Precocious retinal adhesion is affected by furosemide and ouabain

A "precocious" adhesive force develops between the neurosensory retina (NSR) and the retinal pigment epithelium (RPE) 15-30 minutes after eyes are removed from day 15 embryonic chickens and incubated at 37 degrees C. Precocious adhesion has been reported to be blocked by exposure to cold but to be unaffected by exposure to furosemide and ouabain. Since RPE transport is thought to play a major role in the adhesion between the RPE and NSR of adult mammals, and since ouabain and furosemide block RPE transport in embryonic chickens, it has been thought that precocious adhesion in embryonic chickens is not a good model for studying adhesion between the RPE and the NSR of adult mammals. We have found, however, that when steps are taken to ensure that ouabain and furosemide reach the transport sites on RPE apical membrane before precocious adhesion develops, that ouabain and furosemide do affect precocious adhesion.