Studies of Sulfobromophthalein Sodium (BSP) Metabolism in Man. III. Demonstration of a Transport Maximum (Tm) for Biliary Excretion of BSP*

Schoenfield, Leslie J.; McGill, Douglas B.; Foulk, William T.

doi:10.1172/jci105018

Cited by 20 publications

(10 citation statements)

References 14 publications

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“…However, in accordance with the view of a retardation of the excretory Tm in man (8,9), we found a statistically significant correlation between Tm and biliary excretion of BSP during the last 20 min of the second infusion period. In any case, it seems that Tm figures are much below the actual values of biliary excretion of BSP.…”

Section: Discussionsupporting

confidence: 90%

“…This finding is in contrast to observations made in dogs by Wheeler et al (1,6) which led to the hypothesis of a limited excretory transport mechanism and to the design of the maximal rate of transport for biliary excretion of BSP. The variability in the recovery rates of free BSP throughout the study period, which does not appear to be related to the method of bile collection (7), is consistent with observations previously made by others in man (8,9). Evidence provided by Schoenfield et al (8) and Milanese et al (9) suggests the view that in case of achievement of a constant biliary excretory rate, this is attained in the space of more than 2 h. This hypothesis would be supported by results obtained in rats (7), in which a delay in obtaining a constant biliary excretion of the dye was observed when the animals were previously submitted to obstruction of the common bile duct.…”

Section: Discussionsupporting

confidence: 88%

“…The variability in the recovery rates of free BSP throughout the study period, which does not appear to be related to the method of bile collection (7), is consistent with observations previously made by others in man (8,9). Evidence provided by Schoenfield et al (8) and Milanese et al (9) suggests the view that in case of achievement of a constant biliary excretory rate, this is attained in the space of more than 2 h. This hypothesis would be supported by results obtained in rats (7), in which a delay in obtaining a constant biliary excretion of the dye was observed when the animals were previously submitted to obstruction of the common bile duct. However, the degree of previous cholestasis established by serum concentrations of bilirubin and alkaline phosphatase, does not appear to exert a significant effect on T m values and biliary recovery of BSP, as may be expected from data in rats (7).…”

Section: Discussionsupporting

confidence: 88%

“…(1) is consistent with the study of Monroe and Kittinger (10), who obtained BSP biliary concentrations between 23% and 61% ofTm. The discrepancy between Tm values and biliary recovery of BSP does not seem to correspond to an extrahepatic excretion of the dye, as shown by data on urinary excretion of BSP after infusion (8,11). Different authors (9,12,13) have suggested that BSP-Tm measurements with Wheeler's method estimate only 50-80% of the theoretical Vmax.…”

Section: Discussionmentioning

confidence: 96%

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Maximal biliary transport of sulfobromophthalein in patients with a T-tube placed in the common bile duct

Serra

Caballero

Olmo

et al. 1997

European Journal of Drug Metabolism and Pharmacokinetics

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In 19 adult patients with choledocholithiasis who were operated on, excretion of free and conjugated sulfobromophthalein (BSP) in the bile collected through a T-tube inserted in the common bile duct was determined. The transport maximum (Tm) for BSP was calculated by the constant-infusion technique after an intravenous infusion of the dye at a rate of 0.3 and 0.09 mg/kg/min for the first and second hour, respectively. Free and conjugated BSP were measured in blood samples obtained at 30, 40, and 50 min of each hourly-infusion period, and in bile collected during the first 30 min (sample A) and between 30-50 min (sample B) after starting the first BSP infusion, and during the first 30 min (sample C) and between 30-50 min (sample D) after starting the second infusion. No correlations between Tm of BSP and glutathione transferase activity and between Tm and bilirubin and alkaline phosphatase in serum were found. Although there was an overall correlation between Tm of BSP and biliary excretion of BSP after 30 min of starting the BSP infusion (samples B, C and D) (r = 0.4716; P = 0.41), Tm values were always lower than recoveries of free BSP in bile. It seems that Tm of BSP (measured with the Wheeler's method) overestimates the actual values of biliary excretion of free BSP, and that the percentage of conjugated BSP in serum is related to the degree of impairment of biliary transport of BSP.

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Section: Discussionsupporting

confidence: 90%

Section: Discussionsupporting

confidence: 88%

Section: Discussionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 96%

See 2 more Smart Citations

Maximal biliary transport of sulfobromophthalein in patients with a T-tube placed in the common bile duct

Serra

Caballero

Olmo

et al. 1997

European Journal of Drug Metabolism and Pharmacokinetics

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“…The concepts of hepatic storage (14) and maximal biliary transport (transfer maximum, Tm) (15) have received support from recent studies utilizing continuous-infusion technics with simultaneous bile collections in dog and man (16,17). With infusion of BSP at a rate calculated to maintain a steady level of BSP in the plasma, the quantity cleared by the liver during a given interval is assumed to be equal to the quantity of the substance injected into the blood during that same time.…”

mentioning

confidence: 99%