EFFECT OF PRETREATMENT OF GERMANIUM-132 ON NA-K+-ATPASE AND GALACTOSECATARACTS()

Purpose. Recently, we reported that topical administration of 2-carbox yethyl germanium sesquioxide (Ge-132) concurrently with 50% galactose feeding delayed the establishment of mature cataracts and reduced adva nce glycation product, This study was to determine the effect of pretr eatment of Ge-132 on galactose associated morphological changes and Na +-K+-ATPase activity. Methods. Young Sprague Dawley rats received topi cal eye drops four times a day of either saline or Ge-132 seven days p rior to the 50% galactose diet and during galactose feeding, At desire d intervals the lenses were extracted, photographed and processed for either light microscopy, scanning electron microscopy or the determina tion of Na+-K+-ATPase activity. Results. In Ge-132 pretreated lenses a s compared to saline pretreated lenses the following results were obse rved: (a) the galactose-induced morphological alterations in the major ity of lenses were delayed and (b) Na+-K+-ATPase activity was protecte d. Conclusions. Our previous and current studies show that in addition to osmotic stress post-translational protein modification, such as gl ycation, including enzymes may play a role in initiating changes that lead to cataract development. The inhibition of protein glycation by a ntiglycating compounds, such as Ge-132, delays sugar cataract formatio n. Currently, we are investigating the status of protein glycation and advanced glycation end products following pretreatment with Ge-132 an d the role of Ge-132 on the activities of enzymes such as aldose reduc tase and Na+-K+-ATPase.