A STUDY OF CAPILLARY PERMEABILITY IN EXPERIMENTAL BURNS AND BURN SHOCK USING RADIOACTIVE DYES IN BLOOD AND LYMPH 1

Abstract

Capillary permeability was studied in dogs by injecting radioactive colloids into the blood stream and measuring their appearance in the lymph from various areas. The colloids represent tagged molecules and their conc. in the lymph is a function of capillary permeability. Radioactive brominated di-azo dyes which form a bond with plasma proteins, and brominated and iodinated radioactive plasma proteins were used. Radioactive bromide ion is found in the leg, cervical, and thoracic lymph within 5 mins. after intraven. inj.; in 20 mins., radioactive equilibrium has been reached between these lymphs and the blood serum. This observation indicates the rapidity with which an inorganic ion traverses the capillary membrane and the interstitial space. In contrast, the rise in conc. of radioactivity in the lymph following inj. of the radioactive colloids is slow and equality is not reached under control conditions. Following a hot water burn of a leg, the conc. of radioactive colloids in the lymph from this leg rises abruptly and approaches that encountered after inj. of the inorganic ion. This indicates that in a pathologic state the capillary membrane may become as permeable to colloids as it formerly was only to ions. The ratio of conc. of radioactivity to conc. of protein (specific activity) furnishes a measure of the extent to which equilibrium has been reached in the distr. of the tagged protein in the body fluids. Under control conditions, equal specific activities are eventually reached on either side of the capillary membrane. Following a burn, a specific activity higher in the lymph than in the blood serum may be observed, indicating a preferential escape through the capillary wall of one fraction of the plasma protein. Evidence of increased capillary permeability, in an area remote from the burn, appeared in only one expt. late in shock. Adrenal cortical extract injected intraven. exerted no detectable effect on either local or remote changes in capillary permeability.