title: Conditioned medium from mixed retinal pigmented epithelium and Müller cell cultures reduces in vitro permeability of retinal vascular endothelial cells.
abstract: OBJECTIVE
  To investigate the in vitro effect of laser photocoagulation on blood-retinal barrier permeability.
  
  
  METHODS
  Retinal capillary endothelial cells were exposed to supernatants from long term co-cultured cells that were argon laser treated. Endothelial cell permeability was analysed by (1) measurement of transendothelial electrical resistance and (2) equilibration of [(3)H] inulin and [(14)C] albumin across the cell monolayer.
  
  
  RESULTS
  Laser photocoagulation of various retinal cells and control ECV304 cells in the lower chamber did not appreciably improve permeability of the endothelial cell monolayer compared with that of unlasered cells. However, medium that was conditioned by mixed retinal pigmented epithelium and Müller cells significantly reduced both inulin (43.2% (SD 6.5%) equilibration in mixed cultures v 59.8% (SD 7.0%) control cells, p<0.05) and albumin (15.1% (SD 3.8%) v 31.1% (SD 6.7%), p<0.05) permeability of the endothelial cell monolayers. A fourfold increase in transendothelial electrical resistance was also seen.
  
  
  CONCLUSIONS
  These results are consistent with the hypothesis that interaction of Müller cells with retinal pigmented epithelium induced by laser treatment results in secretion of soluble factor(s), which reduces permeability of retinal vascular endothelium. Identification of these factor(s) may have implications for the clinical treatment of macular oedema secondary to diabetic retinopathy and other diseases.
authors.affiliation: Save Sight Institute, Department of Clinical Ophthalmology, University of Sydney 2001, Australia. marina@eye.usyd.edu.au
authors.forename: M
authors.initials: M
authors.lastname: Tretiach
authors.forename: M C
authors.initials: MC
authors.lastname: Madigan
authors.forename: M C
authors.initials: MC
authors.lastname: Gillies
mesh_terms: D000818:Animals; D001813:Blood-Retinal Barrier / Q000187:drug effects* / Q000378:metabolism; D002196:Capillaries; D002199:Capillary Permeability / Q000187:drug effects* / Q000502:physiology; D002417:Cattle; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000737:chemistry / Q000494:pharmacology*; D017097:Electric Impedance; D004730:Endothelium, Vascular / Q000378:metabolism* / Q000502:physiology; D007150:Immunohistochemistry; D017075:Laser Coagulation; D010857:Pigment Epithelium of Eye / Q000187:drug effects* / Q000378:metabolism*; D012171:Retinal Vessels / Q000187:drug effects* / Q000378:metabolism
chemical_list: D017077:Culture Media, Conditioned