Influence of ouabain on the fine structure of teleost retina

In this study the effect of intraocular injection of 10 mul 10(-5) M ouabain on the retinal fine structure of the cyprinide teleost Carassius carassius is described. The final concentration of the drug in the eye-bulb was approximately 3-10(-6)M. After 8--24 h the ouabain application produces alterations in the retinal ganglion cells, that progress subsequently to necrobiosis. The outer horizontal cells of the inner nuclear layer show a severe cytoplasmic swelling that is reversible and disappears 8 days after ouabain injection. Amacrines, bipolars and receptor cells are relatively insensitive to the ouabain-induced Na+-K+-ATPase-inhibition. The differential susceptibility to ouabain in the retina possibly reflects a cell-specific pattern of Na+-K+-ATPase-activity or -concentration, whose physiological significance is discussed.