Effect of a Bacterial Polysaccharide and of Several Other Tumor-Necrotizing Agents on Carotid Blood Pressure in Mice2

Abstract
The effect of several tumor-necrotizing agents on systemic blood pressure in mice was studied by a method that permitted continuous recording of pressure directly from the carotid artery. The polysaccharide from Serratia marcescens did not depress the blood pressure immediately. When the continuous recording was prolonged for hours, a gradual fall of blood pressure was observed in the control as well as in the treated mice. However, when the recording was limited to a half-hour period a significant fall was not produced within the first 6 hours after administration of polysaccharide. Analogously, the tracings obtained in mice treated with podophyllotoxin, colchicine, and several of their derivatives showed no evidence of induced fall of blood pressure on comparison with the tracings yielded by the controls. The production by these drugs of a sustained systemic hypotension, which had been postulated as a necessary prerequisite for their elicitation of hemorrhagic necrosis in tumors, is not supported by this study.