Answer: Constrict the blood vessels and inhibit the kidneys from removing water from the blood
Explanation: Antidiuretic hormone(ADH) is an hormone produced in hypothalamus its helps regulate water in the body by it activity in the kidney and control blood pressure.
when ADH is at higher concentration it causes the blood vessels to constrict thereby preventing water from being loss from the kidney leading to high blood pressure.
High blood pressure also occur in adult whose blood vessels are weak and have constrict.