Non-renal effects

ADH has a variety of non-renal effects:

• smooth muscle: binds to V1 receptors on surface causing an increase in cytosolic calcium and contractility. V1 receptors have a reduced affinity for ADH relative to V2 and so large concentrations of the hormone are required. Physiologically, most vasoconstriction tends to occur in the gastrointestinal tract and skin. This is the basis for the function of ADH vasopressor analogues.
• stimulation of aggregation and degranulation of platelets
• putative central nervous system transmitter
• increases hepatic glycogenolysis
• increase in factor VIII of blood cascade; the basis for the analogue desmopressin's use in mild haemophilia and von Willebrand's disease
• stimulation of corticotrophin release in the anterior pituitary