[Functional characterization of microcirculation in tumors: chemotherapeutic implications].

This report describes some aspects of tumor vessels and the functional characteristics of tumor microcirculation with regard to selective increase in tumor blood flow. Elevation of the mean arterial blood pressure to about 150mmHg by angiotensin II resulted in a several-fold increase in blood flow in tumor tissues without increasing blood flow in normal tissues. Pressure elevation by angio-tensin II also selectively increased tumor blood flow in intra-corneally transplanted microfoci and influx of lymph flow from the primary lesion to lymph node metastatic lesions. New techniques for analyzing microhemodynamics of tumor vessels showed that the vascular level in tumor tissues and the hydrostatic pressure difference between the tumor vessels and extravascular tissue were enhanced. Thus a new approach to cancer chemotherapy (ATII-induced hypertension chemotherapy) has been demonstrated in which the delivery to tumor tissue of systemically administered anticancer drugs can be selectively enhanced.