ADH – Antidiuretic Hormone. ADH is secreted when there is excessive loss of fluid from the body. ADH facilitates water reabsorption from distal convoluted tubule, collecting tubule and collecting duct, thereby preventing diuresis. ADH can also affect the kidney function by its constrictory effects on blood vessels. This causes an increase in blood pressure, which increases the glomerular blood flow and thereby the GFR.