Studies on the Exchange of Fluids Between Host and Tumor. III. Regulation of Blood Flow in Hepatomas and Other Rat Tumors

Abstract

The response of the vascular net of hepatomas and other rat tumors to epinephrine, acetyl-ß-methylcholine, cold, and ganglionectomy has been studied in ovarian and renal “tissue-isolated” transplants. With this technique the vascular response of the tumor can be separated from the response of the vascular net of the host. Under the action of the stimuli tested, the vessels of a tumor behaved like the vessels of the host organs, even when the tumor was 200-fold larger, and no residue of the host-tissue was demonstrable in the histologic sections. Acetyl-β-methyl-choline produced an increase of blood flow in tumors, the other stimuli produced a drop in the blood supply. The transformation of the vascular tree of the host into the vascular tree of the tumor was followed by the preparation of vinylite casts of the blood vessels. By this technique it was possible to demonstrate that the main vascular branches which supply the host organ became the main vascular branches which supply the tumor. These vessels do not increase in number but greatly increase in length and diameter. The vessels of a regenerating liver behaved in the same manner.