The posterior pituitary (neurohypophysis) stores and releases vasopressin (also called ADH) . Vasopressin acts mainly at the kidney and stimulates resorption of water and electrolytes by the distal tubules, thereby reducing loss of water through urine (diuresis) . In contrast, the corpus luteum secretes mainly progesterone, which supports pregnancy, while estrogen is secreted by growing ovarian follicles . Thyroxine regulates the basal metabolic rate, whereas Thyrocalcitonin (TCT) regulates blood calcium levels , . Oxytocin is released by the posterior pituitary, not the anterior pituitary , .