STUDIES ON HYPOTHALAMIC CONTROL OF TSH SECRETION

Thyroidal radioiodine metabolism was examined after either radiofrequency lesions or implantation of thyroxine in agar into the anterior hypothalamus of hypophysectomized rats bearing multiple pituitary transplants under the kidney capsule. Bilateral lesions in the region of the paraventricular nuclei depressed 1311 uptake by the thyroid gland measured 24 h after lesioning. Thyroidal 1311 release was also depressed by such lesions. Similarly, thyroxine-in-agar pellets implanted bilaterally in the region of the paraventricular nuclei depressed 1311 uptake and release. It is concluded that the anterior hypothalamus participates in the regulation of TSH secretion from transplanted pituitaries. © 1969 S. Karger AG, Basel.