Fig. 3.

Tissue distribution of human aquaporin-5 (AQP5). In the eye AQP5 is expressed in the cytoplasm and/or plasma membrane of lens fibber cells depending on its differentiation, in the cytoplasm and plasma membrane of corneal epithelium and in the apical membrane of acinar cells in lacrimal glands. In the inner ear this isoform is expressed in the cochlea, in the apical membrane of outer sulcus cells of the apical turn. In the respiratory system AQP5 is expressed in airways at the apical membrane of columnar epithelial cells and at the apical membrane of serous acinar cells of sub-mucosal glands. In lungs, AQP5 is expressed at the apical membrane of type I pneumocytes. It is also expressed in the apical membrane of ductal cells in mammary glands. In the digestive system this isoform is expressed in the pancreas, at the apical membrane of intercalated and intralobular ductal cells and at the apical membrane of acinar cells in salivary glands, as well as at the apical and basolateral membranes of secretory cells of Brunner’s glands in the duodenum. In integumentary system AQP5 is expressed in the plasma membrane of keratinocytes in the skin granular layer and in apical and basolateral membranes of secretory cells in sweat glands. AQP5 is also expressed in renal cortex, in the apical membrane of type B intercalated cells in the collecting duct. In the female reproductive system AQP5 is expressed in the cytoplasm of vaginal epithelial cells, in the basolateral membrane of endometrial glandular epithelial cells and in the plasma membrane of uterus smooth muscle cells