AVP and diabetes insipidus: The antidiuretic function of AVP was first demonstrated in 1913 by F. Farini in Venice and, independently, by von den Velden in Düsseldorf, who injected extracts from the posterior lobe of the pituitary gland into anesthetized men to control excessive water loss due to diabetes insipidus (a rare condition unrelated to type 1 diabetes (reviewed in [6]) or pituitary damage [7,8,9].