Studies in thyroid transplantation

Abstract

During the past two years we have utilized the method of thyroid transplantation in rabbits in the attempt to get further data concerning certain questions in the physiology and pathology of this tissue. One of these questions is that of the necessity or not of specific secretory nerves to the gland. The observations of Anderson, Berkeley and Rhinehart have shown that in the thyroid both vessels and gland cells are abundantly supplied with nerve fibers. Stewart, Francois Frank and others have demonstrated the richness of the vasoconstrictor nerve supply, and Von Cyon demonstrated the presence of vasodilator fibers, both sets of fibers for the most part reaching the gland through the superior laryngeal nerves. More recently Asher and Flack and Ossokin have published physiological evidence which they think supports the view that the gland is under the control of secretory nerves, and Beebe and his associates have found that prolonged stimulation of the thyroid nerves causes a slight reduction in the iodin content which they interpret as indicating the presence of secretory nerves.

The method of transplantation eliminates many of the physiological and technical difficulties and objections of the acute experiments.

It has been found that under certain conditions thyroid tissue may be readily transplanted in widely separated parts of the body, as for example in the adrenal, ovary, subperitoneal tissues, muscle, subcutaneous fascia of the neck, chest and abdomen, and also, though with more difficulty, in the spleen and bone marrow. By transplanting and removing a sufficient amount of the main gland, care being taken to avoid all contact with iodin, we have always obtained compensatory hyperplasia of the remaining stump, and in addition a simultaneous and similar degree of hyperplasia of any existing transplants independent of their location.