Expression of amiloride-sensitive sodium channel in rat eye.

To study the expression of the amiloride-sensitive sodium channel, a putative mechano-receptor in the rat eye, reverse transcriptase-polymerase chain reaction and in situ hybridization were done. The gene for the alpha subunit of the amiloride-sensitive sodium channel was shown by polymerase chain reaction to be expressed in mRNA isolated from the whole eye tissue. In situ hybridization demonstrated that the gene was expressed in basal layers of the corneal and conjunctival epithelium, ciliary epithelial cells, lens epithelial cells at the equator, retinal and iris pigment epithelial cells, ganglion cells and cells in the inner and outer nuclear layers of the retina. The results suggest that the amiloride-sensitive sodium channel plays a role in maintaining sodium balance as well as in possible mechanosensation in these ocular tissues.