Physiology and pathophysiology of aquaporins

Aquaporins (AQPs) are water channels that facilitate a rapid transport of water, across cell membranes. In some cases, these pores are also permeated by small solutes, particularly glycerol. Thirteen aquaporins (AQP0-12) have been identified so far in mammalian tissues. The disruption of the genes encoding aquaporins in transgenic mice has revealed their implication in physiological and pathophysiological processes, including renal water absorption, neural function, digestion, tumour angiogenesis, and reproduction. A subset of aquaporins that transport both water and glycerol, the ‘aquaglyceroporins’, regulate glycerol content in epidermal, fat and other tissues, and are involved in skin hydration, fat metabolism and gluconeogenesis. Better understanding of the exact mechanisms and regulation of aquaporins might be useful for designing potential drug targets against different metabolic disorders, such as stroke, glaucoma, brain ooedema, cancer, diabetes and obesity