Effects of serum uric acid and parotid flow rate on concentration and secretion rate of uric acid in parotid fluid.

Abstract

Parotid fluid was collected without exogenous stimulation from 508 healthy young adult males. The mean uric acid concentration in serum was 5.70 mg/100 ml and that for parotid fluid was 9.52 mg/100 ml. A significant correlation (r = .398) was found between serum and parotid fluid uric acid concentrations. Parotid flow rate was negatively correlated (P<.001) with uric acid concentration (r = —.524) but positively correlated (P<.001) with the secretion rate (μg/min) for uric acid (r = .796). A tentative explanation of uric acid transport in the parotid system is offered. Reabsorption, probably in the proximal portion of the duct system, brings uric acid to a relatively common concentration by a total or limited capacity process and uric acid is secreted into the saliva by cells of other ductal segments. Final concentration thus depends upon the length of time the fluid spends in the ducts— the longer the time (the lower the flow rate), the higher the uric acid concentration. This concept is being tested.