To discuss the role of autocrine/paracrine signaling of urothelial arginine vasopressin (AVP) on mammalian bladder capacities and micturition thresholds, impact of distension on water/urea reabsorption from the bladder, review of the literature to better characterize the central/peripheral effects of AVP, desmopressin (dAVP) toxicity, and urine biomarkers of nocturia.