Characterization and Regulation of Gap Junctions in Porcine Ciliary Epithelium.

Purpose: Gap junctions provide a conduit between the intracellular fluids of the pigmented (PE) and non-pigmented (NPE) ciliary epithelial cells, and are therefore critical in the secretion of the aqueous humor (AH). However, opinions differ concerning the connexin (Cx) composition of the gap junctions. Therefore, we aimed to characterize the expression of Cx in the porcine ciliary epithelium (CE), a favorable model for humans; and determine the contribution of the highest expressed Cx to AH secretion.

cAMP Stimulates Transepithelial Short-Circuit Current and Fluid Transport Across Porcine Ciliary Epithelium.

Purpose: To investigate the effects of cAMP on transepithelial electrical parameters and fluid transport across porcine ciliary epithelium.

Methods: Transepithelial electrical parameters were determined by mounting freshly isolated porcine ciliary epithelium in a modified Ussing chamber. Similarly, fluid movement across intact ciliary body was measured with a custom-made fluid flow chamber.

Characterisation of Cl⁻ transporter and channels in experimentally induced myopic chick eyes.

Background: Experimental evidence has shown that myopic and hyperopic optical defocus induces thickening and thinning of the choroids, respectively, moving the retina forward and backward toward the plane of focus; however, the underlying mechanism of this phenomenon remains elusive. It has been hypothesised that the change in choroidal thickness might be elicited by the alteration of ion and fluid transport across the retinal pigment epithelium (RPE). Therefore, the aims of the present study were to determine the content of specific Cl(-) transporter/channel mRNA and proteins in chick RPE in a normal, untreated state and in lens-induced myopia.

Regulation of gap junction coupling in bovine ciliary epithelium.

Aqueous humor is formed by fluid transfer from the ciliary stroma sequentially across the pigmented ciliary epithelial (PE) cells, gap junctions, and nonpigmented ciliary epithelial (NPE) cells. Which connexins (Cx) contribute to PE-NPE gap junctional formation appears species specific. We tested whether small interfering RNA (siRNA) against Cx43 (siCx43) affects bovine PE-NPE communication and whether cAMP affects communication.