Thyroparathyroidectomy in the rabbit

Abstract

In reviewing the literature on the parathyroids, one is struck by the lack of agreement in the results obtained by different experimenters following complete removal of the glands, in animals of the same species. For example, Gley, in 1892, when he rediscovered the parathyroids, in his first series of experiments on rabbits, removed the thyroid and parathyroids from sixteen animals. In fourteen of these acute symptoms developed very rapidly and death followed within a day or two. In the same year Moussu repeated Gley's experiment on rabbits and of the eleven individuals on which he performed the complete operation not one showed the acute tetany described by Gley.

In late August and early September 1920, the writer thyroparathyroidectomized seventeen half-grown rabbits, keeping six of the same litters as controls. Of the seventeen, one died within twenty-four hours in acute tetany, another succumbed in two days and the remaining fifteen lived for months. Some were killed for want of space, and several that were allowed to live showed the chronic changes which follow thyroidectomy.

In January, 1921, the same operation-complete thyroparathyroidectomy-was performed on twenty-four rabbits, most of them adults. Five died in tetany one day after the operationtracings of the muscular contractions were obtained from two,- four died on the second day, six had succumbed between the second and the tenth days, one on the eighteenth day, and the remaining eight lived until they were killed months afterwards. In this second series the proportion showing acute symptoms was much greater than in the first.

Accessory parathyroid tissue is said to be present in the rabbit fairly frequently. This is small in amount, no doubt, but the first explanation one thinks of to account for the survivals is that some of this tissue has been inadvertently left behind.