Brain Barrier Tissues: End Organs for Atriopeptins

Little is known about the pathophysiology of cerebral edema and other disturbances of water balance that involve the barrier tissues at the interface of blood and brain. The present experiments show that these barrier tissues contain receptors and second messenger systems for atriopeptins, recently identified cardiac peptides involved in peripheral water regulation. They also show that atriopeptins can alter the rate of cerebrospinal fluid production. Because the blood-brain and blood-cerebrospinal fluid barriers are involved in normal water movements in the central nervous system, these studies suggest that brain barrier tissues may be important end organs for the atriopeptins and that atriopeptins could have therapeutic application to disorders of water balance in the central nervous system. An isolated, purified population of atriopeptin receptor cells, obtained from choroid epithelium, was used in these experiments. This cell population may provide a valuable model system for investigating the intracellular biochemical mechanisms through which atriopeptins exert their actions.