Aquaporins in complex tissues: distribution of aquaporins 1-5 in human and rat eye

J. Physiol. 274 (Cell Physiol. 43): C1332–C1345, 1998.—Multiple physi-ological fluid movements are involved in vision. Here we define the cellular and subcellular sites of aquaporin (AQP) water transport proteins in human and rat eyes by immuno-blotting, high-resolution immunocytochemistry, and immuno-electron microscopy. AQP3 is abundant in bulbar conjunctival epithelium and glands but is only weakly present in corneal epithelium. In contrast, AQP5 is prominent in corneal epithe-lium and apical membranes of lacrimal acini. AQP1 is heavily expressed in scleral fibroblasts, corneal endothelium and keratocytes, and endothelium covering the trabecular mesh-work and Schlemm’s canal. Although AQP1 is plentiful in ciliary nonpigmented epithelium, it is not present in ciliary pigmented epithelium. Posterior and anterior epithelium o