On the role of the hypothalamic-neurohypophyseal neurosecretion in the liberation of the adenohypophyseal hormones.

In previous works (Shibusawa and Inou, 1951; Shibusawa, Inou and Itou, 1952; Shibusawa, Inou and Osono, 1953; Shibusawa, Inou, Osono and Yoshimura, 1953; Shibusawa, Inou, Osono and Toshima, 1954; Shibusawa 1955) we have shown that the antidiuretic substance is released in the blood as a result of the hypothalamic-neurohypophyseal neurosecretion immediately after surgery. The antidiuretic substance in the serum during the immediate postoperative period has been proved to contain the antidiuretic hormone in a larger portion, and we were also able to prove that the release of adrenocortical hormone begins to take place concomitantly with this liberation of the neurosecret, by assaying the blood level of 17-hydroxycorticoids. When the endogenous secretion of the antidiuretic hormone is hindered by destroying the median eminence, the secretion of the adrenal cortical hormone is also inhibited. It is shown that the Gomori's positive substance exists around the special blood vessels in the peripheral zone of the infundibulum, and it is possible that this substance enters the anterior pituitary via the portal vessels and plays its hypothetical role as a stimulator for the release of anterior lobe hormones. The present experiments were undertaken to clarify the possible role of the hypothalamic-pituitary neurosecretion as the natural stimulator for the liberation of anterior pituitary hormones by exogenous administration of neurosecretory products.