamide (CPA) was performed on a human malignant hemangiopericytoma serially transplanted into nude mice with a genetic background of BALB/c and the changes or histological findings and microangiograms (MAG) were investigated. The treatment was performed 2 weeks after tumor inoculation. Either 120 mg/kg or 240 mg/kg of CPA, dissolved in 0.2 ml of physiological saline, was administered once intraperitoneally. On days 1, 2, 4 and 7 after the treatment, mice were sacrificed and each tumor was examined in terms of histological findings and MAG. Although the tumors treated with 120 mg/kg of CPA were suppressed temporarily, the regrowth of the tumors were observed. The tumors treated with 240 mg/kg of CPA regressed without any regrowth. From the observations of MAG, the former showed an avascular area on day 4 after the treatment and the tumor vessels regenerated on day 7 after the treatment. On the other hand, in the latter group, it was found that the normal vascular network developed after the formation of an avascular area 2 days after the treatment. From the histological findings, the former showed to reduce mitotic indeces of 1 or 2 days after the treatment, however the mitotic indeces were found to recover 7 days after the treatment. Mitotic indeces of tumors treated with 240 mg/kg of CPA were observed to be depressed after the treatment. These results suggested that the changes of interstitial tissue were closely correlated well with the destruction and regrowth of tumor cells observed by the growth curve and histological findings. Tumor vessels were thought to play an important role in the cancer chemotherapy, not only as the transport systems of drugs but also as the target of antitumor agents.
D000818:Animals; D002196:Capillaries / Q000187:drug effects / Q000473:pathology; D003520:Cyclophosphamide / Q000494:pharmacology*; D006393:Hemangiopericytoma / Q000098:blood supply* / Q000188:drug therapy / Q000473:pathology; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000098:blood supply / Q000188:drug therapy / Q000473:pathology
D003520:Cyclophosphamide