Eine neue Funktion des nicht-pigmentierten Epithels der Ziliarkörperfortsätze bei der Kammerwasserproduktion

Abstract

The invagination of the optic vesicle has, as one of its consequences, the apposition of the apices of the nonpigmented and pigmented epithelia of the ciliary processes of the eye. There are well developed intercellular ciliary "channels" formed at the apices of these cells. Embryologically the ciliary epithelia are homologous to the epithelia of the choroid plexus, a characteristically differentiated ependyma. These epithelial cells have a polarity. For example, the supranuclear region of the nonpigmented epithelia has Golgi apparatus. While stimulation of the epithelia of the choroid plexus by beta adrenergics or cholera toxin increases the rate of production of cerebrospinal fluid, similar stimulation of the adenylate complex within the ciliary epithelia decreases aqueous humor production. When the secretory function of the nonpigmented epithelial cell is activated, fluid is probably reabsorbed from the posterior chamber and secreted apically into the intercellular ciliary channels, in accord with cell polarity, thereby reducing net aqueous inflow. The fluid may enter the ciliary stroma thereafter and thus may become part of what may be called "uveal scleral" flow, or in this instance, uveal flow. The anatomy, physiology, and chemistry fit this hypothesis and form the basis for new investigations of a two-way transport across the ciliary epithelia.

Anatomy of Ciliary Body, Ciliary Processes, Anterior Chamber Angle and Collector Vessels

“…There is a potential space between the two epithelial layers, called "ciliary channels". The aqueous humor may be secreted into this space after beta-adrenergic agonist stimulation, but this notion requires additional studies [20].…”

Functional Morphology of Rabbit Iridial Ciliary Processes

“…After topical application of the adenylate stimulator forskolin [29], Fujita et al [30] found a striking enlargement of the ciliary channels in the anterior portion of the rabbit ciliary body. In this respect they discuss fluid reabsorption from the posterior chamber and transport of solutes and molecules into the ciliary channels by the nonpigmented epithelium.…”