The patient, 27 years old, consulted a doctor with next complaints: thirst, dry mouth, daily urine output - more than 10 liters. Urinalysis showed a low relative density - 1004 g/l, the absence of protein and glucose in the urine. An increased sodium level was found in the blood. 1. Assume the patient's diagnosis, explain your answer. 2. What is the cause of this disease? Name the hormone (the change in its level), associated with this disease. 3. Indicate the place of hormone synthesis and give a brief description of its function in the regulation of water-salt metabolism. 4. Name the secondary messenger involved in the cell signaling of this hormone.