Early Effects of Beta Irradiation on Dermal Vascular Permeability to Plasma Proteins

Radiation-induced changes in vascular permeability of skin have been studied by many workers, but the results are rather inconclusive (1). Until recently, injection of dye was used by the majority of workers as a means of visualizing an increase in cutaneous vascular permeability. Rigdon and Curl (2) observed an increased diffusion of circulating trypan blue into rabbit skin injected 1 hour after 680 to 2720 R of X-irradiation, and no significant change when injected 2 to 21 hours postirradiation. McCutcheon (3) suggested that vascular permeability might be increased immediately after irradiation, although the effect was extremely transient. Mount and Bruce, using I'25-rabbit serum albumin (I125-RSA) (4), reported no increase in the vascular permeability in rabbit ear until the fifth to tenth day after 8000 rads of X-irradiation; there was a twofold increase in vascular volume 24 hours after irradiation. On the other hand, Devik (5) reported no vasodilation and/or increase in vascular permeability of the skin before 5 to 7 days after 2700 R of X-irradiation of hairless mice. Because of the contradictory nature of the above findings, several series of experiments have been conducted in an attempt to further clarify the effect of ionizing radiation on the cutaneous blood vessels. The changes in vascular permeability (transfer rate) and vascular plasma volume in guinea pig skin were determined by the injection of I25-labeled plasma protein after Sr90-Y90 -irradiation.