Vasostrict

Vasopressin, also called antidiuretic hormone (ADH), arginine vasopressin (AVP) or argipressin,[5] is a hormone synthesized from the AVP gene as a peptide prohormone in neurons in the hypothalamus,[6] and is converted to AVP. It then travels down the axon terminating in the posterior pituitary, and is released from vesicles into the circulation in response to extracellular fluid hypertonicity (hyperosmolality). AVP has two primary functions. First, it increas... [wikipedia]