Last update:
08-Jul-2009

After a series of experiments, a protein was discovered on the membrane of the red blood cell with water channel characteristics, which was named "aquaporin". This discovery revolutionized the study of water movement between the cells and intercellular spaces of the human body which until then was thought to be carried out only by diffusion. Until today 13 different aquaporins have been identified in cells of various systems. Of special interest is the effort to find the relation between aquaporins and pathological conditions of which the pathophysiology is not clear. The conclusions reached from studies on animal experimental models show a possible relation between aquaporin dysfunction and diseases of the kidney, brain, lungs, eye, ear, the circulatory system, the gastrointestinal system and other systems. Stroke, pulmonary edema, diabetes insipitus, atheromatosis, epilepsy, cystic fibrosis, asthma, obesity, cataract, glaucoma, inflammatory bowel diseases, ascites and hepatorenal syndrome are some of the diseases that are connected with aquaporin disorder, according to present evidence. The possible relation of these water channels with tumor angiogenesis is very challenging. Many researchers have examined the possibility of intervention in the normal aquaporin function for therapeutic purposes, and believe that the discovery of drugs to stimulate or block the water channels will bring a new era in the treatment of many diseases. The purpose of this article is to review the experimental data on the role of aquaporins in water homeostasis and in the pathophysiology of various diseases.

Key words: Aquaporins, Homeostasis, Systems, Water.