ADH, short for antiduretic hormone, is produced when the concentration of solutes in blood plasma increases - this is detected by receptors in the brain. ADH is then released into the bloodstream, where it reaches kidneys to affect collecting ducts. The hormone opens up pores in the tubules allowing for reabsorption of water from the urine. This results in smaller volume of more concentrated urine produced.ADH is released unless the solute concentration in blood plasma reaches its norm. ADH release is an example of a negative feedback loop.