How do we know that regulatory factors travel
through the portal circulation to the pituitary?
Geoffrey Harris was a famous neurobiologist
responsible for showing that that the
hypothalamus exerts control of the pituitary
gland.
In the 1950s, Harris and colleagues carried out a
series of transplantation experiments.
It had already been shown that endocrine glands (e.g.
testes, ovaries, adrenal cortex) can function in a
regulated manner when transplanted to a remote
location in the body.
Harris showed that when the anterior pituitary was
transplanted away from its original site, it did not
function normally.