Phagocytosis of outer segments by cultured rat pigment epithelium. Reduction by cyclic AMP and phosphodiesterase inhibitors.

Phagocytosis of isolated outer segments by cultured rat pigment epithelium was decreased by cyclic 3',5'adenosine monophosphate (cyclic AMP), dibutyryl cyclic AMP, and three phosphodiesterase inhibitors (isobutylmethylxanthine, papaverine, and SQ 65442). Cyclic GMP and its dibutyryl derivative had little effect on phagocytosis. Phagocytosis was moderately reduced by several other purine nucleotides and nucleosides and substantially reduced by adenine.