Organ Replacement of the Pituitary Gland

The pituitary gland first attracted notice as a potentially transplantable gland when doctors found it enlarged after thyroid extirpation. Using the model of other glands, physiologists began probing into pituitary gland function with the help of extirpation experiments in the 1880s. Victor Horsley, for instance, carried out experimental ablations of this organ in 1886, and Eugène Gley destroyed pituitary glands experimentally in rabbits in 1891. Some researchers observed symptoms after pituitary gland removal that were similar to those after thyroidectomy. Because of the technical difficulties associated with the organ’s complete removal, however, the experiments were not, at the time, very convincing to doctors and scientists. Using tested and proven experimental procedures, researchers also performed transplantations. In 1894 Otto Lanz reported that he had “implanted 8 pituitary glands into a dog, some under the skin, some under and some into the peritoneum, and [some] into the tunica vaginalis testis.” Because he wanted to determine whether this gland could possibly replace the thyroid, Lanz’s next step was to remove the animal’s thyroid. The transplants, however, remained ineffective and were “completely resorbed.” The next year, Edward Schäfer included the pituitary gland in his discussion of internal secretions. He had discovered that the secretion of the gland caused contractions of the coronary arteries. Using the same methods of measurement he had used to investigate adrenal gland extract, he consistently found that the same parameters—blood pressure, vascular tension—changed after the administration of extract. The organ continued to attract considerable attention for studies of this nature and finally, after being identified as having a whole range of functions, ended up being included among the endocrine organs.

This process involved other experimental organ ablations and (mostly autogenous) transplantations. The experiments presented researchers with great technical challenges. For transplantation, surgeons tried out a wide variety of implantation sites, including the brain. As for ablation experi ments, it was especially difficult to remove the organ without causing the laboratory animal’s immediate death. Work on this organ was further complicated by the fact that the organ became associated with a confusing multitude of different functions.