Estimation of Mouse Tumour Blood Volumes employing a Radioactive Isotope Technique

Abstract

CHANGES in radiosensitivity and growth-rate in a serially irradiated line of the mouse sarcoma 37 have been reported elsewhere¹. The effect of oxygen concentration on radiosensitivity has been reviewed recently by Gray² and might have contributed to the results obtained with sarcoma 37. The reduction in growth-rate in the serially irradiated line may have been due wholly, or in part, to a less-adequate development of blood vessels and capillaries within the tumour—resulting in longer diffusion paths. The evaluation of the internal vascularity of control and irradiated-line tumours was undertaken in an attempt to elucidate the causes of the observed changes. Macroscopic observations of the tumours in situ (developing on the abdominal skin) indicated a comparable increase in size of the cutaneous vessels in control and irradiated-line tumours.