The liver-like anion transport system in the rabbit uvea does not eliminate iodipamide from the eye.

Iodipamide is known to be actively taken up in vitro by the rabbit iris-ciliary process preparation. This uptake is partly resistant to high concentrations of hippurate and the resistant part has been called the 'liver-like' system. In vivo iodipamide is eliminated from the rabbit eye after injection into the vitreous by a saturable process. This process is hippurate-sensitive and no role for any hippurate-resistant system was found. Two explanations for the discrepancy between the results in vitro and in vivo are offered: (1) Iodipamide may be a less than perfect model substance for physiological compounds that normally are transported by a liver-like system from the vitreous cavity and the posterior aqueous humour to the blood. (2) Iodipamide is a model for compounds that are taken up by the non-pigmented epithelium of the ciliary processes by a liver-like system and transported to the pigmented epithelium for metabolic modification.