THE DISAPPEARANCE RATE OF THYROTROPHIC HORMONE FROM THE BLOODSTREAM OF NORMAL AND THYROIDECTOMIZED RABBITS

Abstract
There was no difference in the rate of disappearance of 30 mg thyroid stimulating hormone (TSH) injected intravenously into normal and thyroidectomized rabbits. In both cases, the initial blood level was restored within 3 hours. The presence of functional thyroidal glandular tissue has no influence on the disappearance of exogenous TSH from the blood. However, if the thyroidectomized rabbits were tested 42-152 days after operation, the disappearance rate of exogenous TSH was diminished in 4 of 5 cases.