Abstract
Multiple physiological 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 immunoblotting, high-resolution immunocytochemistry, and immunoelectron 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 epithelium and apical membranes of lacrimal acini. AQP1 is heavily expressed in scleral fibroblasts, corneal endothelium and keratocytes, and endothelium covering the trabecular meshwork and Schlemm's canal. Although AQP1 is plentiful in ciliary nonpigmented epithelium, it is not present in ciliary pigmented epithelium. Posterior and anterior epithelium of the iris and anterior lens epithelium also contain significant amounts of AQP1, but AQP0 (major intrinsic protein of the lens) is expressed in lens fiber cells. Retinal Müller cells and astrocytes exhibit notable concentrations of AQP4, whereas neurons and retinal pigment epithelium do not display aquaporin immunolabeling. These studies demonstrate selective expression of AQP1, AQP3, AQP4, and AQP5 in distinct ocular epithelia, predicting specific roles for each in the complex network through which water movements occur in the eye.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.