The content of protein in the perivascular connective tissue as a factor of permeability 1 2

Abstract

Using the vitalmicrospectrophotometric technique the protein content was measured in exposed rat mesentery at 280 nm absorbance. In intravascular circulating blood plasma there was a linear relationship between the protein content and the measured absorbance which proved the methodical reliability of the technique. In cellfree perivascular tissue the protein content was higher around venules than around capillaries and arterioles. There was a decrease in the protein content of the interstitial tissue with increasing distance from the vessel wall. This concentration gradient is highest around venules. A change in the colloidosmotic pressure of blood leads to a change of the protein content of the perivascular tissue. Accordingly a decrease in colloidosmotic pressure will result in loss of tissue protein while an increase in plasma protein will lead to an outward shift of proteins into the perivascular tissue.