THE EFFECT OF MANNITOL AND SECRETIN ON THE BILIARY TRANSPORT OF URATEIN HUMANS

No evidence is available on the transport of biliary mate and the poss ible role of choleretic agents in the regulation of biliary mate elimi nation in humans. To test this hypothesis we studied the following: (1 ) 45 cholecystomized patients to determine mate levels in hepatic bile and gallbladder bile, and (2) 13 cholecystomized patients fitted with T-tubes to determine the effects of secretin injection (either 70 U o f porcine secretin or 0.02 mg . kg(-1) of synthetic human secretin, as a single dose) and/or mannitol infusion (5 cm(3) . min(-1) for 90 min utes) on biliary mate excretion. In the latter group, samples of bile and serum were analyzed for mate under basal state and after the admin istration of both agents. In our first approach, results showed that m ate concentrations present in hepatic as well as in gallbladder bile w ere much lower than the corresponding values in serum (P < .001). The mean gallbladder bile urate concentration was not significantly increa sed over the concentration in hepatic bile. When compared with basal s tate values, porcine and synthetic secretin induced a significant incr ease in mean mate clearance (P < .001) because of a significant increa se in mean bile flow (P < .001), whereas the mean biliary mate concent ration significantly decreased (P < .001) with a concomitant decrease in the mean serum mate concentration (P < .02). Mannitol also induced a significant increase in the mean mate clearance (P < .002) because o f a significant increase in the mean biliary urate concentration (P < .01) with a concomitant decrease in the mean serum mate concentration (P < .01) and without changes in the mean bile now (P > .05). Therefor e, it appears that a substantial amount of urate is eliminated by bili ary route. The load of biliary urate excreted may be modified by manni tol and secretin and possibly other factors, a finding that could have an application in some pathological conditions associated with decrea sed renal urate excretion.