Effect of Anti-Inflammatory Compounds on Beta-Irradiation-Induced Increase in Vascular Permeability

The ability of anti-inflammatory compounds to suppress an increase in vascular permeability to plasma protein in guinea pig skin following 3000 rep of β-irradiation has been studied. To assess the vascular permeability to plasma protein,¹²⁵ I-labeled serum albumin was injected into the heart immediately after irradiation, animals were killed 18 hours later, and the amount of¹²⁵ I-labeled albumin in epidermis and dermis was measured. Anti-inflammatory compounds were given to animals 1 hour before and 9 hours after irradiation. Pronounced suppression of increase in vascular permeability to plasma protein (up to 18 hours) was observed with Cl-583, indomethacin, promethazine HCl, and ε-amino-n-caproic acid, the effectiveness decreasing in the order cited, based on the milligrams per kilogram of body weight given. Triamcinolone and chloroquine diphosphate showed slight but insignificant effect. The relation of these results to suggested mediators of the inflammatory reaction was discussed.