A STUDY OF THE DIGITOXIN BINDING POWER OF SERUM AND OTHER SOLUBLE TISSUE-PROTEINS OF THE RABBIT

¹ Departments of Biochemistry, Pharmacology and Physiology, American University of Beirut, Lebanon

Rabbit serum protects the isolated frog heart against digitoxin, this protective action being solely attributable to the albumen fraction. Furthermore this protective action is directly proportional to the protein content of the solution. This quantitative relationship, as well as the results of our dialysis experiments, indicate that the mechanism of the protective action lies in a combination of digitoxin with serum albumen, which can be split and the digitoxin recovered quantitatively by treatment with alcohol. Rabbit serum globulin and serum lipoids, as well as the soluble proteins of the heart, liver and striated muscle, show no protective action against digitoxin.