Characterization of cholinesterase activities in primary cultures of retinal pigment epithelium.

This report presents a comparative description of the acetylcholinesterase and butyrylcholinesterase activities and their molecular forms in primary cultures of retinal pigment epithelium (RPE). Acetylcholinesterase activity increases during differentiation of the cells. Sucrose sedimentation analysis of acetylcholinesterase and butyrylcholinesterase molecular forms revealed the presence of A12, G4, G2, and G1 and A8, G4, G2 and G1, respectively. RPE cells in culture release both cholinesterases into the growth medium, sedimenting as the G4 molecular form. Changes in the molecular forms of both enzymes were observed during differentiation. The results suggest a possible relationship between butyrylcholinesterase activity and cell proliferation and acetylcholinesterase activity and cell differentiation.