Abstract
Vasopressin is a 9-amino acid peptide synthesized by magnocellular neurons of the hypothalamus and released from posterior pituitary gland. The primary physiological role of vasopressin is the maintenance of fluid homeostasis. In this review, the classification of vasopressin receptors, namely V1 vascular, V2 renal, V3 pituitary, oxytocin receptors, and purinergic receptors, and the effects of vasopressin on vascular smooth muscles, the heart, and the kidneys are discussed. Mortality rates of vasodilatory (or distributive), for example septic shock, are high. The use of vasopressin is an alternative therapy for vasodilatory shock with better outcome. Vasopressin is effective in resuscitation of adults after ventricular fibrillation or pulseless tachycardia, when epinephrine is not effective.