Effect of the administration of thyroid stimulating hormone on the hypothalamo-thpopyseal thyroidal system.

Abstract

The neurosecretory phenomena in the paraventricular and supraoptic nuclei demonstrated by Gomori's CH and phloxine method was studied in relation to the change of thyroid function at the end of 2, 4, 6, 12 and 24hrs.after the injection of TSH.1) In the cells of supraoptic nucleus, Nissl substance temporarily increased in the early period after the injection of TSH, then rapidly declined to the control level.2) The production of the neurosecretory material in the cells and the release of the material from the cells into the nerve fibers arising from the cells in paraventricular nucleus were gradually increasing in the later period after the injection. On the other hand, the synthesis of thyroxin in the thyroid was accelerated in the early period and thereafter the release from the gland into the blood stream was accelerated. It seems that the neurosecretory material in the anterior hypothalamus, especially in the paraventricular nucleus, has something to do with the facts that the effect of the exogenous thyrotrophin reaches the maximum after it had been excreted or broken down.