Abstract

Ultrafiltration studies have shown that rose bengal and bromsulphalein, dyestuffs that are excreted in the bile, and bilirubin are in vitro completely bound to the proteins of the blood. Sodium taurocholate exerts a marked activity in the liberation of these substances from the proteins.

Phenolsulphonephthalein circulates in the blood partly bound of the proteins. Bile salts are also capable of freeing the bound portion of this dye, so that in vitro it becomes almost entirely diffusible.

Sodium taurocholate possesses the property of increasing the degree of permeability of semipermeable collodion membranes to dyestuffs.

These properties of the bile salts indicate their physiological function in the liberation from a bound state of substances that are combined with the body proteins, and suggest a further influence upon membrane permeability.