1st International Conference on Recent Advances in Anaesthesiology (INCRAA - 2009), 30 Jan – 01 Feb 2009 · Nehru Auditorium, AIIMS New Delhi

Introduction: Vasopressin is an endogenous nonapiptide hormone released by the posterior pituitary in response to hypovolaemia and hyper tonicity. It is derived from prehormone precursor that is synthesized in the hypothalamus and stored in vesicles at the posterior pituitary. Most of it is to be released into the blood stream, but some of it is also released into the brain. Normal levels of plasma vasopressin are 0-4 pg/ml. Levels of 5-7 pg/ml cause maximum urinary concentration, and at higher concentration it causes vasoconstriction via V1 receptors. It is metabolized by amino peptidases throughout the body and has a half life of about 10 minutes.