Vasopressin, also known as anti-diuretic hormone (ADH), acts mainly at the kidney and stimulates resorption of water and electrolytes by the distal tubules, thereby reducing the loss of water through urine (diuresis). It is released from the neurohypophysis (posterior pituitary). Aldosterone is secreted by the adrenal cortex (not medulla). ANF opposes the regulation mechanism that conserves water.