Phagocytosis in the retinal pigment epithelium of the RCS rat.
The retinal pigment epithelium of RCS rats, previously thought not to phagocytize photoreceptor outer segments, exhibited a peak of phagocytosis in vivo when animals were kept under conditions of cyclic lighting (12 hours of darkness and 12 hours of light). The peak occurred at 1 hour after the onset of light, with maximum and minimum levels of phagocytosis averaging about 5 percent of that found in  the pigment epithelium of Osborn-Mendel rats used as a control. Eyecups that were obtained from Osborn-Mendel rats and maintained for up to 3 hours in organ culture demonstrated levels of phagocytosis that were sevenfold greater than those of unincubated controls. Likewise a tenfold increase occurred in incubated as opposed to unicubated RCS eyes, raising the possibility that phagocytosis could be experimentally stimulated in vivo.
D000818:Animals; D002452:Cell Count; D002940:Circadian Rhythm; D009924:Organ Culture Techniques; D010586:Phagocytes / Q000648:ultrastructure; D010587:Phagocytosis; D010857:Pigment Epithelium of Eye / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains / Q000378:metabolism*; D013997:Time Factors