RESTORATION OF THE URICOSURIC EFFECT OF PROBENECID AFTER TRIGLYCYLVASOPRESSINE ADMINISTRATION IN A GOUTY PATIENT

A 35-year-old patient with severe gout and mild renal insufficiency pr esented very low urinary urate excretion. Volume expansion induced by fludrocortisone combined or not with a uricosuric drug (Benzbromarone) was unable to significantly increase his urate excretion. A combined Probenecid (PB) and Pyrazinamide (PZA) test was performed. These drugs being considered to affect renal tubular reabsorption or secretion. N o significant modification of uric acid fractional excretion (FE.uric acid) was observed after PB and PZA. When the same test was performed after the administration of Triglycyl-lysine vasopressine (TGLV), a po tent V-1 receptor stimulator, we observed a three fold increase in FE. uric acid after PB intake (from 6 to 18%) followed by a decrease after PZA (from 18 to 5.6%). When TGLV was administered alone their was no significant modification of uric acid fractional excretion. We propose that TGLV decrease proximal tubular urate reabsorption that could onl y be detected when postsecretory reabsorption is blocked by an uricosu ric drug.