Long-Term Transplants of Infantile Rat Pituitaries cultivated in vitro and grafted in the Anterior Eye Chamber of Young Cats

DURING the past few years, we have made a number of attempts to obtain successful grafts between widely unrelated species of mammals. In most of these experiments the rat was used as the donor of the graft and the cat, an animal known for its refractoriness to foreign proteins, as receptor. The anterior eye chamber was chosen as the site of transplantation. In every experiment the anterior pituitary of 17-day old rats served as the graft, and kittens of between 21 and 60 days as graft receptors. In all, six cats with eighteen grafts were used as controls, and seventeen cats with eighty-three grafts as experimental animals. Early in the investigation it became evident that normal infantile rat pituitaries transplanted into the eye of the cat failed to survive for long periods. With one exception, where the grafted pituitary tissue was still present after thirty-five days, in twenty-four days the grafts were completely resorbed, although in every case vascular connexion with the host tissue was established.