GLYCATION OF HUMAN LENS CRYSTALLINS - EFFECT OF AGE AND ASPIRIN TREATMENT

Human lenses of three different ages were used to study the effect of age and aspirin treatment on glycation of alpha-, beta- and gamma-crys tallins. Soluble lens proteins were subjected to in vitro glycation wi th 5 mM [C-14]glucose in the presence and absence of 10 mM aspirin. Wi th crystallins from a 27-year-old lens alpha-crystallin was the most r eadily glycated protein. Glycation of all crystallins decreased substa ntially (37-77%) in 46- and 67-year-old lenses indicating an age-depen dent decline in glycation sites. On the basis of a sensitive chemical assay for protein-bound glycogroups in lenses of 2-82 years of age thi s decline is apparently due to a 60% increase in in vivo glycation. As pirin did not show any selectivity with regard to its ability to inhib it glycation of various crystallins. Irrespective of the age glycation of all crystallins was inhibited to a varying extent.