Abstract
Abstract: :
Purpose: To determine if stimulation of purinergic receptors in animal and human crystalline lens can induce disruption of fiber membrane and lens opacities in the equatorial cortical area. Methods: Rat,rabbit and human lenses were cultured in vitro in either TC–199 or AAH media. Purinergic stimulation followed exposure to ATP,UTP or specific agonists for receptors P2Y1, P2Y2or P2X5–P2X7. Bleb formation , membrane disruption of dissected lens fibers and opacities were determined by microscopy and video, Purinergic agonists were injected into the anterior chamber and vitreous cavity, cataract was documented by digital photography and the size of opacities/vacuoles determined by image analysis. Results: Rat,rabbit and human lenses exposed to purinergic agonists( 5–150 micromols) developed lens fibers blebs and cortical lens opacities in vtro within 24–72 hours. Small capsular incisions allowed faster access to lens fibers and lesions developing quicker and at lower agonists concentrations.Conclusions: Previous studies have shown purinergic agonists can facilitate tranport of Ca++ ions into the equatorial area of the lens and disrupt membrane integrity in cultured cells. Our studies indicate purinergic stimulation and/or nucleotide excess may initate cataracts in the cortical equatorial area the lens.
Keywords: cataract • adenosine • receptors: pharmacology/physiology