title: Inhibition of bovine retinal microvascular pericyte proliferation in vitro by adenosine.
abstract: Adenosine acts on bovine retinal microvascular pericytes through one or more adenosine receptor subtypes present on the cell surface. Retinal pericytes cultured in medium containing adenosine at concentrations from 10(-6) to 10(-4) M showed significant reduction in proliferation following several days in vitro compared with control cultures. The effects of adenosine were mimicked by polyadenylic acid and inhibited by 8-phenyltheophylline, indicating involvement of a cell surface receptor. Metabolites of adenosine had no effect on pericyte proliferation. An A2 adenosine receptor-specific analogue also inhibited pericyte growth, suggesting that inhibition by adenosine is mediated by A2-receptors and might involve a transient increase in adenosine 3',5'-cyclic monophosphate levels. The results of the present study demonstrate that in addition to demonstrated stimulatory effects on capillary endothelial cells, adenosine also has a direct inhibitory effect on retinal pericytes. We hypothesize a dual function of adenosine within the capillary wall resulting in loss of inhibition of endothelial cells and suggest a role for this nucleoside in pathological neovascularization processes such as proliferative diabetic retinopathy.
authors.affiliation: Department of Anatomy and Cell Biology, University of North Dakota School of Medicine, Grand Forks 58202.
authors.forename: J A
authors.initials: JA
authors.lastname: Jackson
authors.forename: E C
authors.initials: EC
authors.lastname: Carlson
mesh_terms: D000241:Adenosine / Q000378:metabolism / Q000494:pharmacology* / Q000502:physiology; D000818:Animals; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D008833:Microcirculation / Q000187:drug effects; D011983:Receptors, Purinergic / Q000378:metabolism; D012171:Retinal Vessels / Q000166:cytology* / Q000187:drug effects
chemical_list: D011983:Receptors, Purinergic; D000241:Adenosine