INFLUENCE OF AGE ON THE EFFECT OF THYROIDECTOMY IN THE RHESUS MONKEY1

Abstract
In 6 adult rhesus monkeys (Macaca mulatto) total thyroidectomy had no effect on their appearance, activity or serum cholesterol level. The animals survived the thyroidectomy from 44 to 487 days. The completeness of the thyroidectomy was demonstrated both by anatomic search and by physiologic tests with thyrotrophin. In addition, 2 infant rhesus monkeys were thyroidectomized at the age of about 8 mos. Both animals showed a sharp rise of serum cholesterol following thyroidectomy. Complete cessation of growth also was observed. The data presented suggest that the age factor is of great importance in determining the effect of thyroidectomy in the rhesus monkey.