The Effect of Hyaluronidase on the Absorption of Parenterally Administered Radioactive Plasma Proteins in the Dog 1

There are numerous circumstances in which it would be desirable to administer substances sub- cutaneously, intramuscularly or intraperitoneally that cannot or should not be given intravenously. Since the need for parenterally administered protein and fat is one of the most urgent problems in clinical medicine, we felt it worthwhile to ex- plore the possibility of facilitating their absorption from the tissues by the use of hyaluronidase,2 a non-antigenic "spreading factor" first isolated from the testicle (1-3). Sannella (4) observed that this enzyme hastened the absorption of saline solution from the subcutaneous tissues of the rab- bit. Hechter (5) found this to be true also in man, not only for saline solution but for plasma as well. Studies were therefore undertaken for a more pre- cise determination of the facts for plasma by the use of plasma tagged with radioactive iodine. Similar observations with respect to fat will be reported (6).