It increases secretion of ADH in the posterior pituitary and secretion of ACTH in the anterior pituitary.
From the en.wikipedia.org
Any significant rise in plasma osmolality is detected by the hypothalamus, which communicates directly with the posterior pituitary gland.
From the en.wikipedia.org
With male puberty there comes an increased activity of the anterior pituitary, while with female puberty an augmentation of the activity of the posterior pituitary takes place.
From the theatlantic.com
Oxytocin, an extract from the human posterior pituitary gland, was discovered in 1909 when the British pharmacologist Sir Henry H Dale found it could contract the uterus of a pregnant cat.