Effect of pretreatment of germanium-132 on Na(+)-K(+)-ATPase and galactose cataracts.

Abstract

PURPOSE:

Recently, we reported that topical administration of 2-carboxyethyl germanium sesquioxide (Ge-132) concurrently with 50% galactose feeding delayed the establishment of mature cataracts and reduced advance glycation product. This study was to determine the effect of pretreatment of Ge-132 on galactose associated morphological changes and Na(+)-K(+)-ATPase activity.

METHODS:

Young Sprague Dawley rats received topical eye drops four times a day of either saline or Ge-132 seven days prior to the 50% galactose diet and during galactose feeding. At desired intervals the lenses were extracted, photographed and processed for either light microscopy, scanning electron microscopy or the determination of Na(+)-K(+)-ATPase activity.

RESULTS:

In Ge-132 pretreated lenses as compared to saline pretreated lenses the following results were observed: (a) the galactose-induced morphological alterations in the majority of lenses were delayed and (b) Na(+)-K(+)-ATPase activity was protected.

CONCLUSIONS:

Our previous and current studies show that in addition to osmotic stress post-translational protein modification, such as glycation, including enzymes may play a role in initiating changes that lead to cataract development. The inhibition of protein glycation by antiglycating compounds, such as Ge-132, delays sugar cataract formation. Currently, we are investigating the status of protein glycation and advanced glycation end products following pretreatment with Ge-132 and the role of Ge-132 on the activities of enzymes such as aldose reductase and Na(+)-K(+)-ATPase.

• Authors: N J Unakar, J Tsui, M Johnson
• Journal: Current eye research (Curr Eye Res) Vol. 16 Issue 8 Pg. 832-7 (Aug 1997) ISSN: 0271-3683 [Print] England
• PMID: 9255513 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Antineoplastic Agents
• Ophthalmic Solutions
• Organometallic Compounds
• Propionates
• Germanium
• propagermanium
• Sodium-Potassium-Exchanging ATPase
• Galactose

Topics

• Animals
• Antineoplastic Agents (administration & dosage, pharmacology)
• Cataract (chemically induced, enzymology, prevention & control)
• Galactose
• Germanium (administration & dosage, pharmacology)
• Glycosylation
• Lens, Crystalline (drug effects, enzymology, ultrastructure)
• Microscopy, Electron, Scanning
• Ophthalmic Solutions
• Organometallic Compounds (administration & dosage, pharmacology)
• Propionates
• Rats
• Rats, Sprague-Dawley
• Sodium-Potassium-Exchanging ATPase (metabolism)