Purchase this article with an account.
C.R. Fleschner; Membrane associated spectrin and ankyrin in selenite cataract . Invest. Ophthalmol. Vis. Sci. 2004;45(13):2648.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To examine changes of membrane fraction associated spectrin and ankyrin B associated with selenite–induced cataracts. Methods: Cataracts were induced in young Sprague–Dawley rats by a single subcutaneous injection of sodium selenite. Uninjected, age matched rats served as controls. Control and cataractous lenses were dissected, decapsulated, and divided into cortex and nucleus. Each region was homogenized in buffer with a protease inhibitor cocktail. Membrane fractions were isolated from the water insoluble fraction by discontinuous sucrose gradient centrifugation. Membrane fractions were extracted with 8 M urea, and the urea soluble extracts were examined for spectrin and ankyrin by western blot analysis, using monoclonal antibodies. Results: The selenite cataract was characterized by the well documented increase in both USP and UIP, which was restricted to the lens nucleus. Each of the 3 major nuclear membrane fractions contained significantly, but unequally, increased amounts of USP. The cataractous nuclear 25/45 and 45/50 fractions (quantitatively the two major nuclear membrane fractions) contained about 2 fold and 1.5 fold more USP respectively, than control samples. The nuclear â‰¥50 fraction contained about 20 fold more USP than control. The increased UIP of the cataractous nucleus was associated only with the â‰¥50 fraction, and was about 20 fold greater than control. A significant decrease of membrane–associated spectrin was found only with the cortical 25/45 fraction from cataractous lenses. No other significant differences of spectrin were found in any other membrane fraction, nor were any significant differences in the relative amounts of any spectrin proteolytic products found. In contrast, a significant decrease in the relative amount of ankyrin was found only in the cataractous nuclear 25/45 fraction. Conclusions:These results suggest that (presumably) cataract related alteration of membrane associated ankyrin, but not spectrin, may be associated with the development of nuclear opacity in the selenite cataract model.
This PDF is available to Subscribers Only