Glaucoma, capillaries and pericytes. 2. Identification and characterization of retinal pericytes in culture

As cell cultures of pericytes derived from bovine retina are in regular use by a number of investigators, we decided to confirm the identity of these cells, to show them different from other cells that might contaminate cultures derived from retinal tissue, to characterize the properties they share with pericytes in situ and to establish a practical and effective means for confirmation of the cell type of each batch of cultured cells used in scientific studies. Cultured pericytes differed in immunocytochemical reactions and phagocytic properties from vascular smooth muscle, vascular endothelial cells, astroglia, conjunctival fibroblasts or retinal pigment epithelium. Like vascular smooth muscle, pericytes in situ and those in culture have the contractile proteins actin and myosin, which implies a potential role in blood flow control. In routine studies of cultured pericytes, they can be identified by their unique reaction in situ and in vitro with the antiganglioside monoclonal antibody 3G5. The presence of any contaminating endothelial cells can be recognized by their ability to take up acetylated low-density lipoprotein.