Attempts to Produce Hyperplasia in Thyroid by Destruction of Part of the Adrenals and by Infection

Abstract

Several methods may produce retrogression in the hyperplastic thyroid, viz., resection of the thyroid, administration of iodine, x-ray, but it is more difficult to produce the hyperplasia characteristic of exophthalmic goiter at will.

The purpose of these experiments was to note the microscopic changes occurring in the thyroid after injury to and destruction of part of the adrenals or in the organism suffering from an infection. In these experiments dogs were used. Dogs in this locality apparently very rarely have goiter. The thyroid of a 6 to 10 kg. dog is usually about 2.2 × 1.2 cm. in size.

To have a section of thyroid to compare the result by, from each of the dogs a piece of thyroid about 2×2 mm. was removed at a preliminary operation. Sections removed from the same dog at subsequent operations or at necropsy were compared with this first section. Sections removed subsequently from control dogs in whom no other procedure but this preliminary operation was done did not show any hyperplasia, as has been proven to occur when larger pieces of the thyroid gland are removed.

Two dogs were fed 3 grains of thyroid extract a day for 46 and 47 days, respectively. These dogs became extremely restless, nervous, excitable, and had even a stare but no exophthalmos. Sections removed from the thyroids of these dogs after feeding the animals thyroid extract for 46 and 47 days showed retrogressive changes in the thyroid; smaller epithelial cells with more colloid in the vesicles. This response to thyroid extract has been described before. 1

Cole and Womack² found that infection in dogs resulted in hyperplasia of the thyroid gland. I implanted a small coil of wire contaminated by a pure culture of staphylococci into the sternocleidomastoid muscle of dogs.