Inhibition of Sodium Urate Crystal Adherence to Bladder Surface by Polysaccharide

Bladder surface glycosaminoglycan (polysaccharide) has been shown to act in a nonspecific manner as an antiadherence factor and may potentially be important in the pathogenesis (and prevention) of renal calculi. It has been shown that when present, bladder surface GAG will reduce the adherence of both calcium and calcium oxalate crystals. This study was conducted to see if a similar effect would be found with uric acid crystals, in that the presence of the normal bladder mucus with its contained GAG and exogenously supplied polysaccharide, pentosanpolysulfate, would be inhibitory to crystal adherence. Radioactively labeled uric acid crystals were made by dissolving 14C labeled sodium urate to a point of saturation at pH 7.5 and then rapidly lowering the pH to 5.5. These crystals were placed into four groups of bladders: 1) normal bladders, 2) bladders rendered mucus deficient with hydrochloric acid, 3) mucus deficient bladders which were pre-treated with sodium pentosanpolysulfate prior to crystal addition and 4) mucus deficient bladders to which were added crystals pretreated with pentosanpolysulfate. There was a significant rise in crystal adherence after acid treatment of the bladder, a 2.3-fold increase, which was blocked with prior treatment of the crystals with pentosanpolysulfate and to a lesser degree by pretreating mucus deficient bladders with pentosanpolysulfate.