Topographical variation in growth in cultured bovine retinal pigment epithelium.

Cell cultures of adult bovine retinal pigment epithelium (RPE) were propagated from posterior and equatorial regions of the same eyes to study topographical differences in cell growth. To generate the cultures, the retina was removed, eyecups were incubated in collagenase followed by trephining three zones from the posterior area centralis and three zones from the equatorial region of the tapetal retina. Outgrowth in primary cultures and proliferation in passaged cultures were evaluated in paired cultures derived from the same eyes. Relative to cells from the more peripheral regions, RPE cells from the area centralis showed lower growth potential which was manifested as reduced cell numbers in primary outgrowth and a smaller fraction of serum-responsive cells when cultures were serially passaged. Cells from older donors have been shown to exhibit similar reductions in in vitro growth potential, making it appear as if, with regards to proliferation, RPE from the area centralis is more "aged" than RPE from more peripheral regions of the same eyes.