PARALLELISM IN THE RESPONSE OF THYROID AND PARATHYROID TO VARIOUS HORMONES AND HORMONE-LIKE SUBSTANCES1

Abstract
Adm. of acid extract of ant. hypophysis, hypophyseal implants, and feeding of KI resulted in increased mitotic activity in both the thyroid and parathyroid glands. Hypophyseal extract produced the greatest degree of proliferation, followed by implants of ant. hypophysis and KI in order of diminishing effect. This order applied equally to thyroid and parathyroid. Underfeeding as well as administration of thyroid substance resulted in a marked diminution of mitotic activity in both the thyroid and parathyroid glands. In both, increased growth under the influence of stimulating substances consisted in the processes of hyperplasia as well as hypertrophy.