HYPOXANTHINE AND XANTHINE LEVELS IN HUMAN AQUEOUS-HUMOR FROM CATARACTOUS EYES

Purine nucleotide degradation products have been determined by HPLC in aqueous humor obtained during cataract surgery and from plasma of 22 patients (12 women). Uric acid, cytosine, guanosine monophosphate, ura cyl, guanine, adenosine, adenosine monophosphate, thymine, adenine, in osine, cyclic guanosine monophosphate, hypoxanthine and xanthine were evaluated. Uric acid and the last two were the only compounds detectab le in measurable amounts in aqueous humor and in plasma of all patient s. Aqueous humor xanthine levels were not significantly different from plasma; aqueous humor hypoxanthine concentrations were lower than tho se of xanthine and than plasma oxypurine levels. In 8 patients, treate d with allopurinol, oxypurinol concentrations in aqueous humor and in plasma were comparable suggesting that oxypurines are transported thro ugh the blood-aqueous humor barrier.